Altered dietary salt intake for preventing and treating diabetic kidney disease

Rebecca J Suckling; Feng J He; Graham A MacGregor

doi:10.1002/14651858.CD006763.pub2

Ingesta de sal dietética modificada para la prevención y el tratamiento de la nefropatía diabética

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References

Referencias de los estudios incluidos en esta revisión

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excluded studies
additional references

De'oliveira JM, Price DA, Fisher NDL, Allan DR, McKnight JA, Williams GH, et al. Autonomy of the renin system in type II diabetes mellitus: dietary sodium and renal hemodynamic responses to ACE inhibition. Kidney International 1997;52(3):771‐7. [MEDLINE: 9291199]

Dodson PM, Beevers M, Hallworth R, Webberley MJ, Fletcher RF, Taylor KG, et al. Sodium restriction and blood pressure in hypertensive type II diabetics: randomised blind controlled and crossover studies of moderate sodium restriction and sodium supplementation. BMJ 1989;298(6668):227‐30. [MEDLINE: 2493869]

Houlihan C, Allen T, Hovey A, Jenkins M, Cooper M, Jerums G. A low salt diet in patients with type II diabetes significantly amplifies the effects of angiotensin II receptor blockade with losartan [abstract]. Nephrology 2000;5:32. [CENTRAL: CN‐00509238]

Houlihan CA, Akdeniz A, Tsalamandris C, Cooper ME, Jerums G, Gilbert RE. Urinary transforming growth factor‐beta excretion in patients with hypertension, type 2 diabetes, and elevated albumin excretion rate: effects of angiotensin receptor blockade and sodium restriction. Diabetes Care 2002;25(6):1072‐7. [MEDLINE: 12032117]

Houlihan CA, Allen T, Hovey A, Jenkins M, Cooper M, Jerums G. Comparison of regular versus low sodium diet on the effects of losartan in hypertensive subjects with type II diabetes [abstract]. Journal of the American Society of Nephrology 2000;11(Sept):116A. [CENTRAL: CN‐00615874]

Google Scholar

Houlihan CA, Allen TJ, Baxter AL, Panangiotopoulos S, Casley DJ, Cooper ME, et al. A low‐sodium diet potentiates the effects of losartan in type 2 diabetes. Diabetes Care 2002;25(4):663‐71. [MEDLINE: 11919122]

Houlihan C, Allen T, Hovey A, Jenkins M, Cooper M, Jerums G. A low salt diet in patients with type II diabetes significantly amplifies the effects of angiotensin II receptor blockade with losartan [abstract]. Nephrology 2000;5:32. [CENTRAL: CN‐00509238]

Houlihan CA, Akdeniz A, Tsalamandris C, Cooper ME, Jerums G, Gilbert RE. Urinary transforming growth factor‐beta excretion in patients with hypertension, type 2 diabetes, and elevated albumin excretion rate: effects of angiotensin receptor blockade and sodium restriction. Diabetes Care 2002;25(6):1072‐7. [MEDLINE: 12032117]

Houlihan CA, Allen T, Hovey A, Jenkins M, Cooper M, Jerums G. Comparison of regular versus low sodium diet on the effects of losartan in hypertensive subjects with type II diabetes [abstract]. Journal of the American Society of Nephrology 2000;11(Sept):116A. [CENTRAL: CN‐00615874]

Google Scholar

Houlihan CA, Allen TJ, Baxter AL, Panangiotopoulos S, Casley DJ, Cooper ME, et al. A low‐sodium diet potentiates the effects of losartan in type 2 diabetes. Diabetes Care 2002;25(4):663‐71. [MEDLINE: 11919122]

Imanishi M, Yoshioka K, Okumura M, Konishi Y, Okada N, Morikawa T, et al. Sodium sensitivity related to albuminuria appearing before hypertension in type 2 diabetic patients. Diabetes Care 2001;24(1):111‐6. [MEDLINE: 11194215]

Lopes de Faria JB, Friedman R, de Cosmo S, Dodds RA, Mortton JJ, Viberti GC, et al. Renal functional response to protein loading in type 1 (insulin‐dependent) diabetic patients on normal or high salt intake. Nephron 1997;76(4):411‐7. [MEDLINE: 9274838]

Luik PT, Hoogenberg K, Van Der Kleij FG, Beusekamp BJ, Kerstens MN, De Jong PE, et al. Short‐term moderate sodium restriction induces relative hyperfiltration in normotensive normoalbuminuric Type I diabetes mellitus. Diabetologia 2002;45(4):535‐41. [MEDLINE: 12032630]

Miller JA. Sympathetic vasoconstrictive responses to high‐ and low‐sodium diets in diabetic and normal subjects. American Journal of Physiology 1995;269:R380‐8. [MEDLINE: 7653660]

Miller JA. Renal responses to sodium restriction in patients with early diabetes mellitus. Journal of the American Society of Nephrology 1997;8(5):749‐55. [MEDLINE: 9176844]

Mulhauser I, Prange K, Sawicki PT, Bender R, Dworschak A, Schaden W, et al. Effects of dietary sodium on blood pressure in IDDM patients with nephropathy. Diabetologia 1996;39(2):212‐9. [MEDLINE: 8635674]

Petrie JR, Morris AD, Minamisawa K, Hilditch TE, Elliott HL, Small M, et al. Dietary sodium restriction impairs insulin sensitivity in noninsulin‐dependent diabetes mellitus. Journal of Clinical Endocrinology & Metabolism 1998;83(5):1552‐7. [MEDLINE: 9589654]

Trevisan R, Bruttomesso D, Vedovato M, Brocco S, Pianta A, Mazzon C, et al. Enhanced responsiveness of blood pressure to sodium intake and to angiotensin II is associated with insulin resistance in IDDM patients with microalbuminuria. Diabetes 1998;47(8):1347‐53. [MEDLINE: 9703338]

Vedovato M, Lepore G, Coracina A, Dodesini AR, Jori E, Tiengo A, et al. Effect of sodium intake on blood pressure and albuminuria in Type 2 diabetic patients: the role of insulin resistance. Diabetologia 2004;47(2):300‐3. [MEDLINE: 14704836]

Yoshioka K, Imanishi M, Konishi Y, Sato T, Tanaka S, Kimura G, et al. Glomerular charge and size selectivity assessed by changes in salt intake in type 2 diabetic patients. Diabetes Care 1998;21(4):482‐6. [MEDLINE: 9571328]

Referencias de los estudios excluidos de esta revisión

Jump to:

included studies
additional references

Ames RP. The effect of sodium supplementation on glucose tolerance and insulin concentrations in patients with hypertension and diabetes mellitus. American Journal of Hypertension 2001;14(7 Pt 1):653‐9. [MEDLINE: 11465650]

Bakris GL, Smith A. Effects of sodium intake on albumin excretion in patients with diabetic nephropathy treated with long‐acting calcium antagonists. Annals of Internal Medicine 1996;125(3):201‐4. [MEDLINE: 8686978]

Barsotti G, Cupisti A, Morelli E, Meola M, Meriggioli M, Giovannetti S. Implications of dietary treatment in diabetic nephropathy [abstract]. 12th International Congress of Nephrology; 1993 Jun 13‐18; Jerusalem, Israel. 1993:440. [CENTRAL: CN‐00740508]

Google Scholar

Bellini C, Ferri C, Carlomagno A, Necozione S, Lepore AR, Desideri G, et al. Impaired inactive to active kallikrein conversion in human salt‐sensitive hypertension. Journal of the American Society of Nephrology 1996;7(12):2565‐77. [MEDLINE: 8989735]

Boero R, Pignataro A, Iadarola GM, Guarena C, Alfieri V, Quarello F. Effects of salt on intrarenal hemodynamics in essential hypertensive patients [abstract]. Journal of the American Society of Nephrology 1998;9(Program & Abstracts):321A. [CENTRAL: CN‐00444466]

Google Scholar

Boero R, Pignataro A, Iadarola GM, Quarello F. Effects of high salt intake on 24 hour blood pressure and systemic hemodynamics in essential hypertensive patients [abstract]. 35th Congress. European Renal Association. European Dialysis and Transplantation Association; 1998 Jun 6‐9; Rimini, Italy. 1998:87. [CENTRAL: CN‐00483277]

Google Scholar

Boero R, Pignataro A, Iadarola GM, Quarello F. Renal effects of high salt intake in patients with essential hypertension [abstract]. 35th Congress. European Renal Association. European Dialysis and Transplantation Association; 1998 Jun 6‐9; Rimini, Italy. 1998:89. [CENTRAL: CN‐00483278]

Google Scholar

Buter H, Hemmelder M, Navis G, de Jong P, de Zeeuw D. The blunting of the antiproteinuric efficacy of ACE inhibition by high sodium intake can be restored by hydrochlorothiazide. Nephrology Dialysis Transplantation 1998;13(7):1682‐5. [MEDLINE: 9681711]

Cianciaruso B, Bellizzi V, Minutolo R, Tavera A, Capuano A, Conte G, et al. Salt intake and renal outcome in patients with progressive renal disease. Mineral & Electrolyte Metabolism 1998;24:296‐301. [MEDLINE: 9554571]

Cuzzola F, Mallamaci F, Tripepi G, Parlongo S, Cutrupi S, Cataliotti A, et al. Urinary adrenomedullin is related to ET‐1 and salt intake in patients with mild essential hypertension. Salt Sensitivity Group of Italian Society of Hypertension. American Journal of Hypertension 2001;14(3):224‐30. [MEDLINE: 11281233]

Del Rio A, Rodriguez‐Villamil JL. Metabolic effects of strict salt restriction in essential hypertensive patients. Journal of Internal Medicine 1993;233(5):409‐14. [MEDLINE: 8487006]

Dengel DR, Hogikyan RV, Brown MD, Glickman SG, Supiano MA. Insulin sensitivity is associated with blood pressure response to sodium in older hypertensives. American Journal of Physiology 1998;274(3):E403‐9. [MEDLINE: 9530121]

Dodson PM, Pacy PJ, Bal P, Kubicki AJ, Fletcher RF, Taylor KG. A controlled trial of a high fibre, low fat and low sodium diet for mild hypertension in Type 2 (non‐insulin‐dependent) diabetic patients. Diabetologia 1984;27(5):522‐6. [MEDLINE: 6096193]

Donovan DS, Solomon CG, Seely EW, Williams GH, Simonson DC. Effect of sodium intake on insulin sensitivity. American Journal of Physiology 1993;264(5 27‐5):E730‐4. [MEDLINE: 8498495]

ISRCTN50137410. Dual renin‐angiotensin system‐blockade by angiotension‐converting enzyme‐inhibition and angiotension receptor type 1 receptor blockade, role of the angiotension‐converting enzyme inhibitor or D genotype and low sodium diet in non‐diabetic proteinuric patients. controlled‐trials.com/ISRCTN50137410 (accessed 16 August 2010).

Egan BM, Stepniakowski K. Effects of enalapril on the hyperinsulinemic response to severe salt restriction in obese young men with mild systemic hypertension. American Journal of Cardiology 1993;72(1):53‐7. [MEDLINE: 8517428]

Evrenkaya R, Kurtoglu S, Atasoyu EN, Onde E, Ersoz HO, Tulbek MY. Assessment of the relation between sodium sensitivity and insulin resistance in norm and hypertensive non‐diabetic individuals [abstract]. Nephrology Dialysis Transplantation 1999;14(9):A64. [CENTRAL: CN‐00483894]

Google Scholar

Feldman RD, Logan AG, Schmidt ND. Dietary salt restriction increases vascular insulin resistance. Clinical Pharmacology & Therapeutics 1996;60(4):444‐51. [MEDLINE: 8873692]

Feldman RD, Schmidt ND. Moderate dietary salt restriction increases vascular and systemic insulin resistance. American Journal of Hypertension 1999;12(6):643‐7. [MEDLINE: 10371376]

Feldt‐Rasmussen B, Mathiesen ER, Deckert T, Giese J, Christensen NJ, Bent‐Hansen L, et al. Central role for sodium in the pathogenesis of blood pressure changes independent of angiotensin, aldosterone and catecholamines in Type 1 (insulin‐dependent) diabetes mellitus. Diabetologia 1987;30(8):610‐7. [MEDLINE: 3653559]

Fliser D, Fode P, Arnold U, Nowicki M, Kohl B, Ritz E. The effect of dietary salt on insulin sensitivity. European Journal of Clinical Investigation 1995;25(1):39‐43. [MEDLINE: 7705385]

Gerdts E, Svarstad E, Myking OL, Lund‐Johansen P, Omvik P, Gerdts E, et al. Salt sensitivity in hypertensive type‐1 diabetes mellitus. Blood Pressure 1996;5(2):78‐85. [MEDLINE: 9162448]

Gilleran G, O'Leary M, Bartlett WA, Vinall H, Jones AF, Dodson PM. Effects of dietary sodium substitution with potassium and magnesium in hypertensive type II diabetics: a randomised blind controlled parallel study. Journal of Human Hypertension 1996;10(8):517‐21. [MEDLINE: 8895035]

Gomi T, Shibuya Y, Sakurai J, Hirawa N, Hasegawa K, Ikeda T. Strict dietary sodium reduction worsens insulin sensitivity by increasing sympathetic nervous activity in patients with primary hypertension. American Journal of Hypertension 1998;11(9):1048‐55. [MEDLINE: 9752889]

Grey A, Braatvedt G, Holdaway I. Moderate dietary salt restriction does not alter insulin resistance or serum lipids in normal men. American Journal of Hypertension 1996;9(4 Pt 1):317‐22. [MEDLINE: 8722434]

Gruska S, Wolf E, Jendral I, Wedler B, Kraatz G. Salt sensitivity and insulin resistance in normotensives. Experimental & Clinical Endocrinology & Diabetes 1997;105 Suppl 2:22‐6. [MEDLINE: 9288538]

Google Scholar

Heeg Jan E, De Jong Paul E, Van der Hem Gjalt K, De Zeeuw D. Efficacy and variability of the antiproteinuric effect of ACE inhibition by lisinopril. Kidney International 1989;36(2):272‐9. [MEDLINE: 2550696]

Iwaoka T, Umeda T, Inoue J, Naomi S, Sasaki M, Fujimoto Y, et al. Dietary NaCl restriction deteriorates oral glucose tolerance in hypertensive patients with impairment of glucose tolerance. American Journal of Hypertension 1994;7:460‐3. [MEDLINE: 8060581]

Jafar TH. Blood pressure, diabetes, and increased dietary salt associated with stroke ‐ results from a community‐based study in Pakistan [1]. Journal of Human Hypertension 2006;20(1):83‐5. [MEDLINE: 16151442]

Jones‐Burton C, Mishra SI, Fink JC, Brown J, Gossa W, Bakris GL, et al. An in‐depth review of the evidence linking dietary salt intake and progression of chronic kidney disease. American Journal of Nephrology 2006;26(3):268‐75. [MEDLINE: 16763384]

Juncos L, Cade R, Fuller T, Mahoney J, Grubb W. Comparison of the effects of hydrochlorothiazide (H) and triamterene (T) in combination with low salt diet on both supine and standing systolic (SBP) and diastolic blood pressure (DBP), serum potassium (K+), weight (W) and peripheral plasma renin activity (PRA) and prostaglandin E2 concentration (PGE2). [abstract]. Kidney International 1976;10:531. [CENTRAL: CN‐00583692]

Google Scholar

Keven K, Yalcin S, Canbakan B, Kutlay S, Sengul S, Erturk S, et al. The impact of daily sodium intake on posttransplant hypertension in kidney allograft recipients. Transplantation Proceedings 2006;38(5):1323‐6. [MEDLINE: 16797292]

Kirby R. Salt sensitivity of blood pressure and diabetic nephropathy. Nature Clinical Practice Nephrology 2006;2(1):6. [EMBASE: 2006115437]

Kuroda S, Uzu T, Fujii T, Nishimura M, Nakamura S, Inenaga T, et al. Role of insulin resistance in the genesis of sodium sensitivity in essential hypertension. Journal of Human Hypertension 1999;13(4):257‐62. [MEDLINE: 10333344]

Mallamaci F, Cuzzola F, Tripepi G, Parlongo S, Malatino L, Bellanuova I, et al. Renal excretion of adrenomedullin is strongly influenced by salt intake and it is tightly linked to endothelin‐1 excretion in patients with essential hypertension (EH) [abstract]. Nephrology Dialysis Transplantation 1999;14(9):A67. [CENTRAL: CN‐00583530]

Google Scholar

Mazouz H, Kacso I, Ghazali A, El Esper N, Moriniere P, Makdassi R, et al. Risk factors of renal failure progression two years prior to dialysis. Clinical Nephrology 1999;51(6):355‐66. [MEDLINE: 10404696]

Meland E, Laerum E, Aakvaag A, Ulvik RJ, Hstmark AT. Salt restriction: effects on lipids and insulin production in hypertensive patients. Scandinavian Journal of Clinical and Laboratory Investigation 1997;57(6):501‐5. [PUBMED: 9350069]

Melander O, Groop L, Hulthen UL. Effect of salt on insulin sensitivity differs according to gender and degree of salt sensitivity. Hypertension 2000;35(3):827‐31. [MEDLINE: 10720602]

Metcalf PA, Baker JR, Scragg RK, Dryson E, Scott AJ, Wild CJ. Dietary nutrient intakes and slight albuminuria in people at least 40 years old. Clinical Chemistry 1993;39(10):2191‐8. [MEDLINE: 8403406]

Pacy PJ, Dodson PM, Kubicki AJ, Fletcher RF, Taylor KG. Comparison of the hypotensive and metabolic effects of metoprolol therapy with a high fibre, low sodium, low fat diet in hypertensive type 2 diabetic subjects. Diabetes Research 1984;1(4):201‐7. [MEDLINE: 6099231]

Perry CG, Palmer T, Cleland SJ, Morton IJ, Salt IP, Petrie JR, et al. Decreased insulin sensitivity during dietary sodium restriction is not mediated by effects of angiotensin II on insulin action. Clinical Science 2003;105(2):187‐94. [MEDLINE: 12691602]

Price DA, De'Oliveira JM, Fisher ND, Williams GH, Hollenberg NK, Price DA, et al. The state and responsiveness of the renin‐angiotensin‐aldosterone system in patients with type II diabetes mellitus. American Journal of Hypertension 1999;12(4 Pt 1):348‐55. [MEDLINE: 10232494]

Raji A, Williams GH, Jeunemaitre X, Hopkins PN, Hunt SC, Hollenberg NK, et al. Insulin resistance in hypertensives: effect of salt sensitivity, renin status and sodium intake. Journal of Hypertension 2001;19(1):99‐105. [MEDLINE: 11204310]

Rudberg S, Lemne C, Persson B, Krekula A, De Faire U, Aperia A, et al. The dopaminuric response to high salt diet in insulin‐dependent diabetes mellitus and in family history of hypertension. Pediatric Nephrology 1997;11(2):169‐73. [MEDLINE: 9090656]

Sharma AM, Ruland K, Spies KP, Distler A. Salt sensitivity in young normotensive subjects is associated with a hyperinsulinemic response to oral glucose. Journal of Hypertension 1991;9(4):329‐35. [MEDLINE: 1646259]

Sharma AM, Schorr U, Distler A. Insulin resistance in young salt‐sensitive normotensive subjects. Hypertension 1993;21(3):273‐9. [MEDLINE: 8478036]

Suzuki M, Kimura Y, Tsushima M, Harano Y. Association of insulin resistance with salt sensitivity and nocturnal fall of blood pressure. Hypertension 2000;35(4):864‐8. [MEDLINE: 10775552]

Swift PA, Markandu ND, Sagnella GA, He FJ, MacGregor GA. Modest salt reduction reduces blood pressure and urine protein excretion in black hypertensives: a randomized control trial. Hypertension 2005;46(2):308‐12. [MEDLINE: 15983240]

Swift PA, Markandu ND, Sagnella GA, MacGregor GA. A double blind randomised control trial of modest salt reduction in black people with normal blood pressure [abstract]. Journal of the American Society of Nephrology 2006;17(Abstracts):657A. [CENTRAL: CN‐00716093]

Google Scholar

Townsend RR, Kapoor S, McFadden CB, Townsend RR, Kapoor S, McFadden CB. Salt intake and insulin sensitivity in healthy human volunteers. Clinical Science 2007;113(3):141‐8. [MEDLINE: 17425514]

Trujillo A, Eggena P, Barrett J, Tuck M. Renin regulation in type II diabetes mellitus: influence of dietary sodium. Hypertension 1989;13(3):200‐5. [MEDLINE: 2646216]

Tuck M, Corry D, Trujillo A. Salt‐sensitive blood pressure and exaggerated vascular reactivity in the hypertension of diabetes mellitus. American Journal of Medicine 1990;88(3):210‐6. [MEDLINE: 2309737]

Weir MR, Dengel DR, Behrens MT, Goldberg AP. Salt‐induced increases in systolic blood pressure affect renal hemodynamics and proteinuria. Hypertension 1995;25(6):1339‐44. [MEDLINE: 7768584]

Weir MR, Dworkin LD. Antihypertensive drugs, dietary salt, and renal protection: how low should you go and with which therapy?. American Journal of Kidney Diseases 1998;32(1):1‐22. [MEDLINE: 9669419]

Zanchi A, Chiolero A, Maillard M, Nussberger J, Brunner HR, Burnier M. Effects of the peroxisomal proliferator‐activated receptor‐gamma agonist pioglitazone on renal and hormonal responses to salt in healthy men. Journal of Clinical Endocrinology & Metabolism 2004;89(3):1140‐5. [MEDLINE: 15001599]

Zarraga IGE, Schwarz ER. Impact of dietary patterns and interventions on cardiovascular health. Circulation 2006;114(9):961‐73. [MEDLINE: 16940205]

Referencias adicionales

Jump to:

included studies
excluded studies

Adler A, Stratton I, Neil H, Yudkin J, Matthews D, Cull C, et al. Association of systolic blood pressure with macrovascular and microvascular complications of type 2 diabetes (UKPDS 36): prospective observational study. BMJ 2000;321(7258):412‐9. [MEDLINE: 10938049]

Allen TJ, Waldron MJ, Casley D, Jerums G, Cooper ME. Salt restriction reduces hyperfiltration, renal enlargement, and albuminuria in experimental diabetes. Diabetes 1997;46(1):19‐24. [MEDLINE: 8971091]

Cianciaruso B, Bellizzi V, Minutolo R, Tavera A, Capuano A, Conte G, et al. Salt intake and renal outcome in patients with progressive renal disease. Mineral & Electrolyte Metabolism 1998;24(4):296‐301. [MEDLINE: 9554571]

Da Costa Lima NK, Lima FB, Dos Santos EA, Okamoto MM, Matsushita DH, Hell NS, et al. Chronic salt overload increases blood pressure and improves glucose metabolism without changing insulin sensitivity. American Journal of Hypertension 1997;10(7 Pt 1):720‐7. [MEDLINE: 9234825]

Daviglus M, Greenland P, Stamler J, Elliott P, Appel L, Carnethon M, et al. Relation of nutrient intake to microalbuminuria in nondiabetic middle‐aged men and women: International Population Study on Macronutrients and Blood Pressure (INTERMAP). American Journal of Kidney Diseases 2005;45:256‐66. [MEDLINE: 15685502]

DeFronzo RA. The effect of insulin on renal sodium metabolism. A review with clinical implications. Diabetologia 1981;21(3):165‐71. [MEDLINE: 7028550]

Giunti S, Barit D, Cooper M. Mechanisms of diabetic nephropathy: role of hypertension. Hypertension 2006;48(4):519‐26. [MEDLINE: 16952978]

Harvey JN. Trends in the prevalence of diabetic nephropathy in type 1 and type 2 diabetes. Current Opinions in Nephrology & Hypertension 2003;12:317‐22. [MEDLINE: 12698072]

He FJ, MacGregor GA. Effect of modest salt reduction on blood pressure: a meta‐analysis of randomized trials. Implications for public health. Journal of Human Hypertension 2002;16(11):761‐70. [MEDLINE: 12444537]

He FJ, MacGregor GA. How far should salt intake be reduced?. Hypertension 2003;42(6):1093‐9. [MEDLINE: 14610100]

He FJ, Marciniak M, Visagie E, Markandu ND, Anand V, Dalton RN, et al. Effect of modest salt reduction on blood pressure, urinary albumin, and pulse wave velocity in white, black, and Asian mild hypertensives. Hypertension 2009;54(3):482‐8. [MEDLINE: 19620514]

He F, MacGregor GA. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes. Journal of Human Hypertension 2009;23(6):363‐84. [MEDLINE: 19110538]

Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta‐analyses. BMJ 2003;327(7414):557‐60. [MEDLINE: 12958120]

Hillege HL, Fidler V, Diercks GFH, Van Gilst WH, De Zeeuw D, Van Veldhuisen DJ, et al. Urinary albumin excretion predicts cardiovascular and noncardiovascular mortality in general population. Circulation 2002;106(14):1777‐82. [MEDLINE: 12356629]

Hooper L, Bartlett C, Davey Smith G, Ebrahim S. Systematic review of long term effects of advice to reduce dietary salt in adults. BMJ 2002;325(7365):628‐34. [MEDLINE: 12242173]

Jones‐Burton C, Mishra SI, Fink JC, Brown J, Gossa W, Bakris GL, et al. An in‐depth review of the evidence linking dietary salt intake and progression of chronic kidney disease. American Journal of Nephrology 2006;26(3):268‐75. [MEDLINE: 16763384]

Law MR, Frost CD, Wald NJ. By how much does dietary salt reduction lower blood pressure? III ‐ Analysis of data from trials of salt reduction. BMJ 1991;302(6780):819‐24. [MEDLINE: 1827353]

Law MR, Frost CD, Wald NJ. By how much does dietary salt reduction lower blood pressure? I ‐ Analysis of observational data among populations. BMJ 1991;302(6780):811‐5. [MEDLINE: 2025703]

Lefebvre C, Manheimer E, Glanville J. Chapter 6: Searching for studies. In Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.0 (updated February 2008). The Cochrane Collaboration. Available from www.cochrane‐handbook.org.

MacGregor G, Markandu ND, Singer DR, Cappuccio FP, Shore AC, Sagnella GA. Moderate sodium restriction with angiotensin converting enzyme inhibitor in essential hypertension: a double blind study. British Medical Journal Clinical Research Ed 1987;294(6571):531‐4. [MEDLINE: 3103761]

Midgley JP, Matthew AG, Greenwood CM, Logan AG. Effect of reduced dietary sodium on blood pressure: a meta‐analysis of randomized controlled trials. JAMA 1996;275(20):1590‐7. [MEDLINE: 8622251]

Nishiyama A, Seth D, Navar L. Renal interstitial fluid concentrations of angiotensins I and II in anesthetized rats. Hypertension 2002;39(1):129‐34. [MEDLINE: 11799091]

Price DA, De'Oliveira JM, Fisher ND, Williams GH, Hollenberg NK. The state and responsiveness of the renin‐angiotensin‐aldosterone system in patients with type II diabetes mellitus. American Journal of Hypertension 1999;12(4 Pt 1):348‐55. [MEDLINE: 10232494]

Willis NS, Mitchell R, Higgins GY, Webster AC, Craig JC. Cochrane Renal Group. About The Cochrane Collaboration (Cochrane Review Groups (CRGs)) 2010, Issue 9. Art. No.: RENAL(accessed October 2010).

Google Scholar

Scientific Advisory Committee on Nutrition. Salt and Health. http://www.sacn.gov.uk/pdfs/sacn_salt_final.pdf 2003 (accessed August 2010).

Schrier RW, Estacio RO, Esler A, Mehler P. Effects of aggressive blood pressure control in normotensive type 2 diabetic patients on albuminuria, retinopathy and strokes. Kidney International 2002;61(3):1086‐97. [MEDLINE: 11849464]

Sowers JR, Epstein M, Frohlich ED. Diabetes, hypertension, and cardiovascular disease: an update. Hypertension 2001;37(4):1053‐9. [MEDLINE: 11304502]

Swift PA, Markandu ND, Sagnella GA, He FJ, MacGregor GA. Modest salt reduction reduces blood pressure and urine protein excretion in black hypertensives: a randomized control trial. Hypertension 2005;46(2):308‐12. [MEDLINE: 15983240]

Verhave JC, Hillege HL, Burgerhof JG, Janssen WM, Ganesvoort RT, Navis GJ, et al. Sodium intake affects urinary albumin excretion especially in overweight subjects. Journal of Internal Medicine 2004;256(4):324‐30. [MEDLINE: 15367175]

World Health Organization. The World Health Report 2002 ‐ Reducing Risks, Promoting Healthy Life. http://www.who.int/whr/2002/en/index.html(accessed August 2010).

Woods LL, Mizelle HL, Hall JE. Control of renal hemodynamics in hyperglycemia: possible role of tubuloglomerular feedback. American Journal of Physiology 1987;252(1 Pt 2):F65‐73. [MEDLINE: 3812702]

Characteristics of studies

Characteristics of included studies [ordered by study ID]

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excluded studies

De'oliveira 1997

Methods	Study design: Parallel RCT Time frame: NS
Participants	Inclusion criteria Setting: Hospital Country: USA DM: Type 2 Hypertensive SBP > 140 mm Hg and DBP > 90 mm Hg on at least 3 outpatient visits Mean BMI: 30 ± 1 Number (treatment/control): 9/10 Mean age ± SD: 55 ± 2 years Treatment/control: 56 ± 3 years/55 ± 2 years Sex (M/F): 16/3 Treatment: 7/2 Control: 9/1 Exclusion criteria Age < 30 years
Interventions	Treatment group Low salt diet: 50 mmol/d Duration: 5‐7 days Control group High salt diet: 200 mmol/d Duration: 5‐7 days Co‐interventions: No
Outcomes	MAP RPF GFR
Notes	Exclusions post randomisation but pre‐intervention: None Stop or end point/s: Not stated Additional data requested from authors: Yes but no response to request Completeness of follow‐up Analysed 100% Per cent followed 100%
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Low risk	Yes
Blinding? Investigators	Low risk	Yes
Blinding? Outcome assessors	Low risk	Yes
Blinding? Data analysers	Low risk	Yes
Intention‐to‐treat analysis	High risk	ITT analysis not performed
Funding source	Low risk	NIH, Canadian Medical Research Fellowship Award, Northern Ireland Council for Postgraduate Education Award

Dodson_P 1989

Methods	Study design: Parallel RCT followed by crossover study Time frame: not stated Follow‐up period: 3 months Loss to follow‐up: 0
Participants	Inclusion criteria Setting: Hospital Country: UK Hypertension SBP > 160 mm Hg or DBP > 95 mm Hg DM: type 2 No past or current history of treatment with insulin Number (treatment/control): 17/17 Mean age (SD) Treatment: 61.9 (7.5) years Control: 61.1 (6.3) years Sex (M/F) Treatment: 12/5 Control: 11/6 Exclusion criteria DKD or hypertensive kidney disease (proteinuria or raised serum creatinine concentration), cardiac failure, pregnancy
Interventions	Treatment group (parallel study) Moderate sodium restriction: Dietary advice Duration: 3 months Control group (parallel study) Usual diabetic diet: No advice Duration: 3 months Co‐interventions: none
Outcomes	SBP DBP Weight HbA1c
Notes	Stop or end point/s: Not stated Per cent followed: 100%
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Low risk	Yes
Blinding? Investigators	Low risk	Yes
Blinding? Outcome assessors	Low risk	Yes
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	High risk	No
Funding source	High risk	Ciba provided slow sodium and placebo

Dodson_X 1989

Methods	Study design: Parallel RCT followed by crossover study Time frame: not stated Follow‐up period: 3 months Loss to follow‐up: 4
Participants	Inclusion criteria Setting: Hospital Country: UK Hypertension SBP > 160 mm Hg or DBP > 95 mm Hg DM: type 2 No past or current history of treatment with insulin Number: 9 Mean age (SD): 62 (6.5) years Sex (M/F): 6/3 Exclusion criteria DKD or hypertensive kidney disease (proteinuria or raised serum creatinine concentration), cardiac failure, pregnancy
Interventions	Crossover study Sodium restriction diet + slow release sodium supplement (80 mmol/d) for 1 month Sodium restriction diet + placebo for 1 month
Outcomes	SBP DBP Weight HbA1c
Notes	Stop or end point/s: Not stated Per cent followed: 100%
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Low risk	Yes
Blinding? Investigators	Low risk	Yes
Blinding? Outcome assessors	Low risk	Yes
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	High risk	No
Funding source	High risk	Ciba provided slow sodium and placebo

Houlihan_Losartan 2002

Methods	Study design: Parallel for losartan versus placebo, crossover for salt intervention Time frame: not stated Follow‐up period: 12 weeks Loss to follow‐up: 0
Participants	Inclusion criteria Setting: Hospital Country: Australia SBP > 130 mm Hg and/or DBP > 85 mm Hg DM: type 2 AER 10‐200 µg/min HbA1c < 11.0% Number (placebo/losartan): 10/10 Mean age (SD) Placebo: 63.1 (3.9) years Losartan: 60.6 (3.7) years Sex (M/F) Placebo: 9/1 Losartan: 10/0 Exclusion criteria Serious systemic illness; substance abuse; 24 hour urinary sodium > 100 mmol/24 h; SBP > 165 mm Hg, DBP > 100 mm Hg; plasma Cr > 200 µmol/L, long‐term use of NSAID; UTIs; BMI > 35 kg/m²; intolerance of ACEi.
Interventions	Treatment Low sodium phase: 50‐70 mmol/d Control Regular sodium phase: > 100 mmol/d Co‐interventions Losartan versus placebo with parallel study
Outcomes	SBP DBP MAP GFR ERPF HbA1c
Notes	Additional data requested from authors: UAE, no response from authors
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	High risk	Not blinded
Blinding? Investigators	Unclear risk	Not stated
Blinding? Outcome assessors	Unclear risk	Not stated
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	Unclear risk	Not stated
Funding source	High risk	Merck and Apex Diabetes Australia Research Grant

Houlihan_Placebo 2002

Methods	Study design: Parallel for losartan versus placebo, crossover for salt intervention Time frame: not stated Follow‐up period: 12 weeks Loss to follow‐up: 0
Participants	Inclusion criteria Setting: Hospital Country: Australia SBP > 130 mm Hg and/or DBP > 85 mm Hg DM: type 2 AER 10‐200 µg/min HbA1c < 11.0% Number (placebo/losartan): 10/10 Mean age (SD) Placebo: 63.1 (3.9) years Losartan: 60.6 (3.7) years Sex (M/F) Placebo: 9/1 Losartan: 10/0 Exclusion criteria Serious systemic illness; substance abuse; 24 hour urinary sodium > 100 mmol/24 h; SBP > 165 mm Hg, DBP > 100 mm Hg; plasma Cr > 200 µmol/L, long‐term use of NSAID; UTIs; BMI > 35 kg/m²; intolerance of ACEi.
Interventions	Treatment Low sodium phase: 50‐70 mmol/d Control Regular sodium phase: > 100 mmol/d Co‐interventions Losartan versus placebo with parallel study
Outcomes	SBP DBP MAP GFR ERPF HbA1c
Notes	Additional data requested from authors: UAE, no response from authors
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	High risk	Not blinded
Blinding? Investigators	Unclear risk	Not stated
Blinding? Outcome assessors	Unclear risk	Not stated
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	Unclear risk	Not stated
Funding source	High risk	Merck and Apex Diabetes Australia Research Grant

Imanishi_Micro 2001

Methods	Study design: crossover RCT Time frame: not stated
Participants	Inclusion criteria Country: Japan Setting: Hospital DM: type 2 with simple retinopathy divided into microalbuminuria and normoalbuminuria Number (normoalbuminuria/microalbuminuria): 8/8 Mean age ± SD Normoalbuminuria: 59 ± 11 years Microalbuminuria: 61 ± 10 years Sex (M/F) Normoalbuminuria: 5/3 Microalbuminuria: 4/4 Exclusion criteria Non‐diabetic kidney disease; heart disease; UTI; SCr > 97.4 µmol/L
Interventions	Treatment Low salt diet: 80 mmol/d Control Ordinary salt diet: 200 mmol/d
Outcomes	SBP DBP CrCl
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Unclear risk	Not stated
Blinding? Investigators	Unclear risk	Not stated
Blinding? Outcome assessors	Unclear risk	Not stated
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	High risk	No
Funding source	Unclear risk	Not stated

Imanishi_Normo 2001

Methods	Study design: crossover RCT Time frame: not stated
Participants	Inclusion criteria Country: Japan Setting: Hospital DM: type 2 with simple retinopathy divided into microalbuminuria and normoalbuminuria Number (normoalbuminuria/microalbuminuria): 8/8 Mean age ± SD Normoalbuminuria: 59 ± 11 years Microalbuminuria: 61 ± 10 years Sex (M/F) Normoalbuminuria: 5/3 Microalbuminuria: 4/4 Exclusion criteria Non‐diabetic kidney disease; heart disease; UTI; SCr > 97.4 µmol/L
Interventions	Treatment Low salt diet: 80 mmol/d Control Ordinary salt diet: 200 mmol/d
Outcomes	SBP DBP CrCl
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Unclear risk	Not stated
Blinding? Investigators	Unclear risk	Not stated
Blinding? Outcome assessors	Unclear risk	Not stated
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	High risk	No
Funding source	Unclear risk	Not stated

Lopes De Faria 1997

Methods	Study design: crossover RCT Time frame: NS Loss to follow‐up:0
Participants	Inclusion criteria Country: UK Setting: Hospital Normoalbuminuria, normotensive, aged 18‐55 years, body weight within 20% of ideal DM: IDDM Number: 10 Age: 30 ± 3 years Sex (M/F): 7/3 Exclusion criteria Patients on drugs other than insulin
Interventions	Treatment group Regular salt diet: ˜ 100 mmol/d Duration: 7 days Control group Sodium supplemented diet: regular salt diet + salt capsules (0.5g), 32 taken per day to elevate salt intake to ˜ 300 mmol/d Duration: 7 days
Outcomes	Weight MAP HbA1c GFR RPF
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	High risk	Not blinded
Blinding? Investigators	Unclear risk	Not stated
Blinding? Outcome assessors	Unclear risk	Not stated
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	High risk	No ITT
Funding source	Unclear risk	None stated

Luik 2002

Methods	Study design: crossover RCT Time frame: NS Loss to follow‐up: 0
Participants	Inclusion criteria Country: The Netherlands DM: Type 1 BP < 140/85 mm Hg Number: 24 Age: 28.8 ± 6 years Sex (M/F): 15/9
Interventions	Treatment Low salt diet: 50 mmol/d Control Liberal salt diet: 200 mmol/d
Outcomes	SBP DBP SCr CrCl GFR ERPF Urinary albumin/Cr ratio Albuminuria Weight BMI HbA1c
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	High risk	Not blinded
Blinding? Investigators	High risk	Not blinded
Blinding? Outcome assessors	High risk	Not blinded
Blinding? Data analysers	High risk	Not blinded
Intention‐to‐treat analysis	High risk	Not blinded
Funding source	Low risk	Work supported by grants from the Dutch Kidney Foundation and Diabetes Fonds Nederland (Diabetes Research fund)

Miller 1995

Methods	Study design: crossover RCT Time frame: NS Follow‐up period: NS Loss to follow‐up: 0
Participants	Inclusion criteria Country: Canada Setting: Hospital IDDM < 5 years Number: 9 Age: 25.6 ± 1.5 years (range 21‐31) Sex (M/F): 9/0
Interventions	Treatment group Sodium restriction: 20 mmol/d Duration: 7 days Control group Sodium diet: 250 mmol/d Duration: 7 days
Outcomes	MAP
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Low risk	Blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	Unclear risk	Not stated
Funding source	Low risk	This work was supported by Grant 92‐27 from the physicians of Ontario through the Physicians Services Inc. Foundation

Miller 1997

Methods	Study design: crossover RCT Time frame: NS Follow‐up period: NS Loss to follow‐up: 0
Participants	Inclusion criteria Country: Canada Setting: Hospital Early IDDM (duration. 2.8 ± 0.4 years) Number: 12 Age: 23 ± 2 years Se (M/F): 12/0
Interventions	Treatment group Low salt diet: 20 mmol/d Duration: 7 days Control group High salt diet: 200 mmol/d Duration: 7 days
Outcomes	MAP Weight GFR ERPF
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Low risk	Blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	Unclear risk	No ITT
Funding source	Low risk	This work was supported by Grant 92‐27 from the Physicians of Ontario through the Physicians’ Services Inc. Foundation

Mulhauser 1996

Methods	Study design: parallel RCT Time frame: 4 years Follow‐up period: not stated Loss to follow‐up: not stated
Participants	Inclusion criteria Setting: Hospital Country: Germany IDDM > 5 years Number (treatment/control): 8/8 Mean age ± SD Treatment: 35 ± 11 years Control: 27 ± 9 years Sex (M/F) Treatment: 5/3 Control: 7/1 Exclusion criteria UTI; drugs (including oral contraceptives); pregnancy
Interventions	Treatment group Low sodium diet: 90 mmol/d Placebo supplement Duration: 4 weeks Control group Low sodium diet: 90 mmol/d Sodium supplement: 100 mmol/d Duration: 4 weeks
Outcomes	SBP DBP SCr CrCl GFR ERPF Weight BMI HbA1c% Albuminuria
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Low risk	Blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	Unclear risk	No ITT
Funding source	High risk	The study has been supported by Cassella Riedel, Frankfurt, Germany, and by the E Klockner Stiftung, Duisburg, Germany.

Petrie 1998

Methods	Study design: crossover RCT Time frame: NS Follow‐up period: 12 days Loss to follow‐up: 0
Participants	Inclusion criteria Country: UK Setting: Hospital BMI 28.6 ± 3.9 kg/m², fasting plasma glucose 9.0 ± 2.2 mmol/L (range 5.7–12.4 mmol/L), HbA1c 5.7 ± 0.8% (normal range 3.4–4.9%), total cholesterol 5.76 ± 1.25 mmol/L DM: median duration 12 months (range 4‐92) Number: 9 Mean age ± SD: 57 ± 9.7 years Sex (M/F): 8/1
Interventions	Treatment group Low sodium diet: 40 mmol/d for 4 days then addition of placebo for 4 days Control group Low sodium diet: 40 mmol/d for 4 days then addition of sodium tablets (120 mmol/d) for 4 days
Outcomes	SBP DBP Weight
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	Adequate
Blinding? Participants	Low risk	Blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	High risk	No ITT
Funding source	High risk	This work was supported by the British Diabetic Association.

Trevisan_Micro 1998

Methods	Study design: crossover RCT Time frame: NS Follow‐up period: 2 weeks Loss to follow‐up: 0
Participants	Inclusion criteria Setting: Hospital Country: Italy IDDM, duration (mean ± SE) 24 ± 4 years Number: 7 Age (mean ± SE): 38 ± 5 years Sex (M/F): 6/1 Exclusion criteria: No drugs other than insulin, non‐DKD, endocrine disease, liver disease
Interventions	Treatment group Low sodium diet: 20 mEq Control group High sodium diet: 250 mEq
Outcomes	SBP DBP MAP GFR ERPF Weight BMI
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	High risk	Not blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Unclear risk	Not stated
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	Low risk	ITT performed
Funding source	High risk	This work was supported by Consiglio Nazionale delle Ricerche Grants 9603475CT04 and 9504361CT04.

Trevisan_Normo 1998

Methods	Study design: crossover RCT Time frame: NS Follow‐up period: 2 weeks Loss to follow‐up: 0
Participants	Inclusion criteria Setting: Hospital Country: Italy IDDM, duration (mean ± SE) 22 ± 4 years Number: 9 Age (mean ± SE): 42 ± 4 years Sex (M/F): 6/3 Exclusion criteria: No drugs other than insulin, non‐diabetic kidney disease, endocrine disease, liver disease
Interventions	Treatment group Low sodium diet: 20 mEq Control group High sodium diet: 250 mEq
Outcomes	SBP DBP MAP GFR ERPF Weight BMI
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Unclear risk	Not blinded
Blinding? Investigators	Unclear risk	Blinded
Blinding? Outcome assessors	Unclear risk	Not stated
Blinding? Data analysers	Unclear risk	Not stated
Intention‐to‐treat analysis	Unclear risk	ITT performed
Funding source	Unclear risk	This work was supported by Consiglio Nazionale delle Ricerche Grants 9603475CT04 and 9504361CT04.

Vedovato_Micro 2004

Methods	Study design: crossover RCT Time frame: NS Follow‐up period: 2 weeks Loss to follow‐up: 0
Participants	Inclusion criteria Country: Italy Setting: hospital DM: type 2 BP < 140/90 mm Hg; divided into two groups: with and without microalbuminuria Number: 20 Age: 57 ± 1 years Sex (M/F): 15/5 Exclusion criteria On antihypertensives
Interventions	Treatment group Low salt diet: 20 mmol/d Duration: 7 days Control group High sodium diet: 250 mmol/d Duration: 7 days
Outcomes	MAP Albuminuria
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Low risk	Blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	Low risk	ITT performed
Funding source	Low risk	This study was supported by a research grant from the University of Padua, Italy

Vedovato_Normo 2004

Methods	Study design: crossover RCT Time frame: NS Follow‐up period: 2 weeks Loss to follow‐up: 0
Participants	Inclusion criteria Country: Italy Setting: hospital DM: type 2BP < 140/90 mm Hg; divided into two groups: with and without microalbuminuria Number: 21 Age: 60 ± 2 years Sex (M/F): 16/5 Exclusion criteria On antihypertensives
Interventions	Treatment group Low salt diet: 20 mmol/d Duration: 7 days Control group High sodium diet: 250 mmol/d Duration: 7 days
Outcomes	MAP Albuminuria
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	Not stated
Blinding? Participants	Low risk	Blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	Low risk	ITT performed
Funding source	Low risk	This study was supported by a research grant from the University of Padua, Italy

Yoshioka_Adva_alb 1998

Methods	Study design: Crossover RCT Time frame: NS
Participants	Inclusion criteria Country: Japan Setting: Hospital DM: type 2 Number: 19 Divided into 3 groups: normoalbuminuria (8), microalbuminuria (7), advanced albuminuria (4) Age: 60 ± 2 years Sex (M/F): 11/8 Exclusion criteria Heart disease; non‐diabetic kidney disease; UTI, SCr > 1.0 mg/dL; BP > 160/95 mm Hg; on antihypertensives.
Interventions	Treatment Low salt diet: 85 mEq sodium Control High salt diet: 255 mEq sodium
Outcomes	MAP CrCl
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	Adequate
Blinding? Participants	High risk	Not blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	Unclear risk	Not stated
Funding source	Unclear risk	Not stated

Yoshioka_Micro 1998

Methods	Study design: Crossover RCT Time frame: NS
Participants	Inclusion criteria Country: Japan Setting: Hospital DM: type 2 Number: 19 Divided into 3 groups: normoalbuminuria (8), microalbuminuria (7), advanced albuminuria (4) Age: 60 ± 2 years Sex (M/F): 11/8 Exclusion criteria Heart disease; non‐diabetic kidney disease; UTI, SCr > 1.0 mg/dL; BP > 160/95 mm Hg; on antihypertensives.
Interventions	Treatment Low salt diet: 85 mEq sodium Control High salt diet: 255 mEq sodium
Outcomes	MAP CrCl
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	Adequate
Blinding? Participants	High risk	Not blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	Unclear risk	Not stated
Funding source	Unclear risk	Not stated

Yoshioka_Normo 1998

Methods	Study design: Crossover RCT Time frame: NS
Participants	Inclusion criteria Country: Japan Setting: Hospital DM: type 2 Number: 19 Divided into 3 groups: normoalbuminuria (8), microalbuminuria (7), advanced albuminuria (4) Age: 60 ± 2 years Sex (M/F): 11/8 Exclusion criteria Heart disease; non‐diabetic kidney disease; UTI, SCr > 1.0 mg/dL; BP > 160/95 mm Hg; on antihypertensives.
Interventions	Treatment Low salt diet: 85 mEq sodium Control High salt diet: 255 mEq sodium
Outcomes	MAP CrCl
Notes
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	Adequate
Blinding? Participants	High risk	Not blinded
Blinding? Investigators	Low risk	Blinded
Blinding? Outcome assessors	Low risk	Blinded
Blinding? Data analysers	Low risk	Blinded
Intention‐to‐treat analysis	Unclear risk	Not stated
Funding source	Unclear risk	Not stated

ACEi ‐ angiotensin converting enzyme inhibitors; AER ‐ albumin excretion ratio; BMI ‐ body mass index; BP ‐ blood pressure; Cr ‐ creatinine; CrCl ‐ creatinine clearance; DBP ‐ diastolic blood pressure; DKD ‐ diabetic kidney disease; ERPF ‐ effective renal plasma flow; GFR ‐ glomerular filtration rate; HbA1c ‐ glycated haemoglobin; IDDM ‐ idiopathic diabetes mellitus; MAP ‐ mean arterial pressure; NSAID ‐ nonsteroidal anti‐inflammatory drugs; RPF ‐ renal plasma flow; SBP ‐ systolic blood pressure; SCr ‐ serum creatinine; UTI ‐ urinary tract infection

Characteristics of excluded studies [ordered by study ID]

Jump to:

included studies

Study	Reason for exclusion
Ames 2001	Appropriate data in diabetic patients within the study cohort unavailable
Bakris 1996	Not RCT
Barsotti 1993	Study not salt reduction
Bellini 1996	Study not in diabetic patients
Boero 1998	Study not in diabetic patients
Buter 1998	Study not in diabetic patients
Cianciaruso 1998	Not RCT
Cuzzola 2001	Studies not in diabetic patients
Del Rio 1993	Study not in diabetic patients
Dengel 1998	Study not in diabetic patients
Dodson 1984	Multiple randomised interventions
Donovan 1993	Study not in diabetic patients
DUAAL Study	Study not in diabetic patients
Egan 1993	Studies not in diabetic patients
Evrenkaya 1999	Study not in diabetic patients
Feldman 1996	Study not in diabetic patients
Feldman 1999	Study not in diabetic patients
Feldt‐Rasmussen 1987	Not RCT
Fliser 1995	Study not in diabetic patients
Gerdts 1996	Not RCT
Gilleran 1996	Multiple randomised interventions
Gomi 1998	Study not in diabetic patients
Grey 1996	Study not in diabetic patients
Gruska 1997	Study not in diabetic patients
Heeg 1989	Study not in diabetic patients
Iwaoka 1994	Study not in diabetic patients
Jafar 2006	Study not in diabetic patients
Jones‐Burton 2006	Review article
Juncos 1976	Study not in diabetic patients
Keven 2006	Study not in diabetic patients
Kirby 2006	Appropriate data unavailable
Kuroda 1999	Study not in diabetic patients
Mallamaci 1999	Study not in diabetic patients
Mazouz 1999	Not RCT
Meland 1997	Study not in diabetic patients
Melander 2000	Study not in diabetic patients
Metcalf 1993	Not RCT
Pacy 1984	Multiple randomised interventions
Perry 2003	Study not in diabetic patients
Price 1999	Not RCT
Raji 2001	Study not in diabetic patients
Rudberg 1997	Not RCT
Sharma 1991	Study not in diabetic patients
Sharma 1993	Study not in diabetic patients
Suzuki 2000	Study not in diabetic patients
Swift 2005	Study not in diabetic patients
Townsend 2007	Study not in diabetic patients
Trujillo 1989	Not RCT
Tuck 1990	Not RCT
Weir 1995	Study not in diabetic patients
Weir 1998	Review article
Zanchi 2004	Study not in diabetic patients
Zarraga 2006	Review article

Data and analyses

Open in table viewer

Comparison 1. Net change with altering salt diet

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Systolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐7.04 [‐8.71, ‐5.38]
Open in figure viewer Analysis 1.1 Comparison 1 Net change with altering salt diet, Outcome 1 Systolic BP.
1.1 Long‐term studies	5		Mean Difference (Fixed, 95% CI)	‐6.20 [‐9.98, ‐2.43]
1.2 Short‐term studies	6		Mean Difference (Fixed, 95% CI)	‐7.25 [‐9.10, ‐5.40]
2 Diastolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐3.03 [‐3.95, ‐2.11]
Open in figure viewer Analysis 1.2 Comparison 1 Net change with altering salt diet, Outcome 2 Diastolic BP.
2.1 Long‐term studies	5		Mean Difference (Fixed, 95% CI)	‐3.78 [‐5.73, ‐1.84]
2.2 Short‐term studies	6		Mean Difference (Fixed, 95% CI)	‐2.82 [‐3.86, ‐1.78]
3 Systolic BP (excluding Houlihan_Losartan 2002) Show forest plot	10		Mean Difference (Fixed, 95% CI)	‐6.91 [‐8.61, ‐5.20]
Open in figure viewer Analysis 1.3 Comparison 1 Net change with altering salt diet, Outcome 3 Systolic BP (excluding Houlihan_Losartan 2002).
3.1 Long‐term studies	4		Mean Difference (Fixed, 95% CI)	‐5.02 [‐9.38, ‐0.65]
3.2 Short‐term studies	6		Mean Difference (Fixed, 95% CI)	‐7.25 [‐9.10, ‐5.40]
4 Diastolic BP (excluding Houlihan_Losartan 2002) Show forest plot	10		Mean Difference (Fixed, 95% CI)	‐2.76 [‐3.73, ‐1.79]
Open in figure viewer Analysis 1.4 Comparison 1 Net change with altering salt diet, Outcome 4 Diastolic BP (excluding Houlihan_Losartan 2002).
4.1 Long‐term studies	4		Mean Difference (Fixed, 95% CI)	‐2.38 [‐5.00, 0.24]
4.2 Short‐term studies	6		Mean Difference (Fixed, 95% CI)	‐2.82 [‐3.86, ‐1.78]
5 MAP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐2.19 [‐3.32, ‐1.06]
Open in figure viewer Analysis 1.5 Comparison 1 Net change with altering salt diet, Outcome 5 MAP.
5.1 Long‐term studies	2		Mean Difference (Fixed, 95% CI)	‐4.98 [‐8.27, ‐1.69]
5.2 Short‐term studies	9		Mean Difference (Fixed, 95% CI)	‐1.82 [‐3.02, ‐0.62]
6 SCr Show forest plot	2		Mean Difference (Fixed, 95% CI)	‐0.52 [‐4.74, 3.71]
Open in figure viewer Analysis 1.6 Comparison 1 Net change with altering salt diet, Outcome 6 SCr.
7 CrCl Show forest plot	5		Mean Difference (Fixed, 95% CI)	‐6.33 [‐10.47, ‐2.19]
Open in figure viewer Analysis 1.7 Comparison 1 Net change with altering salt diet, Outcome 7 CrCl.
8 GFR Show forest plot	10		Mean Difference (Fixed, 95% CI)	‐1.92 [‐4.49, 0.64]
Open in figure viewer Analysis 1.8 Comparison 1 Net change with altering salt diet, Outcome 8 GFR.
8.1 Long‐term studies	3		Mean Difference (Fixed, 95% CI)	‐2.41 [‐5.97, 1.14]
8.2 Short‐term studies	7		Mean Difference (Fixed, 95% CI)	‐1.39 [‐5.10, 2.32]
9 ERPF Show forest plot	8		Mean Difference (Fixed, 95% CI)	‐1.17 [‐3.25, 0.92]
Open in figure viewer Analysis 1.9 Comparison 1 Net change with altering salt diet, Outcome 9 ERPF.
9.1 Long‐term studies	3		Mean Difference (Fixed, 95% CI)	‐0.73 [‐2.83, 1.37]
9.2 Short‐term studies	5		Mean Difference (Fixed, 95% CI)	‐31.58 [‐49.14, ‐14.02]
10 Proteinuria Show forest plot	1		Mean Difference (Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.10 Comparison 1 Net change with altering salt diet, Outcome 10 Proteinuria.
11 HbA1c Show forest plot	6		Mean Difference (Fixed, 95% CI)	‐0.15 [‐0.31, 0.01]
Open in figure viewer Analysis 1.11 Comparison 1 Net change with altering salt diet, Outcome 11 HbA1c.
11.1 Long‐term studies	4		Mean Difference (Fixed, 95% CI)	‐0.05 [‐0.35, 0.25]
11.2 Short‐term studies	2		Mean Difference (Fixed, 95% CI)	‐0.19 [‐0.38, ‐0.00]
12 Weight Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐1.01 [‐1.20, ‐0.82]
Open in figure viewer Analysis 1.12 Comparison 1 Net change with altering salt diet, Outcome 12 Weight.
12.1 Long‐term studies	3		Mean Difference (Fixed, 95% CI)	‐0.24 [‐1.57, 1.09]
12.2 Short‐term studies	8		Mean Difference (Fixed, 95% CI)	‐1.03 [‐1.22, ‐0.83]
13 BMI Show forest plot	4		Mean Difference (Fixed, 95% CI)	‐0.40 [‐0.53, ‐0.28]
Open in figure viewer Analysis 1.13 Comparison 1 Net change with altering salt diet, Outcome 13 BMI.

Open in table viewer

Comparison 2. Net change in BP in type 1 and type 2 diabetes

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Systolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐7.04 [‐8.71, ‐5.38]
Open in figure viewer Analysis 2.1 Comparison 2 Net change in BP in type 1 and type 2 diabetes, Outcome 1 Systolic BP.
1.1 Type 1 diabetes	4		Mean Difference (Fixed, 95% CI)	‐7.11 [‐9.13, ‐5.10]
1.2 Type 2 diabetes	7		Mean Difference (Fixed, 95% CI)	‐6.90 [‐9.84, ‐3.95]
2 Diastolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐3.03 [‐3.95, ‐2.11]
Open in figure viewer Analysis 2.2 Comparison 2 Net change in BP in type 1 and type 2 diabetes, Outcome 2 Diastolic BP.
2.1 Type 1 diabetes	4		Mean Difference (Fixed, 95% CI)	‐3.13 [‐4.28, ‐1.98]
2.2 Type 2 diabetes	7		Mean Difference (Fixed, 95% CI)	‐2.87 [‐4.39, ‐1.35]
3 MAP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐2.19 [‐3.32, ‐1.06]
Open in figure viewer Analysis 2.3 Comparison 2 Net change in BP in type 1 and type 2 diabetes, Outcome 3 MAP.
3.1 Type 1 diabetes	3		Mean Difference (Fixed, 95% CI)	0.09 [‐1.83, 2.00]
3.2 Type 2 diabetes	8		Mean Difference (Fixed, 95% CI)	‐3.40 [‐4.80, ‐2.00]
4 HbA1c Show forest plot	6		Mean Difference (Fixed, 95% CI)	‐0.15 [‐0.31, 0.01]
Open in figure viewer Analysis 2.4 Comparison 2 Net change in BP in type 1 and type 2 diabetes, Outcome 4 HbA1c.
4.1 Type 1 diabetes	3		Mean Difference (Fixed, 95% CI)	‐0.16 [‐0.32, 0.01]
4.2 Type 2 diabetes	3		Mean Difference (Fixed, 95% CI)	‐0.12 [‐0.58, 0.34]

Open in table viewer

Comparison 3. Net change in BP in hypertensive and normotensive participants

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Systolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐7.04 [‐8.71, ‐5.38]
Open in figure viewer Analysis 3.1 Comparison 3 Net change in BP in hypertensive and normotensive participants, Outcome 1 Systolic BP.
1.1 Hypertensive	6		Mean Difference (Fixed, 95% CI)	‐4.86 [‐8.31, ‐1.41]
1.2 Normotensive	5		Mean Difference (Fixed, 95% CI)	‐7.70 [‐9.60, ‐5.81]
2 Diastolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐3.03 [‐3.95, ‐2.11]
Open in figure viewer Analysis 3.2 Comparison 3 Net change in BP in hypertensive and normotensive participants, Outcome 2 Diastolic BP.
2.1 Hypertensive	6		Mean Difference (Fixed, 95% CI)	‐2.96 [‐4.81, ‐1.11]
2.2 Normotensive	5		Mean Difference (Fixed, 95% CI)	‐3.06 [‐4.11, 0.00]
3 MAP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐2.19 [‐3.32, ‐1.06]
Open in figure viewer Analysis 3.3 Comparison 3 Net change in BP in hypertensive and normotensive participants, Outcome 3 MAP.
3.1 Hypertensive	3		Mean Difference (Fixed, 95% CI)	‐5.25 [‐8.43, ‐2.07]
3.2 Normotensive	8		Mean Difference (Fixed, 95% CI)	‐1.75 [‐2.96, ‐0.54]

Figure 1

Flow chart of study selection process

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Analysis 1.1

Comparison 1 Net change with altering salt diet, Outcome 1 Systolic BP.

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Analysis 1.2

Comparison 1 Net change with altering salt diet, Outcome 2 Diastolic BP.

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Analysis 1.3

Comparison 1 Net change with altering salt diet, Outcome 3 Systolic BP (excluding Houlihan_Losartan 2002).

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Analysis 1.4

Comparison 1 Net change with altering salt diet, Outcome 4 Diastolic BP (excluding Houlihan_Losartan 2002).

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Analysis 1.5

Comparison 1 Net change with altering salt diet, Outcome 5 MAP.

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Analysis 1.6

Comparison 1 Net change with altering salt diet, Outcome 6 SCr.

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Analysis 1.7

Comparison 1 Net change with altering salt diet, Outcome 7 CrCl.

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Analysis 1.8

Comparison 1 Net change with altering salt diet, Outcome 8 GFR.

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Analysis 1.9

Comparison 1 Net change with altering salt diet, Outcome 9 ERPF.

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Analysis 1.10

Comparison 1 Net change with altering salt diet, Outcome 10 Proteinuria.

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Analysis 1.11

Comparison 1 Net change with altering salt diet, Outcome 11 HbA1c.

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Analysis 1.12

Comparison 1 Net change with altering salt diet, Outcome 12 Weight.

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Analysis 1.13

Comparison 1 Net change with altering salt diet, Outcome 13 BMI.

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Analysis 2.1

Comparison 2 Net change in BP in type 1 and type 2 diabetes, Outcome 1 Systolic BP.

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Analysis 2.2

Comparison 2 Net change in BP in type 1 and type 2 diabetes, Outcome 2 Diastolic BP.

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Analysis 2.3

Comparison 2 Net change in BP in type 1 and type 2 diabetes, Outcome 3 MAP.

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Analysis 2.4

Comparison 2 Net change in BP in type 1 and type 2 diabetes, Outcome 4 HbA1c.

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Analysis 3.1

Comparison 3 Net change in BP in hypertensive and normotensive participants, Outcome 1 Systolic BP.

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Analysis 3.2

Comparison 3 Net change in BP in hypertensive and normotensive participants, Outcome 2 Diastolic BP.

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Analysis 3.3

Comparison 3 Net change in BP in hypertensive and normotensive participants, Outcome 3 MAP.

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Table 1. Summary table of characteristics of included studies

Study	Number of participants	Age (years)	Males (%)	Diabetes	Study design	Blinding	Study duration (weeks)	Initial BP (SE)
Dodson_P 1989	34	61	71/65	Type 2	P	SB	12	180(18)/91(11)
Dodson_X 1989	9	62	67	Type 2	X	DB	4	160(20)/88(11)
Miller 1995	9	26	100	Type 1	X	SB	1	‐‐
Mulhauser 1996	14	31	75	Type 1	P	DB	4	‐‐
De'oliveira 1997	19	55	84	Type 2	P	NS	1	MAP 102(3)
Lopes De Faria 1997	10	30	70	Type 1	X	NS	1	MAP 91(9)
Miller 1997	12	23	100	Type 1	X	SB	1	MAP 82(4)
Petrie 1998	9	57	89	Type 2	X	DB	5 days	148(25)/82(7)
Trevisan_Normo 1998	9	42	67	Type 1	X	NS	1	120/72
Trevisan_Micro 1998	7	38	86	Type 1	X	NS	1	125/78
Yoshioka_Normo 1998	8	60	58	Type 2	X	NS	1	134(5)/78(1)
Yoshioka_Micro 1998	7	58	58	Type 2	X	NS	1	133(6)/75(4)
Yoshioka_Adva_alb 1998	4	51	58	Type 2	X	NS	1	131(4)/75(4)
Imanishi_Normo 2001	8	59	63	Type 2	X	SB	1	132(11)/73(7)
Imanishi_Micro 2001	8	61	50	Type 2	X	SB	1	136(9)/82(6)
Houlihan_Placebo 2002	10	63	90	Type 2	X	SB	2	MAP 111(3)
Houlihan_Losartan 2002	10	61	100	Type 2	X	SB	2	MAP 114(3)
Luik 2002	24	29	63	Type 1	X	NS	1	‐‐
Vedovato_Normo 2004	21	60	75	Type 2	X	NS	1	125(2)/79(2)
Yoshioka_Micro 1998	20	57	75	Type 2	X	NS	1	130(2)/80(2)
DB ‐ double‐blind; NS ‐ not stated; P ‐ parallel; X ‐ crossover; SB ‐ single blind; SE ‐ standard error

Table 1. Summary table of characteristics of included studies

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Table 2. Outcomes reported in the included studies

Study	Urinary sodium (24h)	SCr	CrCl or GFR	RPF	Urinary albumin or protein (24h)	ACR	BP	HbA1c	BMI
Dodson_P 1989	X						X	X
Dodson_X 1989	X						X	X
Miller 1995	X						X
Mulhauser 1996	X	X	X	X	X		X	X	X
De'oliveira 1997	X		X	X			X
Lopes De Faria 1997	X		X	X			X	X
Miller 1997	X		X	X			X
Petrie 1998	X						X
Trevisan_Micro 1998; Trevisan_Normo 1998	X		X	X			X		X
Yoshioka_Adva_alb 1998; Yoshioka_Micro 1998; Yoshioka_Normo 1998	X		X				X
Imanishi_Micro 2001; Imanishi_Normo 2001	X		X				X	X
Houlihan_Losartan 2002; Houlihan_Placebo 2002	X		X	X	X	X	X	X
Luik 2002	X	X	X	X	X	X	X	X	X
Vedovato_Micro 2004; Vedovato_Normo 2004	X				X		X
ACR ‐ albumin‐creatinine ratio; BMI ‐ body mass index; CrCl ‐ creatinine clearance; GFR ‐ glomerular filtration rate; HbA1c ‐ glycated haemoglobin; RPF ‐ renal plasma flow; SCr ‐ serum creatinine

Table 2. Outcomes reported in the included studies

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Table 3. Measurements of urine albumin and protein excretion in included studies

Study	Urine measurement	Change from high/normal salt to low salt	Significance
Mulhauser 1996	Reported as proteinuria	‐412.6 mg/d (‐1035 to 210)	NS
Houlihan_Placebo 2002	Reported as % change in geometric mean of albumin excretion (tolerance factor)	+38.5% (CI ‐31.7 to 108.8)	NS
Houlihan_Losartan 2002		‐43.5% (CI ‐77.5 to ‐9.6)	P = 0.02
Luik 2002	Reported as mg/24h of albumin	+1.4 mg/24 h	NS
Vedovato_Normo 2004	Reported as median of albumin (IQR)	9 (6 to 12) µg/min to 8 (5 to 12) µg/min	NS
Vedovato_Micro 2004	Reported as median of albumin (IQR)	108 (84 to 178) µg/min to 80 (37 to 108) µg/min	P < 0.001
IQR ‐ intraquartile range; NS ‐ not significant

Table 3. Measurements of urine albumin and protein excretion in included studies

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Comparison 1. Net change with altering salt diet

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Systolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐7.04 [‐8.71, ‐5.38]

1.1 Long‐term studies	5		Mean Difference (Fixed, 95% CI)	‐6.20 [‐9.98, ‐2.43]
1.2 Short‐term studies	6		Mean Difference (Fixed, 95% CI)	‐7.25 [‐9.10, ‐5.40]
2 Diastolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐3.03 [‐3.95, ‐2.11]

2.1 Long‐term studies	5		Mean Difference (Fixed, 95% CI)	‐3.78 [‐5.73, ‐1.84]
2.2 Short‐term studies	6		Mean Difference (Fixed, 95% CI)	‐2.82 [‐3.86, ‐1.78]
3 Systolic BP (excluding Houlihan_Losartan 2002) Show forest plot	10		Mean Difference (Fixed, 95% CI)	‐6.91 [‐8.61, ‐5.20]

3.1 Long‐term studies	4		Mean Difference (Fixed, 95% CI)	‐5.02 [‐9.38, ‐0.65]
3.2 Short‐term studies	6		Mean Difference (Fixed, 95% CI)	‐7.25 [‐9.10, ‐5.40]
4 Diastolic BP (excluding Houlihan_Losartan 2002) Show forest plot	10		Mean Difference (Fixed, 95% CI)	‐2.76 [‐3.73, ‐1.79]

4.1 Long‐term studies	4		Mean Difference (Fixed, 95% CI)	‐2.38 [‐5.00, 0.24]
4.2 Short‐term studies	6		Mean Difference (Fixed, 95% CI)	‐2.82 [‐3.86, ‐1.78]
5 MAP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐2.19 [‐3.32, ‐1.06]

5.1 Long‐term studies	2		Mean Difference (Fixed, 95% CI)	‐4.98 [‐8.27, ‐1.69]
5.2 Short‐term studies	9		Mean Difference (Fixed, 95% CI)	‐1.82 [‐3.02, ‐0.62]
6 SCr Show forest plot	2		Mean Difference (Fixed, 95% CI)	‐0.52 [‐4.74, 3.71]

7 CrCl Show forest plot	5		Mean Difference (Fixed, 95% CI)	‐6.33 [‐10.47, ‐2.19]

8 GFR Show forest plot	10		Mean Difference (Fixed, 95% CI)	‐1.92 [‐4.49, 0.64]

8.1 Long‐term studies	3		Mean Difference (Fixed, 95% CI)	‐2.41 [‐5.97, 1.14]
8.2 Short‐term studies	7		Mean Difference (Fixed, 95% CI)	‐1.39 [‐5.10, 2.32]
9 ERPF Show forest plot	8		Mean Difference (Fixed, 95% CI)	‐1.17 [‐3.25, 0.92]

9.1 Long‐term studies	3		Mean Difference (Fixed, 95% CI)	‐0.73 [‐2.83, 1.37]
9.2 Short‐term studies	5		Mean Difference (Fixed, 95% CI)	‐31.58 [‐49.14, ‐14.02]
10 Proteinuria Show forest plot	1		Mean Difference (Fixed, 95% CI)	Totals not selected

11 HbA1c Show forest plot	6		Mean Difference (Fixed, 95% CI)	‐0.15 [‐0.31, 0.01]

11.1 Long‐term studies	4		Mean Difference (Fixed, 95% CI)	‐0.05 [‐0.35, 0.25]
11.2 Short‐term studies	2		Mean Difference (Fixed, 95% CI)	‐0.19 [‐0.38, ‐0.00]
12 Weight Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐1.01 [‐1.20, ‐0.82]

12.1 Long‐term studies	3		Mean Difference (Fixed, 95% CI)	‐0.24 [‐1.57, 1.09]
12.2 Short‐term studies	8		Mean Difference (Fixed, 95% CI)	‐1.03 [‐1.22, ‐0.83]
13 BMI Show forest plot	4		Mean Difference (Fixed, 95% CI)	‐0.40 [‐0.53, ‐0.28]

Comparison 1. Net change with altering salt diet

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Comparison 2. Net change in BP in type 1 and type 2 diabetes

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Systolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐7.04 [‐8.71, ‐5.38]

1.1 Type 1 diabetes	4		Mean Difference (Fixed, 95% CI)	‐7.11 [‐9.13, ‐5.10]
1.2 Type 2 diabetes	7		Mean Difference (Fixed, 95% CI)	‐6.90 [‐9.84, ‐3.95]
2 Diastolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐3.03 [‐3.95, ‐2.11]

2.1 Type 1 diabetes	4		Mean Difference (Fixed, 95% CI)	‐3.13 [‐4.28, ‐1.98]
2.2 Type 2 diabetes	7		Mean Difference (Fixed, 95% CI)	‐2.87 [‐4.39, ‐1.35]
3 MAP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐2.19 [‐3.32, ‐1.06]

3.1 Type 1 diabetes	3		Mean Difference (Fixed, 95% CI)	0.09 [‐1.83, 2.00]
3.2 Type 2 diabetes	8		Mean Difference (Fixed, 95% CI)	‐3.40 [‐4.80, ‐2.00]
4 HbA1c Show forest plot	6		Mean Difference (Fixed, 95% CI)	‐0.15 [‐0.31, 0.01]

4.1 Type 1 diabetes	3		Mean Difference (Fixed, 95% CI)	‐0.16 [‐0.32, 0.01]
4.2 Type 2 diabetes	3		Mean Difference (Fixed, 95% CI)	‐0.12 [‐0.58, 0.34]

Comparison 2. Net change in BP in type 1 and type 2 diabetes

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Comparison 3. Net change in BP in hypertensive and normotensive participants

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Systolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐7.04 [‐8.71, ‐5.38]

1.1 Hypertensive	6		Mean Difference (Fixed, 95% CI)	‐4.86 [‐8.31, ‐1.41]
1.2 Normotensive	5		Mean Difference (Fixed, 95% CI)	‐7.70 [‐9.60, ‐5.81]
2 Diastolic BP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐3.03 [‐3.95, ‐2.11]

2.1 Hypertensive	6		Mean Difference (Fixed, 95% CI)	‐2.96 [‐4.81, ‐1.11]
2.2 Normotensive	5		Mean Difference (Fixed, 95% CI)	‐3.06 [‐4.11, 0.00]
3 MAP Show forest plot	11		Mean Difference (Fixed, 95% CI)	‐2.19 [‐3.32, ‐1.06]

3.1 Hypertensive	3		Mean Difference (Fixed, 95% CI)	‐5.25 [‐8.43, ‐2.07]
3.2 Normotensive	8		Mean Difference (Fixed, 95% CI)	‐1.75 [‐2.96, ‐0.54]

Comparison 3. Net change in BP in hypertensive and normotensive participants

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References

Referencias de los estudios incluidos en esta revisión

De'oliveira 1997 {published data only (unpublished sought but not used)}

Dodson_P 1989 {published data only (unpublished sought but not used)}

Dodson_X 1989 {published data only (unpublished sought but not used)}

Houlihan_Losartan 2002 {published data only (unpublished sought but not used)}

Houlihan_Placebo 2002 {published data only}

Imanishi_Micro 2001 {published data only}

Imanishi_Normo 2001 {published data only}

Lopes De Faria 1997 {published data only}

Luik 2002 {published data only}

Miller 1995 {published data only}

Miller 1997 {published data only}

Mulhauser 1996 {published data only}

Petrie 1998 {published data only}

Trevisan_Micro 1998 {published data only}

Trevisan_Normo 1998 {published data only}

Vedovato_Micro 2004 {published data only}

Vedovato_Normo 2004 {published data only}

Yoshioka_Adva_alb 1998 {published data only}

Yoshioka_Micro 1998 {published data only}

Yoshioka_Normo 1998 {published data only}

Referencias de los estudios excluidos de esta revisión

Ames 2001 {published data only}

Bakris 1996 {published data only}

Barsotti 1993 {published data only}

Bellini 1996 {published data only}

Boero 1998 {published data only}

Buter 1998 {published data only}

Cianciaruso 1998 {published data only}

Cuzzola 2001 {published data only}

Del Rio 1993 {published data only}

Dengel 1998 {published data only}

Dodson 1984 {published data only}

Donovan 1993 {published data only}

DUAAL Study {published data only}

Egan 1993 {published data only}

Evrenkaya 1999 {published data only}

Feldman 1996 {published data only}

Feldman 1999 {published data only}

Feldt‐Rasmussen 1987 {published data only}

Fliser 1995 {published data only}

Gerdts 1996 {published data only}

Gilleran 1996 {published data only}

Gomi 1998 {published data only}

Grey 1996 {published data only}

Gruska 1997 {published data only}

Heeg 1989 {published data only}

Iwaoka 1994 {published data only}

Jafar 2006 {published data only}

Jones‐Burton 2006 {published data only}

Juncos 1976 {published data only}

Keven 2006 {published data only}

Kirby 2006 {published data only}

Kuroda 1999 {published data only}

Mallamaci 1999 {published data only}

Mazouz 1999 {published data only}

Meland 1997 {published data only}

Melander 2000 {published data only}

Metcalf 1993 {published data only}

Pacy 1984 {published data only}

Perry 2003 {published data only}

Price 1999 {published data only}

Raji 2001 {published data only}

Rudberg 1997 {published data only}

Sharma 1991 {published data only}

Sharma 1993 {published data only}

Suzuki 2000 {published data only}

Swift 2005 {published data only}

Townsend 2007 {published data only}

Trujillo 1989 {published data only}

Tuck 1990 {published data only}

Weir 1995 {published data only}

Weir 1998 {published data only}

Zanchi 2004 {published data only}

Zarraga 2006 {published data only}

Referencias adicionales

Adler 2000