title: Modest Salt Reduction Lowers Blood Pressure and Albumin Excretion in Impaired Glucose Tolerance and Type 2 Diabetes Mellitus: A Randomized Double-Blind Trial.
abstract: The role of salt restriction in patients with impaired glucose tolerance and diabetes mellitus is controversial, with a lack of well controlled, longer term, modest salt reduction trials in this group of patients, in spite of the marked increase in cardiovascular risk. We carried out a 12-week randomized double-blind, crossover trial of salt restriction with salt or placebo tablets, each for 6 weeks, in 46 individuals with diet-controlled type 2 diabetes mellitus or impaired glucose tolerance and untreated normal or high normal blood pressure (BP). From salt to placebo, 24-hour urinary sodium was reduced by 49±9 mmol (2.9 g salt). This reduction in salt intake led to fall in clinic BP from 136/81±2/1 mm Hg to 131/80±2/1 mm Hg, (systolic BP; P<0.01). Mean ambulatory 24-hour BP was reduced by 3/2±1/1 mm Hg (systolic BP, P<0.01 and diastolic BP, P<0.05), and albumin/creatinine ratio was reduced from 0.73 mg/mmol (0.5-1.5) to 0.64 mg/mmol (0.3-1.1; P<0.05). There was no significant change in fasting glucose, hemoglobin A1c, or insulin sensitivity. These results demonstrate that a modest reduction in salt intake, to approximately the amount recommended in public health guidelines, leads to significant and clinically relevant falls in BP in individuals who are early on in the progression of diabetes mellitus with normal or mildly raised BP. The reduction in urinary albumin excretion may carry additional benefits in reducing cardiovascular disease above the effects on BP.
authors.affiliation: From the South West Thames Renal and Transplantation Unit, Epsom and St. Helier Hospital, London, United Kingdom (R.J.S.); and Centre for Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom (F.J.H., N.D.M., G.A.M.G.).
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Suckling
authors.affiliation: From the South West Thames Renal and Transplantation Unit, Epsom and St. Helier Hospital, London, United Kingdom (R.J.S.); and Centre for Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom (F.J.H., N.D.M., G.A.M.G.).
authors.forename: Feng J
authors.initials: FJ
authors.lastname: He
authors.affiliation: From the South West Thames Renal and Transplantation Unit, Epsom and St. Helier Hospital, London, United Kingdom (R.J.S.); and Centre for Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom (F.J.H., N.D.M., G.A.M.G.).
authors.forename: Nirmala D
authors.initials: ND
authors.lastname: Markandu
authors.affiliation: From the South West Thames Renal and Transplantation Unit, Epsom and St. Helier Hospital, London, United Kingdom (R.J.S.); and Centre for Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom (F.J.H., N.D.M., G.A.M.G.).
authors.forename: Graham A
authors.initials: GA
authors.lastname: MacGregor
mesh_terms: D000368:Aged; D001795:Blood Pressure Determination; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000178:diet therapy* / Q000188:drug therapy; D004039:Diet, Sodium-Restricted / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D018149:Glucose Intolerance / Q000178:diet therapy / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000178:diet therapy*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D017673:Sodium Chloride, Dietary
keywords: blood pressure; diet; hypertension; insulin; type 2 diabetes mellitus