Effect of sodium intake on blood pressure and albuminuria in Type 2 diabetic patients: the role of insulin resistance

Diabetologia. 2004 Feb;47(2):300-3. doi: 10.1007/s00125-003-1303-5. Epub 2003 Dec 24.


Aims/hypothesis: This study was done to measure the effect of Na+ intake on blood pressure and albuminuria, in relation with insulin sensitivity and kidney haemodynamics, in Type 2 diabetic patients with and without microalbuminuria.

Methods: Type 2 diabetic patients, 20 with microalbuminuria, 21 without, spent two consecutive 7-day periods, one on a high (250 mmol), the other on a low-Na+ (20 mmol) diet. Body weight, 24-h blood pressure and albuminuria were measured at the end of each period. At the end of high-Na+ diet insulin sensitivity (euglycaemic insulin clamp; 2 mU.kg(-1).min(-1)) and kidney haemodynamics were measured in nine patients from each group.

Results: Switching from low to high-Na+ diet resulted in an increase in blood pressure (7.4+/-4.7 mmHg; p<0.001), body weight (1.9+/-0.4 kg; p<0.05) and albuminuria [from 80 (31-183) microg/min to 101 (27-965) microg/min; p<0.01) in patients with microalbuminuria. No changes occurred in patients without microalbuminuria. Patients with microalbuminuria also had greater intraglomerular pressure (44+/-1 mmHg vs 36+/-1; p<0.001), calculated from glomerular filtration rate, renal plasma flow, plasma protein concentration and the relationship between pressure and natriuresis. In these patients insulin sensitivity was lower (5.16+/-49 vs 7.36+/-0.63 mg.kg(-1).min(-1); p=0.007). Urinary albumin excretion (r=0.40; p=0.009) and insulin sensitivity (r=-0.59; p=0.01) were correlated with intraglomerular pressure.

Conclusion/interpretation: High salt intake increases blood pressure and albuminuria in Type 2 diabetic patients with microalbuminuria. These responses are associated with insulin resistance and increased glomerular pressure. Insulin resistance could contribute to greater salt sensitivity, increased glomerular pressure and albuminuria.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albuminuria / metabolism*
  • Aldosterone / blood
  • Blood Glucose / metabolism
  • Blood Pressure / drug effects*
  • Body Weight / drug effects
  • Diabetes Mellitus, Type 2 / physiopathology*
  • Diabetes Mellitus, Type 2 / urine
  • Diet
  • Diet, Sodium-Restricted
  • Female
  • Glomerular Filtration Rate / physiology
  • Glucose Clamp Technique
  • Humans
  • Insulin / pharmacology
  • Insulin Resistance / physiology*
  • Linear Models
  • Male
  • Middle Aged
  • Patient Selection
  • Potassium / urine
  • Renal Plasma Flow / physiology
  • Renin / blood
  • Serum Albumin / metabolism
  • Sodium / administration & dosage
  • Sodium / pharmacology*
  • Sodium / urine


  • Blood Glucose
  • Insulin
  • Serum Albumin
  • Aldosterone
  • Sodium
  • Renin
  • Potassium