Effects of angiotensin II receptor antagonist on endothelial vasomotor function and urinary albumin excretion in type 2 diabetic patients with microalbuminuria

Diabetes Metab Res Rev. 2002 Jan-Feb;18(1):71-6. doi: 10.1002/dmrr.255.

Abstract

Background: Microalbuminuria is associated with dysfunction of the vascular endothelium in patients with diabetes mellitus. The objective of the present study was to determine whether treatment with losartan at a dose sufficient to lower urinary albumin excretion was accompanied by an improvement in endothelial function in type 2 diabetic patients with microalbuminuria.

Methods: Endothelial function was measured in 80 type 2 diabetic patients with microalbuminuria and 68 non-diabetic controls using high-resolution vascular ultrasound. The diabetic patients were randomised to receive either losartan 50 mg daily or placebo in a 6-month double-blind study. Urinary albumin excretion and endothelial function were assessed at baseline, 3 and 6 months.

Results: Both endothelium-dependent (p<0.01) and -independent vasodilation (p<0.01) were significantly impaired in diabetic patients with or without history of hypertension compared to the non-diabetic controls. At baseline, the losartan- and placebo-treated groups were comparable in their clinical characteristics. Blood pressure did not change significantly in either group throughout the study. Urinary mean albumin excretion rate (MAER) decreased in the losartan-treated group (p<0.01) whereas an increase was observed in the placebo group (p<0.05). At 6 months, the losartan-treated group had significantly lower MAER than the placebo-treated group [54.5 (58.3) vs 78.5 (100.5) microg/min, p<0.05; median (interquartile range)]. No significant differences were found in endothelium-dependent or -independent vasodilation.

Conclusions: Type 2 diabetic patients with microalbuminuria have impaired endothelium-dependent and -independent vasodilation. Treatment with low-dose losartan is sufficient to reduce microalbuminuria in these patients without alteration in endothelial function and systemic blood pressure.

Publication types

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

MeSH terms

  • Adult
  • Albuminuria / drug therapy*
  • Angiotensin Receptor Antagonists*
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Diabetes Mellitus, Type 2 / physiopathology
  • Double-Blind Method
  • Endothelium, Vascular / physiopathology*
  • Female
  • Humans
  • Losartan / therapeutic use*
  • Male
  • Middle Aged
  • Placebos
  • Vasodilation / drug effects

Substances

  • Angiotensin Receptor Antagonists
  • Placebos
  • Losartan