Microalbuminuria, insulin sensitivity and haemostatic factors in non-diabetic treated hypertensive men. Risk Factor Intervention Study Group

Abstract

Objective: To examine whether microalbuminuria in non-diabetic, treated hypertensive men is associated with insulin resistance and measures of endothelial function, thrombogenesis and fibrinolysis.

Design: Cross-sectional study.

Setting: Outpatient clinic in city hospital.

Patients: Ninety-two treated hypertensive men, aged 57-77 years, either with a serum cholesterol of > or = 6.5 mmol L-1 or smokers, or both. Patients with diabetes mellitus or overnight urinary albumin excretion of > 100 mg 12 h-1 were excluded.

Main outcome measures: Overnight urinary albumin excretion, insulin-mediated glucose disposal (hyperinsulinaemic euglycaemic clamp), blood glucose and plasma insulin during oral glucose tolerance test, fibrinogen, von Willebrand factor and plasminogen activator inhibitor activity.

Results: Microalbuminuric patients had increased blood glucose concentrations during the oral glucose tolerance test and higher plasma fibrinogen levels compared with the normoalbuminuric patients. In a randomly selected subgroup (n = 36), insulin-mediated glucose disposal was lower in microalbuminuric than in normoalbuminuric patients, and an inverse relationship between insulin sensitivity and albuminuria (r = -0.37; P = 0.028) was found. This relationship was not significant after adjustment for body-mass index (P = 0.098). In the univariate analyses including all patients, albuminuria was associated with blood glucose, serum creatinine, body-mass index, systolic blood pressure, fibrinogen, von Willebrand factor and cholesterol (negatively). In a multiple regression analysis, only the body-mass index was independently related to urinary albumin excretion.

Conclusions: Microalbuminuria was associated with insulin resistance but obesity was a confounding factor. Relationships between microalbuminuria and fibrinogen as well as von Willebrand factor were found, but only in univariate analysis.