Insulin sensitivity in clinically healthy individuals with microalbuminuria

In epidemiologic studies microalbuminuria is associated with increased atherosclerotic risk profile, morbidity, and mortality. In order to examine whether such association could be explained by impaired insulin sensitivity, 23 clinically healthy subjects with microalbuminuria (urinary albumin excretion rate (UAER) of 6.6 to 150 μg/min) and 24 age- and sex-matched controls with normoalbuminuria (UAER ≤ 6.6 μg/min) underwent a 3 h hyperinsulinaemic euglycaemic clamp investigation using an intravenous insulin infusion rate on 2 mU/(kg body weight x min). Insulin sensitivity (whole body glucose disposal) was similar in the two groups ((mean (95% C.I.)) 351 (321-381) vs. 364 (339-388) mg/(m² x min); P = 0.51). Among urinary albumin excretion rate, blood pressure, serum lipid concentrations, body mass index waist-hip ratio, fasting concentrations of serum insulin and blood glucose, tobacco and alcohol consumption, physical activity, and age and sex, fasting serum insulin concentration was the only variable independently associated with insulin sensitivity (r = 0.55; P = 0.0001). It is concluded that microalbuminuria is not associated with impaired insulin sensitivity in clinically healthy individuals. The effect of microalbuminuria as predictor of atherosclerotic vascular disease may be mediated through other factors.