The objective of this study was to evaluate the urinary albumin excretion and plasma biochemistry in patients with essential hypertension and impaired glucose tolerance. We studied 82 untreated patients (35 women and 47 men, mean aged 41 +/- 13) with mild to moderate hypertension. Body mass index (BMI) for study subjects was 29.1 +/- 5.0 kg/m2 and mean office blood pressure at entry was 152/97 mmHg. After an oral glucose tolerance test (OGTT) glucose, group was divided into impaired glucose tolerant (n = 16; IGT) and normoglycemic (n = 66; NormGLU) subgroups; patients with diabetes were excluded. 24-hour urinary albumin excretion (UAE) was estimated by the radioimmunoassay during two separate days. The median UAE in the IGT group was 16.0 +/- 28.6 mg/day and in NormGLU group 7.2 +/- 10.7 mg (p < 0.01). The prevalence of microalbuminuria was higher in IGT group (37 vs 18%). In the IGT subgroup total cholesterol, triglycerides and systolic blood pressure were higher. The presence of impaired glucose tolerance in hypertensive patients is correlated with increased urinary albumin excretion, which indicates significant role of metabolic disorders in inducing microalbuminuria.