Objective: Microalbuminuria is a renal marker of general vascular endothelial damage and early atherosclerosis with adverse prognostic implications. Microalbuminuria is associated with diabetes, insulin resistance, central adiposity and hypertension. We evaluated the degree of the association of components of the metabolic syndrome with microalbuminuria in a subsample of a non-diabetic study population.
Design: Men and women aged 25-74 living in the city of Augsburg, Germany, were interviewed and examined in a standardised manner at a population-based survey conducted in 1994/95. Persons with a history of diabetes or HbA1c level > or = 7% were excluded.
Outcome: Albumin and creatinine were determined quantitatively in a spot urine and defined as microalbuminuria via an albumin/creatinine ratio between 30 and 299 mg/g.
Results: Among 920 men and 879 women, the age- standardised prevalence of microalbuminuria was 8.0% and 7.5%, respectively. While a graded, positive increase in prevalence of microalbuminuria across quintiles of waist-to-hip (WHR) was observed in non-hypertensive men and women, microalbuminuria was uniformly high among hypertensives. Multivariate logistic regression models showed that central adiposity (OR 3.3) or hypertension (OR 4.0) alone significantly increased the odds of microalbuminuria while their joint presence (OR 3.6) did not add to the occurrence of microalbuminuria. While obesity was not associated with microalbuminuria once central adiposity was taken into account, elevated percent body fat remained associated with microalbuminuria.
Conclusions: Signs of early endothelial dysfunction as manifested as microalbuminuria are strongly and independently associated with central adiposity and should be considered in the context of the metabolic or insulin resistance syndrome.