Dissociation between microalbuminuria and common carotid thickness in essential hypertensive men

Abstract

Background: The reasons why microalbuminuria (albuminuria ⩾15 μg/min), an expression of a renal microcirculatory abnormality, predicts cardiovascular disease in essential hypertension are unsettled. To test the hypothesis that microalbuminuria represents a marker of subclinical atherosclerosis, we evaluated its association with common carotid artery (CCA) intima media thickness (IMT), a measure of preclinical atherosclerosis and an independent predictor of cardiac and cerebrovascular events, in uncomplicated essential hypertensive individuals.

Materials and methods: Albuminuria, ultrasonographic CCA IMT (the mean of six bilateral far wall measurements within 1.5 cm proximally to the flow divider), brachial blood pressure (BP), smoking habits and lipids were evaluated in 136 stage 1–3 untreated essential hypertensive men free of cardiovascular disease.

Results: CCA IMT did not differ between normo- (n = 99) and microalbuminuric (n = 37) patients. The correlation between CCA IMT and albuminuria was not significant, and the prevalence of microalbuminuria across IMT quartiles was not different. Microalbuminuric patients showed higher systolic BP and that parameter was the only independent correlate in a multivariate logistic regression model including also age, CCA IMT, diastolic BP, lipids and smoking habits as independent variables and microalbuminuria as the dependent one.

Conclusion: This cross-sectional study in hypertensive subjects free of cardiovascular disease has shown a dissociation between microalbuminuria and CCA IMT, a surrogate measure of subclinical atherosclerosis, and a parameter linearly related to cardiovascular events. The data do not support the theory of microalbuminuria as a surrogate measure of subclinical atherosclerosis, while confirming the importance of systolic BP levels as an independent correlate of increased albuminuria in essential hypertension.