Association of serum bilirubin levels with albuminuria in patients with essential hypertension

Objectives: This study was undertaken to evaluate the relationship between serum bilirubin concentrations and the degree of urinary albumin excretion in hypertensive patients. Design and methods: A total of 120 hypertensive subjects were enrolled, in which 80 (67%) with normoalbuminuria (albumin excretion rate [AER] of <20 mu g/min), 30(25%) with microalbuminuria (AER of 20-200 mu g/min) and 10(8%) with macroalbuminuria (AER>200 mu g/min). Logarithmic (log) transformation of urinary albumin excretion was carried out before performing correlation and regression analysis. Results: Patients with micro- or macroalbuminuria had significantly lower serum bilirubin concentrations (P = 0.004). By multivariate regression analysis, serum bilirubin concentration was an independent determinant of albuminuria and had an inverse correlation with log (urinary albumin excretion) in hypertensive patients (beta = -0.189, P = 0.023). Conclusions: These findings may partly explain the pathogenetic processes that link microalbuminuria and enhanced cardiovascular risk in hypertensive patients. (C) 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.