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 μg/min), 30 (25%) with microalbuminuria (AER of 20-200 μg/min) and 10 (8%) with macroalbuminuria (AER > 200 μg/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 (β= -0.189, P= 0.023). Conclusions: These findings may partly explain the pathogenetic processes that link microalbuminuria and enhanced cardiovascular risk in hypertensive patients.