Urine Albumin Excretion and Subclinical Cardiovascular Disease

Abstract

We examined the association between urine albumin excretion (UAE) and common and internal carotid artery intima-media thickness (IMT), end-diastolic left ventricular (LV) mass, and coronary artery calcification (CAC) scores using data from the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of 6814 adults aged 45 to 85 years without clinical cardiovascular disease (CVD). The mean age of the MESA participants was 62.7 years, 47% were male, and 15% had diabetes mellitus (DM). Sex-specific spot urine albumin/creatinine ratios were used to define 4 UAE categories: normal, high normal, microalbuminuria, and macroalbuminuria. CAC scores were log-transformed after adding 1 to all scores. Mean values of subclinical CVD measures were computed by level of UAE after adjustment for blood pressure, DM, and other covariates. After adjustment for all covariates, geometric mean CAC scores were higher among participants with high normal UAE (8.8; P =0.07), microalbuminuria (9.9; P =0.002), and macroalbuminuria (13.1; P =0.02) compared with normal UAE (7.4), but only microalbuminuria reached statistical significance. Mean LV mass (g/m 2.7 ) was significantly higher in participants with high normal UAE (37.0; P =0.001), microalbuminuria (38.3; P ≤0.0001), and macroalbuminuria (42.3; P ≤0.0001) compared with normal UAE (36.0) after adjustment for all covariates. No significant difference in mean carotid IMT was found after adjustment for all covariates. Similar results were noted in MESA participants with and without DM. In conclusion, higher UAE, including levels below microalbuminuria, may reflect the presence of subclinical CVD among adults without established CVD.