Urinary albumin excretion is independently associated with carotid and femoral artery atherosclerosis in the general population

Abstract

In diabetic patients, increased urinary albumin excretion (UAE), termed microalbuminuria when in the range between 30 and 300 mg/dL per day, is associated with a higher risk of atherosclerosis and its complications. Whether or not this notion applies to the general population is a matter of ongoing controversy because none of the few previous investigations among non-diabetics strictly represent the general community. Urinary albumin-to-creatinine ratio (uACR), a measure of UAE, was assessed from overnight spot urine samples in a population-based cohort of 684 individuals. The ratio was significantly related to age, gender, blood pressure, diabetes, markers of systemic inflammation, liver enzymes, and parathyroid hormone levels (P<0.001 each). Moreover, uACR emerged as a highly significant risk predictor of carotid and femoral artery atherosclerosis in the general community and the non-diabetic subpopulation alike (age/sex-adjusted P<0.001 each). In multivariable logistic regression analyses, odds ratios (95% CI) of carotid and femoral atherosclerosis amounted to 1.28 (1.01-1.61) and 1.44 (1.15-1.81) for a one unit increase in log(e)-transformed uACR (P=0.040 and 0.002). Corresponding odds ratios in non-diabetic subjects were 1.41 (1.09-1.84) and 1.54 (1.19-1.99) (P=0.010 and 0.001). Multivariable linear regression analyses yielded significant, or near significant, relations with carotid and femoral artery intima-media thickness and atherosclerosis scores (P=0.058-0.001). The uACR is significantly and independently associated with the presence and severity of atherosclerosis in the general population. The relation obtained was of a dose-response type and extended to levels far below what is termed microalbuminuria. The novel aspects of our study are its focus on various vascular territories and representivity of the general healthy population.