Albuminuria and peripheral arterial disease: results from the multi-ethnic study of atherosclerosis (MESA).

BACKGROUND: The association of albuminuria with cardiovascular disease (CVD) is increasingly recognized, but its association with peripheral arterial disease (PAD) is not well characterized in subjects with or without diabetes.
METHODS: Using data from the Multi-Ethnic Study of Atherosclerosis, a cohort free of clinical vascular disease, we analyzed the cross-sectional association between albuminuria and PAD in diabetic and nondiabetic subjects. A spot urine albumin-creatinine ratio (ACR) was used to define albuminuria in two ways: presence or absence of albuminuria and the degree of albuminuria (no albuminuria defined as urine ACR<17 mg/g for men and <25mg/g for women, microalbuminuria as urine ACR 17 to 249 mg/g for men and 25 to 334 mg/g for women, and macroalbuminuria as urine ACR> or =250 mg/g for men and > or =355 mg/g for women). PAD was defined by ankle-brachial index (ABI)<0.9.
RESULTS: Among the 6760 subjects, aged 45-84 years, 326 (4.8%) had prevalent PAD. Eight hundred and thirteen (12.0%) subjects had microalbuminuria and 100 (1.5%) had macroalbuminuria. Among diabetic subjects, those with albuminuria (micro- and macroalbuminuria combined) were 1.90 times more likely to have PAD (95% CI: 1.19-3.04) than those with no albuminuria. After adjusting for CVD risk factors, the odds ratio modestly attenuated to 1.65 (95% CI: 1.00-2.74). For nondiabetic subjects, there were no statistically significant associations observed in the univariable and multivariable analyses. The degree of albuminuria was not associated with PAD in either diabetic or nondiabetic subjects.
CONCLUSIONS: The presence, but not magnitude of albuminuria, is an important risk factor for PAD in diabetic but not in nondiabetic subjects.