Association of low glomerular filtration rate and albuminuria with peripheral arterial disease: the National Health and Nutrition Examination Survey, 1999-2004.

Microalbuminuria may be an early sign of intra-renal vascular dysfunction and a marker of vascular risk in the general population as well as in high-risk individuals. However, the association between albuminuria and PAD has been demonstrated only in few small studies. The aim of current study is to evaluate the relative impact of albuminuria and glomerular filtration rate on the risk of peripheral artery disease (PAD) in a nationally representative sample population. Data (ankle brachial index [ABI], urine albumin, fasting glucose, and glomerular filtration rate [GFR] estimated using the Modification of Diet in Renal Disease [MDRD] Study equation) were collected on 7068 adults from the National Health and Nutrition Examination Survey (NHANES 1999-2004). PAD was defined as ABI <0.9 or >1.4. There was a trend towards an association between the presence of abnormal renal function (GFR<60mL/min/1.73m(2)) and PAD in the non-diabetic patients (OR of 1.43, 95% CI: 0.98-2.09; P=0.07) where as the presence of abnormal renal function was strongly associated PAD in the diabetic patients (OR of 2.3, 95% CI: 1.34-3.95; P=0.046). On the contrary, albuminuria was independently associated with PAD in the non-diabetic (OR, 1.87; 95% CI, 1.38-2.52; P=0.0003) but not in the diabetic patients (OR: 1.08, 95% CI: 0.68-1.73, P=0.7411). We concluded that albuminuria, independent of renal function, is strongly associated with PAD in non-diabetic subjects. As diabetes develops and HbA1c level increases, the predictive value of albuminuria gradually diminishes after adjustment for renal function.