The prognostic impact of general and abdominal obesity in peripheral arterial disease

Obesity is an independent cardiovascular risk factor, but its prognostic role in patients with peripheral arterial disease (PAD) is not well defined. Accordingly, we assessed the impact of body mass index (BMI) and waist circumference (WC) on cardiovascular risk in a homogeneous cohort of PAD patients.

BMI and WC were measured in 190 consecutive PAD patients with ABI <0.90, referred to our university hospital for intermittent claudication. The occurrence of cardiac, cerebrovascular and peripheral events was prospectively assessed. The ability to classify risk was determined by calculating the hazard ratios (HRs) and c-statistics.

During a median follow-up of 31.5 months, 63 patients (33.2%) had a cardiovascular event. Considered as continuous variables, both adiposity indices were significantly associated with increased cardiovascular risk, even after adjustment for possible confounding factors (HR=1.08, 95% CI 1.01-1.15, P=0.045 for BMI and HR=1.04, 95% CI 1.01-1.07, P=0.004 for WC). When BMI and WC were included together in a fully adjusted Cox model, the significant association between BMI and cardiovascular risk disappeared (HR=0.98, 95% CI 0.88-1.10, P=0.772), whereas WC remained significantly associated with a worse outcome (HR=1.04, 95% CI 1.01-1.08, P=0.033). The better discriminative ability of WC vs BMI was confirmed by the c-statistic, which was significantly higher for WC (0.63, 95% CI 0.56-0.70) than for BMI (0.56, 95% CI 0.51-0.63, P=0.038).

Abdominal obesity and, to a lesser degree, general obesity worsen the prognosis of PAD patients independently of possible confounding factors. Weight reduction should be integrated in the active management of these patients.