Epidemiologic aspects of abnormal ankle brachial index in the HIV infected population

HIV infection is strongly associated with accelerated vascular atherosclerosis and increased cardiovascular events. The prevalence of peripheral arterial disease (PAD) in HIV infected patients is not clearly defined and the results of different reports are contradicting.

To determine the prevalence of abnormal Ankle Brachial Index (ABI) and associated risk factors in HIV infected population.

The ABI was measured manually using 5.0 MHz handheld Doppler probe in 173 HIV infected patients. The cohort was categorized according to the ABI measurements as; normal group (ABI 0.9 to 1.3), peripheral arterial disease (PAD) group (ABI<0.9), and High ABI group (ABI>1.3). Several demographic, atherosclerosis risk factors and HIV infection parameters have been evaluated as potential risk factors.

Median age of the cohort was 49 years (inter-quartile ranges [IQR]: 42.5 to 54); 63.4% were males. Abnormal ABI was found in 47(27.2%) patients; twenty four (13.9%) had PAD and 23(13.3%) had high ABI. Among the risk factors evaluated, we observed that PAD group is associated with diabetes (Relative risk [RR]: 4.19; 95% confidence interval [CL]: 2.13 to 8.27; P=0.0002) and age above 49 (Relative risk [RR]: 3.96; 95% confidence interval [CL]: 1.56 to 10.0; P=0.002). However, the High ABI group was significantly associated with male gender (RR: 3.94; 95% CI: 1.23 to 12.70; P=0.009).

HIV infection is associated with increased prevalence of abnormal resting ABI.