230 Prevalence and risk factors of lower extremity artery disease in subjects without traditional modifiable cardiovascular risk factors. The multi-ethnic study of atherosclerosis

IntroductionLower-extremity peripheral artery disease (PAD) is associated with traditional cardiovascular disease risk factors (smoking, hypertension, dyslipidemia, diabetes). Among participants in the Multi-Ethnic Study of Atherosclerosis (MESA), we sought to assess the prevalence of PAD in a population without these risk factors. We hypothesized that this prevalence is not negligible, and that in this situation, PAD would still remain associated with other measures of subclinical atherosclerosis.MethodsIn the MESA cohort, we selected those (n = 1932) meeting the following criteria: no smoking over the last 10 years, no history of hypertension, dyslipidemia or diabetes, and normal blood pressure (140/90), fasting blood glucose 1.26 g/l, and a total-/HDL-cholesterol ratio <5. Participants were classified according to their ankle-brachial index (ABI) into 3 groups: low (<1.00), normal (1.00–1.30) and high (>1.30) ABI. Measures of subclinical atherosclerosis included any coronary artery calcification (CAC) or carotid plaque.ResultsOverall, the mean estimated Framingham risk score for coronary heart disease was 0.61%/year. Low- and high ABI were found in 176 (9%) and 149 (7.8%) participants, respectively. In multivariable models including age, gender and ethnicity, lower glomerular filtration rates (OR: 0.88/10 units, p = 0.04) and higher interleukin-6 levels (OR:1.42/natural-log unit, p = 0.02) were associated with low ABI. Higher body-mass index (OR:1.07/unit, p<0.001) was associated with high ABI. In a fully-adjusted model, low-ABI, not high-ABI, was significantly associated with CAC prevalence (OR:1.22, p