Objectives: The purpose of this study was to: 1) determine the significance and magnitude of associations between novel cardiovascular disease (CVD) risk factors and peripheral arterial disease (PAD) after adjustment for traditional risk factors; and 2) ascertain the extent to which novel risk factors explain the excess or lower risk for PAD in different ethnic groups. Background: Previous reports have found a significant difference in the risk of PAD by ethnic group, with some of the risk difference attributed to different levels of traditional CVD risk factors. Methods: A total of 6,814 individuals free of clinically apparent CVD were enrolled in the MESA (Multiethnic Study of Atherosclerosis) and underwent standardized testing for the presence of PAD by the ankle-brachial index. These subjects also had fasting blood drawn for serum cholesterol, glucose, and a number of novel biomarkers for CVD. Non-Hispanic whites were the largest ethnic group (38%), followed by African Americans (28%), Hispanics (22%), and Chinese (12%). Results: In this cross-sectional analysis, 6,653 subjects with an ankle brachial index <1.40 were analyzed. The mean (SD) age was 62.2 (10.2) years, and 52.9% were women. Interleukin-6, fibrinogen, D-dimer, and homocysteine were significantly associated with PAD after adjustment for traditional CVD risk factors. Compared with non-Hispanic whites and after adjustment for traditional and "novel" risk factors, the odds for PAD were 1.47 (95% confidence interval [CI]: 1.07 to 2.02) times higher in African Americans, while being 0.45 (95% CI: 0.29 to 0.70) and 0.44 (95% CI: 0.24 to 0.78) in Hispanics and Chinese, respectively. Conclusions: Ethnic associations with PAD remained significant even after adjustment for traditional and novel risk factors. This suggests that unknown factors may account for the residual ethnic differences in PAD.
Bibliographical noteFunding Information:
This research was supported by a grant from the American Heart Association (to Dr. Allison) and contracts N01-HC-95159 through N01-HC-95165 and N01-HC-95169 from the National Heart, Lung, and Blood Institute. A full list of participating MESA investigators and institutions can be found at http://www.mesa-nhlbi.org . Charles H. Hennekens, MD, served as guest editor for this report.