Background: The aim of this study was to determine the risk factors for conversion from a normal to either a low or high ankle-brachial index (ABI). Methods: Participants in the Multi-Ethnic Study of Atherosclerosis who had two separate measurements of the ABI over a 3-year time period were assessed. Results: At baseline, the mean age was 62 years and 50% were women, 28% African American, 12% Chinese, 22% Hispanic and 38% non-Hispanic White. Of the 5514 participants with a baseline ABI between 0.90 and 1.40, 89 (1.6%) had an ABI ≤ 0.90 ("low ABI group") and 71 (1.3%) had an ABI ≥ 1.40 ("high ABI group") 3 years later. On multivariable analysis, the odds for having progressed into the low ABI group were significantly increased for higher baseline age, hypertension, diabetes, greater pack-years of cigarette smoking, and homocysteine levels. The odds for progression into the high ABI group were increased for male gender and higher body mass index. Compared with non-Hispanic Whites, African Americans had a significantly higher odds for progression to the low ABI group (odds ratio [OR]: 2.24, 95% confidence interval [CI]: 1.29-3.88) while having a reduced odds for progression to the high ABI group (OR: 0.50, 95% CI: 0.24-1.00). Neither Chinese nor Hispanic ethnicity was significantly associated with progression to either ABI group. Conclusions: The risk factors for progression to a low or high ABI were distinct and African Americans were at increased risk for progression to a low ABI but at decreased risk for progression into the high ABI group. © 2009 Society for Vascular Surgery.
Allison, M. A., Cushman, M., Solomon, C., Aboyans, V., McDermott, M. M., Goff, D. C., & Criqui, M. H. (2009). Ethnicity and risk factors for change in the ankle-brachial index: The Multi-Ethnic Study of Atherosclerosis. Journal of Vascular Surgery, 50(5), 1049–1056. https://doi.org/10.1016/j.jvs.2009.05.061