Background: There is limited information about whether a diagnosis of metabolic syndrome (MS) predicts peripheral arterial disease independently of diabetes. This study assessed whether MS adds prognostic information beyond that relating to diabetes in the identification of a low ankle-brachial index (ABI).
Design: Cross-sectional population-based study of people aged 50-75 years.
Methods: Eight hundred and fifty-eight participants were randomly selected. The likelihood of low ABI (<0.90) was calculated according to MS status before and after excluding diabetes. The National Cholesterol Education Panel and the International Diabetes Federation (IDF) definitions of MS were used.
Results: The prevalence of National Cholesterol Education Panel-defined and IDF-defined MS, and low ABI was 57.8, 61.1 and 7.5%, respectively. When there were participants with three or more criteria for MS, participants with only three criteria, and participants with four or five criteria were compared with participants without MS, the odds ratio for low ABI was 1.89 (95% confidence interval, 1.08-3.30), 1.34 (0.70-2.60) and 2.70 (1.45-5.03), respectively. The association of MS and low ABI lost statistical significance after excluding diabetes. No difference was observed using the IDF definition of MS.
Conclusion: Screening of participants with MS does not improve the identification of abnormal ABI provided by diabetes.