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Abstract: Background: The clinical significance of a high ankle-brachial index (ABI), defined by the associated risk factor burden and ischemic risk, is largely unknown. Methods: Using data from the Atherosclerosis Risk in Communities Study, we categorized 14,777 participants into normal (ABI between 0.9 and 1.3) and high ABI groups (ABI>1.3, >1.4, and >1.5) and compared the risk factor profile and CVD event rates of the normal ABI group to each high ABI group. Results: The prevalence of high ABI was 5.5% for ABI>1.3, 1.2% for ABI>1.4, and 0.37% for ABI>1.5. Compared with participants with a normal ABI, those with ABI>1.3 had a lower prevalence of hypertension and current smoking. The ABI>1.3 group had a greater mean body mass index, but was characterized by fewer pack years of smoking and lower systolic and diastolic blood pressures than the normal ABI group. The prevalence of diabetes, left ventricular hypertrophy, claudication, and coronary heart disease and mean values of fibrinogen, factor VIII activity, von Willebrand factor, lipoprotein (a), and carotid and popliteal intimal-medial thickness were similar between the two ABI groups. The risk factor profiles of the ABI>1.4 and >1.5 groups were also not statistically significantly different from that of the normal ABI group. Over a mean follow-up time of 12.2 years, the age, sex, and race-adjusted CVD event rates per 1000 person years were 8.1 in the normal ABI group, 7.6 in the ABI>1.3 group, 7.6 in the ABI>1.4 group, and 7.4 in the ABI>1.5 group. The CVD event rates of the high ABI groups were similar to that of the normal ABI group. Conclusion: Individuals with a high ABI are not characterized by a more adverse atherosclerosis risk factor profile and do not suffer greater CVD event rates than those with a normal ABI. [Copyright &y& Elsevier]

Abstract: Background:: Some risk factors for peripheral arterial disease (PAD) have been identified, but little information is available on PAD risk factors in individuals with diabetes. Methods:: Using data from the Atherosclerosis Risk in Communities (ARIC) Study, we assessed the relation of traditional and non-traditional risk factors with the risk of PAD in 1651 participants with diabetes, but not PAD, at baseline. Incident PAD was defined as an ankle–brachial index (ABI)<0.9 assessed at regular examinations; hospital discharge codes for PAD, amputation, or leg revascularization; or claudication assessed by annual questionnaire. Results:: Over a mean of 10.3 years of follow-up, 238 persons developed incident PAD identified, yielding a PAD event rate of 13.9 per 1000 person years. Adjusted for sex, age, race, and center, the risk of developing PAD was increased 1.87-fold (95% confidence interval (95% CI): 1.36–2.57) in persons who were current smokers versus non-smokers, 2.27-fold (95% CI: 1.57–3.26) for baseline coronary heart disease (CHD) versus no baseline CHD, and 1.75-fold (95% CI: 1.18–2.60) for the highest quartile versus lowest quartile of triglycerides. We found no evidence of an association with other blood lipids or hypertension. Compared with the lowest quartiles, comparably-adjusted relative risks for the highest quartiles were 1.60 (95% CI: 1.10–2.33) for waist-to-hip ratio, 2.52 (95% CI: 1.70–3.73) for fibrinogen, 1.70 (95% CI: 1.17–2.47) for factor VIII, 1.73 (95% CI: 1.18–2.54) for von Willebrand factor, 2.15 (95% CI: 1.43–3.24) for white blood cell count, 1.81 (95% CI: 1.19–2.74) for serum creatinine, 0.55 (95% CI: 0.37–0.83) for serum albumin, and 2.73 (95% CI: 1.77–4.22) for carotid intima-media thickness. Persons who had a prior history of diabetes and were taking insulin had a relative risk of 1.97 (95% CI: 1.35–2.87) for future PAD events, compared with those with newly identified diabetes at baseline. In our final multivariable model, current smoking, prevalent CHD, elevated fibrinogen and carotid IMT, and a prior history of diabetes with insulin treatment were independently associated with greater PAD incidence. Conclusion:: These markers might be useful to identify individuals with diabetes at particular risk for PAD. [Copyright &y& Elsevier]