OBJECTIVE: To determine the risk factors for peripheral arterial disease (PAD) in a diabetic population and to examine whether different levels of these risk factors might explain why diabetic subjects have an increased risk of PAD compared with normal glucose tolerance subjects. RESEARCH DESIGN AND METHODS: There were 1,592 men and women aged 55-74 years selected at random from the age-sex registers of 11 general practices in Edinburgh, Scotland. Subjects underwent a comprehensive medical examination, including assessment for PAD (intermittent claudication on World Health Organization questionnaire or major asymptomatic disease on noninvasive testing) and a glucose tolerance test. RESULTS: Of the subjects, 288 (18.7%) were found to have diabetes or impaired glucose tolerance (IGT). The prevalence of PAD was greater in those with diabetes/IGT (20.6%) compared with those with normal glucose tolerance (12.5%) (odds ratio [OR] 1.64, 95% CI 1.17-2.31). Among the diabetes/IGT group, mean levels of smoking, systolic blood pressure, and triglycerides were higher in subjects with PAD than in those without PAD (P < or = 0.05). Mean levels of systolic blood pressure and plasma triglycerides were also higher in diabetic subjects than in nondiabetic subjects with PAD (P < or = 0.05). In multivariate analysis, those with diabetes/IGT no longer had a significantly higher risk of PAD after adjusting separately for systolic blood pressure (OR 1.22, 95% CI 0.85-1.73) and plasma triglycerides (OR 1.26, 95% CI 0.89-1.79). Simultaneous adjustment for both systolic blood pressure and triglycerides reduced the risk of PAD among diabetic subjects to 1.11 (95% CI 0.78-1.58). CONCLUSIONS: Increased mean levels of triglycerides and systolic blood pressure may help to explain the higher prevalence of PAD in diabetic subjects compared with that in normal glucose tolerance subjects.