Thigh circumference and low ankle brachial index in US adults: Results from the National Health and Nutrition Examination Survey 1999–2004

Abstract Objective Recent studies have suggested that smaller thighs are a disadvantage for health and survival, but the association of thigh circumference with atherosclerosis remains uncertain. The purpose of this study was to investigate the association between thigh circumference and peripheral arterial disease (PAD), as measured by ankle brachial index (ABI). Methods This study used data from the National Health and Nutrition Examination Survey (1999–2004), in which participants' ABI and thigh circumference were measured simultaneously. A total of 5716 participants (2959 men and 2757 women) were included in the final analysis. A diagnosis of PAD was determined on the basis of ABI < 0.9. Results The overall prevalence of PAD in this sample was 6.6%. Thigh circumference of those with PAD was 50.1 cm compared to 52.2 cm for those without PAD (p < 0.0001). After adjusting for potential covariates, the prevalence of PAD generally decreased as thigh circumference increased up to 55 cm. In the first quantile (smallest thigh circumference), men and women had as much as a 4.8-fold (95% CI, 2.28–10.29) and a 3-fold (95% CI, 1.45–6.18) increased risk of PAD, respectively. Above 55 cm, PAD was no longer related to thigh circumference. Conclusions Small thigh circumference may be associated with PAD, as measured by ABI.