Results:

A total of 380 subjects were included in this analysis. The mean age of women participants was 76 years; the mean age of the men was 74 years. Women with PAD were more likely to be African American and to have arthritis of the knees or disc disease. Women were less likely to have angina, as compared to the men with PAD. After adjusting for age, women walked fewer blocks per week, and did not perform as well on the 6-minute walk test, as compared to men. Women had smaller calf muscle area, lower calf muscle density, and weaker knee extension strength compared with the men. At 4 years of follow-up, women were more likely to become unable to walk for 6 minutes continuously (hazard ratio [HR], 2.32; 95% confidence interval [CI], 1.31-4.11; p < 0.004), and more likely to develop mobility disability (HR, 1.88; 95% CI, 1.10-3.20; p < 0.021) compared to the men. Women also had faster declines in walking velocity (p < 0.03) and the distance achieved in the 6-minute walk (p < 0.04) compared with men. Sex differences in functional decline were attenuated after additional adjustment for baseline sex differences in calf muscle area.