Physical activity is a predictor of all-cause mortality in patients with intermittent claudication

Abstract

Objective: We examined whether all-cause mortality was predicted by physical activity level in peripheral arterial disease (PAD) patients limited by intermittent claudication.

Methods: This retrospective, natural history follow-up study determined survival status of each patient. Patients with stable symptoms of intermittent claudication were evaluated in the Geriatrics, Research, Education, and Clinical Center at the Maryland Veterans Affairs Health Care System (MVAHCS) at Baltimore between 1994 and 2002, and were classified into a physically sedentary group (n = 299) or a physically active group (n =135), and followed in 2004 using the Social Security Death Index.

Results: Median follow-up was 5.33 years (range = 0.25 to 8.33 years) for the physically active group, and 5.0 years (range = 0.17 to 8.5 years) for the sedentary group. At follow-up, 108 patients (24.9%) had died, consisting of 86 (28.8%) in the sedentary group and 22 (16.3%) in the active group. Unadjusted risk of mortality was lower (P = .005) in the physically active group (hazard ratio [HR] = 0.510, 95% CI = 0.319 to 0.816). In multivariate Cox proportional hazards analysis, age (HR = 1.045, 95% CI = 1.019 to 1.072, P < 0.001), body mass index (BMI) (HR = 0.943, 95% CI = 0.902 to 0.986, P = 0.009), ankle-brachial index (ABI) (HR = 0.202, 95% CI = 0.064 to 0.632, p = 0.006), and physical activity status (HR = 0.595, 95% CI = 0.370 to 0.955, P = .031) were predictors of mortality.

Conclusion: Patients limited by intermittent claudication who engage in any amount of weekly physical activity beyond light intensity at baseline have a lower mortality rate than their sedentary counterparts who perform either no physical activity or only light-intensity activities. The protective effect of physical activity persists even after adjusting for other predictors of mortality, which include age, ABI, and BMI.

Figure 1

Cumulative survival of sedentary and physically active patients limited by intermittent claudication. The survival curves were different between the two groups (log likelihood = −623.7, chi-square = 8.71, p = 0.003).