Leg strength predicts mortality in men but not in women with peripheral arterial disease

Objective

To establish associations between leg strength and mortality in men and women with lower extremity peripheral arterial disease (PAD).

Methods

This was an observational, prospective study of 410 men and women with PAD aged 55 and older recruited from Chicago-area medical centers and followed for a mean of 60 months. The participants were followed for a mean of 60.0 months. Isometric knee extension, knee flexion, hip extension, and hip flexion were measured at baseline. Primary outcomes were all-cause and cardiovascular disease mortality. Cox proportional hazards models were used to assess relations between leg strength and all-cause and cardiovascular disease mortality among men and women, adjusting for age, race, comorbidities, physical activity, smoking, body mass index, and the ankle brachial index.

Results

Among the 246 male participants, poorer baseline strength for knee flexion (P trend = .029), knee extension (P trend =.010), and hip extension (P trend = .013) were each associated independently with higher all-cause mortality. Poorer strength for knee flexion (P trend = .042) and hip extension (P trend = .029) were associated with higher cardiovascular mortality. Compared with those in the fourth (best) baseline knee flexion quartile, hazard ratios for all-cause and cardiovascular disease mortality among men in the first (poorest) knee flexion quartile were 2.23 (95% confidence interval [CI], 1.02-4.87; P = .045) and 4.20 (95% CI, 1.12-15.79; P = .044), respectively. No significant associations of leg strength and all-cause mortality were identified among women.

Conclusions

Poorer leg strength is associated with increased mortality in men, but not women, with PAD. Future study is needed to determine whether interventions that increase leg strength improve survival in men with PAD.