Baseline lower extremity strength and subsequent decline in functional performance at 6-year follow-up in persons with lower extremity peripheral arterial disease

OBJECTIVES: To evaluate associations between baseline lower extremity strength and decline in functional performance over 6 years of follow-up in men and women with lower extremity peripheral arterial disease (PAD). DESIGN: Prospective observational study. SETTING: Three Chicago-area hospitals. PARTICIPANTS: Three hundred seventy-four men and women with PAD. MEASUREMENTS: Baseline isometric hip extension, hip flexion, knee flexion, and knee extension strength were measured using a musculoskeletal fitness evaluation chair. Usual and fastest-paced 4-m walking speed, 6-minute walk, and Short Physical Performance Battery (SPPB) were assessed at baseline and annually thereafter. Analyses were adjusted for age, sex, race, ankle-brachial index (ABI), comorbidities, and other confounders. RESULTS: In women with PAD, weaker baseline hip and knee flexion strength were associated with faster average annual decline in usual-pace 4-m walking speed (P trend <.001 and.02, respectively) and SPPB (P trend=.02 and.01, respectively). In women, weaker hip extension strength was associated with faster decline in usual-pace 4-m walking speed and SPPB (P trend=.01 and <.01, respectively). There were no significant associations between baseline strength and decline in 6-minute walk in women. There were no significant associations between any baseline strength measure and functional decline in men. CONCLUSION: Weaker baseline leg strength is associated with faster functional decline in nonendurance measures of functional performance in women with PAD but not in men with PAD.