Improvement in 6-minute walking distance after supervised exercise training is related to changes in quality of life in patients with lower extremity peripheral artery disease

Abstract

This study aimed to investigate the relationship between supervised exercise training (SET)-induced changes in treadmill performance and 6 min walking distance, and changes in general (physical and mental) self-perceived health-related quality of life (HRQoL) in symptomatic patients with lower extremity peripheral artery disease (PAD). This is an observational study investigating Fontaine stage II PAD patients participating in 3-month SET. Before and following SET, treadmill performance (pain-free (PFWD) and maximal (MWD)), and 6 min walking distance (6MWD) were assessed. Self-perceived HRQoL was assessed with the Medical Outcomes Study Short-Form 36 (SF-36). Ankle-and toe-brachial indexes were also measured. One-hundred forty-seven patients with PAD were included (64.9 ± 9.6 y, 70% men). After SET, PFWD (+102%, p ≤ 0.001), MWD (+87%, p ≤ 0.001), and 6MWD (+14%, p ≤ 0.001) significantly increased. All eight SF-36 subscale scores significantly improved following SET (p ≤ 0.04). SET significantly improved physical and mental component summaries of the SF-36 (p ≤ 0.001). Larger increases in 6MWD were associated with greater improvements in physical (β = 0.19; p = 0.02) and mental (β = 0.24; p = 0.005) component summaries of the SF-36. No significant relationship was observed between changes in treadmill performance and changes in physical and mental component summaries of the SF-36. These results show that improvements in 6MWD following SET are related to improvements in general selfperceived HRQoL in patients with symptomatic lower extremity PAD. On the contrary, changes in treadmill performance were not related to improvements in HRQoL. These results suggest that the 6 min walking test is an essential outcome measure to assess overall patient functional status following interventions in patients with PAD.