Physical activity levels early after lung transplantation.

Abstract

Little is known of the early changes in physical activity after lung transplantation. The purposes of this study were: (1) to describe physical activity levels in patients up to 6 months following lung transplantation and (2) to explore predictors of the change in physical activity in that population. This was a prospective cohort study. Physical activity (daily steps and time spent in moderate-intensity activity) was measured using an accelerometer before and after transplantation (at hospital discharge, 3 months, and 6 months). Additional functional measurements included submaximal exercise capacity (measured with the 6-Minute Walk Test), quadriceps muscle torque, and health-related quality of life (measured with the Medical Outcomes Study 36-Item Short-Form Health Survey 36 [SF-36] and the St George's Respiratory Questionnaire). Thirty-six lung transplant recipients (18 men, 18 women; mean age=49 years, SD=14) completed posttransplant measurements. Before transplant, daily steps were less than a third of the general population. By 3 months posttransplant, the largest improvement in physical activity had occurred, and level of daily steps reached 55% of the general population. The change in daily steps (pretransplant to 3 months posttransplant) was inversely correlated with pretransplant 6-minute walk distance (r=-.48, P=.007), daily steps (r=-.36, P=.05), and SF-36 physical functioning (SF-36 PF) score (r=-.59, P=.0005). The SF-36 PF was a significant predictor of the change in physical activity, accounting for 35% of the variation in change in daily steps. Only individuals who were ambulatory prior to transplant and discharged from the hospital in less than 3 months were included in the study. Physical activity levels improve following lung transplantation, particularly in individuals with low self-reported physical functioning. However, the majority of lung transplant recipients remain sedentary between 3 to 6 months following transplant. The role of exercise training, education, and counseling in further improving physical activity levels in lung transplant recipients should be further explored.