Impact of inspiratory muscle strength on exercise capacity after lung transplantation.-a longitudinal study in early stage-

Rationale: Prolonged exercise intolerance is serious limiting factors for activity of daily living and quality of life of post lung transplantation (LTx). Although weakness of inspiratory muscle strength may contribute to exercise intolerance, it is unclear that inspiratory muscle strength is associated with a time course and/or recovery of exercise capacity after LTx. Aim: To elucidate what physical factors contribute much to recovery of exercise capacity during one year after LTx. Methods: We consecutively enrolled 24 patients who had LTx between June 2017 and September 2018 at Kyoto University Hospital. Exercise capacity (6MWD), quadriceps force (QF), inspiratory muscle strength (maximal inspiratory pressure; MIP), spirometory (VC, FEV1%) were evaluated at 3, 6, and 12 months after LTx. Factors which were associated with 6MWD recovery in 3 to 6 months and 6 to 12months were analyzed. Results: After LTx, BMI, QF, and 6MWD significantly improved continuously (BMI; 17.2/18.2/19.0 kg/m2, QF; 94/107/125 Nm and 6MWD; 468/498/512 m, at 3/6/12months, respectively). Mean MIP and VC showed significant improvement only between 3 and 12 months (MIP; 60 to 69 cmH2O and VC; 2.16 to 2.28L). Changes in MIP from 3 to 6 months after LTx demonstrated significant positive correlations with changes in 6MWD at same period by univariate (p Conclusion: It was suggested that approaches to inspiratory muscle strength might be helpful in recovery of exercise capacity at 3 to 6 months after LTx.