Masatoshi Hanada1, Yuji Ishimatsu2, Noriho Sakamoto3, Hiroki Nagura1, Masato Oikawa1, Yosuke Morimoto4, Shuntaro Sato5, Hiroshi Mukae3, Ryo Kozu1. 1. Cardiorespiratory Division, Department of Rehabilitation Medicine, Nagasaki University Hospital, Nagasaki, Japan; Department of Cardiopulmonary Rehabilitation Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. 2. Department of Nursing, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. Electronic address: yuji-i@nagasaki-u.ac.jp. 3. Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. 4. Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Hyogo, Japan. 5. Clinical Research Center, Nagasaki University Hospital, Nagasaki, Japan.
Abstract
BACKGROUND: Interstitial lung diseases (ILDs) patients receiving steroid treatment tend to be immobilized by dyspnea and muscle weakness as the disease progresses. We therefore expected that steroid treatment for ILDs would have a greater effect on muscle function under severe dyspnea. To test this hypothesis, we evaluated whether the effect of corticosteroid treatment on peripheral muscle force and exercise capacity varied according to patients' dyspnea severity. METHODS: In this retrospective cross-sectional study of 87 ILD patients enrolled between 2008 and 2017, quadriceps force (QF), handgrip force (HF), and 6-min walk distance (6 MWD) were compared between a low (grades 0-2) and a high (grades 3-4) modified-Medical Research Council (mMRC) dyspnea scale score group. RESULTS: In patients with lower levels of dyspnea, corticosteroid treatments were associated with lower QF and HF (20.0 vs. 30.0 kgf, p = 0.01; 22.5 vs. 28.4 kgf, p = 0.03, respectively) values; however, no significant differences were observed between the corticosteroid and control subgroups in the high mMRC group (QF: 18.5 vs. 17.3 kgf, p = 0.64; HF: 21.0 vs. 17.1 kgf, p = 0.24, respectively). Analysis of covariance indicated that both corticosteroid treatment and mMRC dyspnea scale interacted with QF, HF, and 6 MWD. The effects of the corticosteroid treatment varied according to the level of dyspnea (interaction β = 7.52, p = 0.034; interaction β = 8.78, p = 0.048; interaction β = 131.08, p < 0.001). CONCLUSIONS: Muscle weakness and exercise capacity in ILD patients in the low mMRC group were associated with corticosteroid treatment.
BACKGROUND: Interstitial lung diseases (ILDs) patients receiving steroid treatment tend to be immobilized by dyspnea and muscle weakness as the disease progresses. We therefore expected that steroid treatment for ILDs would have a greater effect on muscle function under severe dyspnea. To test this hypothesis, we evaluated whether the effect of corticosteroid treatment on peripheral muscle force and exercise capacity varied according to patients' dyspnea severity. METHODS: In this retrospective cross-sectional study of 87 ILDpatients enrolled between 2008 and 2017, quadriceps force (QF), handgrip force (HF), and 6-min walk distance (6 MWD) were compared between a low (grades 0-2) and a high (grades 3-4) modified-Medical Research Council (mMRC) dyspnea scale score group. RESULTS: In patients with lower levels of dyspnea, corticosteroid treatments were associated with lower QF and HF (20.0 vs. 30.0 kgf, p = 0.01; 22.5 vs. 28.4 kgf, p = 0.03, respectively) values; however, no significant differences were observed between the corticosteroid and control subgroups in the high mMRC group (QF: 18.5 vs. 17.3 kgf, p = 0.64; HF: 21.0 vs. 17.1 kgf, p = 0.24, respectively). Analysis of covariance indicated that both corticosteroid treatment and mMRC dyspnea scale interacted with QF, HF, and 6 MWD. The effects of the corticosteroid treatment varied according to the level of dyspnea (interaction β = 7.52, p = 0.034; interaction β = 8.78, p = 0.048; interaction β = 131.08, p < 0.001). CONCLUSIONS:Muscle weakness and exercise capacity in ILDpatients in the low mMRC group were associated with corticosteroid treatment.