The impact of respiratory training on diaphragmatic function in elderly COPD patients with sarcopenia

Chronic obstructive pulmonary disease (COPD) combined with sarcopenia is a common chronic disease combination in elderly patients, significantly affecting diaphragmatic function, pulmonary function, quality of life, and exercise capacity. This study aims to evaluate the effects of respiratory training on diaphragmatic function and multidimensional health indicators in elderly COPD patients with sarcopenia. This single-center, randomized controlled, prospective study included 80 elderly COPD patients with sarcopenia, who were randomly assigned to the respiratory training group (40 patients) and the conventional treatment group (40 patients) in a 1:1 ratio. The respiratory training group underwent 12 weeks of diaphragmatic breathing training and expiratory resistance training, while the conventional treatment group received standard COPD care only. The primary outcomes included diaphragmatic function (diaphragmatic excursion and diaphragmatic thickness change rate), pulmonary function (FEV1, FEV1/FVC), quality of life (SGRQ total score), exercise capacity (6MWT), and clinical scores (mMRC, BODE index). Paired t-tests, independent t-tests, and multivariable linear regression analyses were used to assess intervention effects and independent influencing factors. Baseline characteristics were well-matched between the two groups, with no significant differences observed (P > 0.05). After 12 weeks, the respiratory training group showed significant improvements in diaphragmatic function: diaphragmatic excursion increased from 1.8 ± 0.3 cm to 3.2 ± 0.4 cm, and diaphragmatic thickness change rate increased from 20.0 ± 3.5% to 40.2 ± 4.2% (both P < 0.001), significantly outperforming the conventional treatment group (intergroup comparison P < 0.001). Improvements in pulmonary function, quality of life, and exercise capacity were also significantly greater in the respiratory training group (FEV1: P < 0.001; FEV1/FVC: P < 0.001; SGRQ total score: P < 0.001; 6MWT: P < 0.001). Multivariable linear regression analysis identified respiratory training as the only significant predictor of improved diaphragmatic function (P < 0.001). Respiratory training significantly improved diaphragmatic function, pulmonary function, quality of life, and exercise capacity in elderly COPD patients with sarcopenia, showing superior efficacy compared to conventional treatment. These findings highlight respiratory training as an effective intervention strategy, providing scientific evidence for the comprehensive management of elderly COPD patients with sarcopenia. ChiCTR2500098349 (Registration Date: 2025-3-6).