Impact of chronic kidney disease on respiratory muscle strength, lung capacity, peripheral muscle strength, and functional capacity in dialysis patients: a systematic review

This systematic review was conducted using PubMed/MEDLINE, LILACS, Embase, SciELO, and the Cochrane Library, with searches performed from July to August 2025. Cross-sectional observational studies evaluating respiratory muscle strength, pulmonary function, peripheral muscle strength, and functional capacity, compared with predicted values for sex and age, were included. Methodological quality was assessed using the Newcastle - Ottawa Scale. Results: A total of 1266 articles were identified, of which 22 met the inclusion criteria. Most studies presented satisfactory methodological quality (scores ≥6). Patients with CKD undergoing hemodialysis exhibited reduced respiratory muscle strength, with mean maximal inspiratory pressure of 53.7 ± 19.5% and maximal expiratory pressure of 49.5 ± 15.8% of predicted values. A moderate to strong correlation between maximal inspiratory pressure and functional capacity was observed (r = 0.38-0.79). Handgrip strength was also reduced compared with healthy individuals, with values approximately 40% below normal (28.18 ± 9.36 kgf; 114.00 ± 39.51% of predicted). Functional capacity was impaired, as indicated by a six-minute walk test distance corresponding to 66.33 ± 20.53% of predicted values. Pulmonary function findings were heterogeneous, with restrictive ventilatory pattern being the most frequently reported abnormality (66.7%). Conclusion: Patients with CKD undergoing hemodialysis present reduced respiratory and peripheral muscle strength, pulmonary capacity, and functional capacity.