O impacto da multimorbidade na capacidade de exercício de indivíduos com doença respiratória crônica: revisão sistemática e meta-análise

Abstract

Chronic respiratory diseases (CRD) are frequently associated with multiple coexisting chronic conditions, characterizing multimorbidity. The presence of these conditions may worsen functional limitation and contribute to exercise intolerance, a key determinant of prognosis and quality of life in this population. However, the magnitude of the association between multimorbidity and exercise capacity in individuals with CRD remains unclear. This study aimed to conduct a systematic review and meta-analysis of the association between multimorbidity and exercise capacity in individuals with CRD. METHODS: Searches were conducted in PubMed, Scopus, Embase, Web of Science, VHL, and CINAHL from inception to July 2025. Observational studies evaluating exercise capacity in individuals aged ≥18 years with CRD, with and without coexisting conditions, using laboratory or field-based tests were included. Methodological quality was assessed using the Joanna Briggs Institute tools. Meta-analyses were performed when at least three studies reported comparable outcomes, using random-effects models. RESULTS: A total of 49 studies were included in the qualitative synthesis, comprising 28,972 participants, of which 26 were included in the quantitative synthesis. The overall meta-analysis showed that multimorbidity was associated with a reduction of approximately 42 m in the six-minute walk distance (6MWD) (mean difference: −42.0 m; 95% CI −55.6 to −28.5; p < 0.001; I² = 83%). Similar reductions were observed for metabolic (−45.5 m; 95% CI −74.0 to −17.2; p = 0.002), cardiovascular (−48.2 m; 95% CI −72.6 to −23.9; p < 0.001), and mental comorbidities (−29.5 m; 95% CI −54.9 to −4.2; p = 0.023), indicating a clinically meaningful impact. The certainty of evidence was rated as very low, mainly due to the observational design of the included studies, heterogeneity across results, and risk of bias. CONCLUSIONS: Multimorbidity is associated with reduced exercise capacity in individuals with CRD, although the certainty of evidence is limited. These findings highlight the importance of considering coexisting chronic conditions in the assessment and clinical management of these patients.