Effect of aerobic exercise on cardiopulmonary fitness among people with knee osteoarthritis: a systematic review and meta-analysis

Abstract

Background: Although aerobic exercise is widely recommended to enhance cardiopulmonary fitness and mitigate cardiovascular risk, the efficacy and effectiveness of aerobic exercise interventions have not been comprehensively evaluated among people with knee osteoarthritis (OA). This systematic review and meta-analysis aimed to synthesize the current evidence on the impact of aerobic exercise on cardiopulmonary fitness in people with knee OA.

Methods: PubMed, Embase, Scopus, and Web of Science were searched from inception to March 1, 2024, for randomized controlled trials (RCTs). Eligible RCTs included those with an aerobic exercise intervention (e.g., aerobic walking, cycling, aquatic aerobics), a primary outcome of maximum oxygen consumption (VO₂ max), and participants with knee OA. The aerobic exercise programs were compared to control interventions (e.g., education, light-intensity exercise, usual activities, and routine care). Secondary outcomes included distance (m) walked during the six-minute walk test (6MWD), and Patient-Reported Outcome Measures (i.e., pain score and disability score). The overall level of evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results: Out of 988 studies, 5 RCTs with 459 people with knee OA were included in the analysis. Aerobic exercise programs included walking, cycling, jumping, stepping, and aquatic aerobics. Pooled mean differences and 95% confidence intervals (CIs) were 0.90 ml/kg/min (95% CI 0.43 to 1.38; moderate evidence), 46.97 m (95% CI 33.71 to 60.23; high evidence), 5.59 points (95% CI 2.93 to 8.25; low evidence), and 3.03 points (95% CI 1.05 to 5.01; moderate evidence) for VO₂ max, 6MWD, pain and disability, respectively.

Conclusion: These results support the hypothesis that aerobic exercise can elicit improvements in cardiopulmonary fitness for people with knee OA. Future research should focus on optimizing current exercise regimens for people with knee OA and exploring how to improve adherence while minimizing symptom exacerbation by other exercise modalities, e.g., Nordic walking and inspiratory muscle training.

Systematic review registration: CRD42022340966, 07/07/2022, PROSPERO.

Keywords: Aerobic exercise; Cardiopulmonary fitness; Knee osteoarthritis.