Cardiorespiratory fitness assessed with cardiopulmonary exercise testing in patients with juvenile idiopathic arthritis: a systematic review and meta-analysis

Objectives JIA is the most common type of arthritis in children and adolescents, causing joint damage, chronic pain and disability. Deconditioning is also prevalent in patients with JIA due to both inactivity and the disease progression, resulting in reduced cardiorespiratory fitness (CRF). We aimed to evaluate CRF of patients with JIA compared with healthy controls. Methods This is a systematic review and meta-analysis of studies using cardiopulmonary exercise testing (CPET) to examine differences in determinants of CRF between patients with JIA vs healthy controls. The primary outcome was peak oxygen uptake (VO(2)peak). Literature search involved PubMed, Web of Science and Scopus databases, manual search of article references and grey literature. Quality assessment was undertaken with Newcastle-Ottawa Scale. Results From 480 literature records initially retrieved, eight studies (538 participants) were included in final meta-analysis. VO(2)peak was significantly lower in patients with JIA compared with controls [weighted mean difference (WMD): -5.95 ml/kg/min (95% CI -9.26, -2.65)]. Exercise duration and VO(2)peak (% predicted) were found to be significantly impaired in patients with JIA compared with controls [standardized mean difference: -0.67 (95% CI -1.04, -0.29) and WMD: -11.31% (95% CI -20.09, -2.53), respectively], while no significant differences were found in maximum heart rate. Conclusion VO(2)peak and other CPET variables were lower in patients with JIA compared with controls, indicating reduced CRF in the former. Overall, exercise programs for patients with JIA should be promoted as part of their treatment to improve physical fitness and reduce muscle atrophy.