Prevalence of rheumatoid cachexia in rheumatoid arthritis : a systematic review and meta-analysis

Abstract

Background: Low muscle mass occurs in patients with rheumatoid arthritis without weight loss; this condition is referred asrheumatoid cachexia. The aim of the current study was to perform a systematic review with meta-analysis to determine therheumatoid cachexia prevalence. Methods: A systematic review with meta-analysis of observational studies published in English, between 1994 and 2016, wasconducted using MEDLINE (via PubMed) and other relevant sources. Search strategies were based on pre-defined keywordsand medical subject headings. The methodological quality of included studies was assessed using the Newcastle-Ottawa Scale.Meta-analysis was used to estimate the prevalence, and because studies reported different methods and criteria to estimatebody composition and prevalence of rheumatoid cachexia, subgroup analyses were performed. Meta-regression adjusted forthe 28-joint disease activity score and disease duration (years) was performed (significance level atP≤0.05). Results: Of 136 full articles (one duplicate publication) screened for inclusion in the study, eight were included. The esti-mated overall prevalence of rheumatoid cachexia was 19% [95% confidence interval (CI) 07–33%]. This prevalence was 29%(95% CI 15–46%) when body composition was measured by dual-energy X-ray absorptiometry. When the diagnostic criteriawere fat-free mass index below the 10th percentile and fat mass index above the 25th percentile, rheumatoid cachexia prev-alence was 32% (95% CI 14–52%). The 28-joint disease activity score and disease duration had no influence on the estimatedprevalence of rheumatoid cachexia (P>0.05). Most studies were rated as having moderate methodological quality. Conclusions: Meta-analysis showed a prevalence of rheumatoid cachexia of 15-32%, according to different criteria, demon-strating that this condition is a frequent comorbidity of rheumatoid arthritis. To better understand its clinical impact, more studies using standardized definitions and prospective evaluations are urgently needed.