- This meta-analysis suggests that increased body mass index (BMI) is associated with an increased risk for rheumatoid arthritis (RA).
Why this matters
- The association between BMI and RA might present a personal prevention or control strategy for RA.
- Meta-analysis of 16 studies involving 406,584 participants identified after a search across PubMed and EMBASE databases published through 20 September 2018.
- Random-effect models and dose-response meta-analyses estimated the pooled risk ratio (RR) with a 95% CI.
- Funding: National Natural Science Foundation, China.
- Compared with normal weight participants, the risk for RA was increased in overweight (RR, 1.12; 95% CI, 1.04-1.20) and obese (RR, 1.23; 95% CI, 1.09-1.39) participants.
- In the sub-group analysis, overweight and obesity were associated with an increased risk for RA among women (RR, 1.16; 95% CI, 1.05-1.29 and RR, 1.30; 95% CI, 1.13-1.49, respectively).
- The risk for RA was not significant in overweight and obese men (RR, 0.94; 95% CI, 0.79-1.12 and RR, 0.87; 95% CI, 0.55-1.38, respectively).
- In dose-response meta-analysis, linear association showed an 8% increased risk for RA with each 5 kg/m2 increase in BMI (RR, 1.08; 95% CI, 1.01-1.15).
- There was evidence of a non-linear relationship between BMI and RA (overall: Pnonlinearity>.001; case-control studies: Pnonlinearity=.025; cohort studies: Pnonlinearity=.0029).
- Majority of included studies were case-control studies.