Objectives: The aim of this study was to investigate the relationship between rheumatoid arthritis (RA) and the occurrence of diabetes mellitus (DM).
Methods: A meta-analysis was conducted to explore the risk of DM in RA patients. All relevant studies were identified by searching PUBMED, EMBASE and MEDLINE database prior to 1 January 2014. Pooled risk estimates were calculated with random-effects models using STATA 11.0.
Results: A total of 11 case-control studies and 8 cohort studies were included in the final analysis. The pooled risk estimate of 11 case-control studies showed a statistically significant increased risk of DM prevalence among RA individuals (OR=1.40, 95% CI: 1.34-1.47). The pooled risk estimate of 8 cohort studies also showed a statistically significant increasing risk of DM (RR=1.43, 95%CI: 1.38-1.47). In a subgroup analysis for case-control studies, the pooled risk estimate of individuals with RA increased the incidence of T1DM (type 1 diabetes mellitus) and the incidence of T2DM (type 2 diabetes mellitus) (OR, 4.78 vs. 1.41). In a subgroup analysis for cohort studies, RA was also found to have a statistically significant increasing risk of T2DM (RR=1.24, 95%CI: 1.14-1.35). Begg funnel plot and Egger test showed no evidence of publication bias.
Conclusions: RA is associated with increased risk of DM, including T1DM and T2DM.