Insulin-sensiting Effects of Tumor Necrosis Factor Alpha Inhibitors in Rheumatoid Arthritis: A Systematic Review and Meta-analysis

Background: Rheumatoid Arthritis (RA) has been associated with insulin resistance (IR), a well-established pathophysiological feature of Type 2 Diabetes (T2DM). Inconsistent literature evidence suggests that IR could be ameliorated by biological medications targeting TNFα. Objective: The aim of this systematic review was to evaluate the effect of TNFα inhibitors (TNFi) on IR in RA patients. Methods: We performed a systematic review in order to identify the available data on the effect of anti- TNFα medications on IR in RA patients. For this purpose, MedLine (via PubMed), Cochrane Central Register of Controlled Trials (CENTRAL) and SCOPUS were searched up to December 2016. Results: The search strategy retrieved 209 individual records. Of these, only 12 articles were included in the systematic review. The pooled analysis under a random-effects model demonstrated a significant improvement of IR after treatment with TNFi quantified with the HOmeostasis Model Assessment of Insulin Resistance (HOMA-IR), with a standardized difference in means (SDM) of -0.847 (95%CI: -1.278 - 0.417, p < 0.0001). Heterogeneity across studies was high (Q = 65.00 with df = 9, p < 0.001, I2 = 89.15%). Conclusion: Our meta-analysis suggests that TNFα blockade might improve IR in RA patients.