Metformin has been used clinically for over 50 years, as a glucose lowering agent.
Direct and indirect anti-inflammatory effects of metformin have been reported in animal and
clinical studies, and this effect is independent of its hypoglycemic effect.
Animal studies showed that metformin decreased serum C-reactive protein (CRP) level in
atherogenic rabbits and decreased proinflammatory cytokines (interleukin (IL)-1β, IL-6 and
tumor necrosis factor (TNF-α) in obese mice .
Moreover, metformin also suppressed osteoclastogenesis ; this may partially result from
decreased expression of inflammatory cytokines that promote osteoclastogenesis in the
arthritic joint.
The objective of this study is to evaluate the efficacy and safety of addition of metformin
to standard disease modifying anti-rheumatic drugs (DMARDs) in patients with rheumatoid
arthritis.