TNF inhibitors increase fat mass in inflammatory rheumatic disease: a systematic review with meta-analysis.

Objectives: To assess body composition of patients with inflammatory rheumatic disease and the effect of TNF inhibitors on it.
Methods: This was systematic review with meta-analysis of studies consulted on PubMed, Cochrane Library and EMBASE and assessing body composition in patients with rheumatoid arthritis or spondyloarthritis. We compared i) patients with healthy controls and ii) body components before and after TNF inhibitors.
Results: Among the 703 articles reviewed, 19 met the inclusion criteria. In patients with rheumatoid arthritis, a significant increase in fat mass (+1.85 kg, p=0.02), adiposity (+3.53%, p<0.00001) and android mass (+1.7 kg, p<0.00001) and a significant decrease in lean mass (-3.03 kg, p=0.01), were observed. In patients with spondyloarthritis, a significant but modest increase in fat mass (+0.69 kg, p=0.03) and a significant decrease in lean mass (-3.74 kg, p=0.03) were observed. Nine studies assessed impact of TNF inhibitors on body composition, with an increase of fat mass in the short and long term in all studies. Data on lean mass were controversial. Two studies found an increase in visceral or android mass under TNF inhibitors.
Conclusions: Patients with inflammatory rheumatic disease have a significant decrease in lean mass and increase in fat mass. The use of TNF inhibitors is associated with a further increase in fat mass including android fat, which could potentially have cardiovascular consequences.