Effects of tumour necrosis factor and interleukin‐6 inhibitor therapy on exercise‐related visceral adipose tissue reduction in rheumatoid arthritis

Excess visceral adipose tissue (VAT) mass increases cardiovascular disease risk. Exercise supports overall health and VAT mass reduction in rheumatoid arthritis (RA). Unlike tumour necrosis factor (TNF), interleukin-6 (IL-6) is upregulated following exercise and is involved in free fatty acid mobilisation and might mediate the reduction in VAT mass. Given that treatment strategies for patients with RA include the inhibition of IL-6 (IL-6i) or TNF (TNFi), in this study we compared the effects of exercise on changes in VAT mass in patients with RA on stable IL-6i or TNFi treatment. In this secondary analysis of a randomised controlled trial, 69 patients with RA on stable TNFi (n = 40) or IL-6i (n = 29) therapy were stratified for treatment and assigned to a 12-week supervised high-intensity interval training (HIIT) intervention or no exercise (control). The primary objective was to investigate the effects of TNFi or IL-6i therapy on exercise-induced changes in VAT mass (in grams) from baseline to 12-week follow-up, assessed by abdominal MRI. Compared with the control group, HIIT did not change VAT mass in either TNFi {-34 g [95% confidence interval (CI), -206 to 139 g; P = 0.696]} or IL-6i [-16 g [95% CI, -228 to 197 g; P = 0.882)] treatment groups. There was no interaction between IL-6i and exercise on changes in VAT mass [18 g (95% CI, -256 to 292); interaction P = 0.895]. Exercise-induced changes to the subcutaneous adipose tissue and insulin sensitivity were negligible and not significantly different between treatment modalities. In conclusion, a 12-week HIIT intervention did not reduce VAT mass in patients with RA undergoing treatment with either TNFi or IL-6i.