Changes in weight associated with tumor necrosis factor inhibition in psoriatic arthritis: results from a retrospective cohort study.

OBJECTIVES

Several studies have reported weight gain with tumor necrosis factor inhibitors (TNFi) in psoriatic disease. However, such analyses have not accounted for the natural propensity for weight gain over time. We aimed to investigate whether therapy with TNFi in psoriatic arthritis (PsA) patients is associated with a change in the rate of weight gain post-treatment initiation.

METHODS

We included patients with at least two weight measurements prior to, and after commencing TNFi and used change point analysis to assess the differences in the rate of weight gain based on the mean slope before and after TNFi initiation, adjusting for clinically relevant variables.

RESULTS

Of 234 patients eligible for inclusion, 62.8% were males. At the first clinic visit, the mean (standard deviation) age was 41.8 (12.2) years, while the mean disease duration was 5.1 (6.8) years. The mean weight immediately prior to TNFi use was 83.8 (17.2) kg, while that at the last available visit on TNFi was 86.4 (18.6) kg (p = 0.39), over an average period of 7.9 (5.8) years. The mean values of the pre- and post-TNFi slopes were 0.52 (95% confidence interval [CI] 0.18-0.87) and 0.28 (95% CI - 0.05-0.61), respectively (p = 0.09); thus, there was a trend towards lower rate of weight gain followed the initiation of TNFi therapy.

CONCLUSIONS

TNFi treatment is not associated with an increase in weight above the expected gain in PsA. Prior trajectory of weight gain with age must be considered while studying the impact of treatment on weight.

KEY POINTS: • TNFi are commonly used in the management of psoriatic disease and may influence body weight. • TNFi treatment is not associated with a significant increase in body weight when accounting for the trend of weight gain with time. • The trends in weight change may differ between etanercept and monoclonal antibody TNFi agents.