Body mass index and achievement of minimal disease activity in psoriatic arthritis across different classes of advanced therapy.

OBJECTIVES

Obesity is a prevalent comorbidity in psoriatic arthritis (PsA). We aimed to evaluate the association between body mass index (BMI) and minimal disease activity (MDA) state in PsA and examine this across different drug classes.

METHODS

In a longitudinal observational study using the Gladman Krembil PsA Program cohort, patients with available BMI measurement over follow-up were included. Univariable and multivariable (MV) generalized estimating equations and linear mixed models were used to assess associations between BMI and MDA (and its components) over time, adjusting for age, sex, anxiety/depression, fibromyalgia, smoking, treatment type and radiographic damage. Subgroup analyses evaluated this association across six drug classes: TNF-α inhibitors (TNFi), IL-17 inhibitors (IL-17i), IL-12/23 inhibitors (IL-12/23i), IL-23 inhibitors (IL-23i), Janus kinase inhibitors (JAKi) and phosphodiesterase-4 inhibitors (PDE4i).

RESULTS

In 1291 patients (mean age 44.7 years, 56% male, mean BMI 28.8 kg/m2), higher BMI was independently associated with lower odds for MDA (MV, odds ratio [OR] 0.97; 95% CI: 0.94, 0.99) along with female sex, older age, smoking, fibromyalgia and radiographic damage. BMI was negatively associated with all MDA components except swollen joint count. Higher BMI at drug initiation was associated with reduced odds for MDA state in TNFi-treated patients excluding infliximab (MV, OR 0.94; 95% CI: 0.92, 0.97), while no significant effect was seen for IL-17i, IL-12/23i, IL-23i or JAKi. Longitudinal BMI assessment similarly showed reduced MDA odds with TNFi (excluding infliximab).

CONCLUSIONS

High BMI decreases the odds for MDA in PsA, mainly affecting subjective disease measures. This effect is most pronounced in patients treated with TNFi (except infliximab). This underscores the importance of weight management in optimizing treatment response.