Psoriatic arthritis and obesity: the role of anti-IL-12/IL-23 treatment

Patients with psoriatic arthritis (PsA) have an increased prevalence of obesity, but mechanisms underlying this association remain unknown and it is unclear if obesity is the cause or effect of PsA. For PsA patients, comorbid obesity may influence their clinical response to systemic treatment, and especially targeted immunomodulators such as anti-tumor necrosis factor (TNF)alpha. Weight gain has also been associated with anti-TNF alpha treatment. Consequently, modification of the therapeutic approach may be needed for patients with an inadequate response to TNF alpha inhibitors. In recent years, interleukin (IL)-12/IL-23 inhibitors have entered clinical practice as a new class of drug for the treatment of PsA, with some data suggesting a lower effect of body weight on their effectiveness. Recent findings demonstrate effective and sustained responses in patients with PsA to ustekinumab, an IL-12/IL-23 inhibitor. This narrative review critically discusses the link between PsA, obesity, and response to therapy. The current role of ustekinumab in this setting is also discussed.