Obesity interferes with TNF-alpha inhibitors in psoriatic arthritis
AT THE NYU SEMINAR IN ADVANCED RHEUMATOLOGY
NEW YORK – Obesity appears to reduce response to anti–tumor necrosis factor–alpha treatment in individuals with psoriatic arthritis, but weight loss can improve it, according to a review of two studies by Dr. Christopher T. Ritchlin.
"These data convincingly show that if we talk to our patients and tell them to lose weight, it can have an impact on how their PsA [psoriatic arthritis] therapies are going to work," Dr. Ritchlin, director of the Translational Immunology Research Center at the University of Rochester (N.Y.), said at a meeting sponsored by New York University.
Dr. Christopher Ritchlin
Dr. Ritchlin said these results fit in with previous epidemiologic studies that show that as body mass index goes up, so does the risk for both psoriasis and PsA (Arch. Intern. Med. 2009;167:1670-5 and Ann. Rheum. Dis. 2012;71:1273-7).
These data support a link between obesity-related chronic tissue inflammation and development of some rheumatic diseases, such as arthritis in psoriatic patients. These same inflammatory processes may also interfere with good clinical response to biologic agents.
In a study published by Dr. Matteo Nicola di Minno of Federico II University in Naples, Italy, and his colleagues, individuals with a BMI in the 30-35 kg/m2 range with PsA had a nearly fourfold increased risk of not responding well to treatment with tumor necrosis factor–alpha inhibitors (TNFis). The risk of a poor response rose more than fivefold for those whose BMIs greater than 35 kg/m2 (Arthritis Care Res. 2013;65:141-7).
The study prospectively followed PsA patients with active disease for 24 months who were starting TNFi therapy (30% adalimumab, 41% etanercept, 29% infliximab). The group comprised 135 obese patients (BMI greater than 30 kg/m2) and 135 controls of normal weight. The primary outcome was achievement of minimal disease activity (MDA), which meant they fulfilled five of seven outcome measures: one or fewer tender joints, one or fewer swollen joints, a score of 1 or less on the Psoriasis Area and Severity Index or body surface area = 3, a score of 15 or less on a visual analog scale (VAS) for pain, a score of 20 or less on a patient global disease severity VAS score, a score on the Health Assessment Questionnaire of 0.5 or less, or one or fewer tender entheseal points.