Weight-loss benefits extend to psoriatic arthritis

Biologic treatment combined with weight loss reduced psoriatic arthritis symptoms in a cohort of overweight or obese patients, according to results of a prospective study published in The Annals of Rheumatic Diseases.

Matteo Nicola Dario Di Minno, MD, from the Regional Reference Center for Coagulation Disorders, at Federico II University in Naples, Italy, and colleagues enrolled 138 overweight/obese patients with active psoriatic arthritis who had failed traditional therapies to evaluate the effect of weight loss on disease symptoms as they began treatment with tumor necrosis factor alpha (TNF-alpha) blockers.

A total of 126 patients completed the 30-month study: 59 patients received etanercept (Enbrel) (50 mg/week); 33 received adalimumab (Humira) (40 mg every other week); and 34 patients received infliximab (Remicade) (3 mg/kg at weeks 0, 2 and 6 and every 8 weeks thereafter). Thirty-seven patients also received concomitant treatment with methotrexate (10–15 mg/week).

Patients were randomly chosen to follow either a hypocaloric diet (HD group) or a free self-managed diet (FD group). Patients in the HD group kept to a calorie intake of less than 1,500 kcal/day; restricted fat intake to 30% to 35% of total daily energy uptake; and had fiber uptake of 30 g/day.

Patients in the FD arm had no quantitative food restriction, but were given guidelines to follow that included eating no more than two pieces of fresh fruit daily; no more than two spoons daily of olive oil; to avoid saturated fats; to increase the daily use of vegetables; and to eat more fish.

Changes in metabolic variables were measured and a complete clinical rheumatological evaluation was made in all patients at baseline and after a six-month follow-up to define the achievement of minimal disease activity.

Minimal disease activity was more often achieved by patients in the HD group compared with patients in the FD group (HR=1.85; 95% CI: 1.019 to 3.345; P=0.043). The diet was successful, defined as at least 5% weight loss, in 74 patients. Regardless of the patient group, after six months of treatment with TNF-alpha blockers, at least 5% of weight loss was a predictor of minimal disease activity (OR=4.20; 95% CI: 1.82 to 9.66, P<0.001).

The best rates of minimal disease activity were found in patients with more than 10% (OR=6.67; 95% CI: 2.41 to 18.41; P<0.001) weight loss in comparison with those with less than 5% weight loss.

“The main finding of this prospective study is that regardless of the type of diet, ≥5% weight loss is the major and independent predictor of minimal disease activity achievement in overweight/obese patients with [psoriatic arthritis] starting treatment with TNF-alpha blockers,” DiMinno and colleagues concluded.