MADRID – Two sets of data presented at the European Congress of Rheumatology support the potential for weight loss to be a valuable adjunctive strategy for improving outcomes in patients with psoriatic arthritis (PsA).
Mitchel L. Zoler/MDedge News
Dr. Stefan Siebert
One set, drawn from the ongoing PsABio observational study, correlated increasing body mass index with greater disease activity and greater disability. Another, based on patients followed for 12 months, showed that a weight loss of about 15% is associated with a significant reduction in PsA activity.
“As clinicians, we largely focus on drugs in the treatment of PsA, but these data draw attention to obesity as a potential target for improving outcomes in PsA,” said Stefan Siebert, MD, a rheumatologist at the Institute of Infection, Immunity, and Inflammation at the University of Glasgow (Scotland).
Dr. Siebert cautioned that his data show association, not causation, but he said these data add to a growing body of evidence that provide compelling support for trials to test the premise that weight loss improves outcomes.
Although not a trial, a study by Eva Klingberg, MD, PhD, of the Sahlgrenska Academy at the University of Gothenburg (Sweden) and her associates tested this premise and showed weight loss was associated with improvement in multiple PsA activity parameters 6 and 12 months after a significant weight loss program.
“This is just one study, so we need more data, but we are already using weight loss to manage PsA in obese patients in Sweden,” said Dr. Klingberg, speaking about her work in advance of the presentation. Like Dr. Siebert, she agreed that weight loss is an important potential treatment strategy in PsA.
In the observational PsABio study, which is following patients with PsA at rheumatology centers in eight European countries, the goal of its analysis was to evaluate disease activity and outcomes in relationship to baseline weight for patients starting a biologic therapy as part of standard clinical practice. Of the 917 patients evaluated, 450 started ustekinumab (Stelara) and 467 started a tumor necrosis factor inhibitor (TNFi). The researchers had weight data for 827 of these patients.
At the time of enrollment, 40% were overweight as defined by a body mass index (BMI) ranging from 25 to 29 kg/m2, and 30.4% were obese as defined by a BMI greater than 30 kg/m2. The mean baseline BMI was 28.1 kg/m2. The mean age of the study population was 49.7 years. Slightly more than half were female.
Relative to a BMI of 30 kg/m2 or less, higher BMI at baseline is shown in multiple regression analysis to be independently and significantly linked to disease activity assessed by the clinical Disease Activity Index for Psoriatic Arthritis (cDAPSA; P = .026), to patient perception of disease impact as measured by Psoriatic Arthritis Impact of Disease (PsAID-12; P less than .0001), and to greater disability as measured with Health Assessment Questionnaire Disability Index (HAQ-DI; P less than .0001).
“There are multiple sets of data that show obesity predicts who develops PsA. Our data further show that, of patients with PsA who are candidates for a biologic, those with obesity have greater disease activity,” Dr. Siebert said. “We are using all of these expensive drugs, but I think there is now a need to also focus on lifestyle interventions, in addition to drug therapy, to reduce disease activity and improve outcomes in PsA.”