Short-term treatment of weight loss with a very low-energy diet is associated with significant positive effects on disease activity in joints, entheses, and skin of patients with psoriatic arthritis (PsA) and obesity at 6 months, according to the results of a prospective, interventional study published in Arthritis Research & Therapy.
The investigators sought to prospectively evaluate the effects of weight loss treatment with a very low-energy diet on disease activity in patients with PsA based on Classification for Psoriatic Arthritis criteria and obesity (body mass index [BMI] ≥33 kg/m2). The participants consumed a very low-energy diet, defined as 640 kcal/d, over 12 to 16 weeks, based on their pre-treatment BMI. Following the very low-energy diet, an energy-restricted diet was reintroduced gradually. Treatment with conventional synthetic or biologic disease-modifying antirheumatic drugs was continued at the same dose from 3 months prior to and 6 months after baseline.
All patients were evaluated with BMI; 66/68 joints count; Leeds enthesitis index; psoriasis body surface area; C-reactive protein (CRP) level; and questionnaires at baseline, 3 months, and 6 months. The primary study outcome was percentage of patients achieving minimal disease activity (MDA). Secondary outcomes included attaining Psoriatic Arthritis Response Criteria (PsARC) and American College of Rheumatology (ACR) response criteria.
A total of 41 patients completed the study; 63% were women and median age was 54 years (interquartile range [IQR], 48 to 62 years). Increased BMI was linked to higher disease activity and poorer function at baseline.
Median weight loss was 18.7 kg (IQR, 14.6 to 26.5 kg), which corresponded to a loss of 18.6% in median baseline weight (IQR, 14.7% to 26.3%). Moreover, a majority of the disease activity parameters improved significantly following weight loss, which included 68/66 tender/swollen joint count, CRP level, body surface area, Health Assessment Questionnaire, and patient visual analog scale for pain, fatigue, and global health.
It should be noted that a larger weight loss was associated with greater improvement in a dose-response fashion. The percentage of patients with MDA increased significantly from 29% to 54% (P =.002). PsARC was achieved in 46.3% of participants; ACR20 (20% improvement in ACR criteria), ACR50, and ACR70 responses were 51.2%, 34.1%, and 7.3%, respectively.
The investigators concluded that the study results support the hypothesis that obesity is involved in the pathophysiology of PsA. The very low-energy diet treatment used in this study was safe, effective, and well tolerated.
Klingberg E, Bilberg A, Björkman S, et al. Weight loss improves disease activity in patients with psoriatic arthritis and obesity: an interventional study. Arthritis Res Ther. 2019;21(1):17.