Effect of Exercise and Diet on Psoriatic Arthritis

There is evidence that obesity is associated with PsA. Obesity leads to increased proinflammatory cytokines which may contribute to the development of multiple disturbances in PsA patients. A 12 month, randomized single blind clinical trial was conducted to determine whether long-term exercise and dietary weight loss are more efficacious, either separately or in combination, than standard care alone in improving physical function, pain, fatigue, depression and systemic inflammation in obese adults with PsA. Fifty-five obese ethnically homogenous adult PsA patients with a body mass index (BMI) ≥30, who satisfied the classification of psoriatic arthritis criteria were recruited. Patients were randomized into usual lifestyle (controls), diet only, exercise only, and diet plus exercise groups together with the continued use of standard treatment. Exclusion criteria included other inflammatory conditions. Detailed skin and rheumatological assessment was conducted. Disease activity was assessed by psoriasis area and severity index (PASI), disease activity score (DAS28CRP), Health Assessment Questionnaire- Disability Index (HAQ-DI), Beck's Depression Inventory (BDI) and fatigue numeric rating scale. Blood samples collected after 12 hours overnight fasting were analysed for glucose, lipid profile, ESR, hsCRP, proinflammatory cytokines; tumour necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-17 (IL-17). The primary outcome measures included improvement in ACR20, systemic inflammation markers, BMI, physical function, pain, fatigue, depression and HAQ-DI. Secondary endpoints included reduction in PASI score, DAS28-CRP response and physician and patient global assessment (PGA). Safety and tolerability were also assessed. Data was collected at baseline and every 6 months.