Obese Patients With Polymyalgia Rheumatica Experience More Pain And Disability At Disease Onset And Require Higher Doses Of Glucocorticoids.

Objective: polymyalgia rheumatica (PMR) is an inflammatory disorder of the elderly characterized by girdle pain and stiffness. Obesity has an influence on disease activity and outcome in rheumatic diseases like osteoarthritis and rheumatoid arthritis, but its relationship to the severity and outcome of PMR is unknown.

Methods: In a post-hoc analysis, 83 patients with recent-onset PMR were studied over six months with clinical examination, laboratory evaluation, and girdle ultrasound. MHAQ, Short Form 36 (SF36), and PMR-VAS, as well as prednisone (PDN) therapy were recorded. Patients were divided according to their body mass index (BMI).

Results: at baseline, the 12 obese patients had significantly more shoulder pain (p=0.03), global pain (p=0.03), PMR VAS (p<0.01), and fatigue (p=0.03), higher MHAQ (p=0.01), and lower physical component summary on SF36 (p=0.048), SF36 social functioning index (p=0.05) and SF36 pain index (p<0.001). The mean initial PDN dose was similar among groups, but obese patients received a lower dose per kg weight (1.9±0.7 mg vs. 2.2±0.7 mg; p<0.01). At six months, obese patients were being treated with higher mean daily PDN doses (8.5±3.2 mg/day vs. 6.2±5.2 mg/day, p=0.02); 40% of them were receiving higher daily PDN dose than per-protocol, vs. 14% non-obese patients (p=0.048). Clinical features, laboratory and ultrasound results were similar.

Conclusion: obesity affects both symptoms severity and PDN utilization in patients with PMR. The reason thereof may relate to different subjective pain perception rather than increased inflammation in obese patients. BMI should be considered when interpreting symptoms in PMR patients and deciding their PDN doses.