Relationship between fibromyalgia and obesity in pain, function, mood, and sleep.

UNLABELLED: Fibromyalgia syndrome (FMS) is a prevalent and disabling chronic pain disorder. Past research suggests that obesity is a common comorbidity and may be related to the severity of FMS. The main objective of the present study was to evaluate the relationships between FMS and obesity in the multiple FMS-related domains: hyperalgesia, symptoms, physical abilities, and sleep. A total of 215 FMS patients completed a set of self-report inventories to assess FMS-related symptoms and underwent the tender point (TP) examination, physical performance testing, and 7-day home sleep assessment. Forty-seven percent of our sample was obese and an additional 30% was overweight. Obesity was related significantly to greater pain sensitivity to TP palpation particularly in the lower body areas, reduced physical strength and lower-body flexibility, shorter sleep duration, and greater restlessness during sleep. The results confirmed that obesity is a prevalent comorbidity of FMS that may contribute to the severity of the problem. Potential mechanisms underlying the relationship are discussed. PERSPECTIVE: This report presents how obesity may be interrelated to fibromyalgia pain, disability, and sleep. We found that obesity is common in FMS. Approximately half of our patients were obese and an additional 30% were overweight. We also found that obesity in FMS was associated with greater pain sensitivity, poorer sleep quality, and reduced physical strength and flexibility. The results suggest that obesity may aggregate FMS and weight management may need to be incorporated into treatments.