Vitamin D Levels in Women with Fibromyalgia and Relationship between Pain, Depression, and Sleep

Abstract

Objective: Fibromyalgia (FM) is a chronic syndrome characterized by widespread musculoskeletal pain, associated with sleep disorders and depression.There are several studies suggesting a possible relationship between musculoskeletal pain and vitamin D deficiency.In this study, we aimed to compare serum 25-hydroxyvitamin D (25(OH)D) levels between FM patients and control groups and determine the relationship between 25(OH)D levels and pain, depression, and sleep disturbance.Material and Methods: This study enrolled 60 fibromyalgia women who fulfilled the American College of Rheumatology (ACR) 1990 criteria (mean age 41.9±9.8 and mean duration of disease 27.3±17.3months) and 30 healthy women (mean age 38.8±12.7).All subjects were evaluated with biochemical markers, including 25(OH)D and parathyroid hormone.The patients were divided into three groups based on their serum 25(OH) D levels (normal, insufficient, deficient).In addition, the fibromyalgia ımpact questionnaire (FIQ), visual analog scale (VAS), Beck depression ınventory (BDI), and Epworth sleepiness scale (ESS) were applied to the patients with FM.Results: Mean serum 25(OH)D levels were lower in the FM group than in the controls (16.7±9.5 ng/mL vs. 21.6±5.9ng/mL, p=0.004).As patients were classified according to the levels of 25(OH)D, no significant difference was found between the groups in terms of pain and sleep disorder VAS, FIQ, BDI, and ESS scores (p>0.05).Also, there was no statistically significant correlation between vitamin D levels and clinical scales (p>0.05). Conclusion:In this study, mean serum 25(OH)D levels were lower in patients with fibromyalgia, and no association was demonstrated between serum 25(OH)D levels and severity of pain, sleep disorder, and depression.