This study aimed to evaluate the impact of fibromyalgia syndrome (FMS) on bone mass assessed by calcaneal quantitative ultrasound (QUS) in pre- and postmenopausal women and determine whether there are associations between bone status and pressure pain thresholds (PPTs), tender point counts (TPCs), self-reported global pain, or disease severity. Ninety-five women with a diagnosis of FMS and 108 healthy controls matched on menopause status were included in this cross-sectional study. PPT and TPC were measured by algometry pressure. Self-reported global pain and disease severity were evaluated by Visual Analogue Scale and Fibromyalgia Impact Questionnaire, respectively. Bone mass was assessed with calcaneus QUS. Broadband ultrasound attenuation (BUA; dB/MHz) and speed of sound (SOS; m/s) were significantly lower in the FMS patients compared with controls ( p = .027 and p = .003, respectively). Linear regression analysis revealed that all PPTs were significantly associated with the BUA parameter after adjustments for body mass index (BMI), menopause status, and physical activity in women with FMS ( p < .05). TPC was also significantly associated with BUA after adjustments for covariables (β = .241, 95% confidence interval [0.333, 3.754], p = .020). No significant differences were found between any QUS measurements and global pain or disease severity. Calcaneal BUA and SOS values were lower in women with FMS compared to healthy controls, and decreased pain thresholds and higher TPCs were associated with lower calcaneal BUA values. Low pain thresholds might be independent predictors for low bone mass in FMS women.
Keywords: Visual Analogue Scale; calcaneal quantitative ultrasound; disease severity; fibromyalgia; pressure pain threshold; tender point counts.