Association between low bone mineral density and fibromyalgia: a meta-analysis

We aimed to evaluate the relationship between bone mineral density (BMD) and fibromyalgia (FM). Meta-analyses were performed comparing BMD in FM patients and healthy controls, and in FM patients in subgroups based on ethnicity, BMD site, age, sex, and measurement method. Twelve studies including 695 FM patients and 784 controls were selected. Meta-analysis by ethnicity revealed a significantly lower BMD in the FM group in Caucasian populations [standardized mean difference (SMD) = -0.144, 95% CI = -0.271-(-0.017), p = 0.026], but not in Turkish populations. Subgroup analysis by BMD site showed that BMD was significantly lower in the FM group than in the control group in the lumbar spine [SMD = -0.588 (medium), 95% CI = -1.142-(-0.033), p = 0.038], but not in the femur neck and hip. Stratification by measurement method revealed a significantly lower BMD in the FM group by dual X-ray absorptiometry and dual-photon absorptiometry [SMD = -0.531 (medium), 95% CI = -1.040-(-0.023), p = 0.041; SMD = -0.315 (small), 95% CI = -0.544-(-0.085), p = 0.007, respectively], but not by quantitative ultrasound, but not by quantitative ultrasound. Subgroup analysis by sex, menopause status, and age revealed a significantly lower BMD in the female FM group [SMD = -0.588 (medium), 95% CI = -1.142-(-0.033), p = 0.038], but not in the pre-menopausal group and the group greater than mean age 50 years old. Our meta-analysis demonstrated that BMD was significantly lower in FM patients in Caucasian and female populations.