Bone turnover and hormonal perturbations in patients with fibromyalgia.

OBJECTIVE

Studies of bone turnover in fibromyalgia (FM) have, to date, shown conflicting results. Although most patients with FM are women, only a few investigations have paid attention to the changes of sex hormones in FM. Moreover, FM is often viewed as a stress related disorder, and abnormalities of the hypothalamic-pituitary-adrenal (HPA) axis have been found in FM. The aim of the study was to assess bone turnover using serum osteocalcin and CTx in patients with FM and study correlation between bone turnover parameters and parathormon and hormones of the HPA axis.

METHODS

A total of 81 subjects participated in this study: 41 healthy volunteers and 40 patients with FM. Serum osteocalcin, crosslaps (C-telopeptide: CTx), parathyroid hormone (PTH), testosterone, estrogen, prolactin, FSH, and LH were measured. The mean age of the study population was 49.5 (7.6) years (32-69) and the mean disease duration was 8.1 (12.0) years (4.5-30.7).

RESULTS

No difference between patients and controls were observed in serum calcium, phosphorus, creatinine, albumin, osteocalcin, testosterone, and urinary calcium. Patients had lower serum levels of CTx, estrogen, PTH and prolactin than controls and higher serum levels of LH and FSH with a significant statistical difference. No significant statistical correlation was observed between intensity of pain and fatigue and bone turnover parameters and PTH or hormones of the HPA axis.

CONCLUSIONS

Our study showed that patients with FM had low bone resorption and normal bone formation compared to a control group. This was not related to several hormonal perturbations observed in these patients and may reflect functional impairment as suggested in previous studies.