Graves' disease and vertebral fracture: Possible pathogenic link in postmenopausal women.

Abstract

Thyrotoxicosis is associated with accelerated bone turnover and increases the risk of fractures and osteoporosis. Graves' disease is the most common cause of hyperthyroidism. However, studies that examined risk factors associated with fragility fractures only in patients with Graves' disease are limited. Here, we investigated whether the risk of vertebral fracture (VF) of postmenopausal Graves' disease patients is high and tried to identify the risk factors for VF in that population. Forty-three postmenopausal women with Graves' disease were enrolled. Physical and biochemical indices, thyroid indices and bone mineral density (BMD) were measured, and lateral X-rays were obtained to evaluate VFs. Age- and sex-matched healthy individuals were enrolled as the control group (n=86). The prevalence of VFs (35% vs 17%, P<.05), osteoporosis (63% vs 33%, P<.01) and severe osteoporosis (40% vs 17%, P<.01) was significantly higher in the Graves' disease group. Although there was no significant difference in either thyroid hormone levels or the positive ratio of thyroid antibodies, the prevalence of thyroid-stimulating antibody (TSAb) was significantly higher in Graves' disease patients with VF compared to without (100% vs 68%, P<.05). Multivariate logistic regression analyses adjusted for age identified Graves' disease as being associated with the presence of VFs (OR 2.72, 95% CI: 1.13-6.54, P<.05) in postmenopausal women. Postmenopausal Graves' disease patients had high risks of VF and severe osteoporosis. TSAb could be involved as a risk factor for VF in postmenopausal Graves' disease.