Fracture incidence in Graves' disease: A population-based study

Background Population-based studies have indicated an increase in bone turnover in hyperthyroidism with a subsequent decrease in bone mineral density and an increased risk of fractures, especially in postmenopausal women. However, heterogeneity between studies prevents a definitive conclusion. Graves' disease (GD) is an autoimmune disease, and it is the most common cause of hyperthyroidism. The aim of this study was to investigate fracture risk in patients with GD. Methods A total of 2134 patients with incident GD and 21261 age, sex- and county-matched controls were included 16-18 years after diagnosis in a retrospective cohort study. Drug and patient national registries in Sweden were used to assess the risk of developing skeletal complications. Up to ten age, sex- and county-matched controls per patient were selected from databases from The National Board of Health and Welfare and Statistics Sweden. Cox proportional hazards models were fitted to estimate hazard ratios (HR) and 95% confidence intervals. Results There were no significant differences in fracture rates between GD and controls but after adjustment for co-morbidities, the data showed higher vertebral fracture rates in male GD patients aged >52 years compared to male controls, HR=2.83 (1.05-7.64). The rates of osteoporosis treatments as well as treatment with corticosteroids were higher in patients with GD. However, HR for the association between GD and fractures remained largely unchanged after adjustment for osteoporosis treatments and treatments with corticosteroids. Conclusions There were no significant differences in total fracture rate between GD and the general population. However, men older than 52 years had a higher vertebral fracture rate. This study also shows that patients with treated GD receive more osteoporosis treatments compared to the general population.