Subclinical hyperthyroidism associated with an increased risk of hip and other fractures

In an analysis that included more than 70,000 participants from 13 studies, subclinical hyperthyroidism was associated with an increased risk for hip and other fractures including spine, according to a study in the May 26 issue of JAMA. Subclinical hyperthyroidism is a low serum thyroid-stimulating hormone concentration in a person without clinical symptoms and normal thyroid hormone concentrations on blood tests.

Overt hyperthyroidism is an established risk factor for osteoporosis and fractures. Associations between subclinical thyroid dysfunction and fractures are unclear and clinical trials are lacking, according to background information in the article.

Nicolas Rodondi, M.D., M.A.S., of the Bern University Hospital, Bern, Switzerland, and colleagues assessed the association of subclinical thyroid dysfunction with hip, nonspine, spine, or any fractures. The authors searched databases for studies with thyroid function data and subsequent fractures. Individual participant data were obtained from 13 prospective cohorts in the United States, Europe, Australia, and Japan. Levels of thyroid function were defined as euthyroidism (normal functioning) (thyroid-stimulating hormone [TSH], 0.45-4.49 mIU/L), subclinical hyperthyroidism (TSH END