‘An important risk factor’
Endocrinologist Michael McClung, MD, founding and emeritus director of the Oregon Osteoporosis Center, Portland, who was not involved in the study, pointed out that both subclinical hypothyroidism and subclinical hyperthyroidism have been linked to greater risk for cardiovascular disease as well as fracture.
The new paper underscores that subclinical hyperthyroidism “should be included as an important risk factor” for fracture as well as cardiovascular risk, Dr. McClung said in an interview. In considering whether to treat osteoporosis, subclinical hyperthyroidism “may be enough to tip the balance in favor of pharmacological therapy,” he added.
Thyroid-stimulating hormone (TSH) tests to assess thyroid function are typically ordered only if a patient has symptoms of hyperthyroidism or hypothyroidism, Ms. Daya said. Depending on the cause and severity of a low TSH level, a physician may prescribe methimazole or radioactive iodine therapy to reduce the production of thyroxine, she said.
However, well-designed studies are needed to evaluate whether treatment of subclinical thyroid dysfunction reduces the risk for fracture or cardiovascular problems and assess downsides such as side effects, costs, and psychological harm, Dr. McClung noted.
The U.S. Preventive Services Task Force concluded in 2015 that the data were insufficient to recommend screening for thyroid dysfunction in adults without symptoms. As of a year ago, no new evidence has emerged to support an update, according to the task force’s website.
“Until those studies are available, selective screening of thyroid function should be considered in all patients undergoing risk assessment for cardiovascular disease or skeletal health,” Dr. McClung said.
The Atherosclerosis Risk in Communities Study has been funded by the National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH) and the U.S. Department of Health and Human Services. Ms. Daya and four study authors reported receiving NIH grants during the study period. Dr. McClung reported no relevant financial conflicts of interest.
A version of this article first appeared on Medscape.com.