Without symptoms, the value of testing for thyroid disease is unclear

There is not enough evidence to recommend for or against testing for thyroid dysfunction in adults without symptoms, according to a U.S. government-backed panel.

“We don’t view this as the final word,” Dr. Kirsten Bibbins-Domingo, vice chairperson of the U.S. Preventive Services Task Force (USPSTF).

“We view this as a call to the research community to help us provide this evidence,” she said in a phone interview with Reuters Health.

The thyroid, which is a gland in the neck, produces hormones that affect several bodily processes, including metabolism and growth. If left untreated, thyroid dysfunction may lead to death or a number of conditions, including heart disease and cancer, the USPSTF writes in the Annals of Internal Medicine.

Doctors can check thyroid function with a blood test that looks for thyroid-stimulating hormone, or TSH. The hormone is what prompts the thyroid to produce its own hormones.

Abnormal tests should be confirmed with repeat testing over three to six months. Then testing for specific thyroid hormones can look for possible or overt dysfunction, the USPSTF writes.

They add that up to a quarter of U.S. adults are screened for thyroid dysfunction every year. Depending on whether the thyroid is over reactive or underactive, the treatment can include drugs or oral hormone therapy.

The USPSTF last reviewed the evidence for thyroid dysfunction screening in 2004.

In the new review, the panel said they could not estimate the balance of benefits and harms of screening for thyroid dysfunction in adults without symptoms who are not pregnant.

“I want to be clear that it’s very clear that this does not apply to patients who have symptoms,” said Bibbins-Domingo, who is also a professor at the University of California, San Francisco.

“Our goal is to review and update recommendations every five years,” she said, adding that the panel also updates recommendations should any evidence become available.

"The call is really to the research community to do more studies to give us the evidence,” Bibbins-Domingo said.