Newswise — Falls Church, Virginia. Sep. 20, 2012—Subclinical hyperthyroidism is not associated with overall or cardiovascular mortality, according to new data presented at the 82nd Annual Meeting of the American Thyroid Association (ATA) in Québec City, Québec, Canada.

“Hyperthyroidism is associated with a number of health concerns, chief among them being cardiovascular disease. Though subclinical hyperthyroidism mimics some of the features of classic hyperthyroidism, new data show that a link to cardiovascular disease is not one of them,” said Douglas Forrest, PhD, of the National Institute of Diabetes and Digestive and Kidney Diseases, and Program Co-Chair of the ATA Annual Meeting.

Subclinical hyperthyroidism is a mild form of hyperthyroidism that affects approximately 1-2% of men and women ages 65 and older. Unlike classic hyperthyroidism, in which a person’s thyroid hormones are high, people with subclinical hyperthyroidism have low-levels of thyroid-stimulating hormone (TSH) levels but normal levels of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). The degree to which subclinical hyperthyroidism persists over time as well as its associated health risks were heretofore unknown.

A team of researchers led by Paige Fortinsky, MD, at the University of Pennsylvania Medical Center in Philadelphia thus undertook a study to examine transitions in the thyroid status over a 2–3-year period and determine the risks of cardiovascular and total mortality in older individuals with subclinical hyperthyroidism. They enrolled 5,009 men and women aged 65 and over who were enrolled in the Cardiovascular Health Study and not taking thyroid medications. They identified 70 subjects with subclinical hyperthyroidism (TSH < 0.45 mU/L with a normal free-T4 level) at their first TSH measurement and examined persistence, resolution, and progression of subclinical hyperthyroidism over 2–3 years.

Of the 70 individuals with subclinical hyperthyroidism, 60% were women, 24% were nonwhite, and their mean age was 73.7 years. Among those with subclinical hyperthyroidism who obtained follow-up thyroid testing or were taking thyroid medication at follow-up (n=44), 43% persisted, 41% reversed to normal levels of thyroid hormone, 5% progressed to overt hyperthyroidism, and 11% initiated thyroid medication. Researchers analyses’ found no association between subclinical hyperthyroidism and total or cardiovascular mortality.

About the ATA Annual Meeting 
The 82nd Annual Meeting of the American Thyroid Association is held Sept.19-23, in Québec City, Québec, Canada. This four-day creative and innovative scientific program, chaired by Elizabeth Pearce, MD, Boston Medical Center, and Douglas Forrest, PhD, National Institute of Diabetes and Digestive and Kidney Diseases, carefully balances clinical and basic science sessions on the latest advances in thyroidology. The ATA meeting is designed to offer continuing education for endocrinologists, internists, surgeons, basic scientists, nuclear medicine scientists, pathologists, endocrine fellows and nurses, physician assistants and other health care professionals. Visit for more information.

About the ATA 
The American Thyroid Association (ATA) is the leading worldwide organization dedicated to the advancement, understanding, prevention, diagnosis and treatment of thyroid disorders and thyroid cancer. ATA is an international individual membership organization with over 1,600 members from 43 countries around the world. Celebrating its 89th anniversary, ATA delivers its mission through several key endeavors: the publication of highly regarded monthly journals, THYROID, Clinical Thyroidology and Clinical Thyroidology for Patients; annual scientific meetings; biennial clinical and research symposia; research grant programs for young investigators, support of online professional, public and patient educational programs through; and the development of guidelines for clinical management of thyroid disease. Visit for more information.

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82nd Annual Meeting of the American Thyroid Association