MIST project

Linda, a 50 year old attorney, was so tired that she had difficulty completing legal briefs on time. She was also gaining weight and found it challenging to concentrate on her work. Her physician attributed her symptoms to menopause and told her to “get used to it”. Linda was not satisfied with the advice and sought a second opinion from a physician who ordered blood tests to assess her thyroid function. It turned out that Linda had subclinical hypothyroidism, a common disorder affecting 10-20% of post-menopausal women. Now, Linda’s physician is uncertain about treating her with thyroid hormone medication because of controversy in the medical literature about the need and effectiveness of treatment. If she is not treated, will Linda have a higher than normal risk of a future heart attack or stroke? This is the research question Dr.Vicky LeGrys of the CLS division and her colleagues (Drs. Hartmann, Lorenz and Funk) at the Center for Women’s Health Research hope to answer.They are the recipients of a 3-year RO1 grant from the National Heart, Lung and Blood Institute of the National Institutes of Health entitled, “Myocardial Infarction (MI) and Stroke in Subclinical Thyroid Disease” (MIST). A butterfly, representing the shape of the thyroid gland, is part of the MIST logo.

According to Dr. LeGrys, defining the relationship between MI and stroke in subclinical hypothyroidism is so important that Congress asked the National Institute of Medicine to address this issue. Congress did so because thyroid dysfunction is the most prevalent endocrine disorder, affecting more than 21 million americans.The annual health care costs known to be associated with thyroid dysfunction exceed 10 billion dollars annually.The conclusions of the Institute of Medicine study were that current research on the topic is insufficient to inform clinical decision making about the need for screening and treatment for subclinical hypothyroidism. Since cardiovascular disease is the leading cause of death for adult women and subclinical hypothyroidism becomes more common with age, research in this area is critical.

The lack of research data on the cardiovascular health risks associated with subclinical hypothyroidism spurred Dr. LeGrys and Dr. Hartmann to develop a multidisciplinary team to investigate this link.“The application of laboratory medicine to cardiovascular epidemiology and women’s health was an extremely attractive proposal to the NIH” says Dr. LeGrys.The MIST project will use the serum and health data obtained from the NIH Women’s Health Initiative (WHI), a 17 year national project involving over 90, 000 women. Specifically the MIST project will measure thyroid hormones in a case-cohort study of 4,750 women enrolled in the WHI and relate this to the outcome of MI and stroke.The answers obtained from this study will be critical for additional research to determine if screening for thyroid disorders among older women can help prevent cardiovascular disease.

CLS alumni have also contributed to the success of this project. Alicia Curtis (class of 2005) worked as a MIST research assistant. Ryan Vann (class of 2003), Shauna Hay (class of 1996), Amanda Ligon (class of 1997), and Lisa Sibley Anderson (class of 2003) taught some of the first year CLS courses so that Dr. LeGrys could work on this grant.

In 2012, the first of two articles was submitted for publication. Dr. LeGrys is the lead author of this publication. The results were very interesting in that they did not show a relationship between hypothyroidism and myocardial infarct. A negative finding is significant and provides important information for health care professionals.