Thyroid Research Roundup

Many studies are published each month that look at various aspects of thyroid disease. Here are highlights from a few new studies that may be of specific interest to thyroid patients.

Treating Borderline Hypothyroidism Can Reverse Heart Abnormalities

Italian researchers, reporting in the International Journal of Cardiology, looked at the impact of the thyroid drug levothyroxine (also known as l-thyroxine, better known by brand names such as Synthroid or Levoxyl) for heart issues in people with subclinical hypothyroidism, and autoimmune thyroiditis but normal TSH levels. The researchers defined “normal” TSH as being less than 3. The researchers found that both the patients with hypothyroidism (and TSH above 3), and those who had autoimmune thyroiditis (and TSH less than 3), had heart abnormalities. These abnormalities were reversible with levothyroxine treatment.

Mild Hypothyroidism Affects Memory

Researchers conducted a study to determine whether subclinical (borderline or mild) hypothyroidism can negatively affect health status, mood, and/or cognitive functions such as memory. The results of the double-blinded, randomized, cross-over study were reported in a study just released by the Journal of Clinical Endocrinology and Metabolism.

To conduct the study, a group of hypothyroid subjects continued their usual dose of levothyroxine, and the other group received a lowered dose (“subclinical” status). The groups then “crossed over” and did the opposite. Health status, mood, and cognition were evaluated in both groups, during both phases. Fatigue and general health worsened slightly when patients were in subclinical status. Working memory was definitely worse during the subclinical status. The researchers concluded that subclinical hypothyroidism specifically impacts brain areas responsible for working memory.

Autoimmune Thyroid Disease and Fibromyalgia

Researchers looked at thyroid abnormalities and autoimmunity in 120 patients affected by fibromyalgia. What they found in the study was that while thyroid hormone levels of the fibromyalgia patients tended to be in the normal range, 41% of the patients had at least one thyroid antibody. Patients with thyroid autoimmunity also had a higher rate of symptoms that include: dry eyes, burning, or pain with urination, body pain, blurred vision, and sore throat. The researchers concluded that autoimmune thyroiditis is seen at higher rates in people with fibromyalgia, and is also associated with the presence of additional symptoms.

_Sources:

Mariotti, S. et. al. Int J Cardiol. 2007 May 9, “Cardiac effects of l-thyroxine administration in borderline hypothyroidism.” Online: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed

Samuels, MH, et. al. “Health status, mood and cognition in experimentally-induced subclinical hypothyroidism.” J Clin Endocrinol Metab. 2007 May 1. Online: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed

Bazzichi, L, et. al. “Association between thyroid autoimmunity and fibromyalgic disease severity.” Clin Rheumatol. 2007 May 9 Online: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed