Heart Valve Defect Common in Patients With Thyroid Disease
Nov. 30, 1999 (New York) -- A heart valve abnormality is commonly found
among people with a specific type of thyroid disease, Greek researchers report
in the journal Thyroid.
M.E. Evangelopoulou and colleagues from Alexandra Hospital at Athens
University School of Medicine, say doctors should look for the heart valve
problem, known as mitral valve prolapse or MVP, in patients with autoimmune
thyroid disease. Autoimmune thyroid diseases, such as Graves' disease and
Hashimoto's thyroiditis, are conditions in which the body acts against
substances such as proteins produced by the thyroid gland.
MVP is a disorder in which the mitral valve does not close properly and
allows blood to leak into the left atrium of the heart. MVP is found in about
5% to 15% of people under age 40 but is most common among very thin women.
Graves' disease is characterized by an enlarged thyroid gland and protrusion
or bulging of the eyes. Over time, the disease can destroy the thyroid gland.
Hashimoto's thyroiditis also is characterized by an enlarged thyroid and an
autoimmune reaction to proteins produced in the thyroid. Both diseases occur
much more frequently in women than in men.
The researchers studied 29 patients with Graves' disease, 35 patients with
Hashimoto's thyroiditis, 20 patients with nonautoimmune goiter (enlarged
thyroid gland), and 30 people with healthy thyroids. Cardiac ultrasound was
performed in all patients to diagnose MVP and blood samples were examined for
presence of substances that signal autoimmune abnormalities.
MVP was found in 28% of patients with Graves' disease, in 23% of patients
with Hashimoto's thyroiditis, and in 10% with nonautoimmune goiter. MVP was not
present in any members of the healthy group.
Autoimmune abnormalities in blood were found in 63% of the patients with MVP
and Graves' disease and in only 14% of the patients with Graves' disease who
did not have MVP. In patients with Hashimoto's disease and MVP, a high
incidence of autoimmune abnormalities in blood were found 63% of the time. In
patients with Hashimoto's thyroiditis who did not have MVP, autoimmune
abnormalities in blood were found in only 19%.
In previous studies, MVP has been found in otherwise healthy people with
autoimmune disorders such as arthralgias (joint pain), alopecia (loss of hair),
and Raynaud's syndrome (a condition in which the fingers get cold and turn blue
because of decreased blood flow). David S. H. Bell, MD, published a study in
1996 showing an increased incidence of MVP in patients with type 1 diabetes
which also has an autoimmune component.
"I found that 45.1% of patients with type I diabetes had documented
mitral valve prolapse," Bell, director of the endocrine clinic at the
University of Alabama School of Medicine in Birmingham, tells WebMD. His
literature search showed that 41% of patients with Graves' disease and 41% with
Hashimoto's thyroiditis also had MVP.