By: Diana Barnes-Brown for Heart1
A research team at the University of Pennsylvania School of Medicine recently found that the best strategy for treating mildly underactive thyroid glands may be to skip treatment altogether. Mildly low thyroid activity, called subclinical hypothyroidism, is commonly diagnosed and, until now, doctors believed that the best way to treat the condition is with medication.
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Know and report symptoms of a thyroid problem
Symptoms of hypothyroidism may include:
Fatigue
Weight gain
Dry skin
Intolerance of cold
Muscle aches and pains
Loss of sex drive
Symptoms of hyperthyroidism may include:
Nervousness and agitation
Irritability
Sweating and intolerance of heat
Shaking or trembling
Rapid heart rate
Weight loss
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The thyroid gland is located in the neck and is responsible for producing the hormones that regulate metabolism. For those whose thyroid glands are overactive or underactive, there can be many symptoms, some mild and others potentially dangerous, so treatment with hormone therapy is the normal course of action.
Subclinical hypothyroidism, or a mildly underactive thyroid, is also usually treated with drug therapy because previous studies showed that fluctuations from the normal hormone levels may result in increased heart risks.
Despite the common practice to prescribe medication, Dr. Anne Cappola wanted to examine the outcomes of subclinical hypothyroidism more carefully, so she measured thyroid function in 3,200 men and women who were 65 or older. Cappola placed the participants into groups based on the results of the thyroid function tests and followed them for 13 years. The objectives of the study, noted Cappola and her team, were “to determine the relationship between baseline thyroid status and incident atrial fibrillation, incident cardiovascular disease, and mortality in older men and women not taking thyroid medication.”
Of the 3,200 people tested, 1.5 percent suffered from a mildly overactive thyroid (subclinical hyperthyroidism), and 15 percent suffered from subclinical hypothyroidism. The group with hyperthyroidism did have an increased risk of developing abnormal heart rhythms or atrial fibrillation, while the group with hypotension showed no higher risk of heart attack, stroke, or death than those with normal levels.
Cappola noted that regular screening might not be necessary for most of the population, but in the event that a patient over 65 is found to have overactive thyroid glands, he or she “may benefit from treatment to prevent atrial fibrillation.”
On the other hand, underactive thyroid glands did not pose much of a threat and thyroid screening may not be as necessary for older adults as was once thought. “Analyses do not support screening older individuals for thyroid disease to prevent [cardiovascular disease],” wrote the authors, adding, “although our data are observational, they do not support treatment of individuals with subclinical hypothyroidism to prevent cardiovascular events.”
The study appeared in JAMA, the Journal of the American Medical Association, in early March and was supported by the American Heart Association; the National Heart, Lung and Blood Institute; and the National Institute on Aging.
