patients sustained a definite increase in heart disease and heart attacks over patients without the condition. Various tests of normal heart function, such as changes in heart rate with exercise, indicated that those functions were impaired in people with subclinical hypothyroidism. The most at-risk people were women over age 50 who smoked and had TSH levels greater than ten. Giving the study patients thyroid medication improved these functions and also improved the levels of fats in the blood. The author of this study felt that these changes justified the use of thyroid treatment in subclinical hypothyroidism. He noted, however, that giving a patient thyroid-replacement hormone tends to speed up the heart rate and may worsen chest pain, which doctors must consider when treating someone with this condition. A more recent study in the Annals of Family Medicine in July 2004 provides further evidence that patients with subclinical hypothyroidism probably don’t need treatment. The authors of the study looked at people who didn’t have a diagnosis of hypothyroidism and weren’t taking thyroid pills. They found that a subgroup of those people had subclinical hypothyroidism, which they defined as a TSH between 6.7 and 14.9 with a normal thyroxine (T4). The authors looked at the fat levels of these patients and found that although they had slightly more total cholesterol, their levels of HDL cholesterol (good cholesterol) and LDL cholesterol (bad cholesterol) as well as triglyceride were no different from people with normal TSH levels. Even the levels of total cholesterol weren’t different in the two groups when adjusted for age and sex. The authors’ conclusion was that subclinical hypothyroidism doesn’t need to be treated, as least as far as treating to benefit fat levels in the body. They raised the possibility that other abnormalities may benefit from treatment. This remains a very controversial topic. At this time, my bias is to treat subclinical hypothyroidism since on balance the evidence suggests that these patients suffer heart abnormalities that are improved by thyroid hormone treatment. If you have subclinical hypothyroidism, you and your doctor should look carefully for subtle evidence of low thyroid function and treat the condition with thyroid-replacement hormone if you find such evidence. Then determining whether thyroid hormone makes a difference in those subtle findings becomes important.
Finding the Right Dose of Hormone A question that keeps coming up among doctors who treat hypothyroidism is “What is the correct dose of thyroid medication?” Some physicians believe that lowering a patient’s level of thyroidstimulating hormone (TSH) to under five is sufficient to eliminate signs and symptoms of low thyroid function, but many patients are still symptomatic at that level. In a study published in the