Hypothyroidism is a common issue that affects many people with Down syndrome. The thyroid hormones play many important roles in our bodies including influencing our metabolism, production of necessary proteins, growth of our bones, development of cells in our brain, and many other important functions.
A thyroid gland that does not produce enough hormones is considered hypothyroid or low thyroid function. The condition can begin during any period of life affecting newborns to adults. There are many reasons why someone might develop a decreased ability of the thyroid to produce the necessary thyroid hormones. A very common reason one might develop hypothyroidism is due to the body mounting an attack through its immune system against the thyroid gland itself. This happens because the immune system inappropriately sees the thyroid gland as foreign and not part of the body. This is known formally as Hashimoto’s Thyroiditis. Hashimoto’s Thyroiditis is very common in people with DS.
The signs and symptoms of hypothyroidism include weakness, dry skin, increased tiredness, slowing of speech, puffy eyelids, increased sensitivity to cold temperatures, decreased ability to sweat, cold skin, thickened tongue, puffiness of the face, weight gain, coarse hair, pale skin, forgetfulness, constipation, difficulty with the thinking process, and disturbances with menstruation in women. It can be a challenge to consider hypothyroidism as a cause for these symptoms since they can be very common in people with DS. To make sure that hypothyroidism is not overlooked, however, it is recommended for people with DS to have their thyroid checked every year with their health care practitioner.
In the event that hypothyroidism is identified through testing of the thyroid hormones, it is important to replace the missing thyroid hormone. The medication given is called levothyroxine, Synthroid or Levoxyl. Important side effects to keep in mind with the medications are that they can increase the heart rate and the blood pressure. These side effects need to be monitored in patients with high blood pressure, heart problems, or who are older in age. Once the medication is started, it is important to return to the doctor’s office after six to eight weeks in order to recheck the thyroid hormone levels. The dose of the medication may need to be changed at that point in order to get normal thyroid hormone levels, which is the ultimate goal.
Once the proper dose of medication leads to normal thyroid hormone levels, the medication will need to be taken for the rest of a person’s life. As mentioned before, some of the signs and symptoms of hypothyroidism may also be a common finding in a person with DS. On replacement thyroid hormone, these symptoms may get better, however, they may not completely go away. Therefore, it is important to monitor for any changes in symptoms and to regularly check the thyroid hormones through blood tests to confirm the dose.
Other things to consider with regards to hypothyroidism and a person with DS include how to adapt to the medications as the person gets older and with the possible development of other conditions that can arise with the aging process. Usually, the medication dose decreases with increasing age. This is because the “carrier proteins” that bind to thyroid hormone decrease with age. As they decrease, more thyroid hormone is available in the active, unbound form and, therefore, an overall lower dose is needed. Another important consideration is the risk of malnourishment in a person with DS. Certain conditions can increase the chances of a person with DS developing malnourishment including Celiac disease, gastroesophageal reflux disease or GERD, and loss of appetite due to Alzheimer disease. All of these conditions can decrease the body’s abilities to make the “carrier proteins” and, therefore, the dose of thyroid medication will need to be reduced.
Hypothyroidism is more common in people with DS but can be readily treated with thyroid hormone replacement. Regular monitoring is required to confirm the dose of medication.
The Guide to Good Health for Teens & Adults with Down Syndrome by Brian Chicoine, MD & Dennis McGuire, PhD
Additional information related to hypothyroidism can be found in the articles linked below.
Does TSH Tell the Whole Story?
Thyroid, Weight, and Metabolism
Prevalence of Endocrine Disorders Among 6078 Individuals with Down Syndrome in the United States