Hypothyroidism and Down syndrome

Helen, the inspiration for It’ll Fit’ll, has been diagnosed with two medical conditions that have affected her size and clothing fit. Those conditions are hypothyroidism and Celiac disease. She takes medicine daily for the hypothyroidism and gluten (wheat, oats, barley and rye) has been eliminated from her diet to address the Celiac disease. Diagnosis and treatment of those two conditions have had a huge impact on Helen. She no longer has the stomach pain (sometimes it had her doubled over) or loose stools associated with Celiac disease. Further, she is more energetic and less irritable. Lastly, she has lost weight. Both conditions are more prevalent in people with Down syndrome than in the general population. So, on the chance that some of you may not be aware of those issues, while your children may have some of the symptoms, I will write about each of them – in separate posts. Today’s post is about hypothyroidism.

Hypothyroidism is also known as “underactive thyroid.” The body does not produce adequate levels of thyroid hormone. Because the function of the thyroid hormone is to control the body’s metabolism, people with hypothyroidism exhibit symptoms consistent with slow metabolism. Symptoms include:

- Fatigue
- Muscle weakness
- Muscle aches, tenderness and stiffness
- Joint pain, stiffness or swelling
- Weight gain or difficulty losing weight
- Constipation
- Irritability
- Memory loss
- Thin, brittle hair and fingernails
- Uncoordinated movement

Children with hypothyroidism may exhibit additional symptoms such as:

- Poor growth and, therefore, short stature
- Delayed development of permanent teeth
- Poor mental development

Since many of the symptoms of hypothyroidism are coincident with Down syndrome (e.g. short stature, low muscle tone, constipation, weight gain) those signs "can be well hidden in children with Down syndrome" as Dr. Len Leshin puts it. So Dr. Leshin, and other medical experts, stress the necessity to annually test children with Down syndrome for underactive thyroid. This is seems quite sensible in light of the fact that the prevalence of hypothyroidism in people with Down syndrome is greater than in the general population. Review of several research studies indicates the prevalence of hypothyroidism in people with DS is 25% to 30%. The prevalence of hypothyroidism in the general population is about 4.6%. So, people with Down syndrome are about 5-1/2 to 6-1/2 times more likely to have underactive thyroids than are people in the general population. More surprising, though, is the fact that one-quarter to one-third of all people with Down syndrome have hypothyroidism. That's one in every three (or four) people!

Hypothyroidism is diagnosed or confirmed through a blood test which measures the level of thyroid hormones. The treatment is hormone replacement therapy. Usually the patient takes a tablet daily. The injectable form of thyroid hormone is prescribed less often. Two types of replacement hormone medications exist: natural - which are derived from pig, cow or sheep thyroid glands - and synthetic. The synthetic hormones are most commonly prescribed. Determining the proper dose seems to be an iterative process. After treatment begins, blood testing is conducted again to determine whether thyroid hormone levels are at proper levels. Often medication dosage is adjusted until the proper balance is achieved.

Helen has a wonderful pediatrician who routinely tested her for hypothyroidism. In February 2006 the results indicated that Helen had become hypothyroid. She has been on a synthetic hormone medication since then. Her dose was adjusted twice, to achieve the right hormone level. As I mentioned earlier, since treatment began she’s had more energy, been less irritable, and has lost weight. Two years ago, when she was 5 years old, she was wearing size 10 pants. Now she wears size 8. There are many, many comparable stories all of which conclude with the parents’ relief at their child’s diagnosis, treatment, and health improvement. And, the frequency of hypothyroidism increases with age. So even if your child is an adult, hypothyroidism is still a possibility. If the signs and symptoms strike a cord with you but your child's doctor hasn't talked with you about hypothyroidism - maybe you should raise the topic for discussion.