Roughly 4 to 7 percent of people over age sixty are definitely hypothyroid. It’s also suspected that a much greater percentage of people over sixty have sub-clinical hypothyroidism that frequently goes unrecognized and untreated. Meanwhile, less than 1 percent of people over sixty suffer from hyperthyroidism. In either case, the symptoms of hypothyroidism and hyperthyroidism are different in older people and do not manifest in the same ways as in a younger person. It is recommended that everyone over sixty be screened for hypothyroidism annually with a TSH test. Older thyroid patients report that they feel better once treated with thyroid hormone and that a lot of their vague health problems get better or even disappear.
Hypothyroidism After Sixty
Most causes of primary hypothyroidism in people over sixty are due to Hashimoto’s thyroiditis. Hashimoto’s disease in younger people frequently causes an enlarged thyroid or goiter. In those over sixty, Hashimoto’s disease tends to quietly damage the thyroid gland until it shrivels up. These people could walk around for years with unrecognized Hashimoto’s disease unless a thyroid function test was done. Unlike younger people with Hashimoto’s disease, thyroid antibody testing in older people is very unreliable as well; many older people with these antibodies are not hypothyroid.
Hypothyroidism in people over age sixty can increase cholesterol levels, which can in turn exacerbate heart disease. Hypothyroidism can also worsen depression, cognitive function, arthritis and muscular aches, memory, respiratory problems, and sleep apnea. It can also aggravate preexisting dementia.
Treating Hypothyroidism in Persons over Sixty
In people over age sixty with a TSH of greater than 10, there is a clear bene?t to treatment with thyroid hormone. In people with a TSH of 5–10, treatment is also likely to be helpful, although the bene?ts in symptom relief are much less obvious. The risk of thyrotoxicosis from excessive dosages of thyroid hormone in an older person with either heart problems and/or osteoporosis means that thyroid hormone dosing needs to follow a “start low, go very slow” approach. Experienced endocrinologists are often able to better choose appropriate dosages that are not excessive without having to delay treatment by starting too low. People over sixty also require less thyroid hormone than younger people, which is why starting doses of thyroid hormone are advised to be conservative. It is in this group, especially, where T3 in combination with T4 has not been properly studied and could have harmful effects. Similarly, “natural” thyroid hormone or thyroid extract is not recommended for this group.
A Note on Heart Disease
In people over age sixty, hypothyroidism symptoms can obscure heart diseases such as angina. Also, less commonly, swelling from hypothyroidism may be mistaken for congestive heart failure. In addition, people in heart failure have a faster pulse than normal; the hypothyroid heart is slower than normal, usually less than 60 beats per minute. There are other distinctions between hypothyroidism and congestive heart failure, but those truly in congestive heart failure don’t usually have other hypothyroid symptoms at the same time. Thyrotoxicosis in Persons over Sixty Hyperthyroidism from Graves’ disease or a nodule occurs in less than 1 percent of the population over age sixty. In fact, it is less than one-tenth as common as hypothyroidism in the same population. When it does occur, the symptoms are not obvious and do not clearly indicate the diagnosis of Graves’ disease to the doctor in the same way as in a younger person. Similar to hypothyroidism, hyperthyroidism can be insidious in the over-sixty crowd; it can manifest as “apathetic” hyperthyroidism. This means that many of the symptoms in young people are absent in the older population, and thyroid disease may contribute to failing health, but may not be obvious or easy to spot. This is one reason why screening for sub-clinical thyroid disease in older groups of people is recommended.