The question is whether or not to use thyroid hormone treatment in older adults. What is the science as it relates to treatment of an underactive thyroid? Is the use of this hormone therapy beneficial to the elderly or not?
The thyroid is a butterfly-shaped gland located in the front of the throat. This gland is responsible for the production of two types of hormones: triiodothyronine (T3) and thyroxine (T4). Together, these are called the thyroid hormones. Overproduction or underproduction of these hormones constitute thyroid disease.
As we age, the production of these hormones naturally decreases. Whether thyroid hormone treatment is beneficial to older adults must be weighed against the possible side effects.
The First Steps in Considering Thyroid Hormone Treatment
Before considering thyroid hormone treatment, a person’s thyroid stimulating hormone (TSH) level must be determined with a lab test prescribed by a doctor. The range for normal TSH levels is .4 to 4.0 milliunits per liter (mU/L). If a person’s level is over 4.0 mU/L after more than one test, he or she is determined to have an underactive thyroid, a condition called hypothyroidism.
Note that the higher the mU/L number, the less active the thyroid is. A high TSH number is caused by the pituitary gland producing TSH in an effort to stimulate an underactive thyroid. That is, the weaker the thyroid’s production of hormones, the more TSH the pituitary gland must produce, resulting in a higher mU/L number from the thyroid test.
Types of Hormone Treatments
According to the American Thyroid Association, there are two types of thyroid hormone treatment:
- Hormone Replacement Therapy (used when the thyroid is not producing enough thyroid hormone)
- Suppression Therapy (used to suppress the cancer that has developed in the thyroid gland)
Symptoms of Hypothyroidism Can Be Confused for Other Age-Related Conditions
Hypothyroidism is more common than hyperthyroidism in elderly persons, especially in women over the age of 50. As a person ages, hormone production decreases. Typical symptoms include weight gain, unusual fatigue, sensitivity to cold temperatures and muscle weakness. These symptoms can be brushed off as just part of the normal aging process when, in fact, they can be due to a significant decrease in thyroid hormone production.
Additional symptoms can include brain fog, moodiness, depression, difficulty focusing and memory loss. It’s possible to believe that dementia is in play because the symptoms of thyroid disease and dementia can appear similar. Hence, the need for thyroid testing is in order when a person exhibits these types of symptoms.
A Thyroid Hormone Treatment Study Calls for Caution
Between 2003 and 2018, a study on thyroid hormone treatment using levothyroxine was done by the Baltimore Longitudinal Study of Aging. In particular, longevity rates of participants 65 years and older were examined. It was determined that thyroid hormone treatment increased mortality risk by 60% each year. As a result, researchers in this study concluded that caution should be used when considering thyroid hormone treatment in older adults.
Further Considerations When Undergoing Thyroid Hormone Therapy
Most patients with hypothyroidism take one pill of synthetic T4 daily. It is important to take the medication faithfully at the same time each day. It is also important to have the amount monitored by the doctor since the dosage depends on age, weight and medical conditions, which do change.
Thyroid hormone therapy can interact with medications that are commonly taken by elderly patients. Medications that can have negative effects on the absorption of thyroid hormones include some prescribed for depression, cholesterol and seizures. Also soy, calcium and iron can change the effectiveness of the induced hormones.
If the thyroid has been removed due to cancer, thyroid hormone therapy is required. The pituitary gland, which gives off TSH in an effort to activate hormone production by the thyroid, may trigger cancer in the body, so a doctor may prescribe high levels of hormones to keep the TSH production low.
If this regimen is continued for a long period of time, additional problems such as rapid or irregular heartbeats can develop. Weak bones, or osteoporosis, can also occur.
The determination of whether to employ thyroid hormone treatment will depend on several factors in the patient: other existing health conditions, severity of symptoms, medications being taken and age.
A decrease in thyroid hormones can lead to an increase in heart disorders. Since heart problems are prevalent in the elderly, thyroid hormone levels should be checked if heart issues are suspected.
In conclusion, if the thyroid has been removed, there is no question that thyroid hormone therapy is in order. But if the therapy is being considered to address symptoms of an underactive thyroid, the possible negative effects of the therapy should be taken into careful consideration.