Ms. A, a woman in her 70s, was diagnosed with hypothyroidism after undergoing tests due to cognitive decline to the point where she could not even remember recent conversations. Ms. B, a man in his 60s, was diagnosed with arrhythmia, but was also diagnosed with hyperthyroidism and decided to receive medication. We will learn about thyroid dysfunction that threatens the brain and heart.
The thyroid gland is an organ that secretes hormones that control the body’s metabolism. If there is a problem with the thyroid gland function, hypothyroidism or hyperthyroidism occurs, in which hormones are either insufficient or excessively secreted. It may start with mild symptoms at first, but if left untreated, serious complications may occur.
Professor Cho Yoon-young of the Department of Endocrinology and Metabolism at Soonchunhyang University Bucheon Hospital said, “Hypothyroidism can cause cardiovascular disease due to cholesterol accumulation, and is closely related to dopamine secretion, which can lead to mood disorders, sleep disorders, and cognitive disorders. Hyperthyroidism is known to increase the mortality rate due to heart disease such as arrhythmia and heart failure by increasing heart rate and cardiac output, and also increase the risk of stroke.”
Hypothyroidism has increased by more than 60% from 2003 to 118 cases per 100,000 people in 2018. 83% of hypothyroidism occurs in women, and the prevalence increases with age. It is estimated that the incidence has increased due to the aging population and increased early detection. On the other hand, hyperthyroidism has decreased from the early 2000s to 40 cases per 100,000 people in 2018, and more than two-thirds are women and it occurs at a relatively young age.
Hypothyroidism causes symptoms such as lethargy, lack of concentration, weight gain, and swelling, as all metabolisms slow down. A representative example is Hashimoto’s thyroiditis, a chronic autoimmune disease. Hyperthyroidism causes symptoms such as palpitations, excessive sweating, tremors, rapid breathing, easy irritability, and weight loss despite the same amount of food intake, as well as increased metabolic rate and heart rate.
Blood tests and thyroid autoantibody tests are performed to diagnose thyroid dysfunction. Thyroid ultrasound may be performed if the thyroid gland is swollen or if subacute thyroiditis needs to be differentiated. If the cause is unclear, a thyroid scan may also be performed.
Treatment of hypothyroidism is mainly thyroid hormone replacement. Thyroid hormone drugs have a long half-life, are stable, and are safe enough to be taken during pregnancy and breastfeeding. More than 40% of patients with hypothyroidism in Korea require long-term treatment for more than 3 years, and appropriate drug concentrations must be maintained through periodic thyroid function tests. In particular, if there were other long-term complications such as heart failure at the time of diagnosis, thyroid hormones must be maintained for a long period of time.
Treatment for hyperthyroidism includes drug therapy, radioisotope therapy, and surgery. In Korea, drug therapy is performed preemptively because it is relatively safe and has less burden on patients, but it has the disadvantage of frequent relapse. If severe side effects occur or the treatment effect is low in drug therapy, secondary treatment such as radioisotope or surgery, which has a higher cure rate than drug therapy, is attempted. In this case, when remission is reached, it usually changes to hypothyroidism, so hormone replacement is necessary.
Professor Cho said, “If a patient with hypothyroidism plans to become pregnant, they should consult with the appropriate doctor in charge to check if their thyroid function is appropriate, and during pregnancy, they should increase the dose of hormone medication to match the increased thyroid hormone demand. Hyperthyroidism can also become pregnant if the thyroid function is well controlled with medication, and they should consult with their doctor in advance because they should change to a safer medication.”
If you have a family history of thyroid dysfunction, you should definitely consider the possibility of thyroid dysfunction and get tested. Environmental factors include iodine intake, viral infections, and stress. If you are taking medication for thyroid dysfunction, you should limit excessive iodine intake.
Professor Cho said, “Many young patients with hyperthyroidism skip taking their medication or miss hospital visits due to their busy social lives. Uncontrolled hyperthyroidism increases the risk of cardiovascular complications such as arrhythmia and heart failure by 1.5 to 3 times, so regular hospital visits and consistent medication are important. If you have persistent fatigue or unexplained weight changes, you should consider a thyroid function test.”
2024-08-29 14:20:37