Levothyroxine, a synthetic thyroid hormone, is one of the most prescribed medications in the United States, consistently ranking among the top three over the past decade. This highlights how common thyroid disorders are.
At the same time, heart disease remains the leading cause of death in the U.S., affecting nearly half of adults aged 20 and older. A recent study from the University of Michigan reveals a concerning connection between thyroid hormone treatment intensity and an increased risk of heart-related deaths.
Thyroid hormone therapy is commonly used to manage conditions like hypothyroidism, where the thyroid gland doesn’t produce enough hormones. However, the treatment can sometimes lead to abnormal levels of thyrotropin (TSH), a hormone that helps regulate thyroid function.
When TSH levels are too low, it can cause exogenous hyperthyroidism, and when too high, it can cause hypothyroidism. Both conditions can strain the heart.
The study, led by Dr. Maria Papaleontiou and published in JAMA Network Open, analyzed data from over 705,000 U.S. veterans who underwent thyroid hormone therapy between 2004 and 2017.
The researchers discovered that up to half of these patients had abnormal TSH levels, either too low or too high. This group was found to have a higher risk of heart-related deaths compared to those with normal TSH levels, known as euthyroidism.
Particularly concerning were patients with TSH levels below 0.1 mIU/L or above 20 mIU/L, as these extremes were associated with the greatest risk. Older patients were especially vulnerable to these adverse effects, emphasizing the need for careful management of thyroid hormone therapy in this population.
The study also excluded certain patients to ensure accurate results. Those with a history of thyroid cancer were not included because low TSH levels are often deliberately maintained in such cases to prevent cancer recurrence.
Additionally, individuals taking medications like lithium or amiodarone, which can affect thyroid function, were excluded.
The findings suggest that the intensity of thyroid hormone treatment is a modifiable risk factor for heart disease. Monitoring and maintaining normal TSH levels could significantly reduce the risk of heart-related deaths in patients receiving thyroid hormone therapy.
This highlights the importance of personalized treatment plans and regular monitoring, especially for older adults.
Heart health and thyroid management are closely linked, and this study underscores the importance of finding a balance in treatment. Over-treatment and under-treatment can both have serious consequences, so maintaining stable thyroid levels is crucial.
For those concerned about heart health, related studies have explored dietary factors and supplements. For instance, eating eggs has been linked to a reduced risk of heart disease, while certain herbal supplements may harm heart rhythm.
Other research shows that Vitamin C, but not Vitamin E, may lower the risk of heart failure, and drinking espresso coffee could influence cholesterol levels.
This research adds to the growing understanding of how interconnected the thyroid and heart are. By focusing on optimal treatment strategies, healthcare providers can better protect patients from preventable heart complications.
If you care about heart health, please read studies that vitamin K helps cut heart disease risk by a third, and a year of exercise reversed worrisome heart failure.
For more health information, please see recent studies about supplements that could help prevent heart disease, stroke, and results showing this food ingredient may strongly increase heart disease death risk.
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