A new study from Johns Hopkins Medicine has found that having too much thyroid hormone in the body can increase the risk of developing cognitive problems in older adults. This condition, known as thyrotoxicosis, can happen in two ways.
It can be caused by taking too much thyroid medication, which is called exogenous thyrotoxicosis. It can also result from thyroid diseases like hyperthyroidism or Graves’ disease, known as endogenous thyrotoxicosis.
Thyroid hormones are very important for controlling many functions in the body, such as metabolism, heart rate, and body temperature. However, when there is too much of this hormone, it can cause health problems, including issues with memory and thinking.
While past research hinted at a link between high thyroid hormone levels and memory loss or confusion, the evidence was not strong, and many studies did not look at people who were taking too much thyroid medicine.
To understand this better, researchers at Johns Hopkins looked at medical records from 65,931 seniors who received care at their health system between 2014 and 2023.
All participants were 65 years or older, with an average starting age of 71, and they had visited their primary care doctor at least twice with more than 30 days between visits. This allowed the researchers to track their health changes over time.
The study found that people with thyrotoxicosis had a 39% higher chance of being diagnosed with cognitive problems compared to those without thyroid issues. This increased risk was seen in all age groups and in both types of thyrotoxicosis—whether it was caused by too much medication or by thyroid disease.
The findings became even clearer when looking at different age groups. By the age of 75, about 11% of those with thyrotoxicosis had been diagnosed with a cognitive disorder, like dementia or memory loss.
In comparison, only 6.4% of people without thyrotoxicosis were diagnosed with these issues. The gap grew wider with age. By 85, 34% of people with thyrotoxicosis had cognitive problems, while 26% of those without the condition did.
The study also showed that the risk of memory and thinking problems got worse with higher levels of thyroid hormone. People with severe thyroid hormone excess had a 65% higher risk of cognitive issues. Even those with moderate excess faced a 23% higher risk compared to people with normal thyroid hormone levels.
These findings are important for doctors who prescribe thyroid hormone treatments to older adults. Taking too much thyroid medication can accidentally cause thyrotoxicosis, increasing the risk of cognitive decline.
The researchers suggest that doctors need to be very careful when adjusting thyroid hormone doses for seniors. Following age-specific treatment guidelines can help reduce the chances of memory and thinking problems.
The study also highlights the need for regular monitoring of thyroid levels in older adults. By keeping thyroid hormones in the right range, doctors might help prevent cognitive problems as people age. This is especially important because memory loss and confusion can greatly affect the quality of life and independence of older people.
The full details of this research were published in JAMA Internal Medicine. The study provides new insight into how hormone levels in the body can affect brain health as people get older. It also calls for more research to understand how best to treat thyroid problems in seniors without increasing the risk of cognitive decline.
Overall, this study serves as a reminder of how important it is to carefully manage hormone levels, especially in older adults, to maintain both physical and mental health.
If you care about dementia, please read studies that eating apples and tea could keep dementia at bay, and Olive oil: a daily dose for better brain health.
For more health information, please see recent studies what you eat together may affect your dementia risk, and time-restricted eating: a simple way to fight aging and cancer.
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