Roughly 20 million Americans have some form of thyroid disease.
New Johns Hopkins research shows the medicine to treat it increases the risk of dementia.
"Hypothyroidism is very common, it is among the most common prescriptions, it's not clear though that everyone that is put on thyroid hormone actually has hypothyroidism,” said Dr. Jennifer Mammen who is the Assistant Professor of Medicine at Johns Hopkins University School of Medicine and the study’s senior author.
A new study from Johns Hopkins medicine raises concern that excess thyroid hormone levels might be contributing to the risk of dementia in older adults.
"We already knew that atrial fibrillation and low bone density were associated with higher level of thyroid hormone and thyroid hormone access, this just adds a third potential risk,” said Mammen.
She said when someone has thyroid issues, it can either be over active or under active
"When the thyroid is under active you get treated with thyroid hormone and if you're over treated with thyroid hormone, that actually turns into the opposite situation of over active or excess thyroid hormone,” said Mammen.
65 thousand participants were used in the study. Selected from a Johns Hopkins medicine electronic health records database.
"Richman Center for Precision Medicine at Johns Hopkins has created a data set that includes patients 65 and older,” said Mammen.
These were patients that received care at Johns Hopkins between January 1, 2014 and May 6, 2023. She said they found that people who were over treated with the thyroid hormone were being diagnosed at a high rate.
"Our hypothesis that it contributes to dementia is that dementia is an inflammatory disease and it's a driven by the damage of inflammation,” said Mammen. “By driving higher rates of metabolism in an inflammatory condition you can speed up that inflammatory process.”
Mammen said as we get older our requirements for the thyroid goes down.
"Each pill lasts longer in our system and so a dose that might have worked for you when you were 50 is no longer the dose you need when you're 70,” said Mammen.
That's why she said those with low levels require monitoring on an annual bases and the doses need to be adjusted.
