Hypothyroid disorders — especially those that require treatment with medication — are linked to dementia, a new study finds.
Hypothyroidism occurs when the thyroid gland is underactive, causing slow metabolism and causing tiredness, weight gain and sensitivity to cold.
To study the link between dementia and this condition, researchers looked at the health records of more than 7,800 people newly diagnosed with dementia in Taiwan. The data was compared to that of a matched control group without dementia.
Adults aged 65 and older with a history of hypothyroidism had an 81% increased relative risk of having dementia, they found. What’s more, patients who required thyroid hormone replacement treatment had more than three-fold increased odds of dementia. Results were adjusted for dementia risk factors such as sex, age, high blood pressure and diabetes.
The dementia-hypothyroidism link was not found among study participants younger than age 65, they noted.
The findings must be confirmed in future studies, but clinicians and patients should be aware of thyroid problems as a possible risk factor for dementia, said study author Chien-Hsiang Weng, MD, MPH, of Brown University.
He also suggested that clinicians be on the lookout for possible therapies that “could prevent or slow irreversible cognitive decline.” There are cases where dementia symptoms were reversed after the patient was treated for hypothyroidism, for example, the investigators noted.
The study was published in the journal Neurology.
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