Hypothyroidism Not Linked to Cognitive Impairment

Hypothyroidism was not found to be connected to mild cognitive impairment in seniors

(RxWiki News) Hypothyroidism is a condition where your thyroid gland isn’t making enough hormone. This can lead to fatigue, weight gain, and many other symptoms, but according to new research, it may not lead to cognitive impairment.

A recent study found that there was no connection between hypothyroidism and mild cognitive impairment - trouble with memory and thinking, in a group of older adults.

The researchers did find however, that those with mild cognitive impairment tended to be older and less educated.

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This study was led by Ajay K. Parsaik, MD, in the Department of Psychiatry and Behavior Sciences at the University of Texas Medical School. The research team examined whether there was a relationship between hypothyroidism and mild cognitive impairment in a group of older adults in Minnesota.

Hypothyroidism is a condition where the thyroid gland (found in the neck) is not producing enough thyroid hormone which can cause many symptoms including fatigue, weight gain, and muscle weakness.

Data was analyzed from 1904 seniors between the ages of 70-89 in Minnesota.

Mild cognitive impairment was determined using a series of tests that measured memory, thinking skills, and language. The final diagnosis was confirmed by a medical team. Hypothyroidism was also confirmed through medical diagnosis.

Several factors were taken into account that could have influenced mild cognitive impairment including: sex, age, years of education, depression, diabetes, hypertension, stroke or heart attack, and coronary artery disease.

In this study, a total of 316 patients or 59 percent of the study population had mild cognitive impairment.

The researchers found that 313 patients had clinical hypothyroidism and 141 patients had subclinical hypothyroidism. Subclinical hypothyroidism means that patients don’t show any symptoms of the disease but still have lower than normal thyroid hormone levels. Clinical hypothyroidism occurs when patients start experiencing the symptoms of hypothyroidism.

There was no relationship found between subclinical or clinical hypothyroidism and mild cognitive impairment.

The researchers did find, however, that patients who had mild cognitive impairment tended to be older, were less educated, and had a lower body mass index (a measure of height and weight) compared to those without mild cognitive impairment.

The study authors concluded that their findings support previous research that has shown that there is no relationship between hypothyroidism and mild cognitive impairment.

This study was published on December 30 in JAMA Neurology.

Some of the study authors reported potential conflicts of interest with companies including Cephalon, Inc, Allon Pharmaceuticals, and GE Healthcare.

Review Date: 
December 30, 2013