Ladies – Check Your Thyroid Function!

Thyroid glands may be overactive (hyperthyroidism) or underactive (hypothyroidism). Overactivity is characterized by sudden loss in weight, a rapid or irregular heartbeat, excess sweating, and nervousness or irritability; underactivity, on the other hand, can cause obesity, joint pain, infertility and heart disease, among other effects. However, both an over- and underactive thyroid can cause reversible dementia. Because of this, Boston researchers examined the possible relationship between thyroids with slightly altered activity – not enough to cause clinical symptoms – and the risk of developing Alzheimer’s disease. Their report is published in the Archives of internal Medicine.

Participants in the Framingham Heart Study who had no clinical symptoms or signs of a thyroid disorder had their serum thyrotropin measured at baseline as an indicator of the gland’s activity. They were classified into three categories according to their thyrotropin levels – below 1.0 mIU/L, 1.0 to 2.0 mIU/L, and above 2.0 mIU/L. During the follow-up, which averaged 12½ years, 209 participants developed Alzheimer’s (142 of them were women).

Women in the lowest thyrotropin group were 2.4 times as likely to develop Alzheimer’s as those in the middle group. And women in the top thyrotropin group were 2.2 times as likely to develop it as those in the middle group. There was no evidence of similar findings in the male participants. Some of the subjects were taking thyroid supplements, but excluding them from the analyses didn’t change anything.

The researchers conclude: “Low and high thyrotropin levels were associated with increased risk of incident Alzheimer’s disease in women but not in men.” Hence my advice to women to ensure their thyrotropin levels are in the absolute middle of the range – between 1.0 and 2.0 mIU/L. As this study showed, getting thyroid function under control with medication reduced the likelihood of developing Alzheimer’s.