Is getting your thyroid hormone measured once a year as you age enough? Elizabeth Tracey reports


People who are taking thyroid hormone should get their blood tested once a year or so just to make sure they’re not taking too much, since a recent Johns Hopkins study shows that’s associated with an increased risk for dementia. Jennifer Mammen, an endocrinologist and one of the study’s authors, explains why.

Mammen: It turns out that thyroid hormone is very long acting the half life is over a week and usually the levels don't change over the course of months. And so typically a once a year check is fine but as we get older our metabolisms change. When women go through menopause for example that's a time of a big shift in hormone metabolism and thyroid hormone tends to last a lot longer as our metabolisms shift. As our muscle mass falls that's another reason why we might need a lower dose of thyroid hormone.  :33

Medical labs throughout the country are adept at making these measurements, Mammen says. At Johns Hopkins, I’m Elizabeth Tracey.