Weight Gain: Thyroid Gland to Blame?
Even Low-Normal Thyroid Function Could Tip the Scales, Study Shows
Results: Thyroid and Weight
"If TSH increased over time, weight was more likely to go up," Fox tells WebMD. They divided the patients into four groups, from those whose TSH increased the least to those whose TSH increased the most. "Women whose TSH changed the most gained 2.3 kilograms [about 5 pounds on average]." Some gained more.
A similar pattern was found in men, she says, although the increases were less. The men whose TSH increased the most gained on average 1.3 kilograms or nearly 3 pounds over the three-and-a-half-year follow-up.
The study, along with the other two recent reports about the association, provide interesting information, says Roy E. Weiss, MD, PhD, the Rabbi Morris Esformes professor of adult and pediatric endocrinology, diabetes, and metabolism at the University of Chicago Medical Center. He co-authored an editorial to accompany the study.
"What may be within the normal range [of thyroid functioning] for a population may not be the normal thyroid levels for a particular individual," he tells WebMD.
But much more needs to be learned, he says. In short: "It may be your thyroid [associated with your weight gain], but there is nothing we can do about it at this point." It would be premature, he says, to recommend thyroid hormone treatment.
Next Steps: Thyroid and Weight
The findings need to be duplicated in still other studies, Fox agrees. "The Framingham subjects are mostly white. It would be important to see if [this finding] applies to other ethnicities."
Agrees Ramachandran S. Vasan, MD, another co-author of the new study and a professor of medicine at Boston University: "While we show an association, we can't claim cause and effect."
Worth a Trip to the Doc?
While it may be tempting to blame the thyroid when weight increases, weight gain has many causes, Fox says.
"If people feel they have gained an excessive amount of weight they should discuss with their physicians whether thyroid function testing is indicated," she says.