Does treatment of hypothyroidism lead to weight loss?

In "Weight Change after Treatment of Hypothyroidism," SY Lee, LE Braverman, and EN Pearce describe the retrospective review of patients with newly diagnosed primary hypothyroidism over an 8-year period, not caused by thyroid cancer or other forms of disease or associated with pregnancy or use of prescription weight loss medication.

About half (52%) of the patients lost weight up to 24 months after initiation of treatment with LT4. Overall, weight loss was modest, with a mean weight loss of 8.4 + 9.7 lbs.

"Because obesity and hypothyroidism are very common, there are many patients who have both conditions," says Ronald J. Koenig, M.D., Ph.D, Program Committee Co-Chair, and Professor, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor. "These patients (and sometimes their physicians) often assume the hypothyroidism is causing the obesity even though this may not be the case. This study is important because it shows, unfortunately, that only about half of hypothyroid patients lose weight after the successful treatment of their hypothyroidism. It will be interesting and important to have follow up data to know whether the patients that lose weight are the ones most in need of weight loss, and to know how significantly their weight loss contributed toward achieving a normal body weight."