Weight gain after hyperthyroid treatment drives concerns
The findings are important because weight gain associated with hyperthyroidism treatment is no small matter for many patients, even prompting a lack of adherence to therapy for some, despite its importance, Dr. Boelaert noted.
“Since the majority of patients lose weight as a consequence of being hyperthyroid, it can be expected that they will at least regain the lost weight and possibly even have a weight overshoot,” she explained. “Indeed, many patients are reluctant to accept definitive treatment with surgery or radioiodine out of fear of weight gain.”
“This may cause difficulties to some patients who occasionally may even stop taking antithyroid drugs to prevent this weight regain. Such lack of adherence may have dire consequences and is likely a contributing factor to the increased mortality in these patients,” she observed.
In a previous study of 1,373 patients, Dr. Boelaert and colleagues found that men treated for hyperthyroidism gained an average of 8.0 kg (17.6 lb), and women gained an average of 5.5 kg (12.1 lb).
Compared with the background population, men were significantly more likely to gain weight over the study period (odds ratio, 1.7; P < .001) as were women (OR, 1.3; P < .001). Also in that study, radioiodine was associated with greater weight gain (0.6 kg; P < .001), compared with antithyroid drug treatment alone.
Dr. Russell added that even when weight gain does occur, the payoff of having treated the potentially serious state of hyperthyroidism is a highly beneficial trade-off.
Ultimately, “the goal of treating any patient with Graves’ should be to get them to become hypothyroid as quickly as possible,” he said. “Patients have options, and all of these options can be safe in the right situation.”
“It is unrealistic to think that going from a hyperthyroid state to a low thyroid state will not result in weight gain for many patients,” Dr. Russell added. “But the key point is that overall health is better despite this weight gain.”
Dr. Boelaert has disclosed consulting fees paid to the University of Birmingham by Lilly and Eisai. Dr. Russell has reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.