cancer, 23 were chosen for this study, because they had a cancer that was considered early stage and low risk, and as such, they needed to maintain slightly higher than normal blood levels of thyroid hormone for at least one year after the surgery. After their treatment was completed, the patients were given the same dose they were on before the surgery and their labs were checked regularly. The doses were adjusted as needed to achieve the same blood level as they had before the surgery.
Despite the fact that patient’s weight and dose was identical before and after surgery, only 2 out of the 23 patients reached a blood level that was similar to their level before surgery without requiring a dose increase. In the remaining 21 patients, the dose needed to be substantially increased in order to be at goal. After 1 year, the patient’s average dose was 30% higher than before the surgery. Despite the increase in dose to get the TSH level to the intended level, the levels of the T3 and T4 hormones did not change significantly.
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study suggests that the thyroid itself may contribute up to 30% of a patient’s levothyroxine requirements. This study also helps to clarify the change in dose needed when a patient with hypothyroidism undergoes a thyroidectomy. This study is important to patients because it adds to the information available regarding adjusting thyroid hormone levels in patients with hypothryoidism. More studies are needed to help us understand why these changes happen so that treatment can be potentially further improved.
—Jessie Block-Galarza, MD
ATA THYROID BROCHURE LINKS
Hypothyroidism: http://www.thyroid.org/hypothyroidism
Thyroid cancer: http://www.thyroid.org/cancer-of-the-thyroid/