This article is more than 5 years old. Information may no longer be current.
TSH levels may predict postoperative hypothyroidism
Click Here to Manage Email Alerts
Monitoring of preoperative and postoperative thyroid-stimulating hormone levels in adults with papillary thyroid carcinoma may help predict which adults will develop postoperative hypothyroidism, study findings show.
Won Gu Kim, MD, PhD, of the department of internal medicine, Asan Medical Center, University of Ulsan College of Medicine in Korea, and colleagues evaluated data from 335 adults (mean age, 47.9 years; 79.4% women) with papillary thyroid carcinoma who underwent lobectomy and were followed up without levothyroxine treatment at Asan Medical Center between 2008 and 2011. Researchers sought to determine the incidence and risk factors of postoperative hypothyroidism to develop a surveillance strategy. Follow-up was a median 56.2 months. Three participants experienced recurrence of papillary thyroid carcinoma through follow-up.
Overall, 64.2% of participants experienced postoperative hypothyroidism; five had overt and 210 had subclinical disease. Postoperative levothyroxine replacement was required by 11.9% of participants.
Initial hypothyroidism developed during a median time interval of 3.98 months. Hypothyroidism developed within 12 months after surgery in 67.4% of participants (early hypothyroidism), and 32.6% developed hypothyroidism after 12 months (late hypothyroidism). Participants with early hypothyroidism had higher preoperative TSH levels (P = .001) and more were thyroid peroxidase autoantibody positive (P = .03) compared with participants with late hypothyroidism.
At 1 year after surgery, 56.7% of participants did not experience hypothyroidism and remained euthyroid.
The development of late hypothyroidism was associated with high postoperative 1-year TSH level (> 3.1 mIU/L; P < .001) and remained significant after adjustment for age and sex.
Of participants with subclinical hypothyroidism who did not receive levothyroxine replacement during follow-up, 68% recovered to euthyroidism. Nearly half (47.4%) recovered within 2 years after development of hypothyroidism. Sustained hypothyroidism was associated with high preoperative TSH level (> 1.7 mIU/L; P = .01) and high postoperative maximal serum TSH level (> 7.1 mIU/L; P < .001).
“These findings highlight the significance of evaluating hypothyroidism risk by preoperative and postoperative serum TSH values to determine the follow-up interval for thyroid-function tests in patients undergoing lobectomy,” the researchers wrote. “Mild postoperative subclinical hypothyroidism might be followed up without immediate levothyroxine replacement with the expectancy of recovery.” – by Amber Cox
Disclosure: The researchers report no relevant financial disclosures.
Click Here to Manage Email Alerts