Thyroid hormone replacement after thyroid lobectomy.
BACKGROUND
The purpose of this study was to determine the incidence of and identify risk factors for postoperative hypothyroidism in patients undergoing thyroid lobectomy.


METHODS
We retrospectively reviewed patients who underwent a thyroid lobectomy for benign disease from May 2004 to December 2007. Patients with known hypothyroidism or on preoperative thyroid hormone replacement were excluded.


RESULTS
In this study, 14.3% of patients developed hypothyroidism and required thyroid hormone supplementation. These hypothyroid patients had a higher mean pre-operative thyroid-stimulating hormone (TSH) and lower mean free thyroxine (T4) serum levels compared with euthyroid patients (TSH, 2.12 vs 1.35 microIU/mL [P = .006]; free T4, 1.03 vs 1.34 ng/dL [P = .01]). When stratified into 3 groups based on their preoperative TSH measurement (< or =1.5, 1.51-2.5, and > or =2.51 microIU/mL), the rate of hypothyroidism increased significantly at each level (13.5%, 20.5%, and 41.3%, respectively [P < .001]). In addition, patients with Hashimoto's thyroiditis were significantly more likely to become hypothyroid (odds ratio, 3.78; 95% confidence interval, 2.17-6.60).


CONCLUSIONS
After thyroid lobectomy, approximately 1 in 7 patients experience hypothyroidism requiring thyroid hormone treatment. Patients with preoperative TSH levels >1.5 microIU/mL, lower free T4 levels, and Hashimoto's thyroiditis are at increased risk and should be counseled and followed appropriately.
Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, Madison, WI, USA.
Samantha J
SJ
Stoll
Susan C
SC
Pitt
Jing
J
Liu
Sarah
S
Schaefer
Rebecca S
RS
Sippel
Herbert
H
Chen
D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013963:Thyroid Hormones / Q000097:blood / Q000627:therapeutic use*; D013965:Thyroidectomy
D013963:Thyroid Hormones