Recombinant Human Thyrotropin Reducing Insulin Resistance in Patients with Differentiated Thyroid Cancer

Context Postsurgical radioactive iodine (RAI) therapy is indicated for adults with differentiated thyroid cancer (DTC) who are at an intermediate-to-high risk of recurrence. Thyrotropin (TSH) stimulation to facilitate RAI uptake can be achieved by injection of recombinant human TSH (rhTSH) or thyroid hormone withdrawal (THW). Objective This study aimed to compare the effects of rhTSH administration and THW programs on insulin resistance. Methods This prospective observational study included 47 patients who received rhTSH injections and 29 patients who underwent THW. All participants underwent a baseline assessment 4 weeks before RAI administration and a follow-up assessment on the day of RAI administration. Blood samples were collected for laboratory analysis, and insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR). Results HOMA-IR significantly decreased after rhTSH administration (from 1.5 [0.8, 1.7] to 1.1 [0.7, 1.4], P = 0.004) and after THW (from 1.4 [0.9, 1.7] to 0.7 [0.5, 1.0], P < 0.001). These changes in HOMA-IR were not significantly different between the rhTSH and THW groups (-0.3 [-0.8, 0.2] vs. -0.5 [-1.1, -0.2], P = 0.120). Logistic regression analysis identified a greater reduction in triglyceride levels (the decrease ≥0.028 mmol/L) as an independent factor for HOMA-IR reduction (the decrease ≥0.4) in the rhTSH group (odds ratio = 6.064, 95% confidence interval: 1.428–25.757, P = 0.015). Conclusion The rhTSH administration program attenuates insulin resistance in patients with DTC. The magnitude of HOMA-IR reduction in the rhTSH administration program is not significantly different from that in the THW program. (Clinical trial registration: ClinicalTrials.gov ID: NCT03624751; https://clinicaltrials.gov/study/NCT03624751).