Endocrine Abstracts

Introduction: Papillary thyroid carcinoma (PTC) is a common thyroid gland malignancy. Postoperative suppression therapy with levothyroxine (LT4) is commonly used to prevent recurrence or progression of the disease. The optimal duration and dose of LT4 suppression therapy remain a matter of debate. The optimal duration and dose of LT4 suppression therapy remain a matter of debate, with recommendations varying based on the patient’s age, sex, tumor characteristics, and risk of recurrence. Therefore, it is important to balance the potential benefits of LT4 suppression therapy against the risks of adverse effects when deciding on the duration and dose of therapy for each patient.

Case Report: We present a case of a 32-year-old male patient who underwent total thyroidectomy after detecting PTC. The patient was evaluated as a low-risk patient by the ATA risk stratification system to estimate the risk of recurrent thyroid tumor. He had been on LT4 suppression therapy with a stable dose of 250 mg daily after the surgery. Physical examination revealed a body mass index (BMI) of 40.56 kg/m², blood pressure of 140/90mmHg, and a heart rate of 98bpm. Laboratory investigations showed elevated levels of serum TSH (9.2mIU/l) and undetectable levels of Thyroglobulin (TG) and Anti-thyroid peroxidase (anti-TPO) antibodies. The patient was administered an increased LT4 dose (275 mg), after which he experienced more severe tachycardia (105-110bpm) despite taking the prescribed beta-blocker medicine. We implemented a weight loss plan for the patient, involving modifications to his diet and an exercise regimen. At 6 months follow-up, the patient had lost 18 kg of weight, and his BMI had decreased to 34.47 kg/m2. His blood pressure and heart rate had also improved. Lab tests showed normal serum levels of TSH (1.5mIU/l) and undetectable TG, anti-TPO levels. The patient was encouraged to continue the weight loss plan and advised to reduce his LT4 dose to 175/200 mg daily, with close monitoring of TSH, TG, anti-TPO.

Conclusion: The use of TSH suppressive therapy should merit careful consideration since it carries an increased risk of complications. Individualized treatment should be based on patient characteristics and risk stratification. While LT4 suppression therapy can be effective in preventing the growth of residual or recurrent thyroid tissue, it can lead to adverse effects, particularly in patients with pre-existing obesity. Thus, we should consider whether the patient benefits more from TSH suppression therapy or an individualized approach to reach even subclinical hypothyroid status, taking into account the low risk of disease recurrence and comorbidities. Lifestyle modifications, including dietary changes and physical activity, should also be implemented as part of the management of obesity and hypothyroidism.