Iodine therapy for thyroidectomy patients exhibiting high thyroid-stimulating hormone values: a randomised study

Area of Science:

• Endocrinology
• Thyroid Surgery
• Nutritional Science

Background:

• Post-thyroidectomy hypothyroidism is a common complication.
• Iodine's effect on thyroid function varies with dosage; pharmacological doses suppress, while physiological doses have mixed effects.
• The role of iodine supplementation in preventing post-surgical hypothyroidism requires clarification.

Purpose of the Study:

• To assess the efficacy of iodine supplementation in preventing hypothyroidism after thyroidectomy.
• To investigate the impact of a 1 mg daily iodine supplement on thyroid remnant function recovery.

Main Methods:

• A prospective randomized trial involving 55 patients with elevated TSH (> 6 mU/l) one month post-thyroidectomy.
• Patients received either a placebo or 1 mg of iodine daily for 20 weeks.
• Thyroid function was assessed using free thyroxine index (FT4I) and TSH levels.

Main Results:

• In patients undergoing bilateral subtotal thyroidectomy, 62% were euthyroid at 6 months without thyroid replacement in the placebo group.
• Conversely, all patients receiving 1 mg of iodine daily became hypothyroid.
• Iodine supplementation significantly delayed the recovery of thyroid remnant function after bilateral subtotal thyroidectomy.

Conclusions:

• A daily supplement of 1 mg of iodine can delay the recovery of thyroid remnant function following bilateral subtotal thyroidectomy.
• Iodine supplementation may exacerbate or induce hypothyroidism in patients after thyroid surgery.
• Caution is advised regarding iodine supplementation in the post-thyroidectomy period.