Decrease in acromegaly-associated thyroid enlargement after normalization of igf-1 levels: A prospective observation and in vitro study

Abstract

Objective: Goiter occurs at high frequency in acromegaly patients. Whether normalization of insulin-like growth factor 1 (IGF-1) levels could decrease goiter and thyroid volume remains unclear. Methods: Thyroid hormone levels and ultrasound measurements were assessed in 101 acromegaly patients, compared with 108 patients with nonfunctioning pituitary adenoma (NFPA) and 55 healthy controls. Thirtyfour acromegaly patients underwent repeat evaluation 1 year post-transsphenoidal surgery. The effect of IGF-1 on thyroid cell proliferation, cell cycle, and apoptosis was evaluated in vitro. Results: Acromegaly patients showed larger thyroid volume than those with NFPAs (18.32 mL vs. 9.91 mL; P