The Effect of Growth Hormone-Secreting Pituitary Adenoma Disease Activity on Thyroid Nodules.

Objective: Previous studies on thyroid nodules in patients with growth hormone-secreting pituitary adenoma (GHPA) had small sample sizes and inconsistent findings. This study aims to summarize the clinical characteristics of thyroid nodules in patients with GHPA, investigate the relationship between thyroid nodule volume and disease activity, and analyze risk factors associated with thyroid nodule development.

Methods: There were 150 patients with GHPA included from a retrospective review of medical records from January 2009 to December 2024. At baseline, correlations were investigated between growth hormone (GH), insulin-like growth factor-1 (IGF-1), thyroid-stimulating hormone (TSH) with maximum thyroid nodule diameter (TND) and total thyroid nodule volume (TTNV). A binary logistic regression analysis was used to explore the risk factors for the development of thyroid nodules in patients with GHPA. Data from 54 patients were available for longitudinal follow-up measures of thyroid nodule characteristics between baseline and last follow-up.

Results: The prevalence of thyroid nodules in patients with GHPA was 74%. Baseline TND and TTNV were positively correlated with age and IGF-1 levels and negatively correlated with TSH levels. Patients with thyroid nodules exhibited higher GH levels. During prospective follow-up, TND significantly decreased following a marked reduction in GH/IGF-1 levels. Logistic regression analysis identified baseline GH level as an independent risk factor for thyroid nodule occurrence.

Conclusion: Chronic elevation of GH/IGF-1 levels in patients with GHPA is associated with the development and progression of thyroid nodules. Following treatment of GHPA, a reduction in GH/IGF-1 levels correlates with a decrease in thyroid nodule volume. Close monitoring of nodule growth and regular thyroid ultrasonography are recommended, particularly for nodules with malignant features.