The insulin tolerance test (ITT) is considered the gold standard for assessment of GH and ACTH reserve in patients with pituitary disease following pituitary surgery and is usually performed after 6–12 weeks.
Berg et al. conducted a study to evaluate dynamic testing 3 and 12 months after transsphenoidal pituitary surgery. Serial dynamic testing was performed in 36 patients (13 women, age 18–78) at 3 and 12 months after transsphenoidal surgery.
They found that there was a significant increase in median GH and cortisol peak levels during ITT after l2 months compared with the 3-month results. This is the first study showing that in the late-postoperative phase after pituitary surgery, there is ongoing recovery of pituitary function demonstrated by a significant improvement of GH and cortisol peak levels in ITT during follow-up. They found that dynamic re-testing at 12 months after pituitary surgery in comparison to a single ITT at 3 months detects a recovery from ACTH and GH insufficiency, in each by 11%. Berg et al. (2010), European Journal of Endocrinology 162.
Read the full article at: DOI: 10.1530/EJE-09-0997