A 17-year-old boy had panhypopituitarism, including diabetes insipidus, following treatment for a craniopharyngioma. He was taking appropriate replacement therapy. In the transition clinic, he was keen to continue growth hormone replacement therapy following a 12-month break after reaching final height.
Which is the most appropriate test to assess his growth hormone status?
A . clonidine test
B . growth hormone day profile
C . insulin-like growth factor 1
D . insulin-like growth factor-binding protein 3
E . insulin tolerance test
Answer: C