Elevated IGF-1 (314) but low/normal GH

Hi...I am new to this forum..

My endocrine history includes a micro pituitary adenoma, multi-nodular goiter and BPH. During recent workouts my ACTH has been elevated (89) and
IGF-1 (March 304 and last week 314). I had a glucose tolerance test which seems to indicate no acromeagaly (waiting for my MD to interpret but GH value pre-test was 1.5 and came down to .1 during test and ended at .6 at the 2 hour mark. Sugar was 99 pre-test 240 at 1hr, 166 at 90 mins and 111 at 2 hrs. I am curios if there are any opinions on why my IGF-1 is
so high? Thanks for any ideas...