What are the recommendations for checking the growth hormone levels after surgery for acromegaly?

Following surgery, it is suggested measuring an IGF-1 level and a random GH at 12 weeks or later. It also suggests measuring a nadir GH level after a glucose load in a patient with a GH greater than 1 mg/L. Although GH testing may be performed as early as postoperative day 1, the role of an immediate postoperative GH value may be limited, because an elevated value may reflect surgical stress with normal somatotroph GH production. The decline in IGF-1 is more delayed compared with GH, likely due to differential half-life of IGF-binding proteins. If the IGF-1 level has declined but is still not normal, measurement of a repeat IGF-1 level is warranted due to variability in the IGF-1 assay. Serum IGF-1 levels should be repeated at 12 weeks after surgery and a normal level suggests surgical cure but if the levels do not show a normal value post 12 weeks then a repeat level should be checked again at 9–11 weeks to check for a delayed normalization of values. The fallacy of IGF-1 level ranges not being the same in different population subsets and lack of normative data for our population has to be kept in mind when interpreting the results of IGF-1.