Early postoperative growth hormone measurement as a predictive marker for acromegaly remission

Abstract Growth hormone (GH) has a short half‐life and declines abruptly following somatotropinoma surgery, enabling its prompt measurement as an indicator of surgical success. This study assesses the predictive value of early postoperative GH levels for 3‐month and >1‐year remission of acromegaly. We conducted a retrospective search in our database of patients who had undergone transsphenoidal surgery of GH‐secreting pituitary adenoma from January 2011 to June 2022. Only the patients who underwent the first pituitary surgery and had GH measurements on the fifth postoperative day were included. The 3‐month and >1‐year remission of acromegaly was defined as achieving the GH nadir of <0.4 μg/L during an oral glucose tolerance test and maintaining normal insulin‐like growth factor 1 levels at the initial follow‐up visit 3 months after surgery and throughout at least the first year postoperation. We included 63 patients in the analysis, with a median follow‐up of 51.8 (13–155) months. The 3‐month remission was achieved in 42 (66.7%) patients, and >1‐year remission without additional therapy in 38 (60.3%) patients. Those who achieved >1‐year remission had significantly lower fifth‐day postoperative GH levels (0.59 [0.09–8.92] vs. 2.63 [0.25–24.64] μg/L, p < .001). Receiver‐operating characteristic analysis revealed a significant value of fifth‐day postoperative GH levels regarding the prediction of 3‐month (area under the curve [AUC], 0.834; p < .0001) and >1‐year (AUC, 0.783; p < .0001) acromegaly remission. The GH threshold of ≤1.57 μg/L yielded a sensitivity of 90.5% and a specificity of 71.4% at 3 months and 89.5% sensitivity and 60% specificity at the >1‐year remission, respectively. Notably, all patients with fifth‐day postoperative GH levels ≤0.23 μg/L exhibited remission of acromegaly throughout the follow‐up period. Early postoperative GH measurement could be a reliable predictor of both 3‐month and >1‐year remission of acromegaly.