Endocrine Abstracts

A 6-hour octreotide suppression test (OST) is useful in the selection of patients with acromegaly for chronic somatostatin depot analogues treatment. However, it is time consuming and that brings inconvenience to patients. We aim to simplify the blood sampling of OST, and determine the reliability of a short version of the classic 6-hour OST. The data provided in the supplementary tables of the primary manuscript were used to re-analyze the efficacies of the simplified OST tests. SPSS Software Version 25 was used for data analyses. To find the best receiver operating characteristic (ROC) curve, several analysis of the shorten-test (including 2-hour, 3-hour, 4-hour and, 6-hour’s tests) were performed, and compared the parameters of ROC with that of 2-day’s examination to find a proper shorten test period. After calculating, ΔGH (0–3 h) more than 80.51% and 91.84% provided the best predictors of a good GH response (sensitivity 96.9%, specificity 85.7%) and a good IGF-1 response (sensitivity 86.7%, specificity 81.3%). ΔAUC (0–3 h) more than 71.07% provided the best predictor of a good tumor size response (sensitivity 81.8%, specificity 90.6%). From these results, we conclude that OST could be simplified as the 3-hour measurements. The ΔGH (0–3 h) is the best optimistic parameter to predict a good GH, or IGF-1, response, while the ΔAUC (0–3 h) is the best for a good tumor size response to short-term efficacy of SSA in acromegaly.

Keywords: acromegaly, somatostatin analogues, remission prediction, octreotide suppression test.