The Preoperative Paradoxical GH Response to Oral Glucose Load Predicts a low Risk of Recurrence in Acromegaly.

Abstract

a paradoxical growth hormone (GH) response to oral glucose load (OGTT) in acromegaly is associated with a milder phenotype. To study whether the GH response to OGTT predicts the risk of recurrence after initial surgical cure. Retrospective, observational study. Two tertiary care centers. We investigated 254 patients with acromegaly who were cured by surgery. All patients underwent OGTT at diagnosis before pituitary surgery. A peak-to-basal GH ratio ≥ 120% within 90 minutes was used to distinguish paradoxical (GH-Par) from non-paradoxical acromegalic patients (GH-NPar). Cox analysis was used to investigate whether the paradoxical GH response to OGTT was associated with the risk of disease recurrence. A paradoxical GH response to OGTT occurred in 87 patients (34.3%, termed GH-Par group). Recurrence of acromegaly occurred in three patients of the GH-Par group (3.4%) and in 20 patients in the GH-NPar group (12.0%). In the multivariate analysis, the paradoxical GH response to OGTT was significantly associated with the risk of recurrence (HR 0.18, 95% CI, 0.05-0.63; P = 0.007). Basal GH level at diagnosis was the only other variable associated with the risk of disease recurrence (HR 1.58, 95% CI, 1.01-2.47; P = 0.04). our study demonstrates that a paradoxical GH response to OGTT in the preoperative setting predicts a lower risk of disease recurrence after initial surgical cure. The pattern of GH responsiveness to OGTT is, therefore, useful to predict the long-term outcome of patients with acromegaly.