Effects of high-dose octreotide LAR on glucose metabolism in patients with acromegaly inadequately controlled by conventional somatostatin analog therapy

Objective: In this study, the effect of high-dose octreotide LAR on glucose metabolism in patients with acromegaly was investigated. Design: A post-hoc analysis of a clinical trial enrolling 26 patients with acromegaly not controlled by standard maximal somatostatin analog (SSAs) dose and randomized to receive high-dose (60 mg/28 days) or high-frequency (30 mg/21 days) octreotide i.m. injection (octreotide LAR) for 6 months. Methods: Glucose metabolic status was defined as worsened when a progression from normoglycemia to impaired fasting glucose (IFG) or from IFG to diabetes occurred or when an increase of HbAlc by at least 0.5% was demonstrated. An improvement of glucose metabolism was defined in the presence of a regression from IFG to normoglycemia and/or when HbAlc decreased by at least 0.5%. Results: Glucose metabolic status remained unchanged in a majority of patients (16/26 patients, 65.3%), worsened in six patients, and improved in four patients. Pre-existing metabolic status did not predict worsening of glucose metabolism, which, conversely, was significantly related to persistent biochemical activity of the disease. In fact, patients with worsened glucose metabolism exhibited a less frequent decrease in serum GH and IGF1 levels, compared with patients with improved or unchanged glucose metabolism (2/6 vs 18/20; P=0.01). Conclusion: An increase in octreotide LAR dose or frequency did not impact on glucose metabolism in most patients. Worsening of glucose metabolic status occurred in close relation with persistently uncontrolled acromegaly.