Endocrine Abstracts

Background: Pasireotide LAR is a multireceptor targeted somatostatin analogue that has been shown to obtain a better biochemical control of acromegaly. However, pasireotide LAR could induce hyperglycemia in acromegalic patients with higher baseline glucose values. The devices that can track interstitial glucose levels such as continuous glucose monitoring (CGM) could be a useful for studying the impact of SSA on patients’ glucose status.

Aim: We aimed to study the glucose metabolism with CGM in a group of acromegalic patients during first generation SSA treatment before pasireotide LAR start.

Methods: We studied 10 patients with uncontrolled acromegaly (Male 5; median age 58y) in therapy with first generation SSA eligible for the treatment with pasireotide. At pasireotide start (T0) we performed a CGM of 9 days to investigate the glycemic variability (J whole, GRADE, MAGE, CONGA). We also collected endocrinological and metabolic data (GH, IGF 1, fasting plasma glucose -FPG-, HbA1c) at T0 and after at least 3 months of therapy (T1).

Results: Analysis of the data, revealed a significant decrease in GH (T0 2.06 vs T1 1.02 ug/L, P 0.01) and in IGF1 (T0 275.5 vs T1 193.5 ug/L, p=NS) after treatment with pasireotide, with a median treatment duration of 9 months. There was also a significant increase in FPG and HbA1c (FPG T0 97 vs T1 124 mg/dL, P 0.01; HbA1c T0 41.5 vs T1 44.5 mmol/mol, P 0.01) At T0, 5 patients (50%) had glycemic alterations: 2 patients had diabetes mellitus (DM) in therapy with metformin and 3 patients had an impaired fasting glucose (IFG). At T1, 5 patients (50%) received antidiabetic medications and among this 60% started antidiabetic treatment after T0. Patients with FPG>100 mg/dl at T0 showed higher glucose variability for most important CGM-based variability indexes (FPG <100 vs FPG >100: J whole 17.3 vs 25,2 P< 0.03, GRADE 2 vs 4 P <0.03, MAGE 54.7 vs 96.1 P < 0.01, CONGA1h 12.8 vs 28.3 P< 0,03).One patient discontinued the drug due to severe hyperglycemia (>500 mg/dl). At T1 there were no significant correlations between HbA1c/FPG and glycemic indexes.

Conclusions: We confirm the efficacy of pasireotide and the effect on glucose metabolism. For the first time in literature we found higher glycemic variability indexes in acromegalic patients with known alterations of glucose metabolism. Further studies are needed to determine the role of CGM in acromegalic patients on pasireotide treatment.