Endocrine Abstracts

JOINT2634

Introduction: Long-acting somatostatin analogues (SSAs), such as Octreotide and Lanreotide remain the main stay of medical management of Neuroendocrine tumours (NETs). SSA use has been observed to impact glucose homeostasis based on results from randomised clinical trials. Although, there are only a limited number of studies which have appraised evidence from real-world clinical practice related to long term impact of SSA on glycaemic control.

Objective: The primary objective of our retrospective observational study was to evaluate impact of long acting SSA on glycosylated haemoglobin (HbA1c) which remains the most commonly used parameter to analyse glycaemic control.

Methodology: By using South Wales NET tertiary clinic electronic data base, we identified all the patients with confirmed diagnosis of NET who were initiated on SSA analogues from year 2014-2024. The NET patients were further sub-divided into 2 sub-groups: with or without Diabetes (prior to initiation of SSA therapy). The baseline clinical and biochemical parameters were recorded with focus on capturing data related to glycaemic control. Changes in body weight, medication dose and/or regimen and HbA1C levels were evaluated post initiation of SSA therapy.

Results: We identified 98 patients (n = 98) with confirmed diagnosis of NET who were initiated on SSA therapy from year 2014-2024. 80 of these NET patients were not known to have diabetes prior to initiation of SSA therapy. It was interesting to note that 12 (15%) out of these 80 NET patients, developed diabetes on long term follow up as evidenced by increase in HbA1C to ≥ 48 mmol/mol (mean HbA1c increase by 10.1 mmol/mol). The mean duration (post SSA initiation) for developing diabetes in this cohort was 27 months. In the other sub-group of 18 patients who were known to have diabetes prior to SSA initiation, 14 were observed to have an increase in HbA1c levels by an average 16.3 mmol/mol. Across the entire cohort, a mean HbA1C increase of 4.1 mmol/mol was documented post-SSA treatment.

Conclusion: Our retrospective observational study data suggests that long term SSA use in patients with NET has a modest detrimental impact on glycaemic control in patients with or without pre-existing diabetes. The sub-group of patients with pre-existing diabetes being initiated on SSA therapy need to be counselled about importance of self-monitoring of blood glucose (SMBG) levels. In case the SBMG readings reflects sub-optimal glycaemic control, a close liaison with primary and secondary care diabetes services can improve clinical outcomes.