ESPE Abstracts

Introduction: Patients with hyperinsulinism suffer recurrent and severe hypoglycaemia. Inpatient glucose monitoring is currently via intermittent, infrequent fingerprick self-monitoring blood glucose (SMBG), and risks missing hypoglycaemia between tests. Continuous glucose monitoring (CGM) offers a supplementary therapy which may identify unexpected hypoglycaemia and ultimately reduce total exposure. However, CGM has never been evaluated for its efficacy in the inpatient setting.

Method: During a 12-month period, all patients treated for biochemically confirmed hyperinsulinism as an inpatient at an International Centre of Excellence for hyperinsulinism were identified. Retrospective review of all CGM and SMBG data, as well as electronic hospital record review was undertaken to identify any CGM identified hypoglycaemic (<3.5mmol/L) episode (defined as per American Diabetes Association criteria) that would have been missed by the SMBG routine at the time.

Results: Data was available for five of the seven patients admitted with hyperinsulinism aged from 9days-15years. Blood glucose monitoring ranged from hourly to 6 hourly with increased frequency when hypoglycaemic events were identified to ensure suitable treatment of the hypoglycaemia. CGM data from 146 days were analysed to find a total of 256 hypoglycaemic events (1.8 per patient day). Of these, 87 (34%) were confirmed as true hypoglycaemia (< 3.5mmol/L) on SMBG check (0.6 per patient day). Of these confirmed hypoglycaemias, 54 events were >15 minutes (mean 93, range 15-329) away from a scheduled SMBG. These events (0.4 per patient day) would have thus gone unnoticed and untreated for a total of 209 hours (42 hours per patient). CGM also identified false positives; 171 CGM-identified hypoglycaemia events (1.2 per patient day) were refuted by fSMBG check (glucose ≥3.5mmol/L).

Conclusion: This first description of CGM in the inpatient CHI setting demonstrates utility with CGM identifying an extra true hypoglycaemia episode every three days per patient. Despite data from only five patients, this resulted in an estimated 209 hours of hypoglycaemia that would have been unidentified and untreated even with frequent hospital prescribed SMBG routines, risking significant neuronal damage. While the significant false positive rate will levy a burden on medical staff and families, CGM has the potential to reduce the burden of severe hypoglycaemia in the inpatient setting through targeting of SMBG and timely treatment of unexpected hypoglycaemia.