Continuous glucose monitors reduce hypoglycemia in adults with type 1 DM and hypoglycemia unawareness (HypoDE)

Reference

Heinemann L, Freckmann G, Ehrmann D, et al. Real-time continuous glucose monitoring in adults with type 1 diabetes and impaired hypoglycaemia awareness or severe hypoglycaemia treated with multiple daily insulin injections (HypoDE): a multicentre, randomised controlled trial. Lancet 2018;391(10128):1367-1377.

Synopsis

The Hypoglycemia in Deutschland (HypoDE) study recruited adults with type 1 diabetes who either had a lack of awareness of their hypoglycemic reactions or had had severe hypoglycemia requiring third-party intervention in the previous year. All patients participated in a run-in phase of at least 4 weeks in which they wore a masked continuous glucose monitor (CGM). At the end of the run-in period, the researchers randomized those who wore the CGMs at least 85% of the time to wear the CGM (n = 75) or to capillary blood glucose testing (n = 74). Both groups used their respective glucose monitoring approaches to make insulin-dosing decisions. At the end of 6 months, the control patients wore the CGMs again for 4 weeks. This allowed the researchers to assess the frequency of hypoglycemic events unobtrusively (recall these are patients who had difficulty sensing their events). They compared the frequency of hypoglycemia during the run-in period and the follow-up period. They defined hypoglycemia as episodes lasting at least 20 minutes in which the glucose level was 3.0 mmol/L (54 mg/dL) or lower as long as these were preceded by at least 30 minutes of higher values. During the baseline 4-week period the CGM patients experienced 10.8 hypoglycemic events compared with 14.4 events for the control patients. At the end of the study, the rates decreased to 3.5 and 13.7, respectively. At the end of the study, 33.3% of the CGM-wearing patients experienced no hypoglycemia compared with 7.6% of the control patients (number needed to treat [NNT] = 4; 95% CI 3 - 8). Additionally the rate of events requiring third-party intervention was 60% and 32%, respectively (NNT = 4; 3 - 10). The authors reported 18 adverse events, but conclude that none were related to the device.