Factors Associated With Progression From Level 1 to Level 2 Sensor-Detected Hypoglycaemia in People With Type 1 and Insulin-Treated Type 2 Diabetes: A Post Hoc Analysis From the Hypo-METRICS Study

AIMS: We investigated the proportion of sensor-detected hypoglycaemic (SDH) events progressing to level 2, and associated variables.

MATERIALS AND METHODS: We used data from Hypo-METRICS, which recruited people with type 1 (pwT1D) and insulin-treated type 2 diabetes (pwT2D) with ≥ 1 hypoglycaemic event in preceding 3 months, wearing blinded continuous glucose monitoring devices (CGM), additional to usual monitoring modality, and FitBits for 10 weeks. We defined: L1: SDH < 3.9 mmol/L for ≥ 15 min but ≥ 3.0 mmol/L; L2: SDH < 3.9 mmol/L with ≥ 15 min of sensor glucose < 3.0 mmol/L; L2 ratio = L2/(L1 + L2), restricted to participants with both event types during the study period. Associations of selected variables on L2 ratio was assessed using beta regression and purposeful variable selection.

RESULTS: We analysed 23 768 SDH events from 212 pwT1D and 213 pwT2D. PwT1D were predominantly female (53% vs. 42% in T2D, p = 0.023) and younger (median age 49 vs. 62 years, p < 0.001), with a higher L2 ratio (16% vs. 14%, p = 0.03). Coefficient of variation (CV), OR = 1.07, 95% CI = 1.06-1.09 (p < 0.001), and mean sensor glucose, OR = 1.13, 95% CI = 1.08-1.18 (p < 0.001) were the principal predictors in T1D and T2D respectively; mean L1-SDH duration, weekly L1-SDH frequency, personal CGM usage, impaired awareness were not. Progression was higher during sleep than wakefulness (21% vs. 11%, p < 0.001); L2 ratios during sleep did not differ by awareness status.

CONCLUSIONS: Approximately one sixth of SDH events progressed to L2, with a higher proportion in T1D than T2D. The principal determinants were CV in T1D and mean glucose in T2D. Awareness status was not associated with progression risk during sleep.