Impact in real-world of intermittent-scanned continuous glucose monitoring with alarms on hypoglycemia and its recognition in type 1 diabetes

Background: Recent studies have demonstrated that real-time CGM use reduce the incidence severe hypoglycemic events and impaired awareness of hypoglycemia (IAH) However, there are few real-world studies evaluating the effect of intermittently scanned continuous glucose monitoring (isCGM) on hypoglycemic episodes and hypoglycemia unawareness (IAH). The present study was designed to cover this research-practice gap.

Methods: This is a real-world, observational, prospective cohort study with 2 years of follow-up in which 60 subjects with T1D who experienced frequent hypoglycemic events were included. All the patients were invited to use isCGM type Abbott FreeStyle Libre 2® on a continuous basis for 2 years. Glucometric parameters were obtained during the initial 2 weeks using isCGM and compared with data collected for the same period at 1 year and at the end of follow-up. The IAH was evaluated using the Clarke questionnaire, and to assess psychological aspects related to hypoglycemia the Hypoglycemia Fear Survey (HFS) was used.

Results: After 2-years of follow-up using isCGM, we observed a decrease in glucose variability (40.3 ± 0.8 % vs. 37.1 ± 0.9 %, p = 0.003), time in low glucose range (54-69 mg/dL) (5.2 ± 0.4 % vs. 3.6 ± 0.3 %, p = 0.001), time in very low glucose range (<54 mg/dL) (3.2 ± 0.5 % vs. 0.8 ± 0.2 %, p < 0.001), less events related to low glucose levels (10.6 ± 1.1 vs 8.0 ± 1.0, p = 0.042) and a short duration of hypoglycemia episodes (106.1 ± 5.9 min vs. 85.7 ± 5.7 min, p = 0.008). In addition, participants presented a reduction of 47 % in the frequency of IAH, assessed by the Clarke questionnaire scores (24.6 % vs. 11.6 %, p = 0.034), as well as hypoglycemia fear (77.8 ± 2.4 vs 68.2 ± 2.1, p < 0.001). Furthermore, a reduction in total insulin dose was also observed (0.64 ± 0.30 UI/Kg/day vs 0.56 ± 0.11 UI/Kg/day, p = 0.018).

Conclusions: In the real-world, long-term use of isCGM could reduce both hypoglycemic episodes and IAH in people with T1D.