Background: New metrics generated by Continuous Glucose Monitoring (CGM) have highlighted the importance of glucose variability, measured as coefficient of variation. It is also suggested that CV may be a more accurate measure to assess time spent in hypoglycemia, as opposed to A1c. This association in older adults is not well studied.
Methods: Older adults (age ≥65 years) with T1D underwent 2 weeks of CGM. Based on the international consensus, CV was calculated by dividing standard deviation of glucose by mean glucose from CGM. The participants were stratified by CV ≤ 36%, or >36%. Duration of clinically significant hypoglycemia (glucose level ≤ 54 mg/dl) and A1c were measured.
Results: We evaluated 76 older adults (mean age 71 years, duration of T1D 39 years, 62% on insulin pump, and 38% on multiple daily injections (MDI)). In participants with CV ≤36% (n=19, 25%), A1c was 6.8±0.8%, and they spent 9.6 min/day in hypoglycemia, while in those with CV>36% (n=57, 75%), A1c was 7.5±0.8%, and they spent 43 min/day in hypoglycemia (p=0.003 and p<0.0001, respectively). In participants with CV>36%, those using MDI had longer duration of hypoglycemia compared to those using insulin pump (61 minutes/day vs. 33 minutes/day, p=0.03), despite similar A1c (7.5% in both groups).
Conclusion: In our cohort of older adults with T1D, CV>36% is associated with higher duration of hypoglycemia despite higher A1c. Keeping CV value <36% in a vulnerable population may help mitigate risk of hypoglycemia independent of A1c value.
E. Toschi: Advisory Panel; Self; Lexicon Pharmaceuticals, Inc. C. Slyne: None. A.B. Dufour: None. A. Atakov-Castillo: None. S. Carl: None. K. Sifre: None. J. Greenberg: None. M. Munshi: Consultant; Self; Lilly Diabetes, Sanofi.
National Institute of Diabetes and Digestive and Kidney Diseases
