Average glucose levels (AG) and glucose time-in-range (TIR; 70-180 mg/dL) are important glucose control measurements for patients with type 1 diabetes (T1D). Continuous glucose monitoring (CGM) systems provide audible alarms for actual/impending hyper/hypoglycemic events; however, there are little data regarding optimal CGM alarm settings to improve these measures. A cross-sectional observational study was conducted enrolling 91 T1D active CGM users (real-time CGM use >3 months and CGM usage time ≥70%). CGM alarm settings and two-week glucose data (total 28,133 hours) were analyzed. Glucose thresholds for hyperglycemia alarm and intra-threshold range (hyperglycemia minus hypoglycemia alarm thresholds) correlated positively with AG (P<0.001, P=0.003) and negatively with TIR (P=0.004, P=0.039, respectively). Compared to quartiles with higher hyperglycemia alarm thresholds and higher intra-threshold ranges; quartiles with, 1) lower glucose threshold settings for hyperglycemia alarm, and 2) lower intra-threshold ranges, were associated with up to 45 mg/dL lower AG and 20% longer TIR. These data indicate the benefits of lower glucose thresholds for hyperglycemia alarm and lower intra-threshold ranges in promoting lower glucose levels and longer glucose time-in-range.


Y. Lin: None. M. Hung: None. A. Sharma: None. O. Chan: Research Support; Self; Zucara Therapeutics Inc. M. Varner: None. D. Groat: None. D. Dopita: None. S. Fisher: None.

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