A study conducted in T1 diabetes adults and children by Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group reveals that nocturnal hypoglycemia is frequent and often prolonged in adults and children with type 1 diabetes. The study group selected 176 subjects and analysed 36,467 nights with ≥4 h of CGM glucose readings between 12 midnight and 6:00 A.M.

   The results show that hypoglycaemic events occurred during 8.5% of nights, with the median percentage of nights with hypoglycemia per subject being 7.4% (interquartile range 3.7-12.1%). The duration of hypoglycemia was >or=2 h on 23% of nights with hypoglycemia. In a multivariate model, a higher incidence of nocturnal hypoglycemia was associated with
1) lower baseline A1C levels (P < 0.001) and 2) the occurrence of hypoglycemia on one or more nights during baseline blinded CGM (P < 0.001).

   It is interesting to note from the results that hypoglycemia frequency was not at all associated with age or with insulin modality (pump versus multiple daily injections). Patients with low A1C levels are at an increased risk for nocturnal hypoglycemia incidences. One week of blinded CGM can positively identify patients who are at an increased risk for nocturnal hypoglycemia.