Hermanns, NorbertNorbertHermanns0000-0002-2903-2677Schumann, BeatrixBeatrixSchumannKulzer, BernhardBernhardKulzerHaak, ThomasThomasHaak2022-10-062022-10-0620131939-327X0012-1797https://fis.uni-bamberg.de/handle/uniba/55801The impact of CGM on the duration of periods with low glucose measured in interstitial fluid is well known. But studies showing an impact of CGM on low blood glucose values, measured by POC-GM are rare. This crossover study examines the impact of CGM on duration of periods spent in low interstitial glucose range (70 mg/dl) as well as on the proportion of low blood glucose (BG) values measured by POC-GM (Glukometer 3000, Bio Sensor Technology, Germany)and time until detection of low BG by use of POC-GM. 41 type 1 diabetic patients (age 42.0 ±11.3 yrs, diabetes duration 15.3 ±10.1; A1c 8.2 ±1.4%) used the DEXCOM 7 Plus CGM system twice; once participants were blinded against the results and in the other study phase (Open GCM) patients received real-time glucose values and current glucose trends, used the CGM data to determine their insulin dose, and were alerted if hypoglycaemic or hyperglycaemic glucose ranges were approached. In addition, BG was routinely measured 6 times a day by POC-GM. The order of study phases was randomized. The time spent in a hypoglycaemic glucose range (< 70 mg/dl) was reduced by open CGM from 180.6 ±125 to 125 ± 89.2 minutes per day (p=.005). Also time spent in the euglycemic glucose range was increased from 946 ±176 to 1023 ±168 minutes per day (p=.003). Open CGM reduced the proportion of low BG measurements by POC-GM from 10.3 ±7.6% to 7.4 ±5.8% (p=.039), whereas the euglycemic POC readings was increased from 68.3 ±12.1% to 73.7 ±12.1% (p=.007). The time until a hypoglycaemic BG value was detected by POC-GM was signifi cantly (p.028) shortened by 33.1 (95% CI 3.8 -62.3) minutes. These results demonstrate that CGM used for insulin dosing and hypoglycaemia alerts not only diminishes low interstitial glucose values but also reduces the proportion of low BG measured by POC-GM. In addition the time for the detection of a hypoglycaemic episode by POC-GM was significantly shortenedengarticle10.2337/db13-859-1394