Safety of using real-time sensor glucose values for treatment decisions in adolescents with poorly controlled type 1 diabetes mellitus: a pilot study

Abstract

Background: This study explored the safety of using real-time sensor glucose (SG) data for treatment decisions in adolescents with poorly controlled type 1 diabetes.

Methods: Ten adolescents with type 1 diabetes, HbA1c ≥9% on insulin pumps were admitted to the clinical research center and a continuous glucose sensor was inserted. Plasma glucose was measured at least hourly using Yellow Springs Instrument's (YSI) glucose analyzer. Starting at dinner, SG rather than YSI was used for treatment decisions unless YSI was <70 mg/dL (<3.9 mmol/L) or specific criteria indicating SG and YSI were very discordant were met. Participants were discharged after lunch the next day.

Results: Ten participants (seven males; 15.2-17.8 year old) completed the study. The range of differences between high glucose correction doses using SG vs YSI for calculations was -2 (SG < YSI dose) to +1 (SG > YSI dose); this difference was two units in only 2 of 23 correction doses given (all SG < YSI dose). There were five episodes of mild hypoglycemia in two patients, two of which occurred after using SG for dose calculations. There was no severe hypoglycemia and no YSI glucose >350 mg/dL (19.4 mmol/L). Mean (±SE) pre- and postmeal YSI glucose were 163 ± 11 and 183 ± 12 mg/dL (9.1 ± 0.6 and 10.2 ± 0.7 mmol/L), respectively.

Conclusion: Use of real-time continuous glucose monitoring for treatment decisions was safe and did not result in significant over- or undertreatment. Use of SG for treatment decisions under supervised inpatient conditions is a suitable alternative to repeated fingerstick glucose monitoring. Outpatient studies using SG in real-time are needed.

Trial registration: ClinicalTrials.gov NCT01586065.

Keywords: continuous glucose monitoring; pediatrics; type 1 diabetes.

Figure 1

Algorithm for treatment of hypoglycemia in Clinical Research Center. YSI refers to glucose using YSI 2300 STAT Plus™ Biochemistry Analyzer (Yellow Springs Instruments, Inc., Yellow Springs, OH). *For asymptomatic patients with YSI glucose <70 mg/dl, YSI glucose was obtained every 30 minutes for the remainder of the study once YSI is >70 mg/dl. All glucose results in mg/dl; divide mg/dl by 18 for mol/L.

Figure 2

Mean (+SE) YSI and sensor pre- and post-meal glucose concentrations for all dinner (n=8), bedtime snack (n=8), and breakfast (BF) (n=10) during the study period. Study procedures ended immediately after lunch, and thus no lunch postprandial sugars were obtained. Solid black = YSI premeal; upward hash = YSI post meal; checker board = SG premeal; solid white = SG post meal.