Blood glucose in neonates with diabetes is variable due to frequent feeding, inexact exogenous insulin dosing and dynamic physiology. Rapid glucose fluctuation makes continuous glucose monitoring (CGM) ideal. We describe the successful use of CGM in an infant with small for gestational age (SGA) and chromosome 6q24-related transient neonatal diabetes mellitus, diagnosed by methylation study. A term male weighing 2650g (5th%) was born following uncomplicated pregnancy and delivery. Glucose checked per SGA-protocol revealed rising glucoses from initial 78 to >300 mg/dL over 24 hours. Hyperglycemia managed with insulin drip until transitioned to subcutaneous dilute regular insulin (U-concentration) administered q6 hours (every other feed) . Trial of sulfonylurea titrated to maximum dose was ineffective.Initially glucoses checked hourly while on insulin drip and transitioned to every 3 hours once on subcutaneous insulin. Dexcom G6 placed in lateral thigh without incident on DOL and impermeable dressing applied to prevent soiling.CGM values were generally within 10% of heelstick POC values though specific MARD was not calculated. In the 7 days prior to CGM placement, there were POC glucoses <80 mg/dL; in the 7 days after placement, there were none. Anecdotally, numerous times the CGM trend provided advanced notice of impending hypoglycemia and was able to be treated proactively (treatment decisions based on confirmatory heelstick) . The subject was discharged home on DOL 20.In followup, insulin degledec 0.5 unit/day was added and total prandial insulin requirements varied from 0-1 unit per day (total daily insulin dose approx. 0.1-0.3 units/kg/day) . By age 2.5 months weight was 6.1 kg (38th%) . CGM ambulatory glucose profile demonstrated mean glucose 185 mg/dL, <70 mg/dL <1%, 71-250 88%, >250 11%.
In summary, Dexcom G6 CGM was successfully used in an infant with SGA and neonatal diabetes to optimize glucose control while minimizing hypoglycemia risk.
E.A. Los: Advisory Panel; Medtronic. K. Wise: None. J. Welsh: Employee; Dexcom, Inc.