Heart Rate Variability Changes Preceed Onset of Nocturnal Hypoglycemia in Children with Type 1 Diabetes - A Way to Predict Hypoglycemia ?

International audienceBackground and Aims: Nocturnal hypoglycemia is most feared in children with diabetes, though often unrecognized. Heart rate variability (HRV) reflects activation of the autonomic nervous system. As hypoglycemia and declining glucose induce sympathoadrenal activation, changes of HRV could be assumed. Hence, the aim of this study was to evaluate, if HRV changes occur before the onset of nocturnal hypoglycemia in children with type 1 diabetes (T1D).Methods: Children aged 1 to 18 y, with T1D for >6 months, participated in an observational study using continuous glucose monitoring (CGM) during 5 days. Simultaneously, Holter ECG was recorded each night. HRV parameters such as time (SDNN) and frequency (VLF and total power) domain and sample entropy were calculated using a 6min moving window from 90mins before until the onset ( = 0mins) of nocturnal hypoglycemia (sensor glucose level