Interactions between hypoglycemia and sleep architecture in children with type 1 diabetes mellitus

Objectives: To assess the interactions between nocturnal hypoglycemia and sleep in children with type 1 diabetes mellitus (DM). Study design: Children with DM (n = 15) and 15 matched control children underwent full night polysomnographic recordings. Blood glucose levels were measured in the diabetic children by means of the MiniMed Continuous Glucose Monitoring System. Six of the diabetic children were also studied by peripheral arterial tonometry (an indirect indicator of sympathetic responses). Results: Five children with DM (33%) had profound nocturnal hypoglycemia, which was associated with increased sleep efficiency, increased slow wave sleep, and increased Δ power in spectral analysis of the electroencephalogram. Hypoglycemic episodes were not associated with sympathetic activation. Rapid decline in glucose levels (>25 mg/dL/hour) but not the absolute degree of hypoglycemia were associated with awakenings from sleep. Conclusions: We conclude that sleep may inhibit sympathetic and arousal response to hypoglycemia. Rapid changes in glucose levels, independent of absolute glucose levels, may result in awakening from sleep. Continuous measurement of glucose levels during sleep may add important features in the treatment of children with DM.