Influence of Circadian Clock on Hormonal, Metabolic, Neurocognitive Markers in Adolescents With and Without Diabetes

Type 1 diabetes mellitus (T1DM), makes its appearance during childhood and youth, but management implications last till late adulthood. Its treatment includes the combination of multiple daily glucose measurements, insulin administration and balanced nutrition. The goals of therapy are to achieve glycemic control (HbA1c < 7.5%), and minimal glycemic excursions. Furthermore, recent studies imply that keeping HbA1c within target range is not sufficient to prevent complications, attributed mainly to blood glucose level fluctuating from high to low, associated with food intake and adolescents behavior. The current implication of glycemic control on the central nervous system (CNS) includes abnormal electrical brain activity, structural changes in brain's white and grey matter, and cognitive impairment. Still, little is known on the effect of sleep pattern, including circadian rhythm reversal ("biological clock) on asymptomatic glycemic excursions, and on CNS functions. There is no data regarding the association of the biologic clock on CNS functionality among adolescents, nonetheless among T1DM adolescents, for whom behavior and circadian rhythm alterations may have harmful effect. The investigators propose a cross-over designed study by examining adolescents with and without T1DM during 2 weeks of regular sleeping pattern (night sleep), and during 2 weeks of sleeping during the day as happens during summer vacation. The main objective of the proposed study is to offer proof of the clinical and metabolic relevance and cognitive effects of the reversal of the circadian clock in adolescents with and T1DM during summer vacations and weekends. Study is designed to demonstrate a difference among healthy and diabetics during reversed night/day circadian clocks in the time spent within target range of glucose, performance on neuro cognitive tasks, electrical brain activity, and hormonal profile.