Metabolic dysfunction and circadian rhythm abnormalities in adolescents with sleep disturbance.

Sleep disturbance attributable to circadian rhythm abnormalities frequently occurs in previously healthy children and adolescents who often complain of gastrointestinal discomfort after meals.Glucose metabolism, autonomic function, and human clock gene expression in whole blood cells were investigated in 18 adolescent patients with circadian rhythm sleep disorder.Glucose tolerance was significantly lower in the patients than in normal controls: the mean sigma blood glucose level was significantly higher (P<0.05) and the insulinogenic index was significantly lower (P<0.05) in the patient group than in controls. Messenger ribonucleic acid level of hPer2 was significantly higher at 6:00 in the control subjects, but in only 3 of the 18 patients. Component analysis of cardiographic R-R interval revealed that high-frequency component peaks were suppressed significantly in the patient group compared to the controls (P<0.001).Metabolic and endocrine dysfunctions were identified in adolescents with sleep disturbance as decreased glucose tolerance and absence of human clock gene regulation in whole blood cells. Their brain dysfunction attributable to sleep disturbances might cause such peripheral autonomic imbalance and carbohydrate metabolic dysfunction.