title: Association between sleep architecture and glucose   tolerance in children and adolescents.
abstract: BACKGROUND
  Short sleep duration is a contributing factor for decreased insulin sensitivity and hyperglycemia. Sleep architecture represents a cyclical pattern of sleep that shifts between sleep Stages N1, N2, N3 (slow wave sleep) and Stage R (rapid eye movement sleep). The aim of the present study was to examine the association between sleep architecture and glucose and insulin metabolism in both normal weight and overweight/obese children and adolescents.
  
  
  METHODS
  A total of 118 subjects participated in the study. Subjects under-went overnight polysomnography (PSG) when the percentage of total sleep time (% TST) spent at each sleep stage was recorded and an oral glucose tolerance test together was performed the next morning. We assessed glucose tolerance, insulin sensitivity and pancreatic β-cell function using 2-h glucose levels, the Matsuda index (IS(OGTT)), and insulin secretion-sensitivity index-2 (ISSI-2), respectively.
  
  
  RESULTS
  After adjustment for age, gender, body mass index z-score, pubertal status, and obstructive apnea hypopnea index, Stage N3 (% TST) was positively associated with IS(OGTT), whereas Stage N1 (%TST) exerted an opposite effect on IS(OGTT). Higher sleep efficiency and longer TST were independently associated with lower 2-h glucose levels, higher ISSI-2 and/or higher IS(OGTT).
  
  
  CONCLUSIONS
  Stage N3, sleep efficiency and TST were protective factors in maintaining glucose and insulin homeostasis; however, Stage N1 functioned in the opposite direction.
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhu
authors.forename: Albert Martin
authors.initials: AM
authors.lastname: Li
authors.forename: Chun Ting
authors.initials: CT
authors.lastname: Au
authors.forename: Alice Pik Shan
authors.initials: AP
authors.lastname: Kong
authors.forename: Jihui
authors.initials: J
authors.lastname: Zhang
authors.forename: Chun Kwok
authors.initials: CK
authors.lastname: Wong
authors.forename: Juliana Chung Ngor
authors.initials: JC
authors.lastname: Chan
authors.forename: Yun Kwok
authors.initials: YK
authors.lastname: Wing
mesh_terms: D000293:Adolescent; D001786:Blood Glucose; D015992:Body Mass Index; D002648:Child; D005260:Female; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006801:Humans; D006943:Hyperglycemia / Q000175:diagnosis / Q000209:etiology*; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells; D008297:Male; D009765:Obesity / Q000150:complications / Q000503:physiopathology*; D017286:Polysomnography; D012893:Sleep Wake Disorders / Q000150:complications / Q000503:physiopathology*
chemical_list: D001786:Blood Glucose