title: Change in Sleep Duration and Type 2 Diabetes: The Whitehall II Study.
abstract: OBJECTIVE
  Evidence suggests that short and long sleep durations are associated with a higher risk of type 2 diabetes. Using successive data waves spanning >20 years, we examined whether a change in sleep duration is associated with incident diabetes.
  
  
  METHODS
  Sleep duration was reported at the beginning and end of four 5-year cycles: 1985-1988 to 1991-1994 (n = 5,613), 1991-1994 to 1997-1999 (n = 4,193), 1997-1999 to 2002-2004 (n = 3,840), and 2002-2004 to 2007-2009 (n = 4,195). At each cycle, change in sleep duration was calculated for participants without diabetes. Incident diabetes at the end of the subsequent 5-year period was defined using 1) fasting glucose, 2) 75-g oral glucose tolerance test, and 3) glycated hemoglobin, in conjunction with diabetes medication and self-reported doctor diagnosis.
  
  
  RESULTS
  Compared with the reference group of persistent 7-h sleepers, an increase of ≥2 h sleep per night was associated with a higher risk of incident diabetes (odds ratio 1.65 [95% CI 1.15, 2.37]) in analyses adjusted for age, sex, employment grade, and ethnic group. This association was partially attenuated by adjustment for BMI and change in weight (1.50 [1.04, 2.16]). An increased risk of incident diabetes was also seen in persistent short sleepers (average ≤5.5 h/night; 1.35 [1.04, 1.76]), but this evidence weakened on adjustment for BMI and change in weight (1.25 [0.96, 1.63]).
  
  
  CONCLUSIONS
  This study suggests that individuals whose sleep duration increases are at an increased risk of type 2 diabetes. Greater weight and weight gain in this group partly explain the association.
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, U.K. Department of Epidemiology and Public Health, University College London, London, U.K. jane.ferrie@bristol.ac.uk.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Ferrie
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, U.K.
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimäki
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, U.K. INSERM U1198, Montpellier, France University of Montpellier, Montpellier, France École Pratique des Hautes Études, Paris, France.
authors.forename: Tasnime N
authors.initials: TN
authors.lastname: Akbaraly
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, U.K. 1st Department of Medicine, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Adam
authors.initials: A
authors.lastname: Tabak
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, U.K.
authors.forename: Jessica
authors.initials: J
authors.lastname: Abell
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, U.K. MRC Centre for Causal Analyses in Translational Epidemiology, University of Bristol, Bristol, U.K.
authors.forename: George
authors.initials: G
authors.lastname: Davey Smith
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Marianna
authors.initials: M
authors.lastname: Virtanen
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, U.K. Institute for Social and Economic Research, University of Essex, Colchester, U.K.
authors.forename: Meena
authors.initials: M
authors.lastname: Kumari
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, U.K.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Shipley
mesh_terms: D000328:Adult; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000209:etiology*; D005215:Fasting / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000150:complications* / Q000453:epidemiology; D013997:Time Factors; D015430:Weight Gain / Q000502:physiology
chemical_list: D006442:Glycated Hemoglobin