title: Diurnal Cortisol Patterns, Future Diabetes, and Impaired Glucose Metabolism in the Whitehall II Cohort Study.
abstract: BACKGROUND
  The hypothalamic pituitary-adrenal axis is thought to play a role in type 2 diabetes (T2D). However, evidence for an association between cortisol and future glucose disturbance is sparse.
  
  
  OBJECTIVE
  The aim was to examine the association of diurnal cortisol secretion with future T2D and impaired glucose metabolism in a community-dwelling population.
  
  
  METHODS
  This is a prospective cohort study of salivary cortisol measured at the 2002-2004 clinical examination of the Whitehall II study, United Kingdom. We measured cortisol (nmol/l) from six saliva samples obtained over the course of a day: at waking, +30 minutes, +2.5 hours, +8 hours, +12 hours, and bedtime. Participants who were normoglycemic in 2002-2004 (phase 7) were reexamined in 2012-2013 (phase 11).
  
  
  METHODS
  The occupational cohort was originally recruited in 1985-1988.
  
  
  METHODS
  A total of 3270 men and women with an average age of 60.85 years at phase 7 (2002-2004).
  
  
  METHODS
  Incident T2D and impaired fasting glucose in 2012-2013 were measured.
  
  
  RESULTS
  Raised evening cortisol at phase 7 was predictive of new-onset T2D at phase 11 (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.01-1.37) with a trend for a flatter slope in participants with incident T2D (odds ratio, 1.15; 95% CI, 0.99-1.33). When expanding this analysis to a broader category of glucose disturbance we found that a flattened diurnal cortisol slope at phase 7 was predictive of future impaired fasting glucose or T2D at phase 11 (OR, 1.12; 95% CI, 1.02-1.22), as was high bedtime cortisol (OR, 1.10; 95% CI, 1.01-1.20).
  
  
  CONCLUSIONS
  In this nonclinical population, alterations in diurnal cortisol patterns were predictive of future glucose disturbance.
authors.affiliation: Department of Epidemiology and Public Health (R.A.H., M.Ki., A.S.), University College London, London, WC1E 6BT, UK; Institute for Social and Economic Research (M.Ku.), University of Essex, Colchester, Essex, CO4 3SQ, UK.
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Hackett
authors.affiliation: Department of Epidemiology and Public Health (R.A.H., M.Ki., A.S.), University College London, London, WC1E 6BT, UK; Institute for Social and Economic Research (M.Ku.), University of Essex, Colchester, Essex, CO4 3SQ, UK.
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimäki
authors.affiliation: Department of Epidemiology and Public Health (R.A.H., M.Ki., A.S.), University College London, London, WC1E 6BT, UK; Institute for Social and Economic Research (M.Ku.), University of Essex, Colchester, Essex, CO4 3SQ, UK.
authors.forename: Meena
authors.initials: M
authors.lastname: Kumari
authors.affiliation: Department of Epidemiology and Public Health (R.A.H., M.Ki., A.S.), University College London, London, WC1E 6BT, UK; Institute for Social and Economic Research (M.Ku.), University of Essex, Colchester, Essex, CO4 3SQ, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Steptoe
mesh_terms: D000368:Aged; D000465:Algorithms; D001786:Blood Glucose / Q000378:metabolism; D002940:Circadian Rhythm; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D006113:United Kingdom
chemical_list: D001786:Blood Glucose; D005947:Glucose; D006854:Hydrocortisone