title: Blunted diurnal cortisol pattern is associated with frailty: a cross-sectional study of 745 participants aged 65 to 90 years.
abstract: BACKGROUND
  The role of neuroendocrine alterations in the etiology of frailty syndrome is still poorly understood. Hypothalamic-pituitary-adrenal axis dysregulation is a plausible candidate pathway contributing to frailty. Thus, we sought to examine the associations of diurnal cortisol secretion with frailty in older adults.
  
  
  METHODS
  A cross-sectional analysis was conducted among 745 study participants (age 65-90 years, mean age 75.1 years) of the population-based KORA Age study. Associations between salivary cortisol measures at awakening (morning 1 [M1]), 30 minutes after awakening (M2), and evening (E) and frailty criteria were determined.
  
  
  RESULTS
  Lower cortisol levels in the first morning sample (M1) (P = .18) and M2 (P = .14) and increased E levels (P = .004) were observed in prefrail (35.17%, n = 262) and frail (3.36%, n = 25) individuals, in a dose-response manner. Frailty was strongly associated with smaller ratios of morning to evening levels; M1 to E ratio (P = .02) and M2 to E ratio (P = .003). Higher evening cortisol levels were associated with a 24% increased risk of a prefrail state (odds ratio, 1.22; 95% confidence interval, 1.03-1.44). A smaller morning to evening ratio was associated with an increased risk of low grip strength (1.42, 1.09-1.86) and gait speed (1.31, 1.02-1.68).
  
  
  CONCLUSIONS
  Frailty status is associated with blunted cortisol reactivity as demonstrated by lower morning and higher evening salivary cortisol levels.
authors.affiliation: Institute of Epidemiology II (H.J., R.T.E., B.T., A.P., M.H., K.-H.L.), Helmholtz Zentrum München, German Research Centre for Environmental Health, 85764 Neuherberg, Germany; Medizinische Klinik und Poliklinik IV (M.B., M.R.), Klinikum der Ludwig-Maximilians-Universität München, 80336 Munich, Germany; and Department of Psychosomatic Medicine and Psychotherapy (K.-H.L.), Klinikum rechts der Isar, Technische Universität München, 81675 Munich, Germany.
authors.forename: Hamimatunnisa
authors.initials: H
authors.lastname: Johar
authors.forename: Rebecca T
authors.initials: RT
authors.lastname: Emeny
authors.forename: Martin
authors.initials: M
authors.lastname: Bidlingmaier
authors.forename: Martin
authors.initials: M
authors.lastname: Reincke
authors.forename: Barbara
authors.initials: B
authors.lastname: Thorand
authors.forename: Annette
authors.initials: A
authors.lastname: Peters
authors.forename: Margit
authors.initials: M
authors.lastname: Heier
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Ladwig
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004700:Endocrine System Diseases / Q000378:metabolism; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D008297:Male; D010913:Pituitary-Adrenal System / Q000378:metabolism; D012463:Saliva / Q000378:metabolism
chemical_list: D006854:Hydrocortisone