title: Telomere length and hypothalamic-pituitary-adrenal axis response to stress in elderly adults.
abstract: OBJECTIVE
  Telomere shortening, a biomarker of cellular aging, has been associated with aging-related diseases. While psychological stress has been implicated in the process of telomere shortening, associations with activity of physiological stress systems have remained elusive. We studied whether leukocyte telomere length (LTL) is associated with hypothalamic-pituitary-adrenal (HPA) axis responses to psychosocial stress in elderly adults.
  
  
  METHODS
  LTL, measured by qPCR method was available in 1964 women and men from the Helsinki Birth Cohort Study at a mean age of 61.5 (SD=2.9) years. At a mean age of 63.5 (SD=2.7) years a subsample of them took part in the Trier Social Stress Test (TSST) during which salivary cortisol (n=283) and plasma cortisol and ACTH concentrations (n=215) were measured.
  
  
  RESULTS
  Mixed model regression analyses showed no linear or non-linear associations between LTL and HPA axis activity during TSST (p-values for LTL main effects >298; p-values for LTL×time interactions >096). Only one non-linear association between LTL and plasma ACTH area under the curve increment was significant after adjustments for covariates and confounders. This association did not survive correction for multiple testing.
  
  
  CONCLUSIONS
  Our findings suggest that LTL is not consistently associated with HPA axis activity during a standardized psychosocial stress test in elderly adults.
authors.affiliation: Institute of Behavioural Sciences, University of Helsinki, PO Box 9, 00014 Helsinki, Finland.
authors.forename: Katri
authors.initials: K
authors.lastname: Savolainen
authors.affiliation: Diabetes Prevention Unit, Department of Chronic Disease Prevention, National Institute for Health and Welfare, PO Box 30, 00271 Helsinki, Finland; Folkhälsan Research Centre, Haartmansgatan 8, 00290 Helsingfors, Finland; Vasa Central Hospital, Hietalahdenkatu 2-4, 65130 Vaasa, Finland; Department of General Practice and Primary Health Care, University of Helsinki, PO Box 20, 00014 Helsinki, Finland.
authors.forename: Johan G
authors.initials: JG
authors.lastname: Eriksson
authors.affiliation: Diabetes Prevention Unit, Department of Chronic Disease Prevention, National Institute for Health and Welfare, PO Box 30, 00271 Helsinki, Finland; Hospital for Children and Adolescents, Helsinki University of Central Hospital, HUS, PO Box 281, 00029 Helsinki, Finland; Department of Obstetrics and Gynecology, MRC Oulu, Oulu University Hospital and University of Oulu, OYS, PO Box 23, 90029 Oulu, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Kajantie
authors.affiliation: Institute of Behavioural Sciences, University of Helsinki, PO Box 9, 00014 Helsinki, Finland.
authors.forename: Jari
authors.initials: J
authors.lastname: Lahti
authors.affiliation: Institute of Behavioural Sciences, University of Helsinki, PO Box 9, 00014 Helsinki, Finland. Electronic address: katri.raikkonen@helsinki.fi.
authors.forename: Katri
authors.initials: K
authors.lastname: Räikkönen
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000368:Aged; D019540:Area Under Curve; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism*; D007962:Leukocytes / Q000378:metabolism; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics; D010913:Pituitary-Adrenal System / Q000378:metabolism*; D012463:Saliva / Q000737:chemistry; D013315:Stress, Psychological / Q000378:metabolism*; D016615:Telomere / Q000378:metabolism*
chemical_list: D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone
keywords: Elderly; Hypothalamic–pituitary–adrenal axis; Leukocyte telomere length; Trier Social Stress Test