title: Ageing, physical function, and the diurnal rhythms of cortisol and dehydroepiandrosterone.
abstract: The present study examined the relationship between ageing, physical function and the diurnal rhythms of cortisol and dehydroepiandrosterone (DHEA). Participants were 36 community dwelling older adults aged between 65 and 86 years old. Salivary cortisol and DHEA were measured over the course of one day: immediately upon awakening, 30 min later, and then 3 h, 6 h, 9 h and 12 h post-awakening. Participants completed the Nottingham extended activities of daily living index, the Berg Balance Scale and their handgrip strength was assessed. Older participants had a significantly higher cortisol area under the curve (AUC), lower overall DHEA levels, lower DHEA AUC, a decreased diurnal slope of decline and increased cortisol:DHEA ratio. Lower diurnal cortisol levels were associated with poorer performance on the Berg Balance Scale and lower handgrip strength, and those with a flattened DHEA diurnal profile reported less independence in carrying out daily tasks. These associations withstood adjustment for age. In conclusion, this study suggests an association between cortisol, DHEA, ageing and physical function.
authors.affiliation: School of Sport and Exercise Sciences, University of Birmingham, Birmingham, West Midlands, B15 2TT, UK.
authors.forename: Jennifer L J
authors.initials: JL
authors.lastname: Heaney
authors.forename: Anna C
authors.initials: AC
authors.lastname: Phillips
authors.forename: Douglas
authors.initials: D
authors.lastname: Carroll
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D003687:Dehydroepiandrosterone / Q000378:metabolism*; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D012463:Saliva / Q000378:metabolism; D014851:Wakefulness
chemical_list: D003687:Dehydroepiandrosterone; D006854:Hydrocortisone