title: Modeling cortisol rhythms in a population-based study.
abstract: The aim of these analyses was to develop and describe easily implementable, yet information rich, approaches for analysis of the temporal profile of cortisol in human populations. A typical waking profile of cortisol in a sample of women aged 15-44 was parameterized by a piecewise linear regression model, implemented as a mixed model to accommodate repeated observations among individuals. The model was extended to distinguish characteristic cortisol profiles of obese women from those of non-obese women. Sharp inflection points for the diurnal profile of cortisol were noted at 30 and 75 min past awakening. Obese women showed a slight tendency to have a less sharply rising and declining response to awakening than non-obese women.
authors.affiliation: Department of Epidemiology, Center for Social Epidemiology and Population Health, School of Public Health, University of Michigan, Ann Arbor, MI 48104, USA. nranjit@umich.edu
authors.forename: Nalini
authors.initials: N
authors.lastname: Ranjit
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Young
authors.forename: Trivellore E
authors.initials: TE
authors.lastname: Raghunathan
authors.forename: George A
authors.initials: GA
authors.lastname: Kaplan
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002940:Circadian Rhythm; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism; D011153:Population; D012044:Regression Analysis; D012463:Saliva / Q000378:metabolism; D015406:Single Parent; D018709:Statistics, Nonparametric; D014937:Work / Q000502:physiology
chemical_list: D006854:Hydrocortisone