title: Relationship between 24-hour urinary-free cortisol excretion and salivary cortisol levels sampled from awakening to bedtime in healthy subjects.
abstract: The utility of repeated salivary cortisol sampling as a substitute for 24-hour urinary-free cortisol (UFC) assessment was examined. Forty-four participants completed both 24-hour collections and 6 salivary collections at wake-up, 08:00, 12:00, 16:00, 20:00 and bedtime, during the same 24-hour period. The results demonstrated that mean, maximum, and amplitude (maximum minus minimum) for salivary cortisol all correlated positively with urinary cortisol, but the associations of these variables with urinary-free cortisol excretion were relatively small. Furthermore, a single salivary sample taken at wake-up was as good an indicator of overall cortisol production as the measures derived from multiple salivary samples. An examination of subject compliance indicated that many subjects failed to collect the timed salivary collections as instructed. The authors conclude that diurnal salivary cortisol sampling versus 24-hour urinary cortisol collections are likely to provide different information about ambient hypothalamic-pituitary-adrenal productivity, and therefore these measures should not be used interchangeably. In addition, subject compliance is a serious consideration in designing studies that employ home salivary collections.
authors.affiliation: Psychiatry OOMH, Mount Sinai School of Medicine and Bronx Veteran Affairs Medical Center, 130 West Kingsbridge Road, Bronx, NY 10468, USA. rachel.yehuda@med.va.gov
authors.forename: Rachel
authors.initials: R
authors.lastname: Yehuda
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Halligan
authors.forename: Ren Kui
authors.initials: RK
authors.lastname: Yang
authors.forename: Ling Song
authors.initials: LS
authors.lastname: Guo
authors.forename: Iouri
authors.initials: I
authors.lastname: Makotkine
authors.forename: Bridgette
authors.initials: B
authors.lastname: Singh
authors.forename: Dov
authors.initials: D
authors.lastname: Pickholtz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012463:Saliva / Q000737:chemistry*; D012737:Sex Factors; D013048:Specimen Handling; D014851:Wakefulness
chemical_list: D006854:Hydrocortisone