TY - JOUR
T1 - Individual differences in the diurnal cycle of salivary free cortisol
T2 - A replication of flattened cycles for some individuals
AU - Stone, Arthur A.
AU - Schwartz, Joseph E.
AU - Smyth, Joshua
AU - Kirschbaum, Clemens
AU - Cohen, Sheldon
AU - Hellhammer, Dirk
AU - Grossman, Steven
N1 - Funding Information:
The Cohen study was supported by a grant (MH50429) and a Senior Scientist Award (MH00721) from the National Institute of Mental Health and a grant from the John D. and Catherine T. MacArthur Foundation Research Network on Socioeconomic Status and Health. The Symth study was supported by a grant from the Fetzer Institute and by the Applied Behavioral Medicine Research Institute, Department of Psychiatry, SUNY at Stony Brook.
PY - 2001
Y1 - 2001
N2 - Free cortisol measured in saliva has been shown to have the same diurnal rhythm as serum cortisol, one that typically declines rapidly throughout the waking day. A recent study showed that over 15% of a sample of community individuals who were monitored over two days did not show the typical diurnal rhythm. The present study specifically tested the hypothesis that there is significant between-subject variation (individual differences) in diurnal rhythms using multi-level, random regression models. Analyses of participants from four studies were conducted; studies varied in terms of the number of saliva samples taken per day, the number of days studied, and participants' demographic and health status. Significant individual differences of diurnal cycle in each of the four samples were found. In at least 10% of each sample no significant diurnal cycles was detected; however, the overall mean level of cortisol of those with flat cycles differed among the samples. These results suggest that some people do not have the expected diurnal rhythm of cortisol secretion. It is not clear what the determinants of this finding are or if there are any health consequences of having a flat cycle.
AB - Free cortisol measured in saliva has been shown to have the same diurnal rhythm as serum cortisol, one that typically declines rapidly throughout the waking day. A recent study showed that over 15% of a sample of community individuals who were monitored over two days did not show the typical diurnal rhythm. The present study specifically tested the hypothesis that there is significant between-subject variation (individual differences) in diurnal rhythms using multi-level, random regression models. Analyses of participants from four studies were conducted; studies varied in terms of the number of saliva samples taken per day, the number of days studied, and participants' demographic and health status. Significant individual differences of diurnal cycle in each of the four samples were found. In at least 10% of each sample no significant diurnal cycles was detected; however, the overall mean level of cortisol of those with flat cycles differed among the samples. These results suggest that some people do not have the expected diurnal rhythm of cortisol secretion. It is not clear what the determinants of this finding are or if there are any health consequences of having a flat cycle.
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U2 - 10.1016/S0306-4530(00)00057-3
DO - 10.1016/S0306-4530(00)00057-3
M3 - Article
C2 - 11166492
AN - SCOPUS:0035134138
VL - 26
SP - 295
EP - 306
JO - Psychoneuroendocrinology
JF - Psychoneuroendocrinology
SN - 0306-4530
IS - 3
ER -