Salivary concentration of progesterone and cortisol significantly differs across individuals after correcting for blood hormone values

Abstract

Between‐individual variation of salivary progesterone (P4) and cortisol levels does not always closely reflect blood hormone concentrations. This may be partly a function of individual differences in salivary hormone excretion. We tested whether time of day at sampling and ethnicity contributed to individual variation in salivary hormones after adjusting for blood hormone levels. Forty‐three Caucasian and 15 Japanese women (18–34 years) collected four sets of matched dried blood spot (DBS) and saliva specimens across a menstrual cycle (N = 232 specimen sets). Linear fixed‐effects (LFE) models were used to estimate the effects of diurnal variation and ethnicity on salivary P4 and cortisol while adjusting for DBS levels. For each hormone, women with exclusively positive or negative residuals (unexplained variance) from the LFE models were categorized as high‐ or low‐saliva‐to‐DBS hormone ratio (SDR; high or low salivary secretors), respectively. We found that salivary P4 (P < 0.05) was significantly higher in early morning compared to the afternoon, after controlling for DBS levels, ethnicity, and BMI. After further adjusting for this diurnal effect, significant individual variation in salivary P4 and cortisol remained: sixteen and nine women, respectively were categorized as low or high salivary secretors for both hormones (P < 0.001), suggesting systematic individual‐specific variation of salivary hormonal concentration. We conclude that when saliva is used to quantify P4 or cortisol levels, time of day at sampling should be controlled. Even with this adjustment, salivary P4 and cortisol do not closely mirror between‐ individual variation of serum P4 and cortisol in a substantial proportion of individuals. Am J Phys Anthropol 149:231–241, 2012. © 2012 Wiley Periodicals, Inc.

Children with recurrent psychosomatic abdominal pain display increased morning salivary cortisol and high serum cortisol concentrations

“…We found a strong positive correlation between salivary and serum cortisol in the morning, which is in agreement with other studies (11). The study verified the earlier notion that morning saliva cortisol can be high, but does not have to be, in children with recurrent abdominal pain of psychosomatic origin.…”

Salivary but not blood cortisol excretion is associated with metabolic biomarkers in healthy young women

“…Little information is available on the relationship between cortisol and metabolic indicators in normal weight population samples. However, recent work has shown that there are systematic salivary cortisol differences relative to blood secretion in a sample of normal weight individuals (Konishi et al, ), raising the question of whether these systematic individual differences in cortisol secretion are associated with variation in metabolic biomarkers.…”

“…Using four matched specimen sets of blood and saliva, Konishi et al () found systematic individual differences in salivary hormone concentration relative to blood hormone concentration, for two different but related hormones, cortisol and progesterone. After correcting for blood hormone values, individuals who were high salivary secretors for one hormone were also high salivary secretors for the other hormone, and the same concordance was observed for medium and low salivary secretors.…”

“…Salivary and plasma cortisol concentrations are not always closely related, though both are used often because of their value for indicating acute circulating levels (Hellhammer et al, ). Although salivary cortisol is widely used (as in the above cited studies on cortisol and health indicators) on the basis that it correlates reasonably well with total and free cortisol concentrations in blood (Hellhammer et al, ), it is not always well appreciated that these correlations are often not strong or consistent across or within individuals (e.g., Konishi et al, ; Levine et al, ; Lewis, ). Proportions of free hormone can be influenced by the concentration and degree of saturation of binding proteins and receptors, which in turn are themselves influenced by factors such as sex hormones, health status, and stress (Hellhammer et al, ).…”

“…Thus, the key assumption of the “free hormone hypothesis”—that free saliva hormone corresponds closely with free circulating blood hormone—does not always hold, including in those conditions we are most interested in with respect to health and psychobiology (Hellhammer et al, ; Levine et al, ). It is possible that violation of the free‐hormone hypothesis may explain in part the differences across individuals in salivary‐to‐blood correlations observed for cortisol and progesterone (salivary secretor status) (Konishi et al ; Lewis ) and testosterone (Lewis ). This literature suggests first, that saliva and blood levels differ from each other in patterned ways for at least three steroid hormones, and second, that depending on the fluids used, the association between hormone levels and health outcomes may vary.…”