ABSTRACT
Objective To investigate the significance of salivary cortisol , dehydroepiandrosterone sulfate (DHEA-S) and cortisol/DHEA-S ratio changes for evaluation of military performance stress .Methods Forty submarine soldiers were selected, whose saliva samples were collected separately at the end of long-term dive training and after nine months of relaxation break.In addition, the saliva samples of thirty-four graduate students were collected the moment they finished a three-hour final examination and one week later .The method of ELISA was used to detect the levels of salivary cortisol and DHEA-S and to count their ratio .Results After long-term dive training , the submarine soldiers showed significantly decreased DHEA-S and an increased cortisol/DHEA-S ratio, but the cortisol level did not change very much .In contrast, the final examination stress did not change the level of cortisol , DHEA-S or the cortisol/DHEA-S ratio among these students.Conclusion This is the first study to show that long-term, chronic military performance stress is associated with the salivary DHEA-S and cortisol/DHEA-S ratio changes .The increase in the cortisol/DHEA-S ratio may be used as an important and useful biomarker to evaluate chronic stress .In addition , it is relatively simple and sensitive to detect stress biomarkers by using saliva samples .
ABSTRACT
OBJECTIVE: The role of steroid hormones in the control of human parturition has been a subject of debate. The objective of the study was to examine if changes in fetal plasma cortisol or dehydroepiandrosterone sulfate (DHEA-S) are associated with human term parturition. METHODS: Fetal plasma cortisol and DHEA-S were measured in 374 singleton pregnancies delivered at term. Umbilical cord blood was obtained from patients in the following 6 groups: 1) preterm gestations undergoing cordocentesis for clinical indications before 36 weeks of gestation (n=93), 2) women undergoing cordocentesis for clinical indications after 36 weeks of gestation (n=9), 3) elective cesarean section (C/S) at term without labor (n=140), 4) C/S at term with early labor (cervical dilatationp36 weeks) but did not increase during active labor; 4) The cortisol/ DHEA-S ratio (stress index) increased with advancing gestation and with active labor at term. CONCLUSION: Human parturition at term is associated with an increase in fetal plasma cortisol and cortisol/DHEA-S ratio, but not DHEA-S.