Biomarking Trait Resilience With Salivary Cortisol in Chinese Undergraduates

This study aimed to examine the relationship between trait resilience and salivary cortisol in a group of Chinese undergraduates. The Chinese versions of the Brief Resilience Scale and a measure of optimism, the revised Life Orientation Test were administered to 49 Chinese undergraduates who provided self-collected saliva samples six times per day (immediately after waking; 0.5, 3, 6, and 12 h thereafter; and at bedtime) over 3 consecutive weekdays. The cortisol data were aggregated across the 3 days to examine the association between resilience and components of the diurnal rhythm of cortisol using multiple regression. The results showed that higher resilience was associated with a stronger cortisol response to awakening and a steeper diurnal decline in cortisol from waking to bedtime. Resilience was positively associated with cortisol output over the course of the day but this relationship was not significant (p = 0.065). This pattern of diurnal rhythm is consistent with that typically observed in better adjusted individuals. Generated by an intensive protocol with compliance objectively monitored, these findings clearly indicate the important role of the hypothalamic-pituitary-adrenocortical axis in health and adjustment and contribute to the growing literature on resilience and cortisol in humans.

Daily hassles, loneliness, and diurnal salivary cortisol in emerging adults

This study used an intensive protocol to examine the effects of daily hassles and loneliness on diurnal salivary cortisol levels. Fifty Chinese undergraduates (28 females) provided six saliva samples each day for two consecutive days (at 0, 0.5, 3, 6, and 12 h after waking and at bedtime) and completed a questionnaire that included scales to measure daily hassles experienced over the previous month, trait loneliness, and depression. Cortisol data were aggregated over two days and used in subsequent analyses, focusing on the cortisol awakening response, diurnal slope, and overall cortisol output operationalized as the area under the curve with reference to the ground (AUC_G). Multiple regression analysis showed that an increase in loneliness had a significant association with an increase in the AUC_G and with a steeper diurnal slope. Loneliness also showed a significant interaction with daily hassles in that the positive association between daily hassles and AUC_G was accentuated in the participants who reported a greater degree of loneliness. Our findings demonstrate for the first time the importance of trait loneliness in modulating the association between daily hassles and diurnal cortisol levels, which has significant clinical implications. Interventions to reduce loneliness should help college students to better cope with daily stressors. Increased attention should also be paid to the health implications of an elevated cortisol level in this relatively young and healthy population.