Longitudinal associations between salivary cortisol to C-reactive protein ratios and psychological well-being in Chinese adults.

BACKGROUND: Salivary C-reactive protein (CRP) could be a viable biomarker of inflammation and has been associated with stress outcomes. The hypothalamic-pituitary-adrenal axis can modulate stress-related inflammation. This study aimed to evaluate the interaction effects of immune-endocrine markers on psychological outcomes. METHODS: The study participants were 52 healthy Chinese adults who collected 10 saliva samples over 2 consecutive days at baseline. The participants completed validated measures on anxiety, depression, positive affect, and sleep disturbance at baseline and 1 month later. The stability and diurnal patterns of salivary cortisol and CRP were investigated via paired t-tests and repeated-measures analyses of variance. Regression analysis was used to examine the longitudinal associations between immune-endocrine markers and their interactions (cortisol [Cort]: morning CRP [CRPmorn] and Cort:CRPeven) and psychological measures. RESULTS: Salivary cortisol and CRP displayed satisfactory stability over 2 consecutive days and diurnal patterns of abrupt and gradual decline during the day, respectively. Controlling for baseline psychological measures and confounding variables, Cortmorn and diurnal cortisol slope was significantly and negatively associated with anxiety symptoms and positive affect 1 month later, respectively. Cort:CRPeven and Cort:CRPmorn was significantly and positively associated with depressive symptoms and sleep disturbance 1 month later, respectively. CONCLUSION: These findings offer initial support for the prognostic utility of salivary cortisol and CRP and their balance as determinants of psychological health in healthy adults.

Adrenocortical responses of emerging adults in California in the two months following the Pulse night club massacre: Evidence for distal stress responses.

This study examined adrenocortical responses in the days following the Pulse nightclub massacre on June 12, 2016, among emerging adults in Northern California (N = 202; M = 23.18 years, SD = 2.56; 25% LGBQ-Latinx, 25% LGBQ-White, 25% Straight-Latinx, and 25% Straight-White) between June 13-August 12, 2016. As predicted, participants tested more proximally to the massacre had higher waking cortisol (intercepts) and flatter diurnal cortisol output (slopes), indicative of time-dependent adrenocortical arousal across the day. The effect of days post-massacre on waking cortisol was moderated by daily distress, with days since the Pulse massacre predicting waking cortisol significant only for participants reporting lower distress; participants who reported feeling higher daily distress had elevated waking cortisol across the testing period. These findings were independent of weekly personal stressors, and consistent across participants' demographic and identity characteristics. The violent attack at the Pulse nightclub was connected to increased waking cortisol and diurnal cortisol production for several days after the massacre, in a distal population exposed to the massacre vicariously, and especially for individuals not experiencing other, personal stressors. Heightened physiological responses to violent crimes support policy efforts to protect vulnerable communities, including violence prevention, gun control, and community-based trauma response services for those directly and indirectly affected by gun violence.

The Health Correlates of Culture: Examining the Association Between Ethnic-Racial Identity and Diurnal Cortisol Slopes.

PURPOSE: The objective of this study was to examine the link between ethnic-racial identity (ERI) components (exploration, resolution, and affirmation) and youths' diurnal cortisol slopes. METHODS: A sample of 103 U.S.-Mexican adolescents (Mage = 15.29 years) living in the Southwest participated in an in-home interview and 3-day salivary sampling protocol. RESULTS: ERI affirmation, but not exploration or resolution, was related to steeper diurnal slopes (greater declines in cortisol from waking to bedtime) after controlling for adolescents' life stressors, acculturation level, ethnic-racial discrimination, and daily behaviors (i.e., caffeine use, hours of exercise, hours of sleep, and medication level). CONCLUSIONS: This study provides initial evidence of the physiological benefits of ERI affirmation. Given that steeper diurnal slopes are thought of as an indicator of positive health, our findings point to the importance of examining cultural processes in the well-being of ethnic-racial minority youth.

Diurnal cortisol slopes and mental and physical health outcomes: A systematic review and meta-analysis.

Changes in levels of the stress-sensitive hormone cortisol from morning to evening are referred to as diurnal cortisol slopes. Flatter diurnal cortisol slopes have been proposed as a mediator between chronic psychosocial stress and poor mental and physical health outcomes in past theory and research. Surprisingly, neither a systematic nor a meta-analytic review of associations between diurnal cortisol slopes and health has been conducted to date, despite extensive literature on the topic. The current systematic review and meta-analysis examined associations between diurnal cortisol slopes and physical and mental health outcomes. Analyses were based on 179 associations from 80 studies for the time period up to January 31, 2015. Results indicated a significant association between flatter diurnal cortisol slopes and poorer health across all studies (average effect size, r=0.147). Further, flatter diurnal cortisol slopes were associated with poorer health in 10 out of 12 subtypes of emotional and physical health outcomes examined. Among these subtypes, the effect size was largest for immune/inflammation outcomes (r=0.288). Potential moderators of the associations between diurnal cortisol slopes and health outcomes were examined, including type of slope measure and study quality indices. The possible roles of flatter slopes as either a marker or a mechanism for disease etiology are discussed. We argue that flatter diurnal cortisol slopes may both reflect and contribute to stress-related dysregulation of central and peripheral circadian mechanisms, with corresponding downstream effects on multiple aspects of biology, behavior, and health.