Daily stress and eating behaviors in adolescents and young adults: Investigating the role of cortisol reactivity and eating styles.

Stress-related eating has been well documented in previous literature. However, there is limited research investigating the role of cortisol reactivity in daily stress-eating associations in samples of adolescents and young adults. 123 participants completed a baseline questionnaire and the Trier Social Stress Test in groups. Four saliva samples were taken at - 10, + 00, + 10 and + 40 min during the stress-induction task. Following this, participants completed an online daily diary each evening for 14 consecutive days to record daily stress and between-meal snack consumption. Multilevel modelling indicated that daily stress was positively associated with daily snack intake, particularly for ego-threatening and work/academic stressors. Emotional and external eating styles were found to moderate the stress-snacking relationship. Cortisol reactivity also moderated stress-eating associations, such that as cortisol reactivity levels increased from lower to higher levels, the impact of stress on eating decreased. The current findings highlight the importance of cortisol reactivity status and eating styles in understanding the complex relationship between daily stress and eating behavior in adolescents and young adults. Future research should continue investigating stress-eating associations in these groups and explore the role of other aspects of hypothalamic-pituitary-adrenal axis functioning.

Stress and eating behaviours in healthy adults: a systematic review and meta-analysis.

Stress leads to detrimental health outcomes through direct biological and indirect behavioural changes. Stress can lead to disruption to normal eating behaviours, although the strength of these associations is unknown. This is the first meta-analysis to determine the strength of the stress-eating relationship in healthy adults and to explore the impact of potential moderators. Studies included had a clearly defined measure of stress (i.e., any noxious event or episode in one's environment with the exclusion of emotional distress) that was linked to non-disordered eating. Key terms were searched in Medline, PsycInfo and Ovid databases (23,104 studies identified). 54 studies (combined N = 119,820) were retained in the meta-analysis. A small, positive effect size was found for the stress-overall food intake relationship (Hedges' g = 0.114). Stress was associated with increased consumption of unhealthy foods (Hedges' g = 0.116) but decreased consumption of healthy foods (Hedges' g = -0.111). Only one significant moderator (restraint on stress-unhealthy eating) was identified. This meta-analysis identified the magnitude of the effect of stress on eating behaviour outcomes. Significant heterogeneity was observed that was not explained by the moderators examined. Further research on moderators of the stress-eating relationship is required and should distinguish effects for healthy versus unhealthy eating.

Elevated levels of hair cortisol concentrations in professional dementia caregivers.

Providing care for people with dementia can be a highly stressful profession. Hair Cortisol Concentration (HCC) levels have been used as a biological marker for HPA axis activity to demonstrate that informal caregivers of people with dementia could be vulnerable to chronic stress. The current study aimed to progress the findings of research conducted with informal caregivers and is the first study to assess HCC as a biological indicator of stress in professional carers of people with dementia. HCC levels were compared between 32 professional dementia caregivers (30 females with a mean age of 45.83 and 2 males with a mean age of 24.50), 45 employees working in higher education settings (42 females with a mean age of 38.66 and 3 males with a mean age of 31.89) and 88 undergraduate students (67 females with a mean age of 24.04 and 21 males with a mean age of 23.91). Analysis of HCC was used to assess HPA axis activity over 1 month. A one-way ANCOVA, with age and gender being included as covariates, revealed that higher levels of HCC were observed in professional dementia carers than people who worked within higher education settings and undergraduate students. The results indicated that professional dementia caregivers may experience stress to the extent of activating biological stress responses at a greater frequency in comparison to people who work in higher education and undergraduate students. However, no significant differences were observed in the perceived stress levels reported across dementia caregivers, professionals working in higher education, and undergraduate students. These findings highlight the requirement to ascertain the extent to which work-related tasks or other factors, specific to the profession of caring for people with dementia, could elicit heightened HPA stress reactivity.

The contribution of childhood adversity to cortisol measures of early life stress amongst infants in rural India: Findings from the early life stress sub-study of the SPRING cluster randomised controlled trial (SPRING-ELS).

BACKGROUND: The majority of the world's children live in low- and middle-income countries and face multiple obstacles to optimal wellbeing. The mechanisms by which adversities - social, cultural, psychological, environmental, economic - get 'under the skin' in the early days of life and become biologically embedded remain an important line of enquiry. We therefore examined the contribution of childhood adversity through pregnancy and the first year of life to hair and salivary cortisol measures of early life stress in the India SPRING home visits cluster RCT which aims to improve early childhood development. METHODS: We assessed 22 adversities across four domains: socioeconomic, maternal stress, family-child relationship, and child and summed them to make a cumulative adversity score & quintiles, and four subscale scores. We cut 3 cm of hair from the posterior vertex and took three saliva samples from morning till late afternoon on each of two days (total six samples). We analysed both for cortisol concentration using ELISA techniques. We used multiple linear regression techniques to assess the relationship between cumulative adversity and log hair cortisol concentration and saliva diurnal slope and area under the curve. RESULTS: We assessed 712 children for hair, and 752 children for saliva cortisol at 12 months of age. We found a strong positive relationship between adversity and hair cortisol; each additional adversity factor was associated with hair cortisol increases of 6.1% (95% CI 2.8, 9.4, p < 0.001) and the increase from adversity quintile one to five was 59.4%. Socioeconomic, relationship and child scales were independent predictors of hair cortisol (socioeconomic 6.4% (95% CI -0.4, 13.6); relationship 11.8% (95% CI 1.4, 23.2); child 7.9% (95% CI -0.5, 16.9). We did not find any association between any measures of adversity and either of the saliva cortisol outcomes. DISCUSSION: This is the largest study of hair cortisol in young children, and the first in a low- and middle-income country setting. Whilst the short-term diurnal measures of cortisol did not appear to be linked with adversity, chronic exposure over several months appears to be strongly associated with cumulative adversity. These findings should spur further work to understand the specific ways in which adversity becomes biologically embedded, and how this can be tackled. They also lend support to ongoing action to tackle childhood adversity in communities around the world.

The anticipatory stress response to sport competition; a systematic review with meta-analysis of cortisol reactivity.

OBJECTIVE: Athletes anticipating sport competition regularly experience distinct emotional and physiological responses as a result of the expected psychosocial and physical stress. Specifically, cortisol, an indicator of hypothalamic-pituitary-adrenal axis activation, prepares the athlete for the psychological and physiological demands of competition. The objective of this meta-analysis is to analyse the magnitude of the anticipatory cortisol response in athletes preparing to participate in sport competition and to examine the influence of gender, level of competition and data collection time. DESIGN: Systematic review with meta-analysis. DATA SOURCES: Four electronic databases were searched to March 2017: PubMed, PsycINFO, SPORTDiscus and Scopus. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: (1) Athletes participating in real sport competition;(2) salivary cortisol concentration collected before competition in addition to baseline sample(s);(3) original research article published in English language. RESULTS: Data from 25 studies provided 27 effect sizes. A significant anticipatory cortisol response of g=0.85, p<0.001 was identified. Males had a stronger trend for greater cortisol reactivity (g=1.07) than females (g=0.56, p=0.07). Females and athletes competing at international level did not demonstrate a significant anticipatory stress response. There were no significant differences between level of competition, type of sport or time of competition. Meta-regression indicated that the anticipatory cortisol response is greater when assessed closer to the start of competition (Q=6.85, p=0.009). SUMMARY/CONCLUSION: The anticipatory cortisol response before sport competition reflects moderate cortisol reactivity that prepares athletes optimally for the demands of sport competition via the influence on cognitive processes and attentional control. However, both female athletes and international competitors did not demonstrate a significant anticipatory cortisol response, possibly due to differences in appraisal of the stress of sport competition.

Measurement of cortisol in saliva: a comparison of measurement error within and between international academic-research laboratories.

OBJECTIVE: Hundreds of scientific publications are produced annually that involve the measurement of cortisol in saliva. Intra- and inter-laboratory variation in salivary cortisol results has the potential to contribute to cross-study inconsistencies in findings, and the perception that salivary cortisol results are unreliable. This study rigorously estimates sources of measurement variability in the assay of salivary cortisol within and between established international academic-based laboratories that specialize in saliva analyses. One hundred young adults (Mean age: 23.10 years; 62 females) donated 2 mL of whole saliva by passive drool. Each sample was split into multiple- 100 µL aliquots and immediately frozen. One aliquot of each of the 100 participants' saliva was transported to academic laboratories (N = 9) in the United States, Canada, UK, and Germany and assayed for cortisol by the same commercially available immunoassay. RESULTS: 1.76% of the variance in salivary cortisol levels was attributable to differences between duplicate assays of the same sample within laboratories, 7.93% of the variance was associated with differences between laboratories, and 90.31% to differences between samples. In established-qualified laboratories, measurement error of salivary cortisol is minimal, and inter-laboratory differences in measurement are unlikely to have a major influence on the determined values.

Exploring day-to-day dynamics of daily stressor appraisals, physical symptoms and the cortisol awakening response.

Stress is associated with the secretion of cortisol throughout the day, but less is known about the dynamic effects of stress on the cortisol awakening response (CAR). More widely, knowledge of the causal factors and functions of the CAR are also not fully understood. This study explored: (1) the effects of daily stressors on the next day CAR and; (2) the effects of the CAR on same day physical and affective outcomes. Sixty-four participants completed a daily diary, reporting on the occurrence of daily stressors and stress appraisals, physical symptoms, and affect. Cortisol was measured at 0, 15, 30, and 45 min after awakening to provide measures of the CAR on 3 consecutive work days. Stress appraisal was found to negatively predict the CAR, such that where stressors were appraised as more stressful (where perceived demands exceeded resources), the CAR increased less the following morning. Furthermore, the CAR significantly predicted same-day physical symptoms such that a lower CAR was associated with more physical symptoms. This study provides evidence for a pathway through which daily stressors may influence physical wellbeing, and highlights the importance of appraisals for future stress-based cortisol research.

Factors underlying caregiver stress in frontotemporal dementia and Alzheimer's disease.

BACKGROUND: Frontotemporal dementia (FTD) has devastating effects on patients and caregivers, yet the factors underlying caregiver stress are poorly understood. METHODS: 108 caregivers (79 = FTD, 29 = Alzheimer's disease) participated in a postal survey. Self-report measures of perceived stress, depression, social networks, as well as patient-based measures of behaviour change and activities of daily living were completed. RESULTS: Depression was a cardinal feature in FTD caregivers, and it accounted for more than 58% of stress scores. Both depression and stress were significantly higher than in AD. Neither the severity of behaviour changes nor functional disability explained caregiver stress. CONCLUSION: Caregiver stress is a multidimensional construct, and FTD caregivers should receive more support than currently available. Depression plays a key role in coping ability.

Stress, distress and mucosal immunity in carers of a partner with fronto-temporal dementia.

OBJECTIVES: This study investigates the psychological and physiological impact of caring for a partner with fronto-temporal dementia (FTD). Carers were expected to exhibit greater stress and poorer psychological well-being in comparison with non-carers, and suppressed mucosal immunity. METHOD: Twenty-five carers and 36 non-carers completed standardised psychological assessments of perceived stress, psychological well-being, coping and social support. Levels of mucosal immunity were assessed in saliva samples collected over the 3 days of the study, alongside daily assessments of stress, arousal and mood. RESULTS: Informal carers as a group reported greater stress and poorer psychological well-being, but there was considerable variation, with some carers reporting better psychological functioning than non-carers. Immune levels were not suppressed in carers compared with non-carers; counter to hypothesis, there was a positive correlation between immunity and poorer psychological well-being. CONCLUSIONS: This research suggests that caring for a partner with FTD increases distress and carers might benefit from psychological intervention. However, the variation in psychological well-being requires explanation. Furthermore, this first examination of mucosal immunity employing participants experiencing enduring stress suggests that, in contrast to previous research, enduring stress does not lead to suppression of mucosal immunity and may actually enhance it.