Epstein-Barr virus antibody titer and its association with the domain scores from the World Health Organization's Quality of Life questionnaire: Findings from Rural Hainan Province, China

Drought-compounded stress and immune function in Kenyan pastoralist boys and girls occupying contrasting climate zones

BACKGROUND AND AIM

We provide ethnographic, photovoice, and psychosocial stress data (food and water insecurity, potentially traumatic events, stress biomarkers) documenting the joys, hazards, and stressors of adolescents engaging in climate-sensitive pastoralist livelihoods in a global climate change hot spot. We aim to holistically capture socio-environmental relationships characterised by climate sensitive livelihoods and forms of precarity exacerbated by climate change.

SUBJECTS AND METHODS

Qualitative and quantitative methods were integrated to understand the embodied toll of hazards that Samburu pastoralists faced based on a sample of 161 young people. Quantitatively, we tested for associations of psychosocial stressors with both psychological distress and cell-mediated immune function (assessed through differences in IgG antibodies to Epstein-Barr virus).

RESULTS

Qualitatively, young Samburu reported drought, food and water insecurity, wildlife encounters, and war exposure. Girls overall endorsed more posttraumatic stress symptoms, although boys reported relatively more stressors; girls overall and young people in the hotter subregion manifested more immune dysregulation.

CONCLUSION

In spite of important differences between climate subregions, the common elements throughout the Samburu pastoralist leanscape include food and water insecurity and overall precarity exacerbated by drought and climate change. Community-driven interventions are needed to reduce precarity for young people pursuing pastoralist livelihoods.

Chronic non-communicable diseases: Hainan prospective cohort study

PURPOSE

The Hainan Cohort was established to investigate the incidence, morbidity and mortality of non-communicable diseases and their risk factors in the community population.

PARTICIPANTS

The baseline investigation of the Hainan Cohort study was initiated in five main areas of Hainan, China, from June 2018 to October 2020. A multistage cluster random-sampling method was used to obtain samples from the general population. Baseline assessments included a questionnaire survey, physical examination, blood and urine sample collection, and laboratory measurements, and outdoor environmental data were obtained.

FINDINGS TO DATA

A total of 14 443 participants aged 35-74 years were recruited at baseline, with a participation rate of 90.1%. The mean age of the participants was 48.8 years; 51.8% were men, and 83.7% had a secondary school or higher education. The crude prevalence of diabetes, coronary heart disease, stroke, hypertension, hyperuricaemia, chronic bronchitis, pulmonary tuberculosis, asthma, cancer, chronic hepatitis and metabolic syndrome were 8.6%, 9.2%, 2.0%, 37.1%, 7.1%, 2.3%, 1.4%, 2.1%, 4.1%, 2.2% and 14.5%, respectively.

FUTURE PLANS

The Hainan Cohort is a dynamic cohort with no end date. All participants will be monitored annually for cause-specific mortality and morbidity until death. Long-term follow-up will be conducted every 5 years. The baseline population is considered to expand in the next wave of follow-up, depending on the availability of funding support.

Applying minimally invasive biomarkers of chronic stress across complex ecological contexts

Chronic stress is both theoretically and methodologically challenging to operationalize through biomarkers. Yet minimally invasive, field-friendly biomarkers of chronic stress are valuable in research linking biology and culture, seeking to understand differential patterns of human development across ecological contexts, and exploring the evolution of human sociality. For human biologists, a central question in measurement and interpretation of biomarkers is how stress-responsive physiological systems are regulated across diverse human ecologies. This article aims to describe a conditional toolkit for human biologists interested in the study of chronic stress, highlighting a mix of longstanding and novel biomarkers, with special focus on hair/fingernail cortisol, latent herpesvirus antibodies, allostatic load indices, and serial/ambulatory data collection approaches. Future trends in chronic stress biomarker research, including epigenetic approaches, are briefly considered. This overview considers: (1) challenges in separating a distinctly psychosocial dimension of chronic stress from adversity more broadly; (2) essential characteristics of human ecology that shape interpretation; (3) retrospective vs. longitudinal sampling; (4) the role of age, developmental effects, and local biologies; (5) different timescales of chronicity; and (6) the role of culture.

Chronic stress and age-related pattern of blood pressure: A cross-sectional study in rural China

OBJECTIVE

Chronic stress is a risk factor for hypertension in adults. However, there is conflicting evidence for older adults. We hypothesized that age-related arterial stiffening, which leads to a lower blood pressure (especially diastolic blood pressure [DBP]), is more pronounced among older adults with high vs low stress. The objectives of this study were (a) to investigate age-related trends in systolic and DBPs among adults in rural Fujian, China, and (b) to examine differences in age-related blood pressure trends according to levels of stress by using Epstein-Barr virus (EBV) antibody titer as a marker of chronic stress status.

METHODS

We collected cross-sectional data from 764 rural community-dwelling adults in rural Fujian, China (mean age = 59.4). Participants were categorized into high and low stress groups by median split of EBV antibody titer. A least-squares regression analysis was used to investigate the association between age and blood pressures.

RESULTS

We observed an inverted U-shaped association between age and DBP, while there was a linear association between age and systolic blood pressure in the overall sample. When stratified by stress, the inverted U-shaped associations with age (both systolic and DBPs) were seen only among those with high stress; DBP peaked at the age of ~68 years, and the declining trend later in life was more clearly observed among those with high chronic stress.

DISCUSSION

Decrease of DBP was more pronounced among older adults with high vs low chronic stress in rural China.

The association between family members' migration and Epstein-Barr virus antibody titers among people left behind in rural Fujian, China

OBJECTIVES

In contrast to the health of migrants, which has been extensively studied, little attention has been paid to the health of adults left behind by family members who out-migrated to other locations. This study was performed to investigate the association between being left behind and the Epstein-Barr virus (EBV) antibody titer, which is an indicator of cellular immune functioning previously shown to be associated with psychological stress.

METHODS

A cross-sectional survey was conducted in rural communities in Fujian, China, in 2015. Questionnaire data and dried blood spot samples were collected from 748 adults. A mixed effect regression analysis was conducted to investigate the association.

RESULTS

Results indicated that the EBV antibody titers were higher among people who had been left behind compared with those who had not.

CONCLUSIONS

Our findings suggest that, in rural Fujian, China, family separation following the out-migration of family members is an important determinant of psychological stress.

Epstein-Barr virus antibody titer as a stress biomarker and its association with social capital in rural Fujian communities, China

OBJECTIVES

There has been little research on the association between social capital and psychological stress measured by a biomarker, particularly in developing countries. Our objective was to investigate the association between Epstein-Barr virus (EBV) antibody titer, an indicator of cellular immune function previously shown to be associated with psychological stress, and social capital among rural community dwellers in Fujian Province, China.

METHODS

We conducted a cross-sectional survey in seven rural communities in Fujian in 2015. We used questionnaire data and dried blood spot samples for the measurement of biomarkers collected from 734 local residents for the analysis. We conducted a mixed effects regression analysis to investigate the association between EBV antibody titer and four social capital variables, which included cognitive and structural social capital assessed both at individual and community levels.

RESULTS

Community-level structural social capital was inversely associated with psychological stress (coefficient = -0.96, 95% confidence interval [CI] = -1.91, -0.01) while individual-level structural social capital was positively associated with it (coefficient = 0.21, 95% CI = 0.07, 0.36). Neither individual- nor community-level cognitive social capital was associated with psychological stress status.

CONCLUSIONS

In rural Fujian, China, social capital seemed to be an important determinant of psychological health. While living in a community with active social interaction may benefit the residents psychologically, social interaction in the form of strongly bonded relationships may be a source of psychological stress at the individual level due to the potential demands and obligations that may be associated with such connections.

Stress and midlife women's health

Stress is ubiquitous in everyday life, and chronic stress can have negative consequences for health and social welfare. Although a growing body of research addresses the relationships between stress, health, and quality of life, there is a gap in the literature with regard to the effects of stress among women at midlife. The purpose of this commentary is to provide a brief history of stress research, including various methods for measuring stress; discuss the physiological effects of stress; and review relevant studies about women at midlife in order to identify unanswered questions about stress. This commentary also serves as an introduction to a thematic series on stress and women’s midlife health where stress is examined in relation to a wide range of symptom experiences, in the context of family and negative life events, as associated with women’s work, and correlated with the challenges of violence and discrimination. The goal of this commentary and thematic series is to extend the conversation about stress to include women at midlife, and to examine where we are, and where we are going, in order to direct future research and provide relevant care for this growing population.

Validation of an Optimized ELISA for Quantitative Assessment of Epstein-Barr Virus Antibodies from Dried Blood Spots

Our objective was to validate a commercially available ELISA to measure antibody titers against Epstein-Barr virus (EBV) in dried blood spots (DBS) to replace a previously validated assay for DBS that is no longer available. We evaluated the precision, reliability, and stability of the assay for the measurement of EBV antibodies in matched plasma, fingerprick DBS, and venous blood DBS samples from 208 individuals. Effects of hematocrit and DBS sample matrix on EBV antibody determination were also investigated, and the cutoff for seropositivity in DBS was determined. A conversion equation was derived to enable comparison of results generated using this method with the former DBS method. There was a high correlation between plasma and DBS EBV antibody titers (R(2) = 0.93) with very little bias (-0.07 based on Bland-Altman analysis). The assay showed good linearity and did not appear to be affected by the DBS matrix, and physiological hematocrit levels had no effect on assay performance. There was reasonable agreement between DBS EBV titer estimates obtained using this assay and the previously validated assay (R(2) = 0.72). The commercially available ELISA assay for EBV antibody titers that we validated for use with DBS will facilitate continued investigation of EBV antibody titers in DBS.

The Effects of Season of Birth on the Inflammatory Response to Psychological Stress in Hainan Island, China

Season of birth (SOB) has been investigated as one of the environmental factors that might epigenetically determine the physiology of individuals. This study investigated the role of SOB in the association between Quality of Life (QOL), a proxy of psychological stress status, and C-reactive protein (CRP) concentration (i.e., inflammatory status) among 1,085 adults (aged 20–57 years old) in Hainan Island, China. High sensitivity CRP concentration was measured in dried blood spot samples, while the abbreviated version of the World Health Organization’s QOL questionnaire was used to gather information on six QOL domains. Analysis stratified by three historically distinct age groups revealed a significant association between CRP concentration, SOB, QOL and an interaction between SOB and QOL among the youngest and oldest groups. In the oldest group, those born in the dry season had a higher CRP concentration with worse QOL whereas in the youngest group, there was a higher CRP concentration with better QOL. Annual per capita rice production, a proxy of population nutritional status in the year of birth, was found to predict CRP concentration only among the second oldest group. These findings suggest that the early environment might affect the immune response to psychological stress in adulthood and that its effect may differ by the time period in which people were born.