Herpesvirus reactivation and socioeconomic position: a community-based study

Early Life Adversity, Microbiome, and Inflammatory Responses

Early life adversity has a profound impact on physical and mental health. Because the central nervous and immune systems are not fully mature at birth and continue to mature during the postnatal period, a bidirectional interaction between the central nervous system and the immune system has been hypothesized, with traumatic stressors during childhood being pivotal in priming individuals for later adult psychopathology. Similarly, the microbiome, which regulates both neurodevelopment and immune function, also matures during childhood, rendering this interaction between the brain and the immune system even more complex. In this review, we provide evidence for the role of the immune response and the microbiome in the deleterious effects of early life adversity, both in humans and rodent models.

Perceived income inadequacy is associated with Epstein-Barr Virus latency and mental health outcomes in informal caregivers who are also employed in the healthcare industry

Finances are a prevalent source of stress. In a sample of 799 nursing home workers measured multiple times over 18 months, we found that higher perceived income inadequacy, the perception that one's expenses exceeds one's incomes, was associated with poorer self-reported mental health indicators and Epstein-Barr Virus antibody titers (a marker of cell-mediated immune function). Perceived income inadequacy predicted outcomes over and above the role of other socioeconomic status variables (objective household income and education). Mental health variables were not related to Epstein-Barr Virus antibody titers. Additionally, we found an interaction between perceived income inadequacy and informal caregiver status on our mental health outcomes; informal caregivers with higher perceived income inadequacy had poorer mental health than non-caregivers with the same perceived income inadequacy. Our findings may add nuance to the reserve capacity model, which states that those at lower socioeconomic levels are at higher risk of adverse health outcomes partly because they have fewer resources to address demands and strain. Perceived income inadequacy may significantly predict mental and physical well-being beyond other socioeconomic status variables, especially among lower-income employees. Caregiving stress and perceived income inadequacy may have synergistic effects on mental health.

Diminished Cellular Immunity and Executive Cognitive Functioning Among Middle-Aged and Elderly Adults

OBJECTIVE

Within the field of psychoneuroimmunology, much attention has been given to immune dysregulation and its impact on cognitive functioning. Some of this work has focused on the association between high levels of basal proinflammatory cytokines and poorer performance on measures of executive functioning; however, effect sizes have been quite small in human studies.

METHODS

We investigated whether Epstein-Barr virus (EBV) antibody titers, a marker of immune dysregulation related to cellular immunity, may be associated with executive functioning while also attempting to replicate prior studies using two markers of proinflammatory cytokine production (i.e., circulating and lipopolysaccharide [LPS]-stimulated cytokines [interleukin 6, interleukin 1β, interferon-γ]). A total of 71 community-dwelling adults (mean [standard deviation] age = 60.87 [6.26] years) who were seropositive for EBV infection participated in the study.

RESULTS

Findings indicated that greater EBV antibody titers were associated with poorer performance on measures of the executive functions of inhibition ( B = -2.36, standard error = 1.06, p = .028) and cognitive flexibility ( B = -2.89, standard error = 1.13, p = .013) when including circulating and LPS-stimulated cytokines and other relevant covariates (i.e., age, sex, and body mass index) in linear regression analyses. Neither circulating nor LPS-stimulated cytokines were associated with performance on the cognitive tasks in the regression analyses.

CONCLUSIONS

These results suggest that EBV antibody titers may be an indicator of immune dysregulation that is more relevant to executive functioning performance than either circulating or stimulated proinflammatory cytokines among community-dwelling adults.

Antibodies to Human Herpesviruses and Rate of Incident Cardiovascular Events and All-Cause Mortality in the UK Biobank Infectious Disease Pilot Study

Background

Associations between human herpesviruses (HHVs) and cardiovascular disease/mortality have been reported, but evidence is inconsistent. We investigated associations between 3 common herpesviruses and (1) incident stroke or myocardial infarction (MI) and (2) all-cause mortality.

Methods

We included participants from the UK Biobank Infectious Disease pilot study with valid serum antibody (IgG) measurements taken at cohort entry (2006-2010) for herpes simplex virus type 1 (HSV1), varicella zoster virus (VZV), and cytomegalovirus (CMV). Linked hospital and mortality records up to December 30 2019 provided information on rates of (1) incident first stroke or MI and (2) all-cause mortality. Hazard ratios (HRs) from Cox proportional hazards regression models were used to assess relationships between (1) HHV seropositivity, (2) HHV titer and incident stroke/MI, and death outcomes. Fully adjusted models accounted for sociodemographic information (age, sex, ethnicity, education, deprivation quintile, birthplace, population density), baseline comorbidities (including diabetes and hypertension), smoking status, body mass index, and serum cholesterol.

Results

Of 9429 study participants (56% female, 95% White, median age 58 years), 41% were seropositive for all 3 HHVs. Human herpesvirus seropositivity was not associated with stroke/MI (fully adjusted HRs and 95% confidence intervals [CIs]: HSV1 = 0.93 [CI, 0.72-1.22], VZV = 0.78 [CI, 0.51-1.20], CMV = 0.91 [CI, 0.71-1.16]) or all-cause mortality (HSV1 = 1.21 [CI, 1.00-1.47], VZV = 0.79 [CI, 0.58-1.07], CMV = 0.90 [CI, 0.76-1.06]). Human herpesvirus titers were not associated with outcomes.

Conclusions

In this mostly White UK Biobank subset, neither HHV seropositivity nor titers were associated with stroke/MI or all-cause mortality.

Examination of control asymptomatic cohorts reveals heightened anti-EBV and HHV-6 A/B dUTPase antibodies in the aging populations

Members of the human Herpesviridae are found in high prevalence in the human virome. While these viruses are known to cause numerous disease pathologies in symptomatic individuals little is known concerning the role that these viruses may have in modulating the host immune system in asymptomatic “healthy” individuals, especially during the aging process. Examination of three cohorts of “healthy asymptomatic” individuals (n = 255) for the presence of antibodies against the herpesviruses deoxyuridine triphosphate nucleotidohydrolase (dUTPase) as a marker for lytic/abortive‐lytic replication demonstrated that all cohorts exhibited differential anti‐herpesvirus dUTPase antibodies positivity frequencies ranging from 40.4% to 84% with some individuals in these cohorts expressing antibodies to the dUTPases of multiple herpesviruses (17.2%–56%). Furthermore, our results demonstrate that there was a statistically significant difference in anti‐human herpesvirus 6 A and 6B (HHV‐6 A/B) dUTPase antibodies in Cohort 3 (age = 66.2 ± 15.02 years) versus Cohort 1 (age 46.88 ± 8.61 years), suggesting that reactivation of HHV‐6 A/B is not attenuated by aging. It is well established/documented that herpesvirus dUTPases induce immune dysfunction, as such it is of critical importance that additional studies be performed to determine how these viral proteins alter immune responses in asymptomatic individuals.

Immune and Epigenetic Pathways Linking Childhood Adversity and Health Across the Lifespan

Childhood adversity is associated with a host of mental and physical health problems across the lifespan. Individuals who have experienced childhood adversity (e.g., child abuse and neglect, family conflict, poor parent/child relationships, low socioeconomic status or extreme poverty) are at a greater risk for morbidity and premature mortality than those not exposed to childhood adversity. Several mechanisms likely contribute to the relationship between childhood adversity and health across the lifespan (e.g., health behaviors, cardiovascular reactivity). In this paper, we review a large body of research within the field of psychoneuroimmunology, demonstrating the relationship between early life stress and alterations of the immune system. We first review the literature demonstrating that childhood adversity is associated with immune dysregulation across different indices, including proinflammatory cytokine production (and its impact on telomere length), illness and infection susceptibility, latent herpesvirus reactivation, and immune response to a tumor. We then summarize the growing literature on how childhood adversity may alter epigenetic processes. Finally, we propose future directions related to this work that have basic and applied implications.

Psychosocial stressors predict lower cardiovascular disease risk among Mexican-American adults living in a high-risk community: Findings from the Texas City Stress and Health Study

The objective of this study was to examine the link between systemic and general psychosocial stress and cardiovascular disease (CVD) risk in a group of U.S. Latinos as a function of acculturation and education within the blended guiding conceptual framework of the biopsychosocial model of the stress process plus the reserve capacity model. We analyzed data from self-identifying Mexican-origin adults (n = 396, 56.9% female, Mage = 58.2 years, 55.5% < 12 years of education, 79% U.S.-born) from the Texas City Stress and Health Study. We used established measures of perceived stress (general stress), neighborhood stress and discrimination (systemic stress) to capture psychosocial stress, our primary predictor. We used the atherosclerotic CVD calculator to assess 10-year CVD risk, our primary outcome. This calculator uses demographics, cholesterol, blood pressure, and history of hypertension, smoking, and diabetes to compute CVD risk in the next 10 years. We also created an acculturation index using English-language use, childhood interaction, and preservation of cultural values. Participants reported years of education. Contrary to expectations, findings showed that higher levels of all three forms of psychosocial stress, perceived stress, neighborhood stress, and perceived discrimination, predicted lower 10-year CVD risk. Acculturation and education did not moderate the effects of psychosocial stress on 10-year CVD risk. Contextualized within the biopsychosocial and reserve capacity framework, we interpret our findings such that participants who accurately reported their stressors may have turned to their social networks to handle the stress, thereby reducing their risk for CVD. We highlight the importance of examining strengths within the sociocultural environment when considering cardiovascular inequities among Latinos.

Racial and Economic Adversity Differences in Stress Markers and Immune Function Among Urban Adolescents

BACKGROUND

Exposure to racism and associated adversities, such as poverty, is hypothesized to contribute to racial inequities in health via stress and immune pathways. Furthermore, the effects of adversity may be more salient during sensitive developmental periods. Our study examined racial differences in stress and immune biomarkers during adolescence and the effects of exposure to economic adversity at distinct developmental time periods and cumulatively in accounting for potential racial differences.

METHODS

Secondary analysis of the Adolescent Health and Development in Context study was conducted. Data were derived from self-administered surveys; interviews; smartphone-based, geographic-explicit ecological momentary assessment; stress biomarkers (evening salivary cortisol over six nights and hair cortisol); and immune biomarkers (salivary shedding of Epstein-Barr virus [EBV] DNA among EBV-positive adolescents). Current socioeconomic status measures included annual household income and caregiver education. Caregivers also reported experiences of bankruptcy, difficulty paying bills, receipt of food stamps/Supplemental Nutrition Assistance Program/electronic benefit transfer, and job loss when the child was of ages birth-5 years, 6-10 years, and 11 years or older. An affirmative response to any item was defined as exposure to economic adversity for that developmental time period (yes/no). A cumulative economic adversity measure was calculated as the sum of exposures across developmental periods (0 = never exposed to 3 = exposed across all time periods). Descriptive and multivariable regression analyses were conducted, accounting for covariates.

RESULTS

Black/African American adolescents had higher salivary cortisol concentration, higher hair cortisol concentration, and an increased odd of salivary shedding of EBV DNA compared to White adolescents. Racial differences were not attenuated by the current socioeconomic status or economic adversity (developmental period or cumulatively).

DISCUSSION

Our study provides evidence that stress and immune biomarkers differ by race as early as adolescence and may be one pathway through which racism and associated adversities contribute to racial health inequities. Further research on the contribution of multiple adversities beyond poverty to racial inequities in physiological stress and health is critical for informing effective prevention and intervention efforts.

Perceived Social Support and Latent Herpesvirus Reactivation: Testing Main and Stress-Buffering Effects in an Ethnically Diverse Sample of Adults

OBJECTIVE

Perceived social support is consistently associated with physical health outcomes, and one potential physiological mechanism underlying this association is immune function. In this study, we tested both the main and stress-buffering effects of perceived social support on cellular immunity measured via latent herpesvirus reactivation.

METHODS

Data were collected from a community-based sample of 1443 ethnically diverse adults between the ages of 25 and 90 years. Participants self-reported measures of perceived social support, stressful life events, daily hassles, and perceived stress, and provided a blood sample to assess antibody titers to the herpes simplex virus type 1 and Epstein-Barr virus (EBV).

RESULTS

In accordance with the main effect hypothesis, results indicated that perceived social support was directly associated with EBV viral capsid antigen antibody titers (β = -0.06, 95% confidence interval = -0.12 to -0.01, p = .029). Perceived social support, however, did not interact with stressful life events, daily hassles, or perceived stress to influence latent herpesvirus reactivation (p values > .05). Neither race/ethnicity nor age moderated any of the interactions between perceived social support and the stress measures on latent herpesvirus reactivation (p values > .10).

CONCLUSIONS

Overall, the current study supports the main effect hypothesis, according to which higher levels of perceived social support were associated with lower levels of herpesvirus antibody titers.

Unhealthy Neighbourhood “Syndrome”: A Useful Label for Analysing and Providing Advice on Urban Design Decision-Making?

Even before the COVID-19 pandemic, there was growing interest in designing healthier neighbourhoods. Adopting this perspective brings attention to how conditions in neighbourhoods (directly and indirectly) affect their inhabitants’ physical health and mental wellbeing. However, considerably less attention has been paid to how to alleviate such conditions through integrated interventions designed to operate specifically at the neighbourhood scale. To address this gap, this paper introduces the term “unhealthy neighbourhood syndrome” (UNS). The conceptual clarity and practical utility offered by using this term are critically examined. The paper contains a rigorous review and critical analysis of academic and grey literature on what are held to be the relationships between key features of the built environment and people’s health and wellbeing. It also examines literature offering advice on how urban designers should make neighbourhoods healthier. It illustrates the complexity of the range of issues involved and the complicated web of top down, bottom up and middling out actors that need to be involved in making decisions about them. Despite having inherent weaknesses, the term “unhealthy neighbourhood syndrome” is judged to be useful. It illustrates how seemingly separate issues operate in urban design, promoted for tackling specific symptoms of ill health, need to be addressed jointly through an integrated programme of parallel work streams operating at the neighbourhood scale. The paper is innovative in identifying the wide cluster of symptoms used to describe unhealthy neighbourhoods in the literature as being a “syndrome”. Its significance lies in its injunction that this syndrome needs to be tackled through integrated streams of remedial action drawing on experience and expertise that lie beyond those offered by the traditional membership of urban design teams.

Relationship satisfaction determines the association between Epstein-Barr virus latency and somatic symptoms after the loss of a spouse

The loss of a spouse is associated with a host of negative health outcomes. While bereaved individuals commonly report somatic symptoms, no investigations exist of the association between reactivation of latent Epstein-Barr virus (EBV) and somatic symptoms among this population. Further, how an individual perceives the quality of their lost relationship in retrospect may impact loss outcomes. Among 99 bereaved spouses, elevated EBV antibody titers were associated with somatic symptoms for those who retrospectively reported high or mean levels of relationship satisfaction (RS), but not among those less satisfied. Further, higher RS was associated with greater grief symptoms. This study identifies higher retrospective RS as a possible risk factor for negative physical and mental health outcomes during bereavement.

Predictors of Epstein-Barr virus serostatus and implications for vaccine policy: A systematic review of the literature

BACKGROUND

Epstein-Barr virus (EBV) is an important human pathogen; it infects >90% people globally and is linked to infectious mononucleosis and several types of cancer. Vaccines against EBV are in development. In this study we present the first systematic review of the literature on risk factors for EBV infection, and discuss how they differ between settings, in order to improve our understanding of EBV epidemiology and aid the design of effective vaccination strategies.

METHODS

MEDLINE, Embase, and Web of Science were searched on 6th March 2017 for observational studies of risk factors for EBV infection. Studies were excluded if they were published before 2008 to ensure relevance to the modern day, given the importance of influencing future vaccination policies. There were no language restrictions. After title, abstract and full text screening, followed by checking the reference lists of included studies to identify further studies, data were extracted into standardised spreadsheets and quality assessed. A narrative synthesis was undertaken.

RESULTS

Seventy-seven papers met our inclusion criteria, including data from 31 countries. There was consistent evidence that EBV seroprevalence was associated with age, increasing throughout childhood and adolescence and remaining constant thereafter. EBV was generally acquired at younger ages in Asia than Europe/North America. There was also compelling evidence for an association between cytomegalovirus infection and EBV. Additional factors associated with EBV seroprevalence, albeit with less consistent evidence, included ethnicity, socioeconomic status, other chronic viral infections, and genetic variants of HLA and immune response genes.

CONCLUSIONS

Our study is the first systematic review to draw together the global literature on the risk factors for EBV infection and includes an evaluation of the quality of the published evidence. Across the literature, the factors examined are diverse. In Asia, early vaccination of infants would be required to prevent EBV infection. In contrast, in Western countries a vaccine could be deployed later, particularly if it has only a short duration of protection and the intention was to protect against infectious mononucleosis. There is a lack of high-quality data on the prevalence and age of EBV infection outside of Europe, North America and South-East Asia, which are essential for informing effective vaccination policies in these settings.

Sex differences in executive functioning and latent herpesvirus reactivation among bereaved and non-bereaved individuals

The death of a spouse is a highly stressful event. Better executive functioning has been shown to benefit men to a greater degree than women during stress. We evaluated potential sex differences in stress and immune dysregulation among control and bereaved participants who completed a self-report measure of perceived stress, neuropsychological measures of inhibition and updating/monitoring of information in working memory, and a blood draw to measure Epstein-Barr virus (EBV) antibody titres. Moderation analyses were conducted to test the hypothesis that better inhibition would be associated with less stress and immune dysregulation among male bereaved participants compared with female bereaved participants. Bereaved females demonstrated greater EBV antibody titres than bereaved males. Male bereaved participants benefited from better inhibition, as evidenced by fewer EBV antibody titres, whereas bereaved female participants did not. In the control group, males with high inhibition reported lower stress than males with low inhibition. Present study results are an important step towards identifying those at greatest risk of stress and poor health.

Early childhood family instability and immune system dysregulation in adolescence

Exposure to stress is one way in which social disadvantages during childhood may alter biological and psychological systems with long-term consequences. Family social and economic conditions are critical for early childhood development and exposure to difficult family conditions may have lasting physiological effects. However, there is little research linking early childhood conditions with physiological indicators of stress and system dysregulation in adolescence. In this study, we assess how family social and economic instability that occurred in early childhood (birth to age 5) is associated with immune system dysregulation in adolescence, as indicated by DNA shedding of the Epstein-Barr virus (EBV). We utilize a biomarker of EBV obtained through saliva, a non-invasive method of collecting immune-system biomarkers, in 674 adolescents 11-17 years old. Multivariable regression results indicated that experiences of moving into a new parent/caregiver household or moving in with a grandparent during early childhood was associated with an estimated 100% increase in EBV DNA shedding among prior EBV-infected adolescents. Other measures of early childhood family instability, total number of family structure changes and economic insecurity, were marginally significant. Contemporaneous family conditions were not associated with adolescents' EBV DNA shedding.

Inflammation-Nature's Way to Efficiently Respond to All Types of Challenges: Implications for Understanding and Managing "the Epidemic" of Chronic Diseases

Siloed or singular system approach to disease management is common practice, developing out of traditional medical school education. Textbooks of medicine describe a huge number of discrete diseases, usually in a systematic fashion following headings like etiology, pathology, investigations, differential diagnoses, and management. This approach suggests that the body has a multitude of ways to respond to harmful incidences. However, physiology and systems biology provide evidence that there is a simple mechanism behind this phenotypical variability. Regardless if an injury or change was caused by trauma, infection, non-communicable disease, autoimmune disorders, or stress, the typical physiological response is: an increase in blood supply to the area, an increase in white cells into the affected tissue, an increase in phagocytic activity to remove the offending agent, followed by a down-regulation of these mechanisms resulting in healing. The cascade of inflammation is the body's unique mechanism to maintain its integrity in response to macroscopic as well as microscopic injuries. We hypothesize that chronic disease development and progression are linked to uncontrolled or dysfunctional inflammation to injuries regardless of their nature, physical, environmental, or psychological. Thus, we aim to reframe the prevailing approach of management of individual diseases into a more integrated systemic approach of treating the "person as a whole," enhancing the patient experience, ability to a make necessary changes, and maximize overall health and well-being. The first part of the paper reviews the local immune cascades of pro- and anti-inflammatory regulation and the interconnected feedback loops with neural and psychological pathways. The second part emphasizes one of nature's principles at work-system design and efficiency. Continually overwhelming this finely tuned system will result in systemic inflammation allowing chronic diseases to emerge; the pathways of several common conditions are described in detail. The final part of the paper considers the implications of these understandings for clinical care and explore how this lens could shape the physician-patient encounter and health system redesign. We conclude that healthcare professionals must advocate for an anti-inflammatory lifestyle at the patient level as well as at the local and national levels to enhance population health and well-being.

Role of serum EBV-VCA IgG detection in assessing gastric cancer risk and prognosis in Northern Chinese population

The study aimed to investigate the role of serum EBV‐VCA IgG in assessing gastric cancer (GC) risk and prognosis. A total of 1790 Northern Chinese participants with pathologically confirmed disease underwent EBV‐VCA IgG serologic testing using enzyme‐linked immunosorbent assay (ELISA), including 821 controls, 410 atrophic gastritis (AG) patients, and 559 GC patients. We found that positive EBV‐VCA IgG was significantly associated with GC and its precursor, conferring a 1.55‐ and 1.36‐fold increased risk of GC and AG, respectively (P = 0.001, 95% CI = 1.21‐1.99; P = 0.011, 95% CI = 1.07‐1.72, respectively). The risk effects were more remarkable in younger, female, and Helicobacter pylori‐negative individuals than in older, male, and H. pylori‐positive individuals. EBV‐VCA IgG‐positive subjects had a lower PGI/II ratio than EBV‐VCA IgG‐negative subjects (median 8.0 vs 8.8, P = 0.001), especially those in the H. pylori‐positive (median 6.1 vs 6.8, P = 0.027) and GC subgroups (median 6.4 vs 7.9, P = 0.020). In the intestinal GC subgroup, the survival of EBV‐VCA IgG‐positive patients was worse than that of EBV‐VCA IgG‐negative patients (P = 0.041, HR = 2.45, 95% CI = 1.04‐5.78). Our study suggests that EBV‐VCA IgG seropositivity has potential in predicting the risk of GC and its precursor as well as the prognosis of histologically classified GC.

This is an innovative report about the role of serum EBV‐VCA IgG detection in assessing the risk of gastric cancer (GC) and its precursor as well as GC prognosis. And this is the first report about the relationship between EBV‐VCA IgG serology assay and gastric function status. Our study provides theoretical and experimental basis for evaluating the potential of serum EBV‐VCA IgG as a biomarker in prediction of GC risk and prognosis.

Depressive symptoms are associated with salivary shedding of Epstein-Barr virus in female adolescents: The role of sex differences

BACKGROUND

Adolescent females have a higher prevalence of depression in comparison to their male peers - a disparity that has been increasing over the past decade. Depression is of concern as it is associated with chronic disease and to immune dysregulation, which may be one mechanism linking depression to future pathology. This study examined the extent to which sex moderated the association between depressive symptoms and immune dysregulation during adolescence using Epstein-Barr virus (EBV) reactivation, a biomarker of cellular immune response, as a model.

METHODS

A representative community sample of 259 female and 279 male adolescents aged 11-17 years who were EBV IgG positive were examined. Trained interviewers collected the data during two home visits, one week apart. Depressive symptoms were measured at the first visit using the 9 item short-form of the Center for Epidemiologic Studies-Depression scale. EBV biomarkers were collected via saliva at the second visit and included a qualitative measure of EBV viral capsid antigen immunoglobulin G to assess prior EBV infection and a quantitative measure of EBV DNA to assess the number of viral copies shed in the saliva.

RESULTS

In multivariable logistic regression analyses, increasing depressive symptoms were significantly associated with salivary shedding of EBV DNA for adolescent females only (logit=0.66, se=0.30, p<0.05), and the interaction between sex and depressive symptoms on salivary shedding of EBV DNA was statistically significant (logit=-1.19, se=0.42, p<0.01). Sensitivity analyses were conducted in which sex was examined as a moderator in the relationship between depressive symptoms and salivary EBV DNA quantitative copies via Tobit regression; results were consistent with the presented findings.

CONCLUSIONS

Depressive symptoms are associated with EBV reactivation among EBV positive female adolescents, but not males. Future research is needed to examine EBV reactivation in female adolescents as a mechanism linking depression to future chronic disease and the role of sex hormones in explaining sex differences in the relationship between depressive symptoms and EBV reactivation.

Systemic Inflammation and Viral Exposure among Young Mexican American Women: Nativity-Related Differences

BACKGROUND

Factors contributing to elevated inflammation in racial/ethnic minority populations are not well understood. We examined the association of viral exposure with C-reactive protein (CRP) in young Mexican American women.

METHODS AND RESULTS

Participants (N=1,141) were currently non-pregnant women of Mexican background, aged 18-39 years, from the cross-sectional National Health and Nutrition Examination Survey (NHANES) 1999-2010. Viral exposure was defined as seropositive status for hepatitis B, and herpes simplex types 1 and 2, and classified as seronegative, seropositive for any one agent, and seropositive for 2 or 3 agents. The association of viral exposure with elevated CRP (3.01-10.00 mg/L) varied by country of birth (P=.001). Among Mexico-born women, those seropositive for 2 or 3 agents had 3.79 times (95% CI: 1.28-11.27) and those seropositive for any one agent 2.56 times (95% CI: 1.12-5.86) the odds of elevated CRP compared with seronegative women, after adjustment for age, country of birth, household density, waist circumference, glycated hemoglobin, and total cholesterol. Among US-born women, the corresponding odds were OR: .32, 95% CI: .12-.86 and OR: .71, 95% CI .43-1.17.

CONCLUSIONS

In Mexico-born Mexican American women, viral exposure is associated with higher odds of elevated CRP.

The effect of self-reported health on latent herpesvirus reactivation and inflammation in an ethnically diverse sample

Self-rated health (SRH) is a reliable predictor of health outcomes including morbidity and mortality. Immune dysregulation is one hypothesized mechanism underlying the association between SRH and health outcomes. Indeed, poorer SRH is associated with greater inflammation. The association between SRH and reactivation of latent herpesviruses is unknown, representing an important gap in the literature given that reactivation of latent herpesviruses leads to enhanced inflammation. The present study addressed this important gap in the literature by examining associations between SRH, inflammation (i.e., peripheral cytokines in the blood), and reactivation of latent herpesviruses among a sample of 1208 individuals participating in the Texas City Stress and Health Study. Participants completed a self-report measure of SRH and a blood draw. Results indicated that higher SRH was associated with lower reactivation of latent herpesviruses and inflammation. Moreover, reactivation of latent herpesviruses partially mediated the association between SRH and inflammation. Accordingly, findings add to our growing understanding of the association between SRH and immune dysfunction.

Physical activity, sedentary behaviors, and Epstein-Barr virus antibodies in young adults

This study aimed to elucidate the associations between physical activity, sedentary behaviors, and Epstein-Barr virus (EBV) antibody levels (as an indirect marker of cell-mediated immunity, CMI). This study made use of a 14-year longitudinal study with a representative sample of adolescents in the US. A total of 3361 participants (42.1% male) aged 11 to 21years at baseline who completed Wave I (1994-1995), Wave III (2001-2002), and Wave IV (2008) surveys of the National Longitudinal Study of Adolescent Health (Add Health) were analyzed. Physical activity and sedentary behaviors at Waves I and III were assessed using interviewer-administered questionnaire. EBV viral capsid antigen (VCA) IgG antibody levels at Wave IV were analyzed from dried blood spot assays. Adjusted for confounders, among males, one additional day spent per week on strenuous sports at Wave III were associated with a decrease of 4.09AU/ml in EBV antibody levels (p=0.012), while one additional hour spent per week viewing videos at Wave I was associated with an increase of 0.83AU/ml in EBV antibody levels (p=0.026). Among females, one additional day spent per week on individual sports at Wave III were associated with a decrease of 4.63AU/ml in EBV antibody levels (p=0.014), while sedentary behaviors were not associated with EBV antibody levels. To conclude, physical activity and sedentary behaviors were associated with CMI among males and physical activity was associated with CMI among females.

Herpesvirus Infections and Risk of Frailty and Mortality in Older Women: Women's Health and Aging Studies

OBJECTIVES

To examine the relationship between herpesvirus infections and mortality and incident frailty risks in community-dwelling older women.

DESIGN

Nested prospective cohort study.

SETTING

Women's Health and Aging Studies I and II.

PARTICIPANTS

Community-dwelling older women aged 70 to 79 (n = 633).

MEASUREMENTS

Baseline serum antibody (immunoglobulin G) levels against four herpesviruses (herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), varicella-zoster virus (VZV), 7 Epstein-Barr virus (EBV)), 3-year incident frailty rates, and 5-year mortality.

RESULTS

Women seropositive for HSV-1 and HSV-2, but not VZV and EBV, had higher risk of 3-year incident frailty (HSV-1: hazard ratio (HR) = 1.90, 95% confidence interval (CI) = 0.96-3.74; HSV-2: HR = 2.10, 95% CI = 1.05-4.37) and 5-year mortality (HR = 1.73, 95% CI = 0.93-3.20; HR = 1.80, 95% CI = 0.94-3.44, respectively) than seronegative women. Incremental increases in serum HSV-1 and HSV-2 antibody levels were associated with incrementally higher risks of incident frailty and mortality. After adjustment for potential confounders, only higher serum HSV-2 antibody level was independently predictive of higher risk of mortality in older women (for each unit increase in antibody index, HR = 1.47, 95% CI = 1.05-2.07).

CONCLUSION

HSV-1 and HSV-2 antibody levels are not independently associated with risk of incident frailty in older women. Only HSV-2 antibody level is independently predictive of 5-year mortality risk, with each incremental increase in the antibody level adding further risk.

Socioeconomic status is associated with depressive severity among patients with advanced non-small-cell lung cancer: treatment setting and minority status do not make a difference

INTRODUCTION

Non-small-cell lung cancer (NSCLC) is the leading cause of cancer-related morbidity and mortality. Unfortunately, patients with NSCLC have relatively poor survival rates compared with patients diagnosed with most other types of cancer. Accordingly, managing physical and mental health symptoms are important treatment goals. In the current investigation, we sought to determine whether individual socioeconomic status (SES; as indexed by level of education), racial/ethnic minority status, and hospital type (public versus tertiary care center) were associated with NSCLC cancer patients' depressive severity. Importantly, we investigated whether NSCLC patients' individual SES was more or less prognostic of their depressive severity compared with minority status and the hospital context where they received treatment.

METHODS

Patients scheduled for chemotherapy were assessed for depressed mood by the Beck Depression Inventory-II (BDI-II). Data were collected at baseline and at approximately 6, 12, and 18 weeks.

RESULTS

NSCLC patients with less education had more depressive severity than those with more education. Treatment setting and minority status were not associated with depressive severity. The interaction between education level and treatment setting predicting depressive severity was not significant, suggesting that the association between education level and depressive severity did not differ by treatment setting.

CONCLUSION

Our study brings heightened awareness to the substantial, persistent SES differences that exist in depressive severity among late-stage NSCLC patients. Furthermore, these findings seem to persist, regardless of minority status and whether the patient is treated at a public hospital or tertiary cancer center.

Seropositivity and determinants of immunoglobulin-G (IgG) antibodies against Herpes simplex virus (HSV) types -1 and -2 in pregnant women in Port Harcourt, Nigeria

BACKGROUND

This study is the first documented prevalence of IgG antibody against HSV-1&-2 in Port Harcourt, Nigeria and thus provides baseline data for future in-depth studies on HSV infection in South-South, Nigeria.

OBJECTIVE

This study determined the seropositivity and determinants of serum IgG antibody against HSV-1 & HIV-2 among pregnant women attending BMSH, Port Harcourt, Rivers State, Nigeria.

METHODS

Serum samples from 180 pregnant women attending antenatal clinic at Braithwaite Memorial Specialist Hospital (BMSH) in Port Harcourt, Nigeria. Serum samples were analysed with commercial HSV type-1&-2 specific IgG Enzyme Linked Immunosorbent Assay (ELISA) kits. Chi-square analysis was used to determine the association of infection with socio-demographic variables.

RESULTS

Of the 180 pregnant women, 179 (99.4%) were seropositive and 1(0.6%) was seronegative for HSV 1&2 IgG antibody. No statistical association existed between the prevalence of HSV-1&-2 IgG antibodies and the socio-demographic variables studied (p>0.05) except for marital status which was significantly associated (p<0.05).

CONCLUSION

Our data shows that HSV-1 & 2 seropositivity among pregnant women in Port Harcourt is high; thus serological screening for HSV-1&-2 might be advisable for antenatal attendees.

A prospective study of the clinical characteristics of patients with herpes simplex and varicella zoster keratitis, presenting to a New Zealand emergency eye clinic

PURPOSE

To identify the demographic and clinical associations of patients presenting with herpetic keratitis in New Zealand compared with presentations of presumed microbial keratitis.

METHODS

A prospective, 6-month, observational case series of presumed microbial keratitis (including marginal keratitis), specifically identifying all cases of herpes simplex and varicella zoster keratitis attending an emergency eye clinic was conducted. Main outcome measures included demographics, presenting signs and symptoms, and medical, ocular, and drug history.

RESULTS

A total of 140 cases of herpetic keratitis were identified, which comprised 125 cases of herpes simplex virus (89%) and 15 cases of varicella zoster virus (11%). Herpes simplex keratitis was associated with a history of keratitis (n = 58, phi = 0.24, P < 0.0001), Maori ethnicity (n = 27, phi = 0.26, P < 0.0001), respiratory disease (n = 18, phi = 0.14, P = 0.009), corticosteroid use (n = 23, phi = 0.22, P < 0.0001), and cardiovascular disease (CVD) (n = 10, phi = 0.11, P = 0.03). Inverse association was observed between herpes simplex keratitis and ocular surface disease (n = 8, phi = -0.16, P < 0.002) and Asian ethnicity (n = 4, phi = -0.11, P = 0.04). Varicella zoster keratitis was associated with CVD (n = 3, phi = 0.15, P = 0.03).

CONCLUSIONS

Patients with asthma, CVD, on long-term corticosteroid inhalers or creams, or of Maori ethnicity need particular assessment to investigate herpes simplex as a possible cause of keratitis. Clinicians prescribing inhaled corticosteroids or topical corticosteroid creams should be aware of possible association with herpes simplex keratitis.

Exposure to neighborhood immigrant concentration from adolescence to young adulthood and immune function among Latino young adults

The immune system plays a critical role in the prevention of infectious and chronic disease. We investigate associations between exposure to neighborhood immigrant concentration across the transition from adolescence to adulthood and immune function among Latino young adults, including moderation by nativity. Data from the National Longitudinal Study of Adolescent Health (1994-2008) were analyzed. Immune function was measured via Epstein-Barr virus (EBV) antibody levels (higher levels indicate impaired immune function) among EBV-positive Latino adults (N=1130). Results indicated the averaged individual exposure to immigrant concentration (mean % of foreign-born residents in the census tract across waves 1-4) was associated with immune function for foreign-born Latinos only (b=-0.37, P<0.05). For waves of exposure, only the cumulative measure of living in an immigrant enclave (census tracts with ≥40% foreign-born residents) across all waves was associated with immune function and only for foreign-born Latinos (b=-0.22, P<0.05). Research on the mechanisms through which neighborhood immigrant concentration confers salubrious physiological outcomes for foreign-born Latinos is needed.

Race/ethnic and socioeconomic differences in stress and immune function in The National Longitudinal Study of Adolescent Health

Stress and immune function may be important mediators of the strong association between social factors and health over the life course, but previous studies have lacked the data to fully explore these links in a population-based sample. This study utilizes data from Waves I-IV of the U.S. National Longitudinal Study of Adolescent Health (Add Health) to test the associations of race/ethnicity and socioeconomic status (SES) with levels of perceived stress and exposure to stressful life events (SLE) among 11,050 adult respondents aged 24-32 in 2008-2009. We further tested whether race/ethnicity and SES were associated with Epstein-Barr Virus (EBV) specific IgG antibodies, an indirect marker of cell-mediated immune function. Finally, we tested whether measures of stress were associated with EBV IgG and whether there was evidence that they explain any associations between race/ethnicity, SES and EBV IgG. We found strong associations between lower SES and higher levels of perceived stress (OR 2.07, 95% CI 1.73-2.48 for < high school vs. college or above) and a high level of stressful life events (OR 7.47, 95% CI 5.59-9.98 for < high school vs. college or above). Blacks had higher odds of a high level of stressful life events compared to whites (OR 2.00, 95% CI 1.63-2.47), but not higher perceived stress (OR 1.11, 95% CI 0.96-1.28). Blacks also had significantly higher EBV levels compared to whites (β = 0.136, p < 0.01), but lower SES was not associated with higher EBV IgG. We found no evidence that stressful life events or perceived stress were associated with EBV IgG in this sample, and thus did not account for racial differences in EBV IgG. These results suggest consistent race/ethnic and SES differences in stressful life events, and confirm race/ethnic differences in markers of immune function that may have health implications across the life course.

Hodgkin lymphoma incidence in California Hispanics: influence of nativity and tumor Epstein-Barr virus

PURPOSE

For classical Hodgkin lymphoma (HL), migrant studies could elucidate contributions of environmental factors (including Epstein-Barr virus (EBV)) to the lower rates in non-whites. Given the well-described etiologic complexity of HL, this research requires a large, immigrant population, such as California Hispanics.

METHODS

With 1988-2004 California Cancer Registry data (2,595 Hispanic, 8,637 white HL cases) and tumor cell EBV status on a subset (218 Hispanics, 656 whites), we calculated ethnicity- and nativity-specific HL incidence rates simultaneously by age, sex, and histologic subtype, and tumor cell EBV prevalence.

RESULTS

Compared with white rates, Hispanic HL rates were lower overall (70 %) and for nodular sclerosis HL, particularly among young adults (60-65 % for females). However, they were higher among children (200 %) and older adults, and for mixed cellularity HL. Compared with rates in foreign-born Hispanics, rates in US-born Hispanics were higher among young adults (>threefold in females), lower for children and adults over age 70, and consistently intermediate compared with rates in whites. EBV tumor prevalence was 67, 32, and 23 % among foreign-born Hispanics, US-born Hispanics, and whites, respectively, although with variation by age, sex, and histology.

CONCLUSIONS

Findings strongly implicate environmental influences, such as nativity-related sociodemographic differences, on HL occurrence. In addition, lower young adult rates and higher EBV prevalence in US-born Hispanics than in whites raise questions about the duration/extent of environmental change for affecting HL rates and also point to ethnic differences in genetic susceptibility. Lesser variation in mixed cellularity HL rates and greater variation in rates for females across groups suggest less modifiable factors interacting with environmental influences.

An ELISA method to compute endpoint titers to Epstein-Barr virus and cytomegalovirus: application to population-based studies

Indirect fluorescence analysis (IFA), the gold standard for determining herpesvirus antibody titers, is labor-intensive and poorly suited for large population-based studies. The enzyme-linked immunosorbent assay (ELISA) is used widely for measuring antiviral antibodies but also suffers drawbacks such as reduced specificity and the qualitative nature of the results due to limited interpretation of the optical density (OD) units. This paper describes a method to titer herpesvirus antibodies using microplates coated with virally-infected cells in which a standard curve, derived from IFA-scored samples, allowed OD units to be converted into titers. A LOOKUP function was created in order to report the data as traditional IFA-based (i.e., 2-fold) titers. The modified ELISA correlated significantly with IFA and was subsequently used to compute endpoint antibody titers to Epstein-Barr virus (EBV)-virus capsid antigen (VCA) and cytomegalovirus (CMV) in blood samples taken from 398 pregnant Hispanic women. Four women were EBV negative (1%), while 58 women were CMV negative (14.6%). EBV VCA antibody titers were significantly higher than CMV antibody titers (p<0.001). This method allows titering of herpesvirus antibodies by ELISA suitable for large population-based studies. In addition, the LOOKUP table enables conversion from OD-derived titers into 2-fold titers for comparison of results with other studies.

Childhood adversity and cell-mediated immunity in young adulthood: does type and timing matter?

Childhood adversity can have powerful effects on health over the life course. Persistent changes in cell-mediated immune function may be one pathway linking adverse childhood experiences with later disease risk. However, limited research has examined childhood adversity in relation to cell-mediated immune function, and in particular, immune response to latent viruses in adulthood. The present study investigated the association of two types of childhood adversity, socioeconomic disadvantage during adolescence and abuse prior to age 18, with Epstein-Barr Virus (EBV) antibody titers in a large nationally representative sample of young adults aged 24-32years. Data were drawn from the National Longitudinal Study on Adolescent Health, Wave 4 (n=13,162). We examined the associations of three indicators of adolescent SES (parental education, household income, and occupational status) and frequency and timing of physical and sexual abuse with EBV antibodies, controlling for age, sex, race/ethnicity, and presence of a smoker in the household during adolescence. Lower parental occupational status and some categories of lower education were associated with elevated EBV antibodies (p<.05), and individuals who reported sexual abuse that occurred more than 10times had elevated EBV antibodies relative to individuals who were not sexually abused (p=0.03). Among individuals exposed to physical abuse, those who were first abused at age 3-5years had heightened EBV antibodies relative to those first abused during adolescence (p=0.004). This study extends prior research linking early adversity and immune function, and provides initial evidence that childhood adversity has a persistent influence on immune responses to latent infection in adulthood.

Stressful early life experiences and immune dysregulation across the lifespan

There is considerable evidence that stressful early life events influence a variety of physical health problems later in life. Childhood adversity has been linked to elevated rates of morbidity and mortality from a number of chronic diseases. Immune dysregulation may be one potential pathway that explains this link. In this mini-review, we summarize human studies demonstrating that severe early life stressors have lasting immune consequences. We propose a model outlining potential biobehavioral pathways that explain how early life stressors leave people vulnerable to these maladaptive outcomes. Finally, we suggest ideas for future work to test different aspects of this model.

Self-boosting vaccines and their implications for herd immunity

Advances in vaccine technology over the past two centuries have facilitated far-reaching impact in the control of many infections, and today's emerging vaccines could likewise open new opportunities in the control of several diseases. Here we consider the potential, population-level effects of a particular class of emerging vaccines that use specific viral vectors to establish long-term, intermittent antigen presentation within a vaccinated host: in essence, "self-boosting" vaccines. In particular, we use mathematical models to explore the potential role of such vaccines in situations where current immunization raises only relatively short-lived protection. Vaccination programs in such cases are generally limited in their ability to raise lasting herd immunity. Moreover, in certain cases mass vaccination can have the counterproductive effect of allowing an increase in severe disease, through reducing opportunities for immunity to be boosted through natural exposure to infection. Such dynamics have been proposed, for example, in relation to pertussis and varicella-zoster virus. In this context we show how self-boosting vaccines could open qualitatively new opportunities, for example by broadening the effective duration of herd immunity that can be achieved with currently used immunogens. At intermediate rates of self-boosting, these vaccines also alleviate the potential counterproductive effects of mass vaccination, through compensating for losses in natural boosting. Importantly, however, we also show how sufficiently high boosting rates may introduce a new regime of unintended consequences, wherein the unvaccinated bear an increased disease burden. Finally, we discuss important caveats and data needs arising from this work.

Epstein-Barr virus reactivation during pregnancy and postpartum: effects of race and racial discrimination

OBJECTIVE

Adverse pregnancy outcomes, including preterm birth, are markedly higher among African-Americans versus Whites. Stress-induced immune dysregulation may contribute to these effects. Epstein-Barr virus (EBV) reactivation provides a robust model for examining cellular immune competence. This study examined associations of EBV virus capsid antigen immunoglobulin G (VCA IgG) with gestational stage, race, and racial discrimination in women during pregnancy and postpartum.

METHODS

Fifty-six women (38 African-American, 18 White) were included. African-Americans and Whites did not differ in age, education, income, parity, or body mass index (ps ≥ .51). During the 1st, 2nd, and 3rd trimester and ~5 weeks postpartum, women completed measures of racial discrimination, perceived stress, anxiety, depressive symptoms and health behaviors. EBV VCA IgG antibody titers were measured via ELISA in serum collected at each visit.

RESULTS

In the overall sample, EBV VCA IgG antibody titers were lower in the 3rd versus 1st trimester (p=.002). At every timepoint (1st, 2nd, 3rd trimester and postpartum), African-American women exhibited higher serum EBV VCA IgG antibody titers than Whites (ps<.001). This effect was most pronounced among African-Americans reporting greater racial discrimination [p=.03 (1st), .04 (2nd), .12 (3rd), .06 (postpartum)]. Associations of race and racial discrimination with EBV VCA IgG antibody titers were not accounted for by other measures of stress or health behaviors.

CONCLUSIONS

Compared to Whites, African-American women showed higher EBV VCA IgG antibody titers, indicative of impaired cellular immune competence, across pregnancy and postpartum. This effect was particularly pronounced among African-American women reporting greater racial discrimination, supporting a role for chronic stress in this association. In women overall, EBV antibody titers declined during late as compared to early pregnancy. This may be due to pregnancy-related changes in cell-mediated immune function, humoral immune function, and/or antibody transfer to the fetus in late gestation. As a possible marker of stress-induced immune dysregulation during pregnancy, the role of EBV reactivation in racial disparities in perinatal health warrants further attention.

Reactivation of herpes simplex virus type 1 is associated with cytomegalovirus and age

Recent studies have shown that cytomegalovirus (CMV) may be an emerging marker of immunosenescence. CMV can affect the immune system by directly infecting leukocytes and hematopoietic cells or by eliciting an expansion of oligoclonal CD8+ T cells/contraction of the naïve T cell compartment that may reduce the host's ability to fight other pathogens. To investigate further CMV-associated changes in immunity, a study was conducted with 1,454 adults (ages 25-91) to determine the association between CMV and reactivation of another latent herpesvirus, Herpes simplex virus type 1 (HSV-1), as indexed by antibody titers. Elevated antibody titers to latent HSV-1 were significantly associated with both CMV seropositivity and high CMV antibody levels. Evaluation by specific age groups (<45, 45-64, and 65+ years old) revealed that this association was detectable early in life (<45 years of age). Increases in HSV-1 antibodies by age occurred in CMV seropositive individuals but not CMV seronegative subjects. Within CMV seropositive subjects, increases in HSV-1 antibodies by age were only found in individuals with low CMV antibody levels as those with high CMV antibodies already exhibited elevated HSV-1 antibodies. These associations remained significant after accounting for body mass index, gender, and socioeconomic status. These results suggest that CMV can influence the immune response to another pathogen and support the concept that CMV may accelerate immunosenescence.

Childhood adversity and herpesvirus latency in breast cancer survivors

OBJECTIVE

Childhood adversity has been linked to greater emotional and physiological sensitivity to stress. Stress has well-documented effects on cellular immunity, including enhanced herpesvirus reactivation. This study assessed whether childhood adversity was associated with the expression of two latent herpesviruses, Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in adults, and whether this association could be detected beyond the psychological distress women experienced in the aftermath of a breast cancer diagnosis and its treatment.

METHODS

One hundred and eight breast cancer survivors completed questionnaires and provided blood samples to assess EBV virus capsid antigen (VCA) IgG antibody titers and CMV IgG antibody titers.

RESULTS

Breast cancer survivors who experienced more childhood adversities had higher EBV and CMV antibody titers than those with fewer childhood adversities. Those who experienced more childhood adversities also had more depressive symptoms, less education, and poorer sleep quality than those with fewer childhood adversities. Depressive symptoms, education, sleep quality, age, BMI, cancer stage, comorbidities, and weekly alcohol consumption were not related to EBV or CMV antibody titers. Time since last treatment was negatively associated with EBV and CMV antibody titers. Elevated antibody titers to latent herpesviruses represent poorer cellular immune system control over viral latency; these data suggest that those with more childhood adversities have poorer cellular immune function.

CONCLUSIONS

These findings add to the emerging literature suggesting that adverse early experiences may make people more vulnerable to immune dysregulation in adulthood. The consequences of early adversity appear to persist across the life span.

Social support and socioeconomic status interact to predict Epstein-Barr virus latency in women awaiting diagnosis or newly diagnosed with breast cancer

OBJECTIVE

Both higher socioeconomic status (SES) and supportive personal relationships confer health benefits, including better immune function. This study assessed the joint impact of SES and social support on the expression of a latent herpesvirus, Epstein-Barr virus (EBV), in a group of highly stressed women.

METHODS

Two-hundred and twenty four women either awaiting further evaluation following an abnormal mammogram or newly diagnosed with breast cancer completed questionnaires and provided blood samples to assess EBV viral capsid antigen (VCA) IgG antibody titers.

RESULTS

More highly educated women with more support from friends had lower EBV VCA antibody titers, reflecting a stronger cellular immune response to the latent virus; however, among less educated women, friend support was not associated with EBV antibody titers. As revealed in an ancillary analysis, more highly educated women with more friend support had lower systolic blood pressure (SBP); however, friend support was not associated with SBP among less educated women. Neither depression nor perceived stress mediated these associations. Neither cancer status nor cancer stage among those diagnosed with cancer was significantly related to these outcomes.

CONCLUSION

Lower SES women may not reap the same immunological benefits from friend support when experiencing a stressful life event as their higher SES counterparts.

The socio-spatial neighborhood estimation method: an approach to operationalizing the neighborhood concept

The literature on neighborhoods and health highlights the difficulty of operationalizing "neighborhood" in a conceptually and empirically valid manner. Most studies, however, continue to define neighborhoods using less theoretically relevant boundaries, risking erroneous inferences from poor measurement. We review an innovative methodology to address this problem, called the socio-spatial neighborhood estimation method (SNEM). To estimate neighborhood boundaries, researchers used a theoretically informed combination of qualitative GIS and on-the-ground observations in Texas City, Texas. Using data from a large sample, we assessed the SNEM-generated neighborhood units by comparing intra-class correlation coefficients (ICCs) and multi-level model parameter estimates of SNEM-based measures against those for census block groups and regular grid cells. ICCs and criterion-related validity evidence using SF-36 outcome measures indicate that the SNEM approach to operationalization could improve inferences based on neighborhoods and health research.

Allostatic load in an environmental riskscape: the role of stressors and gender

Stressors are theorized to be associated with higher allostatic load (AL), a concept of physiological wear measured as a composite of physical biomarkers. Risk of high AL may vary by gender and may be intensified in places with significant environmental risks, otherwise known as 'environmental riskscapes'. Yet, no study has examined the relationship between stressors, gender, and allostatic load in an environmental riskscape. Using primary data collected in a sample (N=1072) exposed to various environmental and social stressors, we find that long-term residence in Texas City (30 or more years), residential proximity to petrochemical plants, perceived poor neighborhood conditions, and daily hassles are associated with higher allostatic load components. Variation in AL differs by gender and the types of biomarkers examined. Gender moderates the effect of length of residence in Texas City on cardiovascular health risk. We discuss our findings in light of current research on stressors, gender, allostatic load, and double jeopardy within environmental riskscapes.