Do chronic stressors lead to physiological dysregulation? Testing the theory of allostatic load

Health for Hearts United Longitudinal Trial: Improving Perceived Stress and Allostatic Load Outcomes of Mid-Life and Older African American Women

Cardiovascular disease (CVD) continues to be the leading cause of death in the United States, with African Americans experiencing higher age-adjusted mortality compared to Whites. African American women in particular carry a high CVD burden due to more exposure to adverse personal and socioenvironmental challenges. Church-based interventions can improve health behaviors and health status of African Americans, yet few have addressed stress-related health. The purpose of this study was to determine the effectiveness of the 18-month Health for Hearts United intervention in relation to stress-related outcomes (perceived stress, allostatic load) of mid-life and older African American women (≥45 years of age; n = 152 overall sample, n = 65 clinical subsample). The results of the repeated measures analysis of variance (ANOVA) analyses showed overall significant decreases in perceived stress and allostatic load for both treatment and comparison groups over the measurement occasions (baseline and 18 months) with educational level remaining as a significant correlate over time. There was no significant interaction between treatment and time, yet there were trends in improvements for the treatment group compared to the comparison group. The findings demonstrate the potential of church-based interventions in reducing both self-reported stress and allostatic load in African American women, and highlight the need for further investigation of educational level and other possible factors influencing stress management in these settings.

The long-term association between exposure to wartime bombing earlier in life and post-traumatic stress later in life among today's older Vietnamese population

This analysis examines the relationship between exposure to American wartime bombardments earlier in life and later-life PTSD among current surviving Vietnamese aged 59+. It also assesses whether the relationship varies by military status during the war - formal military, informal military, or civilian - and whether associations are explained by exposure to violence and malevolent conditions. Data link survey responses from the 2018 Vietnam Health and Aging Study to provincial-wide level bombing intensity using U.S. Department of Defense records from the Theater History of Operations Vietnam database. PTSD measured using nine items from the PTSD Checklist. Analyses employ multivariate logistic quantile regression. Findings examined for a sample of 2290 Vietnamese survivors and a subsample of 736 Vietnamese that moved at least once during wartime. Results show a robust and significant positive association between province-wide bombing intensity and later-life PTSD scores. Interaction effects indicate civilians have overall lower levels of PTSD than those that were in the formal or informal military, but the association between bombing and PTSD is stronger among civilians. Much of the association is a function of exposure to violence and less is a function of exposure to malevolent conditions. Findings confirm earlier studies that have shown severe deleterious impacts of war trauma, and arial bombardments particularly, on long-term psychological health, while extending extant literature to civilian populations living in Vietnam during intense aerial bombing episodes.

Workplace Psychosocial Factors and Their Association With Musculoskeletal Disorders: A Systematic Review of Longitudinal Studies

This systematic review examines literature regarding the relationship between workplace psychosocial factors and musculoskeletal disorders (MSDs). Musculoskeletal disorders are the leading cause of work disability, resulting in billions of dollars of financial losses. Evidence suggests that workplace psychosocial factors can lead to the development and progression of MSDs. A data search was conducted in MEDLINE, EMBASE, PsychINFO, Scopus, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) from August 2009 to May 2020 inclusive. Other eligibility criteria included studies published in English, conducted on adults within a workplace setting, conducted in developed economies, and were stability-control longitudinal observational studies. Studies were independently screened for eligibility, using COVIDENCE (software for managing and streamlining systematic reviews) and assessed for quality by multiple authors, using the JBI Evidence synthesis tool. From 6,812 studies, 47 articles were included in the final analysis. The most common MSDs investigated were lower back pain, neck and shoulder pain, and upper extremity symptoms and disorders. Included articles identified that psychosocial workplace factors of support, collaboration, job control, and job demands were statistically significantly associated with risk and progression of MSDs. Review of the articles included in this article supports the theory that MSDs have a multifactorial, complex etiology that includes psychosocial factors. Interventions to enhance psychosocial work environment provide opportunities to reduce the risk of MSDs.

Potential Role of Oxidative Stress in the Effects of Chronic Administration of Iron on Affective and Cognitive Behavior on Male Wistar Rat

In this work, we studied the impact of chronic iron exposure, in the form of iron sulfate (FeSo4), on affective and cognitive disorders and oxidative stress in the male Wistar rat. The treatment was carried out for 8 weeks, the rats received an intraperitoneal injection of iron at different doses: 0.25, 0.5, and 1 mg/kg. Affective and cognitive disorders are assessed in open field test (OFT), elevated plus maze (EPM), forced swimming test (FST), Morris water maze (MWM), and Y-maze. The hippocampus and prefrontal cortex of each animal were taken for biochemical examination. Our results show that iron exerts anxiogenic and depressogenic effects, which were observed first at the dose of 0.5 mg/kg and continued in a dose-dependent manner up to the maximum tested dose of 1 mg/kg. According to results from the MWM and Y-maze tests, continuous exposure to iron induces cognitive disorders that are defined by the disturbance of working memory and influences spatial learning performance causing a deficit of spatial memory retention. We noted that chronic exposure to iron can be associated with the appearance of a state of oxidative stress in the hippocampus and the prefrontal cortex demonstrated by an increase in lipid peroxidation, an increase in nitric oxide, and also by disturbances in the antioxidant defense systems following a determination of the concentrations of catalase. In conclusion, we can deduce from this work that chronic iron exposure can be related to the induction of cognitive and affective disorders and oxidative stress.

The allostatic load model: a framework to understand the cumulative multi-system impact of work-related psychosocial stress exposure among firefighters

Firefighting is recognised as a profession where health and well-being can be affected by a variety of occupational factors, such as physical, thermal, and chemical stressors. Along with the risks intuitively associated with the fire service, however, psychosocial stress has begun to attract attention as another variable deserving of consideration. Indeed, long-term exposure to work-related psychosocial stress has been linked with poor health outcomes in many workers; however, despite this association, very little has been done to examine how such stressors become biologically embedded in firefighters. To help facilitate research into how psychosocial stress can affect health-related outcomes in the fire service, we propose a framework centered on the notion of allostatic load. First, we reviewed the occupational characteristics that may generate psychosocial stress within firefighters before introducing allostatic load (that is, dysregulation across various physiological systems caused by the need to manage ongoing stressors). Next, we provided a summary of how allostatic load can be measured and touched on the framework's utility for studying the cumulative effects of work-related stress on firefighter health. After this, factors that may influence the steps leading from stress exposure to health outcomes were discussed; in particular, we commented upon how research in this area should consider specific non-modifiable (age, sex, and ethnicity) and modifiable (psychosocial resources and behavioural habits) factors. Finally, we presented methodological barriers and opportunities that may arise when using the allostatic load framework with this professional group. By introducing the framework, we hope to provide a tool that may be used by those interested in stress-health research in firefighters to build the evidence needed to inform primary prevention measures.

Comparing Predictors and Outcomes of Higher Allostatic Load across Zoo-Housed African Great Apes

Stressors over the lifespan can contribute to physiological dysregulation, or allostatic load. Allostatic load has been studied in humans using allostatic load indices (ALIs) for over 25 years, but the same methods are rarely applied to other species. We constructed an ALI for zoo-housed western lowland gorillas, chimpanzees, and bonobos and tested potential predictors of and health outcomes associated with allostatic load. Allostatic load scores ranged from 0–6 for gorillas and chimpanzees and 0–7 for bonobos. Age was significantly associated with allostatic load in gorillas and chimpanzees but not bonobos. Cumulative stressful events were positively associated with allostatic load in chimpanzees. Wild-caught gorillas had higher allostatic load than zoo-born conspecifics, but rearing differences between zoo-born animals were not significant for any species. Age may affect associations of allostatic load with stressful events and birthplace as results change when it is included as a covariate. Allostatic load was not retained in best-fit models for risk of all-cause morbidity, cardiac disease, or mortality risk. Some analyses herein were limited by the use of retrospective data, such as reason for sample collection and length of records provided for individual animals. Nevertheless, these data indicate additional research is needed to optimize ALIs for non-human primates.

The role of combined modifiable lifestyle behaviors in the longitudinal association between stressful life events and allostatic load in Australian adults

Allostatic load is a model that is used to quantify the physiological damage from exposure to stressors. Stressful life events are chronic stressors that can lead to an elevated allostatic load through the physiological and behavioral stress responses. However, there is limited empirical studies that has tested the proposed behavioural pathway. Our study addresses this gap by examining the mediating role of combined modifiable lifestyle behaviors in the 12-years longitudinal association between stressful life events and allostatic load among participants from the Australian Diabetes, Obesity and Lifestyle (AusDiab) Study cohort. A latent profile analysis was performed to identify latent subgroups with distinct behavioral clusters based on five modifiable lifestyle behaviors (smoking, sedentary behavior, physical activity, alcohol consumption, and diet quality). We then used a sequential mediation model design with path analysis to test the mediating effect of these latent subgroups in the associations between stressful life events and three measures of allostatic load. Indirect effects were estimated using the product of coefficient approach and the statistical significance was determined by the 95% bias-corrected bootstrap confidence intervals with 1000 replications. We identified three latent subgroups: "least healthy lifestyle" (12%; n = 396), "moderately healthy lifestyle" (78.7%; n = 2599), and "most healthy lifestyle" (9.2%; n = 306). Exposure to stressful life events was not associated with the allocation of participants in latent subgroups. Compared to the "moderately healthy lifestyle" subgroups, we found that the "least healthy lifestyle" behavioral cluster was not associated with allostatic load. However, there was a significant inverse association between the "most healthy lifestyle" behavioral cluster and allostatic load. Overall, we did not find significant indirect effects between stressful life events and three measures of allostatic load via the "least healthy lifestyle" and the "most healthy lifestyle" groups. In summary, the combinations of modifiable lifestyle behaviors did not explain the association between stressful life events and allostatic load. More longitudinal studies are needed to replicate our study to confirm this finding.

Allostatic Load Measurement: A Systematic Review of Reviews, Database Inventory, and Considerations for Neighborhood Research

BACKGROUND

Neighborhoods are critical to understanding how environments influence health outcomes. Prolonged environmental stressors, such as a lack of green spaces and neighborhood socioeconomic disadvantage, have been associated with higher allostatic load levels. Since allostatic load levels experienced earlier in life have stronger associations with mortality risk, neighborhoods may be uniquely suited to monitor and mitigate the impacts of environmental stressors. Researchers often study allostatic load in neighborhoods by utilizing administrative boundaries within publicly accessible databases as proxies for neighborhoods.

METHODS

This systematic review of reviews aims to identify commonly used biomarkers in the measurement of allostatic load, compare measurement approaches, inventory databases to study allostatic load, and spotlight considerations referenced in the literature where allostatic load is studied in neighborhoods. The review was conducted using the search term "allostatic load" in the MEDLINE, CINAHL, and PsychINFO databases. The search results were filtered to include reviews.

RESULTS

The search returned 499 articles after deduplication. Overall, 18 synthesis reviews met the inclusion criteria and were retained for extraction. The synthesis reviews analyzed represented 238 studies published from 1995 to 2020. The original ten biomarkers were most often used to measure allostatic load. More recently, body mass index and C-reactive protein have additionally been frequently used to measure allostatic load burden.

CONCLUSIONS

The scientific contributions of this study are that we have identified a clear gap in geographic considerations when studying allostatic load. The implication of this study is that we have highlighted geographic concepts when conducting neighborhood-level research using administrative databases as a neighborhood proxy and outlined emerging future trends that can enable future study of allostatic load in the neighborhood context.

State level income inequality affects cardiovascular stress responses: Evidence from the Midlife in the United States (MIDUS) study

RATIONALE

The slow and insidious effects of income inequality on health means that their effects can be difficult to reveal, taking many years to become apparent. These effects can also be experienced differently according to subjective status and ethnicity making the relation between income inequality and health difficult to understand. Cardiovascular reactions to acute stress are indicative of future health outcomes.

OBJECTIVE

To examine whether short to medium term income inequality affected cardiovascular responses to acute stress whilst accounting for ethnic groups and subjective status.

METHOD

Participants state of residence was available for 1155 people who participated in the MIDUS biomarker data project. This detail was used to merge the relevant US state level inequality data 1, 5, 10 and 15 years prior to the MIDUS biomarker data project which assessed cardiovascular responses to acute stress.

RESULTS

Our analysis demonstrated an association between inequality 5, 10 and 15 year prior and cardiovascular reactions to acute stress. Subjective community status and Black and minority ethnic group membership interacted to affect the association between inequality and cardiovascular reactions.

CONCLUSIONS

In states where income inequality was high, less healthy cardiovascular responses were evident. However lower subjective community status and Black and Ethnic minority group members interacted with income inequality such that their impact was variable contingent on state level inequality. These findings extend the literature on income inequality and health and particularly highlights a psychophysiology pathway linking income inequality and health.

Lived experience and allostatic load among transmasculine people living in the United States

BACKGROUND

Transgender and gender diverse people face significant stigma that can adversely affect their physical and mental health. However, the psychobiological link between lived experience and health has been underexplored in this population. We thus examine perceived distress, mental health, and physiological 'wear and tear' by indexing allostatic load (AL) and assess associations with a range of contextual and experiential factors from transmasculine people living in the United States.

METHODS

Sixty-five people who identified as transgender men or along a transmasculine spectrum, living in Massachusetts, Vermont, and Rhode Island participated in The Transition Experience Study (age: M=31.8, range 18-55), which examines lived experience of social and medical transition and embodied gender minority/marginalization stress among a sample of transmasculine people. Based on in-depth in-person interview and survey data and inspired by an ecological systems model, we created indices representing (1) perceived progressive geopolitical climate; (2) socio-demographic advantage; (3) social support and resources; (4) gender minority and marginalization stressors; and (5) health behaviors. The Perceived Stress Scale and psychological symptoms (depression, anxiety, insomnia) were also assessed. AL indexed 10 neuroendocrine, immune, cardiovascular, and metabolic biomarkers.

RESULTS

Regressions revealed that perceived stress and psychological symptoms were negatively correlated with progressive geopolitical climate (respectively B=-1.47, p = 0.19; B=-.77, p < .001) and positively correlated with gender minority and marginalization stressors (respectively B=1.51, p < .001; B =.38, p = .005). AL was negatively associated with perceived progressive geopolitical climate (B=-.55, p = .007) and socio-demographic advantage (B=-3.2, p = .001).

DISCUSSIONS

These findings underline the importance of assessing geopolitical context and indexing lived experiences and life domains along with biomarker sampling. Together, these enable the identification of psychobiological pathways to better nuance multi-level contributors to health and well-being and understand embodied inequalities. These analyses of embodied stigma inclusive of AL biomarkers thus provide a model to further research centering transgender people's health from youth through old age.

Early-life exposure to economic stress and metabolic risks in young adulthood: the children of the reunification in East Germany

BACKGROUND

Research on the long-term health consequences of early-life exposure to economic crises is scarce. We examine for the first time the long-term effects of early-life exposure to an economic crisis on metabolic health risks. We study objective health measures, and exploit the quasi-experimental situation of the postreunification economic crisis in East Germany.

METHODS

Data were drawn from two waves of the longitudinal German Health Interview and Examination Survey for Children and Adolescents (2003-2006, 2014-2017). We compared 392 East Germans who were exposed to the economic crisis in utero and at ages 0-5 with 1123 of their West German counterparts using propensity score matching on individual and family characteristics. We assessed blood pressure, cholesterol, blood fat and body mass index (BMI); both combined as above-average metabolic health risks and individually at ages 19-30.

RESULTS

Early-life exposure to the economic crisis significantly increased the number of above-average metabolic health risks in young adulthood by 0.1482 (95% CI 0.0169 to 0.2796), which was 5.8% higher compared with no exposure. Among individuals exposed in utero, only females showed significant effects. Early-life exposure to the economic crisis was associated with increased systolic (0.9969, 95% CI -0.2806 to 2.2743) and diastolic blood pressure (0.6786, 95% CI -0.0802 to 1.4373), and with increased BMI (0.0245, 95% CI -0.6516 to 0.7001).

CONCLUSION

The increased metabolic health risks found for women exposed to the postreunification economic crisis in-utero are likely attributable to increased economic stress. While the observed differences are small, they may foreshadow the emergence of greater health disparities in older age.

Biological costs and benefits of social relationships for men and women in adulthood: The role of partner, family and friends

Despite numerous studies on social relationships and health, the empirical focus has often been on middle-aged or older adults, even though young adulthood is a period of considerable change in social networks. We investigated whether the associations between social relationships and allostatic load, a multisystem physiological dysregulation index that reflects chronic stress responses, vary by type of relationship and stages of the lifecourse. Relationships with spouse/partner, immediate family and friends were assessed in terms of emotional support and social strain. Poisson regression models on multiple imputed data sets from waves 2-3 (2010-2012) of the UK Household Longitudinal Study (N = 10,380) were estimated. Social strain, particularly from partners and immediate family, appeared to elicit greater stress related dysregulation during early adulthood (age 21-34 years), corresponding to a predicted difference in the allostatic load index (range 0-12) between high and low strained relationships of 1.1 (95% CI: 0.5-1.6) among young women and 0.6 (95% CI: -0.04 to 1.2) among young men. There was little evidence of an association between allostatic load and any of the social relationships among older men and women. Models of social relationships over the lifecourse need to take account of how stressful social relationships become biologically embedded in early adulthood.

Allostatic Load and Its Impact on Health: A Systematic Review

INTRODUCTION

Allostatic load refers to the cumulative burden of chronic stress and life events. It involves the interaction of different physiological systems at varying degrees of activity. When environmental challenges exceed the individual ability to cope, then allostatic overload ensues. Allostatic load is identified by the use of biomarkers and clinical criteria.

OBJECTIVE

To summarize the current knowledge on allostatic load and overload and its clinical implications based on a systematic review of the literature.

METHODS

PubMed, PsycINFO, Web of Science, and the Cochrane Library were searched from inception to December 2019. A manual search of the literature was also performed, and reference lists of the retrieved articles were examined.We considered only studies in which allostatic load or overload were adequately described and assessed in either clinical or non-clinical adult populations.

RESULTS

A total of 267 original investigations were included. They encompassed general population studies, as well as clinical studies on consequences of allostatic load/overload on both physical and mental health across a variety of settings.

CONCLUSIONS

The findings indicate that allostatic load and overload are associated with poorer health outcomes. Assessment of allostatic load provides support to the understanding of psychosocial determinants of health and lifestyle medicine. An integrated approach that includes both biological markers and clinimetric criteria is recommended.

Does COVID-19 infection have an impact on children’s psychological problems?

Background

Coronavirus disease 2019 (COVID-19) has a significant impact on children, adolescents, and their families. So, the purpose of this study is to investigate the prevalence of children’s psychological problems during the COVID-19 pandemic and their association of COVID-19 infection in children and their risk factors. A cross-sectional study was conducted on 148 children aged 6–12 years old categorized into 2 groups based on COVID-19 infection history. Participants were assessed by the Socioeconomic Scale and the Checklist for Children’s Behavior (CBCL).

Results

Children who had COVID-19 had a high percentage of problems regarding family, school, social, financial, and parent problems due to the COVID-19 pandemic. Regarding CBCL, children who had COVID-19 infection had a higher percentage of clinical rating than the other group regarding withdrawal (11.1% vs. 8.9%), anxious/depressed (33.3% vs. 25%), somatic (11.1% vs. 10.7%), internalizing (61.1% vs. 48.2%), externalizing (38.9% vs. 35.7%), and total problems (50% vs. 44.6%). Family history of psychiatric disorder and the presence of three or more offspring were at high risk for internalizing problems, while those with school problems during pandemic were more vulnerable for internalizing and total problems.

Conclusion

Children with COVID-19 infection had a higher risk of developing psychological problems, such as withdrawal, anxiety/depression, somatic, internalizing, externalizing, and total problems.

Salivary cytokine cluster moderates the association between caregivers perceived stress and emotional functioning in youth

Some individuals exposed to early life stress show evidence of enhanced systemic inflammation and are at greater risk for psychopathology. In the current study, caregivers and their offspring (0-17 years) were recruited at a pediatric clinic visit at the University of California, San Francisco (UCSF). Mothers and seven-year-old children from the Growing Up inSingaporeTowards healthy Outcomes (GUSTO) prospective birth cohort were used as a replication cohort. Caregivers perceived stress was measured to determine potential intergenerational effects on the children's functioning and inflammation levels. Children's emotional functioning in the UCSF cohort was evaluated using the Pediatric Quality of Life (PedsQL) inventory. Child emotional and behavioral functioning was measured using the Child Behavior Checklist (CBCL) in GUSTO. Saliva was collected from the children and salivary levels of IL-6, IL-1β, IL-8 and TNF-α were measured using an electrochemiluminescent cytokine multiplex panel. Child IL-6, IL-1β, IL-8 cytokine levels were clustered into low, average, and high cytokine cluster groups using hierarchical cluster analysis. We did not find that salivary cytokine clusters were significantly associated with children's emotional or behavioral function. However, cytokine clusters did significantly moderate the association between increased caregiver perceived stress and reduced child emotional functioning (UCSF cohort) and increased Attention-Deficit-Hyperactivity (ADH) problems (GUSTO cohort, uncorrected Cohen's F2 = 0.02). Using a cytokine clustering technique may be useful in identifying those children exposed to increased caregiver perceived stress that are at risk of emotional and attention deficit hyperactivity problems.

Severe childhood and adulthood stress associates with neocortical layer-specific reductions of mature spines in psychiatric disorders

Severe stress exposure causes the loss of dendritic spines on cortical pyramidal neurons and induces psychiatric-like symptoms in rodent models. These effects are strongest following early-life stress and are most persistent on apical dendrites. However, the long-term impacts and temporal effects of stress exposure on the human brain remain poorly understood. Using a novel postmortem cohort of psychiatric cases with severe stress experienced in childhood, adulthood, or no severe stress, and matched controls, we aimed to determine the impact of stress timing on pyramidal neuron structure in the human orbitofrontal cortex (OFC). We performed Golgi Cox staining and manually measured the morphology and density of over 22,000 dendritic spines on layer-specific pyramidal neuron apical dendrites. We also quantified glucocorticoid receptor mRNA and protein as a marker of stress dysregulation. Both childhood and adulthood stress were associated with large reductions in mature mushroom spine density (up to 56% loss) in both the superficial (II/III) and deeper layers (V) of the OFC. However, childhood stress caused more substantial reductions to both total and mature mushroom spines. No difference in glucocorticoid receptor mRNA and protein were seen between groups, although both negatively correlated with total spine density within the whole cohort. These findings indicate that severe stress, especially when experienced during childhood, persistently affects the fine morphological properties of neurons in the human OFC. This may impact on cell connectivity in this brain area, and at least partly explain the social and emotional symptoms that originate in the OFC in psychiatric disorders.

Can ancient and modern stressors be distinguished? A mixed-methods exploration of psychosocial characteristics and health symptoms in young and older adults

A novel conceptualisation of stress includes a distinction between ancient (AS) and modern stressors (MS); the notion that established adaptive psychophysiological coping processes may enable individuals to better withstand AS than MS. Two consecutive mixed-methods studies assessed the feasibility of distinguishing between AS and MS in young and older adults, using questionnaires and interviews. MS were positively associated with cold symptoms in older adults; and five psychosocial characteristics were identified to profile AS and MS along a continuum. An evolutionary distinction between AS and MS provides an important psychological dimension in better understanding and assessing stress-health processes.

Husbands’ and wives’ stressful work, couple BMI dynamics, and later-life physical health

Previous research has not adequately investigated the persistent influence of stressful work experiences, particularly person-work mismatch (PWM), on later-life physical health outcomes of working husbands and wives. Using prospective data collected from 235 working husbands and wives over a period of 27 years (1991-2017), this study examined PWM in early middle years (40-50 years of age) and body mass index (BMI) trajectories in mid-later years (50-65 years of age) in a dyadic actor-partner interdependence modelling framework. Results showed PWM in early middle years was related to BMI trajectories in mid-later years, which contributed to multiple physical health outcomes in later life. Spouses' PWM influenced not only their BMI trajectories but also their partners' BMI trajectories, providing evidence for partner effects. This couple-level BMI process over the mid-later years was related to spouses' physical health in later years. Husbands' elevated BMI level resulted in adverse physical health outcomes. In contrast, for wives, it was the change in BMI over time that resulted in adverse physical health outcomes in their later years. These findings are particularly important for couple-focused family interventions as they highlight the need to consider couple-level lifestyle and behavioural factors that can safeguard spouses from the negative health consequences of PWM.

Derivation of a measure of physiological multisystem dysregulation: Results from WHAS and health ABC

INTRODUCTION

Multifactorial biological processes underpin dysregulation over several individual physiological systems. However, it is challenging to characterize and model this multisystemic dysregulation and its relationship with individual physiologic systems. We operationalized a theory-driven measure of multisystem dysregulation and empirically tested for measurement differences by key characteristics.

METHODS

We used the Women's Health and Aging Studies (WHAS) I and II (N = 649), and the Health ABC study (N = 1515). Twelve biomarkers representing multiple systems including stress response (e.g., inflammation), endocrine system, and energy regulation were identified. A series of confirmatory factor analyses (CFA) were conducted to evaluate the interplay between physiological systems and underlying multisystem dysregulation. We evaluated convergent criterion validity of a score for multisystem dysregulation against the physical frailty phenotype, and predictive criterion validity with incidence of walking difficulty and mortality.

RESULTS

A bifactor CFA, a model in which dysregulation of individual systems proceeds independently of generalized dysregulation, fit data well in WHAS (RMSEA: 0.019; CFI: 0.977; TLI: 0.961) and Health ABC (RMSEA: 0.047; CFI: 0.874; TLI: 0.787). The general dysregulation factor was associated with frailty (OR: 2.2, 95 % CI: 1.4, 3.5), and elevated risk of incident walking difficulty and mortality. Findings were replicated in Health ABC.

DISCUSSION

Biomarker data from two epidemiologic studies support the construct of multisystem physiological dysregulation. Results further suggest system-specific and system-wide processes have unique and non-overlapping contributions to dysregulation in biological markers.

The longitudinal association of psychological resources with chronic conditions and the mediating roles of health behaviours and allostatic load

Objective: To investigate the association of psychological resources with the prevalence of chronic conditions up to 10 years later, and the mediating roles of health behaviours and allostatic load. Design: Participants from the Midlife in the United States study (N = 850) completed surveys and biomarker assessments over the course of 10 years. Main Outcome Measures: Primary outcome was the prevalence of chronic conditions later in life, controlling for baseline chronic conditions. Secondary outcomes were health behaviours and allostatic load. Direct and indirect associations between psychological resources and chronic conditions were examined. Results: Psychological resources were negatively associated with chronic conditions directly (ƅ = -.177, p < .05) and indirectly through health behaviours (ƅ = -.026, p < .05), but not through allostatic load (ƅ = -.000, p > .05). Psychological resources were positively associated with health behaviours (ƅ = .130, p < .01), but no association was found between psychological resources and allostatic load (ƅ = -.002, p > .05). Health behaviours were negatively associated with chronic conditions (ƅ = -.201, p < .01), and allostatic load was positively associated with chronic conditions (ƅ = .197, p < .05). Conclusion: Findings highlight the beneficial influence of psychological resources on chronic conditions, and the mediating role of health behaviours.

Multi-Systemic Biological Risk and Cancer Mortality: The NHANES III Study

Multi-systemic biological risk (MSBR), a proxy for allostatic load, is a composite index of biomarkers representing dysregulation due to responses to chronic stress. This study examined the association of an MSBR index with cancer mortality. The sample included n = 13,628 adults aged 20–90 from the NHANES III Linked Mortality File (1988–1994). The MSBR index included autonomic (pulse rate, blood pressure), metabolic (HOMA_ir, triglycerides, waist circumference), and immune (white blood cell count, C-reactive protein) markers. We fit Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CI) of overall cancer mortality risk, according to quartiles (q) of the index. In multivariable models, compared to those in q1, q4 had a 64% increased risk for cancer mortality (HR = 1.64, 95% CI:1.13–2.40). The immune domain drove the association (HR per unit = 1.19, 95% CI:1.07–1.32). In stratified analyses, the HR for those with a BMI ≥ 25 was 1.12 per unit (95% CI:1.05–1.19) and those with a BMI < 25 was 1.04 per unit (95% CI:0.92–1.18). MSBR is positively associated with risk for cancer mortality in a US sample, particularly among those who are overweight or obese. The utilization of standard clinical measures comprising this index may inform population cancer prevention strategies.

A time to be chronically stressed? Maladaptive time perspectives are associated with allostatic load

Living in the past, the present, or the future can affect stress and health. Our group has shown that acute stress (cortisol reactivity) is modulated by time perspectives, the ways we psychologically relate to time. Here, we expand this research with a comprehensive measure of multi-systemic chronic stress (allostatic load). Among 204 healthy adults (60 men; 144 women), we examined whether time perspectives modulate allostatic load measured with 23 neuroendocrine, immune, metabolic, and cardiovascular biomarkers. Five time perspective categories were measured (past negative, past positive, present hedonistic, present fatalistic, future). Multiple regressions controlling for sex, age, and depressive symptoms were used. Increased present fatalistic time perspective was positively correlated with allostatic load, while future time perspective was negatively correlated with allostatic load. Our preliminary findings link time perspective to multisystemic chronic stress and are discussed in the context of potential clinical implications.

Pilot Study on the Effect of Biophysical Therapy on Salivary Alpha-Amylase as a Surrogate Measure of Anxiety/Stress: In Search of a Novel Noninvasive Molecular Approach for the Management of Stress

Anxiety and depression impact dramatically on public health, underlying the importance of alternative cost-effective treatments. Previous studies have shown that biophysical treatment can significantly reduce anxiety symptoms and recently, salivary alpha-amylase (SAA) has been identified as an objective correlate of the sympathetic-parasympathetic imbalance related to increased stress burden, defined as allostatic load. The aim of this study was to evaluate the effect of biophysical therapy on SAA levels, in addition to the Depression Anxiety Stress Scale (DASS)-21 questionnaire. Twenty-four workers (sales representatives) presenting with mild anxiety/stress symptoms (Generalized Anxiety Disorder 7-item scale of > 5) were randomized to biophysical treatment (N = 12) or placebo control (N = 12). The biophysical group underwent electromagnetic information transfer through an aqueous system procedure, with daily self-administration for one month. SAA collection and the DASS-21 questionnaire were undertaken at baseline and after one month in all patients. Clinical characteristics and baseline DASS-21 subscale scores were similar between placebo and biophysical group at baseline. After one month, patients receiving biophysical therapy had significantly reduced SAA levels compared to the placebo group (27.8 ± 39.4 vs. 116.8 ± 114.9 U/mL, p = 0.019). All three DASS-21 subscales, depression (9.3 ± 5.1 vs. 5.7 ± 5.5, p = 0.1), anxiety (6.7 ± 25 vs. 3.7 ± 2.2, p = 0.0049) and stress (10.8 ± 4.2 vs. 7.3 ± 3.7, p = 0.041) were also decreased after biophysical treatment compared to placebo after one month. Our findings suggest that biophysical therapy can benefit workers with mild (subclinical) anxiety/stress. These results were also validated by the concomitant reduction of SAA levels and an improvement in DASS-21 subscales. The underlying molecular mechanisms of this therapy remain to be characterized.

Should social disconnectedness be included in primary-care screening for cardiometabolic disease? A systematic review of the relationship between everyday stress, social connectedness, and allostatic load

In the present review, we argue that social disconnectedness could and should be included in primary-care screening protocols for the detection of cardiometabolic disease. Empirical evidence indicates that weak social connectedness represents a serious risk factor for chronic diseases, including cardiovascular disease, diabetes, and various cancers. Weak social connectedness, however, is largely regarded as a second-tier health-risk factor in clinical and research settings. This may be because the mechanisms by which this factor impacts on physical health are poorly understood. Budding research, however, advances the idea that social connectedness buffers against stress-related allostatic load–a known precursor for cardiovascular disease and cancer. The present paper reviews the empirical knowledge on the relationship between everyday stress, social connectedness, and allostatic load. Of 6022 articles retained in the literature search, 20 met predefined inclusion criteria. These studies overwhelmingly support the notion that social connectedness correlates negatively with allostatic load. Several moderators of this relationship were also identified, including gender, social status, and quality of social ties. More research into these factors, however, is warranted to conclusively determine their significance. The current evidence strongly indicates that the more socially connected individuals are, the less likely they are to experience chronic stress and associated allostatic load. The negative association between social connectedness and various chronic diseases can thus, at least partially, be explained by the buffering qualities of social connectedness against allostatic load. We argue that assessing social connectedness in clinical and epidemiological settings may therefore represent a considerable asset in terms of prevention and intervention.

Midlife Family Economic Hardship and Later Life Cardiometabolic Health: The Protective Role of Marital Integration

BACKGROUND AND OBJECTIVES

The current study assesses the unique influences of family economic hardship (FEH) in early and late midlife on husbands' and wives' body mass index (BMI) and the influence of BMI on the onset of cardiometabolic (CM) disease in later adulthood. The protective role of marital integration is also considered in relation to the stress-response link between FEH and BMI.

RESEARCH DESIGN AND METHODS

Analyses were performed using structural equation modeling with prospective data from 257 husbands and wives in enduring marriages over a period of 25 years beginning when they were approximately 40 years old. A multigroup analysis tested the moderating role of marital integration.

RESULTS

The distal influence of FEH in early midlife on BMI in later adulthood remained statistically significant even after controlling for proximal FEH. Proximal FEH in later midlife was influential for wives', but not husbands', BMI. BMI in later midlife was related to the onset of CM disease in their later life. Moderation analysis showed that FEH and subsequent BMI were associated for couples with below average levels of behavioral integration but not for couples with above average levels of integration.

DISCUSSION AND IMPLICATIONS

Taken together, these findings suggest a family-health process stemming from early FEH and operating cumulatively over the life course. FEH in early midlife is a persistent determinant of physiological dysregulation as reflected by BMI. Findings identify BMI as a modifiable leverage point for the long-term reduction of CM disease risk and highlight the role of spouses as a buffer against the detrimental stress-health association.

Life Course Patterns of Concurrent Trajectories of BMI and Affective Symptoms of Rural Mothers: Socioeconomic Antecedents and Disease Outcomes in Later Life

OBJECTIVES

The current study, using prospective data over 25 years (1991-2015), concurrently investigates patterns of body mass index (BMI) and affective symptom trajectories in middle-aged mothers and the socioeconomic antecedents and disease outcomes of these patterns.

METHOD

Growth mixture modeling was used to identify latent classes of conjoint health risk trajectories (BMI, depressive symptoms, and anxiety symptoms) from 1991 to 2001. For each latent class, we identified mean trajectories of each health risk. Then, analyses were conducted identifying how these conjoint health risk classes were associated with respondents' socioeconomic background profiles in 1991 and subsequent chronic health problems in 2015.

RESULTS

Socioeconomic background profiles were significantly associated with initially high-risk trajectories. There was a statistically significant association between membership in certain classes of conjoint trajectories and physical health outcomes in later years. Consistent patterns of association with changes in different health outcomes including onset of diseases were observed when classes of conjoint risk trajectories are examined.

DISCUSSION

The identification of members of various conjoint risk trajectory groups provides a potentially useful prognostic tool for early preventive intervention efforts, treatment, and policy formation. Such interventions should promote and develop resiliency factors, thereby aiding in the redirection of middle-aged women's adverse risk trajectories.

The Association Between Perceived Discrimination and Allostatic Load in the Boston Puerto Rican Health Study

OBJECTIVE

Perceived discrimination is a risk factor for poor health among ethnic and racial minority groups. However, few studies have examined the association between major lifetime and everyday perceived discrimination and allostatic load (AL), a preclinical indicator of disease. We examine the association between two measures of discrimination and AL among Puerto Rican adults.

METHODS

Using primarily wave 3 data from the longitudinal Boston Puerto Rican Health Study, we examined the association between major lifetime and everyday perceived discrimination and AL (multisystem dysregulation of 11 physiological components) among Puerto Rican adults residing in the Boston metro area (N = 882). Five models were tested using multivariable regression. The final model adjusted for demographic factors, migration factors, socioeconomic status and work history, health behaviors/risk factors, and depressive symptom.

RESULTS

Respondents had a M (SD) AL score of 5.11 (1.76; range = 0-11). They had an average score of 0.21 (0.42) for major lifetime perceived discrimination (0-3) and 0.29 (0.49) for everyday perceived discrimination (0-3). In a fully adjusted model, major lifetime perceived discrimination was associated with greater AL (b = 0.56; 95% CI = 0.19 to 0.92), whereas greater everyday perceived discrimination was marginally, but not significantly, associated with lower AL (b = -0.42; 95% CI = -0.87 to 0.04).

CONCLUSIONS

Perceived discrimination remains a common stressor and may be a determinant of AL for Puerto Ricans, although the type of perceived discrimination may have differing effects. Further research is needed to better understand the ways in which major lifetime and everyday perceived discrimination operate to effect physiological systems among Puerto Ricans.

Objective and subjective stress, personality, and allostatic load

INTRODUCTION

Despite the understanding of allostatic load (AL) as a consequence of ongoing adaptation to stress, studies of the stress-AL association generally focus on a narrow conceptualization of stress and have thus far overlooked potential confounding by personality. The present study examined the cross-sectional association of objective and subjective stress with AL, controlling for Big Five personality traits.

METHODS

Participants comprised 5,512 members of the Copenhagen Aging and Midlife Biobank aged 49-63 years (69% men). AL was measured as a summary index of 14 biomarkers of the inflammatory, cardiovascular, and metabolic system. Objective stress was assessed as self-reported major life events in adult life. Subjective stress was assessed as perceived stress within the past four weeks.

RESULTS

Both stress measures were positively associated with AL, with a slightly stronger association for objective stress. Adjusting for personality traits did not significantly change these associations.

CONCLUSIONS

The results suggest measures of objective and subjective stress to have independent predictive validity in the context of personality. Further, it is discussed how different operationalizations of stress and AL may account for some of the differences in observed stress-AL associations.

Perceived Control Mediates Effects of Socioeconomic Status and Chronic Stress on Physical Frailty: Findings From the Health and Retirement Study

Objective

To investigate the psychosocial etiology of physical frailty by examining the influence of chronic stress and perceived control.

Method

Using population-based samples of older adults from the Health and Retirement Study, this study employed structural equation modeling in cross-sectional (N = 5,250) and longitudinal (N = 2,013) samples to estimate the effects of chronic stress and socioeconomic status (SES) on baseline frailty and change in frailty status over 4 years and the extent to which perceived control mediates or moderates effects of chronic stress.

Results

Perceived control fully mediated effects of chronic stress and partially mediated effects of SES on both baseline frailty and change in frailty. Multigroup analyses revealed that the mediating role of perceived control was consistent across age, gender, and racial/ethnic subgroups. There was no evidence to support a moderating role of perceived control in the chronic stress and frailty relationship.

Discussion

Findings provide novel evidence for a mediating role of perceived control in pathways linking SES and chronic stress to frailty, further underscoring the importance of psychosocial constructs to the development and progression of frailty in older adults.

Violence Victimization Predicts Body Mass Index One Decade Later among an Urban Sample of African American Young Adults: Sex as a Moderator and Dehydroepiandrosterone as a Mediator

Psychological stressors such as violence victimization are known contributors to obesity. However, moderators and mediators of this association have not been studied, although they might offer pathways for intervention or prevention. Using a sample of African American young adults, this study tested: (1) the moderating effect of sex on the effect of violence victimization on trajectories of body mass index (BMI), and (2) the mediating effect of dehydroepiandrosterone (DHEA) on this association. This 13-year longitudinal study followed 73 male and 80 female African American young adults who lived in an urban area from 1999 to 2012 when the youth were 20-32 years old. The independent variable was violence victimization measured in 1999 and 2000. The dependent variable was BMI measured in 2002 and 2012. The mediator was DHEA measured in 2001 and 2002. Multilevel path analysis was used to test if males and females differed in violence victimization predicting change in BMI (Model I) and the mediating effect of DHEA change on the above association (Model II). The results of Model I suggested that the change in violence victimization from 1999 to 2000 predicted change in BMI from 2002 to 2012 for females, but not males. Based on Model II, the DHEA change from 2000 to 2001 for females fully mediated the association between violence victimization from 1999 to 2000 and increases in BMI from 2002 to 2012. Our findings suggest that violence victimization in urban areas contributes to the development of obesity among African American female young adults and change in DHEA mediates this link. Violence prevention may have important implications for obesity prevention of African American young women who live in unsafe urban areas. This study also suggests that DHEA may be involved in the violence victimization-obesity link for African American women.

Conservation of physiological dysregulation signatures of aging across primates

Two major goals in the current biology of aging are to identify general mechanisms underlying the aging process and to explain species differences in aging. Recent research in humans suggests that one important driver of aging is dysregulation, the progressive loss of homeostasis in complex biological networks. Yet, there is a lack of comparative data for this hypothesis, and we do not know whether dysregulation is widely associated with aging or how well signals of homeostasis are conserved. To address this knowledge gap, we use unusually detailed longitudinal biomarker data from 10 species of nonhuman primates housed in research centers and data from two human populations to test the hypotheses that (a) greater dysregulation is associated with aging across primates and (b) physiological states characterizing homeostasis are conserved across primates to degrees associated with phylogenetic proximity. To evaluate dysregulation, we employed a multivariate distance measure, calculated from sets of biomarkers, that is associated with aging and mortality in human populations. Dysregulation scores positively correlated with age and risk of mortality in most nonhuman primates studied, and signals of homeostatic state were significantly conserved across species, declining with phylogenetic distance. Our study provides the first broad demonstration of physiological dysregulation associated with aging and mortality risk in multiple nonhuman primates. Our results also imply that emergent signals of homeostasis are evolutionarily conserved, although with notable variation among species, and suggest promising directions for future comparative studies on dysregulation and the aging process.

The first multi-zoo application of an allostatic load index to western lowland gorillas (Gorilla gorilla gorilla)

Vertebrate stress responses are highly adaptive biological functions, maximizing survival probability in life-threatening situations. However, experiencing repeated and/or chronic stressors can generate physiological dysregulation and lead to disease. Because stress responses are multi-systemic and involve a wide range of physiological functions, identifying responses to stressors is best accomplished using integrated biomarker models. Allostatic load, defined as the physiological dysregulation that accumulates over the lifespan due to stressful experiences, is one such model. Allostatic load is measured using allostatic load indices, which are composites of biomarkers from multiple somatic systems. Previously, we reported the use of a 7-biomarker allostatic load index (albumin, CRH, cortisol, DHEA-S, glucose, IL-6, TNF-α) in western lowland gorillas housed at a single zoo. Herein, this index is expanded to examine allostatic load responses to lifetime stressors in gorillas from two additional zoos (n = 63) as well as two pooled samples. The index was created using quartile cut-points for each biomarker. Significant associations were observed between multiple predictor variables and allostatic load, including sex, age, number of stressful events (anesthetic events, zoo transfers, agonistic interactions with wounding, pregnancies), and rearing history (mother-reared, nursery-reared, wild-caught). Additionally, allostatic load was associated with indicators of morbidity (creatinine, cholesterol, triglycerides), age at death, and mortality risk. These results are consistent with those reported in human allostatic load research, suggesting allostatic load indices have potential as an investigative and clinical tool for gorillas and other great apes.

Adult Children's Education and Physiological Dysregulation Among Older Parents

Objectives

Despite growing awareness that children's education benefits the health of older parents, the underlying mechanisms of this relationship are not well-understood. We investigated (a) the associations between children's education and biological functioning of parents, (b) psychosocial and behavioral factors that explain the associations, and (c) gendered patterns in the associations.

Methods

Using longitudinal data from a nationally representative sample of older Taiwanese, we performed mediation analysis of the association between adult children's education and physiological dysregulation of their parents.

Results

Offspring's schooling is inversely associated with parental inflammation after controlling for parental socioeconomic status and baseline health. Parents who have well-educated children report higher social standing and life satisfaction, experience fewer stressful events, and are more likely to engage in healthy behaviors related to smoking and diet. These factors moderately attenuate the associations between children's education and parental inflammation. There is no conclusive evidence that mothers and fathers benefit differently from having well-educated children.

Discussion

Parents who devote family and personal resources to their offspring's schooling may have better biological profiles in later life. Well-educated children may promote their parents' wellbeing by strengthening perceived social status, reducing exposure to stressors, and encouraging a healthy lifestyle.

Childhood abuse and depression in adulthood: The mediating role of allostatic load

BACKGROUND

Traumatic experiences during childhood are considered a major risk factor for depression in adulthood. Childhood trauma may induce physiological dysregulation with long-term effects of increased allostatic load until adulthood, which may lead to depression. Thus, our aim was to investigate whether allostatic load - which represents a multi-system measure of physiological dysregulation - mediates the association between childhood trauma and adult depression.

METHODS

The study sample consisted of 324 depressed inpatients participating in the Munich Antidepressant Response Signature (MARS) project and 261 mentally healthy control participants. The mediation analysis using a case-control approach included childhood trauma, i.e., physical and sexual abuse, as predictor variables and an allostatic load index comprised of 12 stress-related biomarkers as mediator. Age and sex were included as covariates.

RESULTS

Mediation analyses revealed that the influence of physical abuse, but not sexual abuse, during childhood on depression in adulthood was mediated by allostatic load. This effect was moderated by age: particularly young (18-42 years) and middle-aged (43-54 years) adults with a history of physical abuse during childhood exhibited high allostatic load, which in turn was associated with increased rates of depression, but this was not the case for older participants (55-81 years).

CONCLUSIONS

Results support the theoretical assumption of allostatic load mediating the effect of physical abuse during childhood on depression in adulthood. This predominantly holds for younger participants, while depression in older participants was independent of physical abuse and allostatic load. The effect of sexual abuse on depression, however, was not mediated by allostatic load. Identifying allostatic load biomarkers prospectively in the developmental course of depression is an important target for future research.

Relationship between stress coping and sleep disorders among the general Japanese population: a nationwide representative survey

OBJECTIVE

To clarify the prevalence of stress, and examine the relationship between sleep disorders and stress coping strategies among highly stressed individuals in the general Japanese population.

METHODS

A cross-sectional nationwide survey was undertaken in November 2007. Men and women were randomly selected from 300 districts throughout Japan. Data from 7671 (3532 men (average age 53.5 ± 17.0 years) and 4139 women (average age 53.9 ± 17.7 years)) were analyzed. Participants completed a self-reported questionnaire on stress, sleep disorders, and stress coping strategies in the previous month.

RESULTS

Highly stressed individuals comprised 16.6% (95% confidence interval 15.8-17.5%) of the total sample, and most were aged 20-49 years. In multiple logistic regression, symptoms of insomnia (ie, difficulty initiating sleep, difficulty maintaining sleep, and early morning awakening), excessive daytime sleepiness, nightmares, daytime malfunction, and lack of rest due to sleep deprivation were more prone to occur in highly stressed individuals. In addition, logistic regression analysis controlling for other adjustment factors revealed that stress coping strategies such as 'giving up on problem-solving', 'enduring problems patiently', 'smoking' and 'drinking alcohol' were positively associated with the above-mentioned sleep disorders. On the other hand, stress coping strategies such as 'exercising', 'enjoying hobbies', and 'sharing worries' were inversely associated with the above-mentioned sleep disorders.

CONCLUSIONS

Distraction-based stress coping (eg, hobbies, exercise, and optimistic thinking) was found to be preferable to problem-based stress coping in a highly stressed Japanese general population.

An Overview of Literature Topics Related to Current Concepts, Methods, Tools, and Applications for Cumulative Risk Assessment (2007-2016)

Cumulative risk assessments (CRAs) address combined risks from exposures to multiple chemical and nonchemical stressors and may focus on vulnerable communities or populations. Significant contributions have been made to the development of concepts, methods, and applications for CRA over the past decade. Work in both human health and ecological cumulative risk has advanced in two different contexts. The first context is the effects of chemical mixtures that share common modes of action, or that cause common adverse outcomes. In this context two primary models are used for predicting mixture effects, dose addition or response addition. The second context is evaluating the combined effects of chemical and nonchemical (e.g., radiation, biological, nutritional, economic, psychological, habitat alteration, land-use change, global climate change, and natural disasters) stressors. CRA can be adapted to address risk in many contexts, and this adaptability is reflected in the range in disciplinary perspectives in the published literature. This article presents the results of a literature search and discusses a range of selected work with the intention to give a broad overview of relevant topics and provide a starting point for researchers interested in CRA applications.

Relationship of Psychosocial Resources With Allostatic Load: A Systematic Review

OBJECTIVE

Allostatic load (AL) represents cumulative wear-and-tear on the body and is operationalized as a multisystem index of biomarkers. Allostatic load is associated with morbidities and mortality, leading to a growing body of literature that uses AL as an outcome in its own right. Psychosocial resources (PSRs), such as mastery and social support, may influence health outcomes in part via AL, and the current review seeks to characterize the relations between PSRs and AL.

METHODS

A systematic review was conducted by searching PubMed, CINAHL Plus, PsycINFO, Scopus, and Embase for studies examining the relation between PSR(s) and AL in humans. From 1,417 abstracts screened, 60 full-text articles were reviewed, and 24 studies met inclusion criteria.

RESULTS

Mixed evidence exists for a relationship between PSRs and AL. Most (14/24) studies used a cross-sectional design, and only one study investigated whether a PSR predicted change in AL. Compared to cross-sectional studies, longitudinal studies were more likely to report a significant relationship (8/14 versus 8/10, respectively). Studies with statistically significant main or moderated effects had larger sample sizes than those reporting null effects. Whether a study reported a significant main or moderated relationship did not differ by whether psychological (8/11) or social (10/16) resources were assessed.

CONCLUSIONS

Evidence for a relationship between PSRs and AL is equivocal, and obtained significant relationships are generally small in magnitude. Gaps in the current literature and directions for future research are discussed. Longitudinal studies are needed that repeatedly assess PSRs and AL.

Allostatic load: a useful concept for advancing nursing research

AIMS AND OBJECTIVES

To elucidate the historical development of the allostatic load concept, alongside its use in nursing research, and to explore how allostatic load has been investigated among two stress-vulnerable populations.

BACKGROUND

'Stress' is a prominent term in understanding the development of disease. Allostatic load is among several approaches undertaken to quantify the magnitude of stress and understand how stress can affect health.

METHOD

We explored the advent of allostatic load including its antecedents, and consequences. We used an exemplar case to apply the concept. We reviewed studies that used allostatic load among workers and women of childbearing age.

RESULTS

There remains a need to consolidate a common definition and operationalisation of allostatic load. Despite this need for further work, allostatic load is a good fit for nursing science which focuses on the client, environment and health. Only 12 studies explored allostatic load among workers (n = 6) and women of childbearing age (n = 6). In some studies, allostatic load was used as a predictor while in others it was used as an outcome. None of the studies considered it as a mediator.

CONCLUSIONS

The concept of allostatic load holds promise for nursing researchers to operationalise a holistic view of multiple stressors and to quantify their effects on health. Studies are needed to affirm the role of allostatic load as a potential mediator between multiple stressors and outcomes. Longitudinal studies are also needed to demonstrate a causal pathway from stressor exposure to tertiary outcomes such as chronic conditions and morbidity.

RELEVANCE TO CLINICAL PRACTICE

Allostatic load is a useful concept for nurses working with stress-vulnerable populations. With the use of an interpretable allostatic load index, nurses will be able to intervene at various stages of the allostasis-adaptation process (stress-response) and adjust interventions accordingly.

Meeting physical activity guidelines is associated with lower allostatic load and inflammation in Mexican Americans

Examine the relationship between physical activity (PA) and allostatic load in Mexican-Americans as well as variations by gender. Self-reported PA as well as cardiovascular, metabolic and inflammatory markers were assessed in 330 Mexican-American adults in the Cameron County Hispanic Cohort (Brownsville, TX, USA). Dependent variables included total allostatic load, blood pressure, metabolic, and inflammatory scores. PA participation was categorized as sedentary, low, moderate, high, and by whether activity was sufficient to meet public health guidelines. Logistic regression analyses were conducted using cross-sectional data, and tested interaction effects of gender and PA. High active participants had lower allostatic load and inflammatory risk than sedentary participants. These relationships held for meeting versus not meeting guidelines. Males meeting guidelines were less likely to have high inflammation than other groups. The data did not suggest a dose-response association. These findings indicate that PA may reduce accumulation of allostatic load, highlighting the importance of a physically active lifestyle across the life span.

Predictors of quality of life among hospitalized geriatric patients with diabetes mellitus upon discharge

Purpose

Diabetes mellitus is prevalent among older adults, and affects their quality of life. Furthermore, the number is growing as the elderly population increases. Thus, this study aims to explore the predictors of quality of life among hospitalized geriatric patients with diabetes mellitus upon discharge in Malaysia.

Methods

A total of 110 hospitalized geriatric patients aged 60 years and older were selected using convenience sampling method in a cross-sectional study. Sociodemographic data and medical history were obtained from the medical records. Questionnaires were used during the in-person semistructured interviews, which were conducted in the wards. Linear regression analyses were used to determine the predictors of each domain of quality of life.

Results

Multiple regression analysis showed that activities of daily living, depression, and appetite were the determinants of physical health domain of quality of life (R²=0.633, F(3, 67)=38.462; P<0.001), whereas depression and instrumental activities of daily living contributed to 55.8% of the variability in psychological domain (R²=0.558, F(2, 68)=42.953; P<0.001). Social support and cognitive status were the determinants of social relationship (R²=0.539, F(2, 68)=39.763; P<0.001) and also for the environmental domain of the quality of life (R²=0.496, F(2, 68)=33.403; P<0.001).

Conclusion

The findings indicated different predictors for each domain in the quality of life among hospitalized geriatric patients with diabetes mellitus. Nutritional, functional, and psychological aspects should be incorporated into rehabilitation support programs prior to discharge in order to improve patients’ quality of life.

Stress and A1c Among People with Diabetes Across the Lifespan

Stress is known to negatively affect health and is a potentially serious barrier to diabetes-related health outcomes. This paper synthesizes what is known about stress and glycemic control among people with type 1 and type 2 diabetes across the lifespan. Chronic stress-especially in relation to living with diabetes-was most strongly associated with A1c, particularly among subgroups that face disproportionate stress, such as minority groups or adolescents/young adults. Mechanisms of the stress-A1c association include physiological, psychological, behavioral, and environmental links. Understanding the dimensions of stress as they relate to health in diabetes can be of significant clinical importance, and interventions targeting mechanisms that either exacerbate or buffer stress have reported modest improvements in A1c.

Biophysical approach to low back pain: a pilot report

Since biophysical treatment has been reported to be effective in the general management of pain, we decided to assess the specific effect and treatment duration of this therapeutic strategy in low back pain. We were interested in verifying the possibility that a single clinical procedure could reduce pain and improve patients' quality of life within a period of three months. An Electromagnetic Information Transfer Through Aqueous System was employed to record endogenous therapeutic signals from each individual using an electromagnetic recording device (Med Select 729). A highly significant reduction in the Roland Morris low back pain and disability questionnaire score was observed after 3 months following a single biophysical intervention (11.83 ± 6 at baseline versus 2.3 ± 3.25 at 3 months, p < 0.0001). This preliminary report provides further evidence of the theoretical implications and clinical applications of Quantum Electro Dynamic concepts in biology and medicine.

Social-Biological Interactions in Oral Disease: A 'Cells to Society' View

Oral diseases constitute a major worldwide public health problem, with their burden concentrating in socially disadvantaged and less affluent groups of the population, resulting in significant oral health inequalities. Biomedical and behavioural approaches have proven relatively ineffective in reducing these inequalities, and have potentially increased the health gap between social groups. Some suggest this stems from a lack of understanding of how the social and psychosocial contexts in which behavioural and biological changes occur influence oral disease. To unravel the pathways through which social factors affect oral health outcomes, a better understanding is thus needed of how the social 'gets under the skin,' or becomes embodied, to alter the biological. In this paper, we present the current knowledge on the interplay between social and biological factors in oral disease. We first provide an overview of the process of embodiment in chronic disease and then evaluate the evidence on embodiment in oral disease by reviewing published studies in this area. Results show that, in periodontal disease, income, education and perceived stress are correlated with elevated levels of stress hormones, disrupted immune biomarkers and increased allostatic load. Similarly, socioeconomic position and increased financial stress are related to increased stress hormones and cariogenic bacterial counts in dental caries. Based on these results, we propose a dynamic model depicting social-biological interactions that illustrates potential interdependencies between social and biological factors that lead to poor oral health. This work and the proposed model may aid in developing a better understanding of the causes of oral health inequalities and implicate the importance of addressing the social determinants of oral health in innovating public health interventions.