Allostatic load as a predictor of functional decline. MacArthur studies of successful aging

Feasibility of Formal Mindfulness-Based Stress-Resilience Training Among Surgery Interns: A Randomized Clinical Trial

Importance

Among surgical trainees, burnout and distress are prevalent, but mindfulness has been shown to decrease the risk of depression, suicidal ideation, burnout, and overwhelming stress. In other high-stress populations, formal mindfulness training has been shown to improve mental health, yet this approach has not been tried in surgery.

Objective

To test the feasibility and acceptability of modified Mindfulness-Based Stress Reduction (MBSR) training during surgical residency.

Design, Setting, and Participants

A pilot randomized clinical trial of modified MBSR vs an active control was conducted with 21 surgical interns in a residency training program at a tertiary academic medical center, from April 30, 2016, to December 2017.

Interventions

Weekly 2-hour, modified MBSR classes and 20 minutes of suggested daily home practice over an 8-week period.

Main Outcomes and Measures

Feasibility was assessed along 6 domains (demand, implementation, practicality, acceptability, adaptation, and integration), using focus groups, interviews, surveys, attendance, daily practice time, and subjective self-report of experience.

Results

Of the 21 residents included in the analysis, 13 were men (62%). Mean (SD [range]) age of the intervention group was 29.0 (2.4 [24-31]) years, and the mean (SD [range]) age of the control group was 27.4 (2.1 [27-33]) years. Formal stress-resilience training was feasible through cultivation of stakeholder support. Modified MBSR was acceptable as evidenced by no attrition; high attendance (12 of 96 absences [13%] in the intervention group and 11 of 72 absences [15%] in the control group); no significant difference in days per week practiced between groups; similar mean (SD) daily practice time between groups with significant differences only in week 1 (control, 28.15 [12.55] minutes; intervention, 15.47 [4.06] minutes; P = .02), week 2 (control, 23.89 [12.93] minutes; intervention, 12.61 [6.06] minutes; P = .03), and week 4 (control, 26.26 [13.12] minutes; intervention, 15.36 [6.13] minutes; P = .04); course satisfaction (based on interviews and focus group feedback); and posttraining-perceived credibility (control, 18.00 [4.24]; intervention, 20.00 [6.55]; P = .03). Mindfulness skills were integrated into personal and professional settings and the independent practice of mindfulness skills continued over 12 months of follow-up (mean days [SD] per week formal practice, 3 [1.0]).

Conclusions and Relevance

Formal MBSR training is feasible and acceptable to surgical interns at a tertiary academic center. Interns found the concepts and skills useful both personally and professionally and participation had no detrimental effect on their surgical training or patient care.

Trial Registration

ClinicalTrials.gov identifier: NCT03141190.

Prevention Strategies in Post-TBI Depression in Older Adults: A Case Study

PURPOSE

The purpose of this study was to describe a theoretically focused intervention aimed toward chronic stress and depressive symptom management that is coordinated by a case manager and delivered within a home environment by the caregiver.

PRIMARY PRACTICE SETTING

Home care, community setting.

METHODS

A case study of an older adult with traumatic brain injury (TBI) secondary to a fall who had significant allostatic load at the time of his injury. "Allostatic load" is a theoretical construct that suggests the brain is experiencing chronic strain on its systems that flexibly respond to stressors. Sustained allostatic load can contribute to chronic conditions and poor outcomes.

FINDINGS

Through actions with the family as caregivers, the case manager was able to coordinate a structured home setting and gradual resumption of social activities for this older adult. Focus was on establishing structure, meaningful social interactions, and positive home experiences that maximized the older adult's interests and capacity and mitigated chronic stress. Gradually, the older adult returned to his preinjury capacity and lives independently within the family home.

IMPLICATIONS FOR CASE MANAGEMENT PRACTICE

The case management process has the potential to mitigate stressors and improve depression management through family-focused care. Although there is limited guidance on prevention of depression, this approach resulted in attainment of safe home care, no hospital readmissions, and return to previous lifestyle for the older adult. This could be useful in the prevention of post-TBI depression.

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.

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.

Stress and adolescent well-being: the need for an interdisciplinary framework

Stress and strain among adolescents have been investigated and discussed largely within three separate disciplines: mental health, where the focus has been on the negative effects of stress on emotional health; criminology, where the emphasis has been on the effects of strain on delinquency; and biology, where the focus has been to understand the effects of stress on physiology. Recently, scholars have called for increased multilevel developmental analyses of the bio-psychosocial nature of risk and protection for behaviors of individuals. This paper draws on several different but converging theoretical perspectives in an attempt to provide an overview of research relevant to stress in adolescence and puts forth a new framework that aims to provide both a common language and consilience by which future research can analyze the effects of multiple biological, social and environmental factors experienced during specific developmental periods, and cumulatively over time, on harmful behavior during adolescence. We present a framework to examine the effects of stress on diverse behavioral outcomes among adolescents, including substance use, suicidal behavior, self-inflicted harm, and delinquency.

Allostatic load and subsequent all-cause mortality: which biological markers drive the relationship? Findings from a UK birth cohort

The concept of allostatic load (AL) refers to the idea of a global physiological 'wear and tear' resulting from the adaptation to the environment through the stress response systems over the life span. The link between socioeconomic position (SEP) and mortality has now been established, and there is evidence that AL may capture the link between SEP and mortality. In order to quantitatively assess the role of AL on mortality, we use data from the 1958 British birth cohort including eleven year mortality in 8,113 adults. Specifically, we interrogate the hypothesis of a cumulative biological risk (allostatic load) reflecting 4 physiological systems potentially predicting future risk of death (N = 132). AL was defined using 14 biomarkers assayed in blood from a biosample collected at 44 years of age. Cox proportional hazard regression analysis revealed that higher allostatic load at 44 years old was a significant predictor of mortality 11 years later [HR = 3.56 (2.3 to 5.53)]. We found that this relationship was not solely related to early-life SEP, adverse childhood experiences and young adulthood health status, behaviours and SEP [HR = 2.57 (1.59 to 4.15)]. Regarding the ability of each physiological system and biomarkers to predict future death, our results suggest that the cumulative measure was advantageous compared to evaluating each physiological system sub-score and biomarker separately. Our findings add some evidence of a biological embodiment in response to stress which ultimately affects mortality.

A Longitudinal Analysis of Allostatic Load among a Multi-Ethnic Sample of Midlife Women: Findings from the Study of Women's Health Across the Nation

OBJECTIVES

We examined longitudinal patterns and sociodemographic correlates of allostatic load (AL), a measure of cumulative biological risk and aging, in a sample of midlife women consisting of non-Hispanic White, African American, Chinese, and Japanese women.

METHODS

Longitudinal cohort data from the Study of Women's Health Across the Nation were used to examine AL patterns in midlife women ages 42-53 (n = 1,932). AL measures were created using 10 biomarkers representing cardiovascular, inflammatory, neuroendocrine, and metabolic system functioning. We used longitudinal random effects Poisson regression models to assess change in AL over the 7-year follow-up period and associations between sociodemographic factors and AL.

RESULTS

On average, a woman's AL score increased 2% each year over the course of the study. Baseline measures of African American race, low family income, older age, and ability to read and speak only in English were significantly associated with higher levels of AL over the study period. We did not observe significant differences in rates of change in AL by race/ethnicity or socioeconomic status.

CONCLUSIONS

This study demonstrates that AL increases in a cumulative manner as women age. Midlife is an especially important time in women's life course with respect to health maintenance and healthy aging. AL can be an early warning indicator of subsequent disease burden, pointing to subclinical conditions and the need for implementation of medical and public health interventions earlier in the disease process.

The effects of chronic stress on the human brain: From neurotoxicity, to vulnerability, to opportunity

For the last five decades, science has managed to delineate the mechanisms by which stress hormones can impact on the human brain. Receptors for glucocorticoids are found in the hippocampus, amygdala and frontal cortex, three brain regions involved in memory processing and emotional regulation. Studies have shown that chronic exposure to stress is associated with reduced volume of the hippocampus and that chronic stress can modulate volumes of both the amygdala and frontal cortex, suggesting neurotoxic effects of stress hormones on the brain. Yet, other studies report that exposure to early adversity and/or familial/social stressors can increase vulnerability to stress in adulthood. Models have been recently developed to describe the roles that neurotoxic and vulnerability effects can have on the developing brain. These models suggest that developing early stress interventions could potentially counteract the effects of chronic stress on the brain and results going along with this hypothesis are summarized.

Biological age as a health index for mortality and major age-related disease incidence in Koreans: National Health Insurance Service - Health screening 11-year follow-up study

Purpose

A comprehensive health index is needed to measure an individual's overall health and aging status and predict the risk of death and age-related disease incidence, and evaluate the effect of a health management program. The purpose of this study is to demonstrate the validity of estimated biological age (BA) in relation to all-cause mortality and age-related disease incidence based on National Sample Cohort database.

Patients and methods

This study was based on National Sample Cohort database of the National Health Insurance Service - Eligibility database and the National Health Insurance Service - Medical and Health Examination database of the year 2002 through 2013. BA model was developed based on the National Health Insurance Service - National Sample Cohort (NHIS - NSC) database and Cox proportional hazard analysis was done for mortality and major age-related disease incidence.

Results

For every 1 year increase of the calculated BA and chronological age difference, the hazard ratio for mortality significantly increased by 1.6% (1.5% in men and 2.0% in women) and also for hypertension, diabetes mellitus, heart disease, stroke, and cancer incidence by 2.5%, 4.2%, 1.3%, 1.6%, and 0.4%, respectively (p<0.001).

Conclusion

Estimated BA by the developed BA model based on NHIS - NSC database is expected to be used not only as an index for assessing health and aging status and predicting mortality and major age-related disease incidence, but can also be applied to various health care fields.

Apolipoprotein E genotype does not moderate the associations of depressive symptoms, neuroticism and allostatic load with cognitive ability and cognitive aging in the Lothian Birth Cohort 1936

OBJECTIVES

In this replication-and-extension study, we tested whether depressive symptoms, neuroticism, and allostatic load (multisystem physiological dysregulation) were related to lower baseline cognitive ability and greater subsequent cognitive decline in older adults, and whether these relationships were moderated by the E4 allele of the apolipoprotein E (APOE) gene. We also tested whether allostatic load mediated the relationships between neuroticism and cognitive outcomes.

METHODS

We used data from the Lothian Birth Cohort 1936 (n at Waves 1-3: 1,028 [M age = 69.5 y]; 820 [M duration since Wave 1 = 2.98 y]; 659 [M duration since Wave 1 = 6.74 y]). We fitted latent growth curve models of general cognitive ability (modeled using five cognitive tests) with groups of APOE E4 non-carriers and carriers. In separate models, depressive symptoms, neuroticism, and allostatic load predicted baseline cognitive ability and subsequent cognitive decline. In addition, models tested whether allostatic load mediated relationships between neuroticism and cognitive outcomes.

RESULTS

Baseline cognitive ability had small-to-moderate negative associations with depressive symptoms (β range = -0.20 to -0.17), neuroticism (β range = -0.27 to -0.23), and allostatic load (β range = -0.11 to 0.09). Greater cognitive decline was linked to baseline allostatic load (β range = -0.98 to -0.83) and depressive symptoms (β range = -1.00 to -0.88). However, APOE E4 allele possession did not moderate the relationships of depressive symptoms, neuroticism and allostatic load with cognitive ability and cognitive decline. Additionally, the associations of neuroticism with cognitive ability and cognitive decline were not mediated through allostatic load.

CONCLUSIONS

Our results suggest that APOE E4 status does not moderate the relationships of depressive symptoms, neuroticism, and allostatic load with cognitive ability and cognitive decline in healthy older adults. The most notable positive finding in the current research was the strong association between allostatic load and cognitive decline.

Burnout of the Mind – Burnout of the Body?

Abstract. In the present paper we investigate whether patients with a clinical diagnosis of burnout show physiological signs of burden across multiple physiological systems referred to as allostatic load (AL). Measures of the sympathetic-adrenergic-medullary (SAM) axis and the hypothalamic-pituitary-adrenal (HPA) axis were assessed. We examined patients who had been diagnosed with burnout by their physicians (n = 32) and were also identified as burnout patients based on their score in the Maslach Burnout Inventory-General Survey (MBI-GS) and compared them with a nonclinical control group (n = 19) with regard to indicators of allostatic load (i.e., ambulatory ECG, nocturnal urinary catecholamines, salivary morning cortisol secretion, blood pressure, and waist-to-hip ratio [WHR]). Contrary to expectations, a higher AL index suggesting elevated load in several of the parameters of the HPA and SAM axes was found in the control group but not in the burnout group. The control group showed higher norepinephrine values, higher blood pressure, higher WHR, higher sympathovagal balance, and lower percentage of cortisol increase within the first hour after awakening as compared to the patient group. Burnout was not associated with AL. Results seem to indicate a discrepancy between self-reported burnout symptoms and psychobiological load.

Data Science in the Research Domain Criteria Era: Relevance of Machine Learning to the Study of Stress Pathology, Recovery, and Resilience

Diverse environmental and biological systems interact to influence individual differences in response to environmental stress. Understanding the nature of these complex relationships can enhance the development of methods to: (1) identify risk, (2) classify individuals as healthy or ill, (3) understand mechanisms of change, and (4) develop effective treatments. The Research Domain Criteria (RDoC) initiative provides a theoretical framework to understand health and illness as the product of multiple inter-related systems but does not provide a framework to characterize or statistically evaluate such complex relationships. Characterizing and statistically evaluating models that integrate multiple levels (e.g. synapses, genes, environmental factors) as they relate to outcomes that a free from prior diagnostic benchmarks represents a challenge requiring new computational tools that are capable to capture complex relationships and identify clinically relevant populations. In the current review, we will summarize machine learning methods that can achieve these goals.

Assessment of cumulative health risk in the World Trade Center general responder cohort

BACKGROUND

Multiple comorbidities have been reported among rescue/recovery workers responding to the 9/11/2001 WTC disaster. In this study, we developed an index that quantifies the cumulative physiological burden of comorbidities and predicts life expectancy in this cohort.

METHODS

A machine learning approach (gradient boosting) was used to model the relationship between mortality and several clinical parameters (laboratory test results, blood pressure, pulmonary function measures). This model was used to construct a risk index, which was validated by assessing its association with a number of health outcomes within the WTC general responder cohort.

RESULTS

The risk index showed significant associations with mortality, self-assessed physical health, and onset of multiple chronic conditions, particularly COPD, hypertension, asthma, and sleep apnea.

CONCLUSION

As an aggregate of several clinical parameters, this index serves as a cumulative measure of physiological dysregulation and could be utilized as a prognostic indicator of life expectancy and morbidity risk.

Discrimination and anger control as pathways linking socioeconomic disadvantage to allostatic load in midlife

OBJECTIVE

Recent evidence suggests that experiences of discrimination contribute to socioeconomic status health disparities. The current study examined if the experience and regulation of anger-an expected emotional response to discrimination-serves as an explanatory factor for the previously documented links between socioeconomic disadvantage (SED), discrimination, and allostatic load.

METHODS

Data were drawn from the second wave of the Midlife in the United States (MIDUS) study and included 909 adults who participated in the biomarkers subproject.

RESULTS

Results revealed that perceived discrimination was associated with higher levels of allostatic load. Furthermore, we found evidence that perceived discrimination and anger control sequentially explained the relationship between SED and allostatic load, such that greater discrimination was associated with lower levels of anger control, which, in turn accounted for the effects of discrimination on allostatic load. These results remained significant after controlling for negative affect, positive affect, other forms of anger expression, as well as demographic covariates.

CONCLUSIONS

Our findings suggest that low anger control may be an important psychological pathway through which experiences of discrimination influence health.

Changes in Allostatic Load during workplace reorganization

OBJECTIVE

Allostatic Load (AL) represents the strain on the body produced by repeated physiologic or allostatic responses activated during stressful situations. Several cross-sectional studies have found empirical substantiation for the relationship between impaired psychosocial work environment and high AL. The aim of this longitudinal study is to investigate changes in AL during workplace reorganization that has been shown to cause impaired psychosocial work environment. Moreover, we aim to investigate the association between changes in AL and changes in psychosocial work environment (job strain, effort-reward imbalance) and psychological distress (stress symptoms and perceived stress).

METHODS

A major reorganization of non-state public offices was effectuated in Denmark on 1 January 2007. In 2006 and 2008, we collected clinical and questionnaire data from 359 participants, 265 women and 94 men, employed in seven municipality or county administrations. Four municipalities and one county merged with others, while one municipality and one county remained unmerged. We calculated the AL score based on 13 physiological markers reflecting stress responses of the cardiovascular, metabolic, neuroendocrine and immune systems. We analysed changes in AL from 2006 to 2008.

RESULTS

AL increased significantly during workplace reorganization in the whole study group but we observed only a tendency of significant increase in AL in the merger group compared with the control group. Moreover, we observed no association between the changes in AL and changes in psychosocial work environment and psychological distress.

CONCLUSIONS

This result leaves the conclusion unclear but contributes to the limited research in this area with a longitudinal design and focus on low-risk levels and small changes in AL in healthy people as predictor of future disease.

Preliminary evidence of attenuated blood pressure reactivity to acute stress in adults following a recent marital separation

OBJECTIVE

This study explores cardiovascular reactivity during an acute-stress task in a sample of recently separated adults.

DESIGN

In a cross-sectional design, we examined the association between adults' subjective separation-related distress and changes in heart rate and blood pressure across the acute-stress laboratory paradigm in a sample of 133 (n = 49 men) recently separated adults.

MAIN OUTCOME MEASURES

Heart rate (HR) and Blood pressure (BP) were recorded across a resting baseline period, a math stressor task, and a recovery period.

RESULTS

Multilevel analyses revealed that adults who reported greater separation-related distress exhibited higher initial BP and a slower linear increase in BP across the study period. In addition, adults reporting greater separation-related distress evidenced significantly slower declines in diastolic blood pressure (DBP) following the acute-stress task. HR reactivity was not moderated by separation-related distress.

CONCLUSIONS

In recently separated adults, preliminary evidence suggests that the context of the stressors may reveal differential patterns of problematic reactivity (exaggerated or blunted responding). Greater emotional intrusion and hyperactivity symptoms may index increased risk for blunted cardiovascular reactivity to general stressors. This pattern of reactivity is consistent with models of allostatic load that emphasise the deleterious effect of hyporesponsivity to environmental demands.

Physiological Dysregulation, Frailty, and Risk of Mortality Among Older Adults

This study examines whether frailty is associated with mortality independently of physiological dysregulation (PD) and, if so, which is the more accurate predictor of survival. Data come from the Social Environment and Biomarkers of Aging Study. We use Cox proportional hazard models to test the associations between PD, frailty, and 4- to 5-year survival. We use Harrell's concordance index to compare predictive accuracy of the models. Both PD and frailty are significantly, positively, and independently correlated with mortality: Worse PD scores and being frail are associated with a higher risk of dying. The overall PD score is a more accurate predictor of survival than frailty, although model prediction improves when both measures are included. PD and frailty independently predict mortality, suggesting that the two measures may be capturing different aspects of the same construct and that both may be important for identifying individuals at risk for adverse health outcomes.

Religious Participation and Biological Functioning in Mexico

OBJECTIVE

Although several studies suggest that religious involvement tends to favor healthy biological functioning, most of this work has been conducted in the United States. This study explores the association between religious participation and biological functioning in Mexico.

METHOD

The data are drawn from two waves of the Mexican Health and Aging Study (2003-2012) to assess continuous and categorical biomarker specifications.

RESULTS

Across specifications, religious participation in 2003 is associated with lower levels of waist-to-hip ratio, total cholesterol, pulse rate, and overall allostatic load in 2012. Respondents who increased their participation over the study period also exhibit a concurrent reduction in pulse rate. Depending on the specification, participation is also associated with lower levels of diastolic blood pressure and C-reactive protein. Participation is generally unrelated to body mass index, glycosylated hemoglobin, and systolic blood pressure.

DISCUSSION

Our results confirm that religious participation is associated with healthier biological functioning in Mexico.

Resilience and biomarkers of health risk in Black smokers and nonsmokers

OBJECTIVES

Blacks are disproportionately affected by tobacco-related illnesses as well as traumatic events associated with psychiatric conditions and smoking. We examined the potential protective nature of resilience within this context, hypothesizing resilience differentially moderates the associations of traumatic experiences to depressive symptoms and to biomarkers of health risk among Black ever versus never smokers.

METHOD

Measures of resilience, traumatic experiences, depressive symptoms, and biomarkers (interleukin-6 [IL-6], C-reactive protein [CRP], allostatic load) were obtained among 852 Blacks recruited from Grady Memorial Hospital in Atlanta.

RESULTS

Ever smokers experienced more trauma (p < .001) and depressive symptoms (p = .01). Structural equation modeling indicated that, in ever smokers, childhood trauma was positively associated with depressive symptoms (p < .001); resilience was negatively associated with depressive symptoms (p = .01). Depressive symptoms were positively associated with IL-6 (p = .03), which was positively associated with allostatic load (p = .01). Adulthood trauma was associated with higher CRP levels (p = .03). In never smokers, childhood (p < .001) and adulthood trauma (p = .01) were associated with more depressive symptoms. Adulthood trauma was also associated with higher CRP levels (p < .001), which was positively associated with allostatic load (p < .001). Never smokers with higher resilience had a negative association between childhood trauma and depressive symptoms whereas those with lower resilience had a positive association between childhood trauma and depressive symptoms. Resilience was negatively associated with CRP levels (p < .001).

CONCLUSIONS

Interventions targeting resilience may prevent smoking and adverse health outcomes. (PsycINFO Database Record

Allostatic load as a predictor of all-cause and cause-specific mortality in the general population: Evidence from the Scottish Health Survey

Allostatic load is a multiple biomarker measure of physiological ‘wear and tear’ that has shown some promise as marker of overall physiological health, but its power as a risk predictor for mortality and morbidity is less well known. This study has used data from the 2003 Scottish Health Survey (SHeS) (nationally representative sample of Scottish population) linked to mortality records to assess how well allostatic load predicts all-cause and cause-specific mortality. From the sample, data from 4,488 men and women were available with mortality status at 5 and 9.5 (rounded to 10) years after sampling in 2003. Cox proportional hazard models estimated the risk of death (all-cause and the five major causes of death in the population) according to allostatic load score. Multiple imputation was used to address missing values in the dataset. Analyses were also adjusted for potential confounders (sex, age and deprivation). There were 258 and 618 deaths over the 5-year and 10-year follow-up period, respectively. In the fully-adjusted model, higher allostatic load (poorer physiological ‘health’) was not associated with an increased risk of all-cause mortality after 5 years (HR = 1.07, 95% CI 0.94 to 1.22; p = 0.269), but it was after 10 years (HR = 1.08, 95% CI 1.01 to 1.16; p = 0.026). Allostatic load was not associated with specific causes of death over the same follow-up period. In conclusions, greater physiological wear and tear across multiple physiological systems, as measured by allostatic load, is associated with an increased risk of death, but may not be as useful as a predictor for specific causes of death.

An Introduction to Primary Care in Underserved Populations: Definitions, Scope, and Challenges

This article addresses the scope of the problem primary care physicians face when caring for the underserved, both nationally and internationally. It touches on the statistics used to define medically underserved communities, the pervasiveness of poverty, and how primary care physician shortages may soon reach a crisis point. The definitions of socioeconomic status, allostatic load, and structural violence are also reviewed.

Physical Function in an Aging Population in Rural South Africa: Findings From HAALSI and Cross-National Comparisons With HRS Sister Studies

OBJECTIVES

We use recently-collected data from the Health and Aging in Africa: a Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) cohort from Agincourt, South Africa, to describe physical functioning in this aging population, and place the overall level and age-trajectories of physical health in the context of other Health and Retirement Study (HRS) sister studies in low- and middle-income countries (LMICs).

METHOD

We conduct multiple regression to estimate associations of physical functioning assessed from both self-report (activities of daily living [ADL] limitation, self-reported health) and performance (grip strength, gait speed) with socio-demographic and health characteristics in HAALSI, and use fully-interacted regression models to compare age-patterns of physical functioning outcomes cross-nationally.

RESULTS

Gender differences in self-reported health are minimal, and men had 30% higher odds of being ADL limited controlling for socio-demographic and health characteristics. Measured physical performance is closely tied with socioeconomic conditions, but self-reported measures have a much smaller or weaker socioeconomic gradient. In international age-adjusted comparisons, the HAALSI sample had lower physical performance outcomes than most comparison populations.

DISCUSSION

As the first HRS sister study undertaken in Africa, HAALSI adds vital information on population aging and health in the region. Continuing waves of HAALSI data will be a key resource for understanding differences in the complex processes of disability across LMIC contexts.

Accelerated aging in adults with knee osteoarthritis pain: consideration for frequency, intensity, time, and total pain sites

INTRODUCTION

Individuals with osteoarthritis (OA) show increased morbidity and mortality. Telomere length, a measure of cellular aging, predicts increased morbidity and mortality. Telomeres shorten with persisting biological and psychosocial stress. Living with chronic OA pain is stressful. Previous research exploring telomere length in people with OA has produced inconsistent results. Considering pain severity may clarify the relationship between OA and telomeres.

OBJECTIVES

We hypothesized that individuals with high OA chronic pain severity would have shorter telomeres than those with no or low chronic pain severity.

METHODS

One hundred thirty-six adults, ages 45 to 85 years old, with and without symptomatic knee OA were included in the analysis. Peripheral blood leukocyte telomere length was measured, and demographic, clinical, and functional data were collected. Participants were categorized into 5 pain severity groups based on an additive index of frequency, intensity, time or duration, and total number of pain sites (FITT). Covariates included age, sex, race or ethnicity, study site, and knee pain status.

RESULTS

The no or low chronic pain severity group had significantly longer telomeres compared with the high pain severity group, P = 0.025. A significant chronic pain severity dose response emerged for telomere length, P = 0.034. The FITT chronic pain severity index was highly correlated with the clinical and functional OA pain measures. However, individual clinical and functional measures were not associated with telomere length.

CONCLUSION

Results demonstrate accelerated cellular aging with high knee OA chronic pain severity and provide evidence for the potential utility of the FITT chronic pain severity index in capturing the biological burden of chronic pain.

Cumulative Risk and Physiological Stress Responses in African American Adolescents

OBJECTIVE

To investigate associations between components of cumulative risk (CR) and physiological stress responses in African American adolescents and evaluate emotion regulation as a mediator and sex as a moderator of these associations.

METHODS

Cortisol and salivary alpha amylase (sAA) were collected in adolescents ( N = 205; 55% female; 12.1 ± 1.6 years at baseline) as part of a longitudinal study of stress and adjustment in families. CR was assessed at baseline and emotion regulation was assessed at baseline and 2 years later at Wave 3 (W3) using caregiver and adolescent reports. Cortisol and sAA responses to the social competence interview were assessed at W3.

RESULTS

Repeated-measures analyses of variance predicting cortisol and controlling for time of day, adolescent age, medication usage, and pubertal status revealed significant interactions of time with both psychosocial and sociodemographic risk. In both analyses, youths with higher levels of risk showed a steeper decline in cortisol than youths with lower levels of risk. In parallel analyses predicting sAA, time interacted with psychosocial but not with sociodemographic risk. There were no interactions with sex in any of the analyses. Although CR was associated with changes in emotion regulation, there was no evidence that these changes accounted for the observed CR-stress response associations.

CONCLUSIONS

These findings illustrate the potential importance of disentangling CR and suggest that additional work is needed to help explicate why and how CR is associated with specific physiological responses to stress.

Lead exposure is related to hypercortisolemic profiles and allostatic load in Brazilian older adults

Lead levels (Pb) have been linked to both hyper- and hypo-reactivity of hypothalamic-pituitary-adrenal axis (HPA) axis to acute stress in animals and humans. Similarly, allostatic load (AL), the 'wear and tear' of chronic stress, is associated with inadequate HPA axis activity. We examined whether Pb levels would be associated with altered diurnal cortisol profile, as a primary mediator of AL, during aging. Pb levels were measured from blood samples (BPb) of 126 Brazilian individuals (105 women), between 50 and 82 years old. Six neuroendocrine, metabolic, and anthropometric biomarkers were analyzed and values were transformed into an AL index using clinical reference cut-offs. Salivary samples were collected at home over 2 days at awakening, 30-min after waking, afternoon, and evening periods to determine cortisol levels. A multiple linear regression model showed a positive association between BPb as the independent continuous variable and cortisol awakening response (R²=0.128; B=0.791; p=0.005) and overall cortisol concentration (R²=0.266; B=0.889; p<0.001) as the outcomes. Repeated measures ANOVA showed that individuals with high BPb levels showed higher cortisol at 30min after awakening (p=0.003), and in the afternoon (p=0.002) than those with low BPb values. Regarding AL, regression model showed that BPb was positively associated with AL index (R²=0.100; B=0.204; p=0.032). Correlation analyzes with individual biomarkers showed that BPb was positively correlated with HDL cholesterol (p=0.02) and negatively correlated with DHEA-S (p=0.049). These findings suggest that Pb exposure, even at levels below the reference blood lead level for adults recommended by the National Institute for Occupational Safety and Health and by the Center for Disease Control and Prevention, may contribute to AL and dysregulated cortisol functioning in older adults. Considering these findings were based on cross-sectional data future research is needed to confirm our exploratory results.

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.

A Conceptual Model to Assess Stress-Associated Health Effects of Multiple Ecosystem Services Degraded by Disaster Events in the Gulf of Mexico and Elsewhere

Few conceptual frameworks attempt to connect disaster-associated environmental injuries to impacts on ecosystem services (the benefits humans derive from nature) and thence to both psychological and physiological human health effects. To our knowledge, this study is one of the first, if not the first, to develop a detailed conceptual model of how degraded ecosystem services affect cumulative stress impacts on the health of individual humans and communities. Our comprehensive Disaster-Pressure State-Ecosystem Services-Response-Health (DPSERH) model demonstrates that oil spills, hurricanes, and other disasters can change key ecosystem components resulting in reductions in individual and multiple ecosystem services that support people's livelihoods, health, and way of life. Further, the model elucidates how damage to ecosystem services produces acute, chronic, and cumulative stress in humans which increases risk of adverse psychological and physiological health outcomes. While developed and initially applied within the context of the Gulf of Mexico, it should work equally well in other geographies and for many disasters that cause impairment of ecosystem services. Use of this new tool will improve planning for responses to future disasters and help society more fully account for the costs and benefits of potential management responses. The model also can be used to help direct investments in improving response capabilities of the public health community, biomedical researchers, and environmental scientists. Finally, the model illustrates why the broad range of potential human health effects of disasters should receive equal attention to that accorded environmental damages in assessing restoration and recovery costs and time frames.

Allostatic load and pain severity in older adults: Results from the English Longitudinal Study of Ageing

Pain is common in older adults, is frequently experienced as stressful, and is associated with increased morbidity and mortality. Stress regulatory systems are adaptive to challenge and change, allostasis, until demands exceed the adaptive capacity contributing to dysregulation, resulting in a high allostatic load. A high allostatic load is associated with increased risk of morbidity and mortality. Pain severity, based on the average intensity of frequent pain, was hypothesized to be positively associated with AL. Four formulations of AL were investigated. Cross-sectional data from Wave 4 (2008-2009) of the English Longitudinal Study of Aging (ELSA) were analyzed. Covariates in the model included age, sex, education, smoking status, alcohol consumption, activity level, depression and common comorbid health conditions. A total of 5341 individuals were included; mean age 65.3(±9.2) years, 55% female, 62.4% infrequent or no pain, 12.6% mild pain, 19.1% moderate pain, and 5.9% severe pain. Severe pain was associated with greater AL defined by all four formulations. The amount of variance explained by pain severity and the covariates was highest when allostatic load was defined by the high risk quartile (12.9%) and by the clinical value (11.7%). Findings indicate a positive relationship between pain severity and AL. Further investigation is needed to determine if there is a specific AL signature for pain that differs from other health conditions.

Physiological wear-and-tear and later subjective health in mid-life: Findings from the 1958 British birth cohort

OBJECTIVE

Our body adapts continuously to environmental challenges and stressful conditions. Allostatic load (AL) is a concept that aims to capture the overall physiological wear-and-tear of the body triggered by the repeated activation of compensatory physiological mechanisms as a response to chronic stress. Growing evidence has shown a link between AL and later health decline, morbidity and mortality. However, due to the global physiological effect captured by the AL concept, it is particularly pertinent to examine its association with subsequent health by taking a broad definition of the latter. We examined the association between AL at 44 years and general health as measured by a latent multidimensional measure of subjective health at 50 years integrating sleep patterns, physical and mental health.

METHODS

AL was constructed using 14 biomarkers representing four physiological systems on 7573 members of the 1958 British birth cohort. Health status was captured using self-reported information about subjective health and summarized using a principal component analysis including: seven dimensions of the SF-36 questionnaire of health-related quality of life, the sleep subscale of the Medical Outcomes Study characterizing quality of sleep patterns, and a malaise inventory score detecting depressive symptoms.

RESULTS

Higher AL score was gradually associated with worse subjective health, after taking into account classic confounders.

CONCLUSIONS

Using a physiological index to grasp how the environment can "get under the skin" leading to poor health is of great interest, permitting a better understanding of life course origins of disease and social gradients in health.

The streamlined Allostatic Load Index: a replication of study results

According to the World Health Organization stress in the workplace is becoming a major challenge of employers worldwide. While perceived stress levels can be assessed by questionnaires there is growing evidence that stress-related wear and tear of our body can be measured by the Allostatic Load Index (ALI). In a sample of 12,477 German industrial employees (19.6% female, 18-65 years) self-rated stress was explored by the effort-reward imbalance (ERI) questionnaire. A voluntary health check included biomarkers such as diastolic blood pressure, waist circumference, glycosylated hemoglobin, low-density lipoprotein, and heart rate variability. Based on predefined subclinical cutoff values, a 5-variable ALI was calculated. Differences in ALI according to low (ERI ≤1.0) and high (ERI >1.0) stress levels were tested. The association of ERI and ALI was explored using logistic regression analysis controlling for multiple confounders. Employees perceiving high stress levels showed significant higher ALI scores (p < .001) compared to lower stressed employees. This association was stronger in men and independent of age. ALI was associated with work stress in adjusted models (OR 1.18 ± .08 [95% CI 1.03, 1.36]; p < .05). This study replicates former results in a large sample of industrial employees indicating that work stress is associated with a short form ALI.

Index of cardiometabolic health: a new method of measuring allostatic load using electronic health records

OBJECTIVE

We developed a measure of allostatic load from electronic medical records (EMRs), which we named "Index of Cardiometabolic Health" (ICMH).

METHODS

Data were collected from participants' EMRs and a written survey in 2005. We computed allostatic load scores using the ICMH score and two previously described approaches.

RESULTS

We included 1865 employed adults who were 25-59 years old. Although the magnitude of the association was small, all methods of were predictive of SF-12 physical component subscales (all p < 0.001).

CONCLUSION

We found that the ICMH had similar relationships with health-related quality of life as previously reported in the literature.

Work Stressors in Late Midlife and Physical Functioning in Old Age

OBJECTIVE

The aim of this study was to explore the relationship between work stressors in late midlife and physical functioning in old age.

METHOD

Two linked nationally representative Swedish surveys were used: the 1991 Level of Living Survey (age 57-65) and the 2011 Swedish Panel Study of Living Conditions of the Oldest Old. Work stressors were measured with the job demand-control model and physical functioning in old age with physical performance tests, lung function tests, and self-reported mobility. Ordered logistic and linear regressions were performed ( n = 166-214).

RESULTS

High demands, low control, and high strain (i.e., high demands combined with low control) were associated with limited physical functioning in women. Low control and passive jobs were associated with limited physical functioning in men.

DISCUSSION

Work stressors in late midlife are important predictors of physical functioning in older adults. However, women and men seem to be vulnerable to different work stressors.

The Role of Psychosocial Processes in Explaining the Gradient Between Socioeconomic Status and Health

The gradient between socioeconomic status (SES) and health is well established: Many measures of health show that health increases as SES increases. However, the mechanisms underlying this association are not well understood. Behavioral, cognitive, and affective tendencies that develop in response to the greater psychosocial stress encountered in low-SES environments may partially mediate the impact of SES on health. Although these tendencies might be helpful for coping in the short term, over time they may contribute to the development of allostatic load, which increases vulnerability to disease. Debate remains regarding the direction of causation between SES and health, the impact of income inequality, the interaction of SES with race-ethnicity and gender, and the effects of SES over the life course.

Work-related stress in midlife and all-cause mortality: can sense of coherence modify this association?

BACKGROUND

Survival reflects the accumulation of multiple influences experienced over the life course. Given the amount of time usually spent at work, the influence of work may be particularly important. We examined the association between work-related stress in midlife and subsequent mortality, investigating whether sense of coherence modified the association.

METHODS

Self-reported work-related stress was assessed in 1393 Swedish workers aged 42-65 who participated in the nationally representative Level of Living Survey in 1991. An established psychosocial job exposure matrix was applied to measure occupation-based stress. Sense of coherence was measured as meaningfulness, manageability and comprehensibility. Mortality data were collected from the Swedish National Cause of Death Register. Data were analyzed with hazard regression with Gompertz distributed baseline intensity.

RESULTS

After adjustment for socioeconomic position, occupation-based high job strain was associated with higher mortality in the presence of a weak sense of coherence (HR, 3.15; 1.62-6.13), a result that was stronger in women (HR, 4.48; 1.64-12.26) than in men (HR, 2.90; 1.12-7.49). Self-reported passive jobs were associated with higher mortality in the presence of a weak sense of coherence in men (HR, 2.76; 1.16-6.59). The link between work stress and mortality was not significant in the presence of a strong sense of coherence, indicating that a strong sense of coherence buffered the negative effects of work-related stress on mortality.

CONCLUSIONS

Modifications to work environments that reduce work-related stress may contribute to better health and longer lives, especially in combination with promoting a sense of coherence among workers.

Investigating the Burden of Chronic Pain: An Inflammatory and Metabolic Composite

Background. Chronic pain is associated with increased morbidity and mortality, predominated by cardiovascular disease and cancer. Investigating related risk factor measures may elucidate the biological burden of chronic pain. Objectives. We hypothesized that chronic pain severity would be positively associated with the risk factor composite. Methods. Data from 12,982 participants in the 6th Tromsø study were analyzed. Questionnaires included demographics, health behaviors, medical comorbidities, and chronic pain symptoms. The risk factor composite was comprised of body mass index, fibrinogen, C-reactive protein, and triglycerides. Chronic pain severity was characterized by frequency, intensity, time/duration, and total number of pain sites. Results. Individuals with chronic pain had a greater risk factor composite than individuals without chronic pain controlling for covariates and after excluding inflammation-related health conditions (p < 0.001). A significant "dose-response" relationship was demonstrated with pain severity (p < 0.001). In individuals with chronic pain, the risk factor composite varied by health behavior, exercise, lower levels and smoking, and higher levels. Discussion. The risk factor composite was higher in individuals with chronic pain, greater with increasing pain severity, and influenced by health behaviors. Conclusions. Identification of a biological composite sensitive to pain severity and adaptive/maladaptive behaviors would have significant clinical and research utility.

Biological costs of economic transition: Stress levels during the transition from communism to capitalism in Poland

At the end of the 1980s, Poland began the transformation from an essentially one-party communist system to a politically pluralistic democratic system. These political and economic changes had major social consequences, among others unemployment and a sharp decrease in real personal income. The aim of the study was to investigate the possible relationship between stress in adult men, measured by the Allostatic Load, and the socio-economic deterioration during the first part of the economic transition. The Allostatic Load included eleven markers assessing adverse nutritional intake, cardiovascular activity, inflammatory processes, and lung, hepatic and renal functions. The results indicate a significantly higher risk of metabolic dysregulation in men examined after 1990, compared to men from previous years. After adjustment for socioeconomic variables and lifestyle variables, men examined in 1991 had a 31% greater risk of higher Allostatic Load compared with men examined in 1985 (OR=1.31; p=0.0541), in 1992, this risk was 50% greater (OR=1.50; p<0.01), and in 1993, the risk was 66% greater (OR=1.66; p<0.05). The conclusion is drawn that significantly more stressogenic factors for men were those directly connected with the financial situation of their families, than a sudden but short increase of prices for goods and services.

Allostatic Load and Personality: A 4-Year Longitudinal Study

OBJECTIVE

Dysregulation across multiple physiological systems, referred to as allostatic load, has pervasive consequences for an individual's health. The present study examined whether allostatic load is associated with personality and personality changes during a 4-year follow-up.

METHODS

A total of 5200 participants aged from 50 to 99 years (59.5% women, mean [standard deviation] age = 66.91 [8.88] years) from the Health and Retirement Study provided data on cardiovascular, metabolic, and immune markers at baseline and personality both at baseline and at 4 years later.

RESULTS

Higher allostatic load was related to higher neuroticism (β = 0.03, p = .042), lower extraversion (β = -0.06, p < .001), and lower conscientiousness (β = -0.06, p < .001) at baseline, and to declines in extraversion (β = -0.03, p = .007), conscientiousness (β = -0.04, p < .001), and agreeableness (β = -0.02, p = .020) over the 4-year period, controlling for demographic covariates. A significant quadratic relation between allostatic load and changes in openness (β = -0.03, p = .002) suggested that openness declines when individuals exceed a high level of cumulative physiological dysregulation. No association was found with changes in neuroticism.

CONCLUSIONS

Allostatic load is associated with personality change across adulthood and old age. The findings indicate that physiological dysregulation across multiple systems challenges personality stability and is associated with accelerated personality traits change.

Does income relate to health due to psychosocial or material factors? Consistent support for the psychosocial hypothesis requires operationalization with income rank not the Yitzhaki Index

Research on why income influences health has produced mixed findings. Many, but not all, studies suggest that the relationship between income and health is due to income indicating psychosocial position rather than the associated material benefits. The inconsistent findings may be partly due to the use of the Yitzhaki Index, a function which calculates the accumulated income shortfall for an individual relative to those with higher income, in order to represent the psychosocial position conferred by income. The current study tests whether an alternative specification - income rank - provides more consistent conclusions regarding the psychosocial effect of income on health. We used data from two nationally representative samples: 14,224 observations from 9,404 participants across three waves (2004, 2008, and 2012) of the English Longitudinal Study of Ageing (ELSA) and 29,237 observations from 8,441 individuals across seven waves (2007-2013) of the Longitudinal Internet Studies for the Social Sciences (LISS). Multilevel regression models indicated that income rank was a stronger and more consistent predictor than both the Yitzhaki Index and actual income of self-rated and objective health. The psychosocial hypothesis is more consistently supported when income rank is used to test it.

Homeostatic dysregulation proceeds in parallel in multiple physiological systems

An increasing number of aging researchers believes that multi-system physiological dysregulation may be a key biological mechanism of aging, but evidence of this has been sparse. Here, we used biomarker data on nearly 33, 000 individuals from four large datasets to test for the presence of multi-system dysregulation. We grouped 37 biomarkers into six a priori groupings representing physiological systems (lipids, immune, oxygen transport, liver function, vitamins, and electrolytes), then calculated dysregulation scores for each system in each individual using statistical distance. Correlations among dysregulation levels across systems were generally weak but significant. Comparison of these results to dysregulation in arbitrary 'systems' generated by random grouping of biomarkers showed that a priori knowledge effectively distinguished the true systems in which dysregulation proceeds most independently. In other words, correlations among dysregulation levels were higher using arbitrary systems, indicating that only a priori systems identified distinct dysregulation processes. Additionally, dysregulation of most systems increased with age and significantly predicted multiple health outcomes including mortality, frailty, diabetes, heart disease, and number of chronic diseases. The six systems differed in how well their dysregulation scores predicted health outcomes and age. These findings present the first unequivocal demonstration of integrated multi-system physiological dysregulation during aging, demonstrating that physiological dysregulation proceeds neither as a single global process nor as a completely independent process in different systems, but rather as a set of system-specific processes likely linked through weak feedback effects. These processes--probably many more than the six measured here--are implicated in aging.

Change in cardiometabolic score and incidence of cardiovascular disease: the multi-ethnic study of atherosclerosis

PURPOSE

Examine the relationship between changes in cardiometabolic risk profiles and subsequent cardiovascular disease (CVD).

METHODS

The study sample included 5557 Multi-Ethnic Study of Atherosclerosis participants, recruited in 2000 from six U.S. counties. Standardized scores were calculated for metabolic and cardiovascular components relative to accepted clinical cut points and summed to create an index of cardiometabolic risk. CVD events and/or deaths were assessed after examination 3 (years, 2004-2005) through December 2011. Cox proportional hazards models were used to examine the association between change in the cardiometabolic index (examination 3 minus examination 1) and subsequent cardiovascular outcomes adjusted for demographics, socioeconomic status, medication, and stratified by tertiles of baseline cardiometabolic risk.

RESULTS

We found a 31% relative increase in the CVD event rate per SD change in the cardiometabolic index among those in the highest tertile of baseline cardiometabolic risk (Hazard ratio = 1.31, 95% CI = 1.14-1.50); associations were not statistically significant in the lower tertiles of baseline risk.

CONCLUSIONS

We found that larger increases in the cardiometabolic index over time were significantly associated with higher risk for subsequent CVD events among those with elevated cardiometabolic risk at baseline. These findings highlight the importance of monitoring temporal changes in risk factor profiles for predicting cardiovascular outcomes.

Purpose in life predicts allostatic load ten years later

OBJECTIVE

Living a purposeful life is associated with better mental and physical health, including longevity. Accumulating evidence shows that these associations might be explained by the association between life purpose and regulation of physiological systems involved in the stress response. The aim of this study was to investigate the prospective associations between life purpose and allostatic load over a 10-year period.

METHODS

Analyses were conducted using data from the Midlife in the United States (MIDUS) survey. Assessment of life purpose, psychological covariates and demographics were obtained at baseline, while biomarkers of allostatic load were assessed at the 10-year follow-up.

RESULTS

We found that greater life purpose predicted lower levels of allostatic load at follow-up, even when controlling for other aspects of psychological well-being potentially associated with allostatic load. Further, life purpose was also a strong predictor of individual differences in self-health locus of control-i.e., beliefs about how much influence individuals can exert on their own health-which, in turn, partially mediated the association between purpose and allostatic load. Although life purpose was also negatively linked to other-health locus of control-i.e., the extent to which individuals believe their health is controlled by others/chance-this association did not mediate the impact of life purpose on allostatic load.

CONCLUSION

The current study provides the first empirical evidence for the long-term physiological correlates of life purpose and supports the hypothesis that self-health locus of control acts as one proximal psychological mechanism through which life purpose may be linked to positive biological outcomes.