The Effects of Allostatic Load on Racial/Ethnic Mortality Differences in the United States

Looking Upstream to Understand Race/Ethnicity as a Moderator for Poststroke Neuroinflammation and a Social Determinant for Poststroke Aphasia Outcomes

INTRODUCTION

Over the past decade, the stroke literature has begun to acknowledge and explore explanations for longstanding racial/ethnic differences in stroke outcomes. Poststroke cognitive impairment (PSCI) and poststroke aphasia are two such negative poststroke outcomes where racial/ethnic differences exist. Physiological differences, such as stroke type and lesion size, have been used to partially explain the variation in PSCI and aphasia. However, there is some evidence, although limited, that suggests neuroinflammatory processes as part of allostatic load may be a key contributor to the observed disparities.

METHOD

In this tutorial, we explore the influence of race differences in inflammation on poststroke cognitive outcomes. We suggest lifetime stress and other external determinants of health such as neighborhood environment and discriminatory practices through "weathering" explain differences in inflammation. While using an allostatic load framework, we explore the literature focusing specifically on the role of neuroinflammation on poststroke outcomes.

CONCLUSIONS

Examination of the immune response poststroke provides a foundation for understanding the mechanisms of PSCI and poststroke aphasia and the potential contributions of neuroinflammatory processes on poststroke cognitive outcomes. Furthermore, understanding of racial differences in those processes may contribute to a better understanding of racial disparities in general stroke outcomes as well as poststroke aphasia.

Physiological Dysregulation Proceeds and Predicts Health Outcomes Similarly in Chinese and Western Populations

BACKGROUND

A decade ago, we proposed an index of physiological dysregulation based on Mahalanobis distance (DM) that measures how far from the norm an individual biomarker profile is. While extensive validation has been performed, focus was mostly on Western populations with little comparison to developing countries, particularly at a physiological system level. The degree to which the approach would work in other sociocultural contexts and the similarity of dysregulation signatures across diverse populations are still open questions.

METHODS

Using 2 data sets from China and 3 from Western countries (United States, United Kingdom, and Italy), we calculated DM globally and per physiological system. We assessed pairwise correlations among systems, difference with age, prediction of mortality and age-related diseases, and sensitivity to interchanging data sets with one another as the reference in DM calculation.

RESULTS

Overall, results were comparable across all data sets. Different physiological systems showed distinct dysregulation processes. Association with age was moderate and often nonlinear, similarly for all populations. Mahalanobis distance predicted most health outcomes, although differently by physiological system. Using a Chinese population as the reference when calculating DM for Western populations, or vice versa, led to similar associations with health outcomes, with a few exceptions.

CONCLUSIONS

While small differences were noticeable, they did not systematically emerge between Chinese and Western populations, but rather diffusively across all data sets. These findings suggest that DM presents similar properties, notwithstanding sociocultural backgrounds, and that it is equally effective in capturing the loss of homeostasis that occurs during aging in diverse industrial human populations.

Race, ovarian responsiveness, and live birth after in vitro fertilization

OBJECTIVE

To determine if ovarian responsiveness to gonadotropin stimulation differs by race/ethnicity and whether this predicts live birth rates (LBRs) in non-White patients undergoing in vitro fertilization (IVF).

DESIGN

Retrospective cohort study.

SETTING

Academic infertility center.

PATIENT(S)

White, Asian, Black, and Hispanic patients undergoing ovarian stimulation for IVF.

INTERVENTION(S)

Self-reported race and ethnicity.

MAIN OUTCOME MEASURE(S)

The primary outcome was ovarian sensitivity index (OSI), defined as (the number of oocytes retrieved ÷ total gonadotropin dose) × 1,000 as a measure of ovarian responsiveness, adjusting for age, body mass index, infertility diagnosis, and cycle number. Secondary outcomes included live birth and clinical pregnancy after first retrievals, adjusting for age, infertility diagnosis, and history of fibroids, as well as miscarriage rate per clinical pregnancy, adjusting for age, body mass index, infertility diagnosis, duration of infertility, history of fibroids, and use of preimplantation genetic testing for aneuploidy.

RESULT(S)

The primary analysis of OSI included 3,360 (70.2%) retrievals from White patients, 704 (14.7%) retrievals from Asian patients, 553 (11.6%) retrievals from Black patients, and 168 (3.5%) retrievals from Hispanic patients. Black and Hispanic patients had higher OSIs than White patients after accounting for those with multiple retrievals and adjusting for confounders (6.08 in Black and 6.27 in Hispanic, compared with 5.25 in White). There was no difference in OSI between Asian and White patients. The pregnancy outcomes analyses included 2,299 retrievals. Despite greater ovarian responsiveness, Black and Hispanic patients had lower LBRs compared with White patients, although these differences were not statistically significant after adjusting for confounders (adjusted odds ratio, 0.83; 95% confidence interval [CI], 0.63-1.09, for Black; adjusted odds ratio, 0.93; 95% CI, 0.61-1.43, for Hispanic). Ovarian sensitivity index was modestly predictive of live birth in White and Asian patients but not in Black (area under the curve, 0.51; 95% CI, 0.38-0.64) and Hispanic (area under the curve, 0.50; 95% CI, 0.37-0.63) patients.

CONCLUSION(S)

Black and Hispanic patients have higher ovarian responsiveness to stimulation during IVF but do not experience a consequent increase in LBR. Factors beyond differences in responsiveness to ovarian stimulation need to be explored to address the racial/ethnic disparity established in prior literature.

Age differences in Allostatic Load among adults in the United States by rural-urban residence

•Rural residence is associated with allostatic load levels by age groups.•Allostatic load is higher among rural adults with the exception of the oldest age group.•Evidence of a rural-urban convergence in allostatic load levels among oldest old.•These rural disadvantages remained strong even when accounting for covariates.•The study of allostatic load can improve our understanding of rural disparities.

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.

Allostatic Load and Mortality: A Systematic Review and Meta-Analysis

INTRODUCTION

Allostatic load, a measure of stress-related physiologic dysregulation, is associated with numerous mortality risk factors. This systematic review and meta-analysis examines the relationship between high allostatic load (i.e., increased dysregulation versus low dysregulation) and mortality (cardiovascular disease and all-cause mortality).

METHODS

Systematic searches of 2 databases conducted in May 2021 yielded 336 unique records; 17 eligible studies (2001-2020) were included.

RESULTS

High allostatic load was associated with increased risk of all-cause mortality across all the 17 individual studies (hazard ratio=1.08-2.75) and in 6 of 8 studies examining cardiovascular disease mortality (hazard ratio=1.19-3.06). Meta-analyses indicated that high allostatic load was associated with increased risk of all-cause mortality, overall (hazard ratio=1.22, 95% CI=1.14, 1.30, n=10) and across subgroups (hazard ratio=1.11-1.41), and similarly for cardiovascular disease mortality (hazard ratio=1.31, 95% CI=1.10, 1.57, n=6). Although studies were generally of good quality (n=13), heterogeneity was high in most pooled estimates (I²>90%).

DISCUSSION

In this review of relatively good-quality studies, high allostatic load was associated with an increased mortality risk of 22% for all-cause mortality and 31% for cardiovascular disease mortality. Thus, allostatic load is an emerging and potent modifiable risk factor for all-cause and cardiovascular disease mortality that shows promise as a prognostic indicator for mortality. The heterogeneity in allostatic load assessment across studies highlights the need for standardized measurement. The findings underscore the importance of allostatic load's dynamic nature, which may be especially relevant for mitigating mortality risk in younger adults. Because older adults are oversampled, future allostatic load research should prioritize younger adults and longitudinal monitoring and specific cardiovascular disease mortality risk associations and individualize behavioral and lifestyle targets for reducing allostatic load.

Allostatic load in the context of disasters

Environmental disasters, pandemics, and other major traumatic events such as the Covid-19 pandemic or war contribute to psychosocial stress which manifests in a wide range of mental and physical consequences. The increasing frequency and severity of such events suggest that the adverse effects of toxic stress are likely to become more widespread and pervasive in the future. The allostatic load (AL) model has important elements that lend themselves well for identifying adverse health effects of disasters. Here we examine several articulations of AL from the standpoint of using AL to gauge short- and long-term health effects of disasters and to provide predictive capacity that would enable mitigation or prevention of some disaster-related health consequences. We developed a transdisciplinary framework combining indices of psychosocial AL and physiological AL to produce a robust estimate of overall AL in people affected by disasters and other traumatic events. In conclusion, we urge researchers to consider the potential of using AL as a component in a proposed disaster-oriented human health observing system.

Allostatic load as predictor of mortality: a cohort study from Lolland-Falster, Denmark

OBJECTIVES

The purposes of the present study were to determine the association between (1) 10 individual biomarkers and all-cause mortality; and between (2) allostatic load (AL), across three physiological systems (cardiovascular, inflammatory, metabolic) and all-cause mortality.

DESIGN

Prospective cohort study.

SETTING

We used data from the Lolland-Falster Health Study undertaken in Denmark in 2016-2020 and used data on systolic blood pressure (SBP) and diastolic blood pressure (DBP), pulse rate (PR), waist-hip ratio (WHR) and levels of low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), triglycerides, glycated haemoglobin A1c (HbA1c), C-reactive protein (CRP) and serum albumin. All biomarkers were divided into quartiles with high-risk values defined as those in the highest (PR, WHR, triglycerides, HbA1c, CRP) or lowest (HDL-c, albumin) quartile, or a combination hereof (LDL-c, SBP, DBP). The 10 biomarkers were combined into a summary measure of AL index. Participants were followed-up for death for an average of 2.6 years.

PARTICIPANTS

We examined a total of 13 725 individuals aged 18+ years.

PRIMARY OUTCOME MEASURE

Cox proportional hazard regression (HR) analysis were performed to examine the association between AL index and mortality in men and women.

RESULTS

All-cause mortality increased with increasing AL index. With low AL index as reference, the HR was 1.33 (95% CI: 0.89 to 1.98) for mid AL, and HR 2.37 (95% CI: 1.58 to 3.54) for high AL.

CONCLUSIONS

Elevated physiological burden measured by mid and high AL index was associated with a steeper increase of mortality than individual biomarkers.

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.

University online education file management under the background of big data

With the rapid development of computer communication technology, the level of archives information services in colleges and universities continues to improve. More and more universities have created archives management halls to promote digital archives services in depth. As an important part of information resources, the development and use of archive information resources have also attracted the attention of all walks of life. University archives are the pioneers in the development of archives in my country, and their computerization level will directly affect the development and utilization of information resources in my country’s archives. This article aims to analyze the management of online education archives in colleges and universities under the background of big data, analyze the management of online education archives in colleges and universities, and explore the management of archives under the background of online education in colleges and universities. Use the university network archives construction evaluation model calculation and investigation research method to study the current situation and mode of university network education archives management, and provide reference value for the rational connection of various tasks of university network education archives management under the background of big data. The experimental results of this article show that 55% of college students believe that the current college archives need to be combined with the requirements of the development of the times, and it is necessary to innovate the archive management methods of colleges and universities to improve the quality of archive management services in universities and ensure the real-time storage of network information and maximize the development of archive information the value of.

A latent class approach to inequity in health using biomarker data

We adopt an empirical approach to analyse, measure and decompose inequality of opportunity (IOp) in health, based on a latent class model. This addresses some of the limitations that affect earlier work in this literature concerning the definition of types, such as partial observability, the ad hoc selection of circumstances, the curse of dimensionality and unobserved type-specific heterogeneity that may lead to biased estimates of IOp. We apply our latent class approach to measure IOp in allostatic load, a composite measure of biomarker data. Using data from Understanding Society: The UK Household Longitudinal Study (UKHLS), we find that a latent class model with three latent types best fits the data, with the corresponding types characterised in terms of differences in their observed circumstances. Decomposition analysis shows that about two thirds of the total inequalities in allostatic load can be attributed to the direct and indirect contribution of circumstances and that the direct contribution of effort is small. Further analysis conditional on age-sex groups reveals that the relative (percentage) contribution of circumstances to the total inequalities remains mostly unaffected and the direct contribution of effort remains small.

Allostatic Load Indices With Cholesterol and Triglycerides Predict Disease and Mortality Risk in Zoo-Housed Western Lowland Gorillas (Gorilla gorilla gorilla)

Allostatic load, or the physiological dysregulation accumulated due to senescence and stress, is an established predictor of human morbidity and mortality and has been proposed as a tool for monitoring health and welfare in captive wildlife. It is estimated by combining biomarkers from multiple somatic systems into allostatic load indices (ALIs), providing a score representing overall physiological dysregulation. Such ALIs have been shown to predict disease and mortality risk in western lowland gorillas. In these prior analyses, we were unable to include lipid markers, a potential limitation as they are key biomarkers in human models. Recently, we were able to assay serum cholesterol and triglycerides and add them to our previous ALI. We then re-examined associations with health outcomes using binomial generalized linear models. We constructed ALIs using 2 pooling strategies and 2 methods. By itself, a 1-unit increase in allostatic load was associated with higher odds of all-cause morbidity and mortality, but results were mixed for cardiac disease. However, the best fit models for all-cause morbidity and cardiac disease included only age and sex. Allostatic load was retained alongside age in the best fit models for mortality, with a 1-unit increase associated with 23% to 45% higher odds of death. Compared with previous results, ALIs containing cholesterol and triglycerides better predict disease risk in zoo-housed western lowland gorillas, as evidenced by larger effect sizes for some models and better goodness of fit for all ALIs. Based on these results, we address methodology for future allostatic load research on wildlife.

Racial/ethnic inequities in the associations of allostatic load with all-cause and cardiovascular-specific mortality risk in U.S. adults

Non-Hispanic blacks have higher mortality rates than non-Hispanic whites whereas Hispanics have similar or lower mortality rates than non-Hispanic blacks and whites despite Hispanics' lower education and access to health insurance coverage. This study examines whether allostatic load, a proxy for cumulative biological risk, is associated with all-cause and cardiovascular (CVD)-specific mortality risks in US adults; and whether these associations vary with race/ethnicity and further with age, sex and education across racial/ethnic groups. Data from the third National Health and Nutritional Examination Survey (NHANES III, 1988-1994) and the 2015 Linked Mortality File were used for adults 25 years or older (n = 13,673 with 6,026 deaths). Cox proportional hazards regression was used to estimate the associations of allostatic load scores (2 and ≥3 relative to ≤1) with a) all-cause and b) CVD-specific mortality risk among NHANES III participants before and after controlling for selected characteristics. Allostatic load scores are associated with higher all-cause and CVD-specific mortality rates among U.S. adults aged 25 years or older, with stronger rates observed for CVD-specific mortality. All-cause mortality rates for each racial/ethnic group differed with age and education whereas for CVD-specific mortality rates, this difference was observed for sex. Our findings of high allostatic load scores associated with all-cause and CVD-specific mortality among US adults call attention to monitor conditions associated with the allostatic load's biomarkers to identify high-risk groups to help monitor social inequities in mortality risk, especially premature mortality.

Racial/Ethnic Differences in Physiological Stress and Relapse among Treatment Seeking Tobacco Smokers

Stress is robustly associated with tobacco smoking and relapse. African Americans experience greater difficulty quitting compared to whites, yet no studies have examined race differences in physiological stress biomarkers during a quit attempt. This pilot study compared cortisol levels among treatment-seeking African American and white smokers, and relapse rates. Adult smokers (N = 115; n = 72 African American, n = 43 White) received eight sessions of group cognitive behavioral therapy plus transdermal nicotine patches. Assessments included demographics, salivary cortisol (collected at session 1, the end-of-therapy [EOT], and one-month post-therapy), and carbon monoxide-verified smoking relapse. Overall, cortisol levels declined over the course of the day at baseline, the EOT, and the one-month follow-up. African Americans exhibited lower cortisol levels compared to Whites at baseline and the EOT, but not at the one-month follow-up. In addition, African American smokers exhibited flatter slopes compared to Whites at each time point. Relapse rates were greater among African Americans at the EOT and one-month follow-up. The attenuated cortisol pattern observed in African Americans may indicate hypothalamic-pituitary-adrenal axis (HPA) exhaustion and aid our understanding of tobacco-related disparities. There is a need to focus on stress mechanisms and specific intervention approaches in order to eliminate racial/ethnic differences.

The weathering hypothesis as an explanation for racial disparities in health: a systematic review

PURPOSE

The weathering hypothesis states that chronic exposure to social and economic disadvantage leads to accelerated decline in physical health outcomes and could partially explain racial disparities in a wide array of health conditions. This systematic review summarizes the literature empirically testing the weathering hypothesis and assesses the quality of the evidence regarding weathering as a determinant of racial disparities in health.

METHODS

Databases (Web of Science, Ovid MEDLINE, PubMed, and Embase) were searched for studies published in English up to July 1, 2017. Studies that tested the weathering hypothesis for any physical health outcome and included at least one socially or economically disadvantaged group (e.g., Blacks) for whom the weathering hypothesis applies were assessed for eligibility. Threats to validity were assessed using the Quality in Prognostic Studies tool.

RESULTS

The 41 included studies were rated as having overall good methodological quality. Most studies found evidence in support of the weathering hypothesis, although the magnitude of support varied by the health outcome and population studied.

CONCLUSIONS

Future evaluations of the weathering hypothesis should include an examination of additional health outcomes and interrogate mechanisms that could link weathering to poor health.

Foreign-Born Hispanic Women's Health Patterns in Allostatic Load Converge to U.S.-Born Hispanic Women at a Slower Tempo Compared With Men

OBJECTIVES

We investigated the patterns of foreign-born Hispanic health convergence to U.S.-born Hispanics using an allostatic load index, a subjective biological risk health profile, and we explored whether the health convergence patterns differ by sex.

METHODS

The analytic sample consisted of 3,347 Hispanics from the pooled 2005-2010 National Health and Nutrition Examination Survey. We used negative binomial regression models to investigate the association between duration in the United States and the allostatic load index, while controlling for potential covariates.

RESULTS

Foreign-born Hispanics who had lived in the United States for 0-9 years and 10-19 years had lower levels of allostatic load than U.S.-born Hispanics; however, those who had lived in the United States for 20 or more years had a level of allostatic load similar to their U.S.-born counterparts. The pattern of immigrant health convergence shows a clear sex difference. In the sex-stratified models, we found that foreign-born Hispanic men converged to the level of allostatic load of U.S.-born Hispanic men after having lived in the United States for approximately 10 years. The health convergence pattern qualitatively differed for foreign-born Hispanic women, who remained healthier than U.S.-born Hispanic women regardless of duration in the United States.

CONCLUSIONS

Foreign-born Hispanics are healthier than their U.S.-born counterparts, providing support for the healthy migrant hypothesis. This relatively better health of foreign-born Hispanics disappears with a longer duration in the United States, providing support for the health convergence hypothesis, but is most noticeable for men. Foreign-born Hispanic women converge to U.S.-born Hispanic women's health status at a slower tempo, compared with foreign-born Hispanic men.

Racial-ethnic Disparities in Inflammation: Evidence of Weathering in Childhood?

Building on the weathering hypothesis, we advance health disparities research by assessing racial-ethnic differences in low-grade inflammation, a marker of chronic stress exposure, in young children. Using nationally representative data from the National Health and Nutrition Examination Survey (N = 6,652) and logistic regression, we find an increased risk of low-grade inflammation among Hispanic and African American children compared to white children. The risk of inflammation appears to be stronger for Hispanic and African American children with foreign-born parents compared to children of the same race-ethnicity with U.S.-born parents. Low parental education and elevated child body mass index work as partial mediators of these associations. Our findings suggest the need to understand the psychosocial challenges faced by Hispanic and African American children, particularly, those with foreign-born parents, if we are to make further progress in reducing health disparities.

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.

Using Allostatic Load to Validate Self-rated Health for Racial/Ethnic Groups in the United States

This study evaluates the validity of subjective health measurement for racial/ethnic comparisons in the United States, by assessing whether allostatic load (AL) is equally associated with poor/fair self-rated health (SRH) for different racial/ethnic groups. This study used data from the National Health and Nutrition Survey (NHANES) for 2006-2010. Multivariable logistic regression models were fit and stratified by race/ethnicity to study the association between AL and poor/fair SRH. Higher levels of AL were associated with higher odds of reporting poor/fair SRH. However, this association differs by race/ethnicity. Analysis of interactions and racial/ethnic-stratified models suggest that AL is less associated with poor/fair SRH status for non-Hispanic Blacks and Hispanics populations. These results demonstrate that subjective health ratings potentially underestimate actual measures of biological health risk, especially for racial/ethnic minorities. As a result, population-based assessments of racial/ethnic health disparities based on SRH may be significantly understated.

The contribution of three dimensions of allostatic load to racial/ethnic disparities in poor/fair self-rated health

Objective

This study evaluates whether different dimensions of physiological dysregulation, modeled individually rather than additively mediate racial/ethnic disparities in self-reported health.

Methods

Using data from the National Health and Nutrition Examination Survey (2005–2010) and the Karlson, Hold, and Breen (KHB) mediation model, this paper explores what operationalization of biomarker data most strongly mediate racial/ethnic disparities in poor/fair self-rated health (SRH) among adults in the United States, net of demographic, socioeconomic, behavioral, and medication controls.

Results

Non-Hispanic blacks and Hispanics had significantly higher odds of reporting poor/fair self-rated health in comparison to non-Hispanic whites. Operationalizations of allostatic load that disaggregate three major dimensions of physiological dysregulation mediate racial/ethnic disparities strongly between non-Hispanic blacks and non-Hispanic whites, but not between Hispanics and non-Hispanic whites. Disaggregating these dimensions explains racial/ethnic disparities in poor/fair SRH better than the continuous score. Analyses on sex-specific disparities indicate differences in how individual dimensions of allostatic load contribute to racial/ethnic disparities in poor/fair SRH differently. All individual dimensions are strong determinants of poor/fair SRH for males. In contrast, for females, the only dimension that is significantly associated with poor/fair SRH is inflammation. For the analytic sample, additive biomarker scores fit the data as well or better than other approaches, suggesting that this approach is most appropriate for explaining individual differences. However, in sex-specific analyses, the interactive approach models fit the data best for men and women.

Conclusions

Future researchers seeking to explain racial/ethnic disparities in full or sex-stratified samples should consider disaggregating allostatic load by dimension.

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Non-Hispanic blacks and Hispanics have higher rates of poor/fair self-rated health and levels of allostatic load

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Allostatic load mediates the race/ethnicity-self rated health relationship.

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Overall, dividing allostatic load into three dimensions better explains the white-black gap

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In sex-specific models interactive approaches better explain self-rated health

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.