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

Allostatic Load and Cardiovascular Disease: A Systematic Review

INTRODUCTION

Cardiovascular disease is a leading cause of morbidity and mortality. In the past 3 decades, allostatic load-a physiological representation of cumulative life stress-has been associated with increased risk of cardiovascular disease incidence and mortality. Additionally, differences in allostatic load may partially explain persistent disparities in cardiovascular disease outcomes. However, there is notable variation in cardiovascular disease types and subsequent impairments suggesting this association may not be similar across cardiovascular disease types and demographic characteristics.

METHODS

This study is a systematic review conducted in 2024 of current knowledge on the relationship between allostatic load and cardiovascular disease. A literature search using the electronic databases PubMed, SCOPUS, and Web of Science and the keywords allostatic load and cardiovascular disease was conducted. A total of 233 articles were identified in initial review and 22 studies were identified for inclusion in this review.

RESULTS

This review found that allostatic load was associated with a composite score of cardiovascular disease incidence but there was less clarity on the relationship with cardiovascular disease mortality and other cardiovascular disease outcomes. Additionally, there was some variation between cardiovascular disease types and the relationship with allostatic load as well as intersectional race and gender differences.

CONCLUSIONS

This review revealed notable gaps in the current knowledge of the relationship between cardiovascular disease and allostatic load. Future research is necessary to evaluate how this relationship differs across demographic characteristics, cardiovascular disease types, cardiovascular disease outcomes such as impairment, and disease processes. Future research should also identify standardized measures of allostatic load and determine how the social determinants impact allostatic load across the lifespan.

Effects of Allostatic Load on Long-Term Survival After Stroke

BACKGROUND

Allostatic load index (ALI) is often utilized to quantify the physiological response to stress. This study assesses the relationship between ALI and its impact on all-cause, cardiovascular, and stroke mortality in individuals with a self-reported history of stroke and within the general National Health and Nutritional Examination Survey sampled population.

METHODS

Using data from the National Health and Nutritional Examination Survey (III, 1988-1994) and the 2015 Linked Mortality File, we selected adults aged ≥25 years with self-reported stroke. We computed the weighted prevalence of each ALI category to obtain nationally representative estimates with higher ALI corresponding to a higher stress burden. We evaluated the relationship between ALI category and mortality outcomes using the Cox proportional hazard model, considering the survey design variables and adjusting for age, sex, race/ethnicity, education, marital status, income, drinking, and smoking status.

RESULTS

Of 17 284 people screened in the National Health and Nutritional Examination Survey sample population, 15 567 individuals were included in the study. The ALI distribution was 48.3% ALI ≤1, 21.7% ALI=2, and 30% ALI ≥3. Of 414 individuals with a reported history of stroke, there were 11.8% ALI ≤1, 22.1% ALI=2, and 66.1% ALI ≥3. There was an association between a higher ALI and older age, Black and Mexican American race, and >1 comorbidity in the overall sampled population. In the population with prior stroke, those with ALI ≥3 had 2.7× higher adjusted all-cause mortality (hazard ratio, 2.7 [CI, 1.5-4.9]) and 4.5× higher adjusted cardiovascular mortality (hazard ratio, 4.5 [CI, 1.4-14.3]) compared with those with ALI ≤1. In the general sampled National Health and Nutritional Examination Survey population, the ALI ≥3 group had 1.8× higher adjusted stroke mortality (hazard ratio, 1.8 [CI, 1.1-3.1]).

CONCLUSIONS

Baseline higher ALI is associated with greater all-cause and cardiovascular mortality in stroke survivors and greater stroke mortality in the overall sampled National Health and Nutritional Examination Survey population.

Hidden in plain text: Uncovering hidden heterogeneity and social stratification in Ireland AD 1150-1800

OBJECTIVES

Between the Irish late medieval (AD 1150-c.1550) (LMP) and post-medieval (AD c.1550-1800) (PMP) periods, colonial practices changed land ownership. Contextualizing these periods within a biocultural political economy framework supports increasing social inequality in the PMP, which we expect to be reflected in different skeletal markers of longevity and stress. Therefore, we hypothesized that widespread exposure to stressors and resource deprivation contributed to lower longevity in the PMP compared to the LMP, and that there would be greater variation between sites in the frequency of linear enamel hypoplasias (LEH) in the PMP.

MATERIALS AND METHODS

We estimated age and counted matched pairs of LEH on 526 adult skeletons from the Irish counties of Dublin, Kildare, Louth, and Meath. Age-at-death was compared through Kaplan-Meier survival functions and non-parametric tests. Linear enamel hypoplasias prevalences were analyzed with Mann-Whitney U tests and Generalized Linear Models.

RESULTS

Age-at-death distribution changed between the LMP and PMP for males, with males experiencing an increase in median-age-at-death. The same was untrue for females, who show no changes in median age-at-death. Analysis of LEH frequency per individual showed that variation between sites was significant in the post-medieval period but not in the late medieval period.

CONCLUSION

These results suggest that social organization contributed to embodied health experiences that varied across time periods. Specifically, populations from the PMP appear to have embodied greater social inequality in their more varied susceptibility to stress. Our work demonstrates the strength of pairing historical texts with the analysis of skeletal remains to evaluate the impact of social structures on biological frailty.

The physiological toll of arrests: An examination of arrest history on midlife allostatic load

PURPOSE

To understand how allostatic load - cumulative physiologic burden of stress - varies by amount and timing of arrests stratified by race/ethnicity and by sex.

METHODS

Using The National Longitudinal Study of Adolescent to Adult Health, we calculated descriptive statistics and mean differences in bio-marker measured allostatic load by arrest history stratified by race/ethnicity and sex.

RESULTS

One-third of participants experienced at least one arrest, and most experienced arrests only as adults. Allostatic load scores were higher for those that had ever experienced an arrest compared to never (mean difference: 0.58 (0.33, 0.84)). Similar results held for men and women and across race/ethnicity, but Black non-Hispanic individuals had higher allostatic load at all levels compared to other individuals.

CONCLUSIONS

Experiencing both any arrest and multiple arrests were associated with higher allostatic load. The stress of arrests may contribute to physiological maladaptations and poor health. The public health and law enforcement fields must recognize the detrimental consequences of arrests on physiological stress and search for non-carceral solutions.

Emerging Theories of Allostatic-Interoceptive Overload in Neurodegeneration

Recent integrative multilevel models offer novel insights into the etiology and course of neurodegenerative conditions. The predictive coding of allostatic-interoception theory posits that the brain adapts to environmental demands by modulating internal bodily signals through the allostatic-interoceptive system. Specifically, a domain-general allostatic-interoceptive network exerts adaptive physiological control by fine-tuning initial top-down predictions and bottom-up peripheral signaling. In this context, adequate adaptation implies the minimization of prediction errors thereby optimizing energy expenditure. Abnormalities in top-down interoceptive predictions or peripheral signaling can trigger allostatic overload states, ultimately leading to dysregulated interoceptive and bodily systems (endocrine, immunological, circulatory, etc.). In this context, environmental stress, social determinants of health, and harmful exposomes (i.e., the cumulative life-course exposition to different environmental stressors) may interact with physiological and genetic factors, dysregulating allostatic interoception and precipitating neurodegenerative processes. We review the allostatic-interoceptive overload framework across different neurodegenerative diseases, particularly in the behavioral variant frontotemporal dementia (bvFTD). We describe how concepts of allostasis and interoception could be integrated with principles of predictive coding to explain how the brain optimizes adaptive responses, while maintaining physiological stability through feedback loops with multiple organismic systems. Then, we introduce the model of allostatic-interoceptive overload of bvFTD and discuss its implications for the understanding of pathophysiological and neurocognitive abnormalities in multiple neurodegenerative conditions.

Population-enriched innate immune variants may identify candidate gene targets at the intersection of cancer and cardio-metabolic disease

Both cancer and cardio-metabolic disease disparities exist among specific populations in the US. For example, African Americans experience the highest rates of breast and prostate cancer mortality and the highest incidence of obesity. Native and Hispanic Americans experience the highest rates of liver cancer mortality. At the same time, Pacific Islanders have the highest death rate attributed to type 2 diabetes (T2D), and Asian Americans experience the highest incidence of non-alcoholic fatty liver disease (NAFLD) and cancers induced by infectious agents. Notably, the pathologic progression of both cancer and cardio-metabolic diseases involves innate immunity and mechanisms of inflammation. Innate immunity in individuals is established through genetic inheritance and external stimuli to respond to environmental threats and stresses such as pathogen exposure. Further, individual genomes contain characteristic genetic markers associated with one or more geographic ancestries (ethnic groups), including protective innate immune genetic programming optimized for survival in their corresponding ancestral environment(s). This perspective explores evidence related to our working hypothesis that genetic variations in innate immune genes, particularly those that are commonly found but unevenly distributed between populations, are associated with disparities between populations in both cancer and cardio-metabolic diseases. Identifying conventional and unconventional innate immune genes that fit this profile may provide critical insights into the underlying mechanisms that connect these two families of complex diseases and offer novel targets for precision-based treatment of cancer and/or cardio-metabolic disease.

Berry Consumption in Relation to Allostatic Load in US Adults: The National Health and Nutrition Examination Survey, 2003-2010

INTRODUCTION

Berries are a rich source of antioxidant polyphenols and other nutrients that are associated with good health. Allostatic load (AL) is an aggregate measure of chronic stress-induced physiological dysregulations across cardiovascular, metabolic, autonomic, and immune systems; the extent of these dysregulations, collectively or in each system, can be characterized by a composite score or a domain score assessed by integrated biomarkers. It was hypothesized that the anti-inflammatory and other effects of berries lower AL. The association was determined between berry consumption and AL composite and domain scores in the 2003-2010 National Health and Nutrition Examination Survey (NHANES).

METHODS

Berry intake was measured using two 24 h dietary recalls collected from US adults in the 2003-2010 NHANES (n = 7684). The association with AL and its specific domains was examined using population weight-adjusted multivariable linear regression.

RESULTS

The mean AL composite scores for consumers of any berries (11.9), strawberries (11.6), and blueberries (11.6), respectively, were significantly lower than nonconsumers (12.3), after fully adjusting for sociodemographic, lifestyle, and dietary confounders. A significant dose-response relationship was determined between greater consumption of total berries, strawberries, and blueberries and lower mean AL composite scores (p-trend < 0.05, for all). Consistently, mean cardiovascular and metabolic domain scores remained significantly lower in the consumers of total berries (mean cardiovascular domain score: 4.73 versus 4.97 for nonconsumers; mean metabolic domain score: 2.97 versus 3.1), strawberries (4.73 versus 4.95; 2.99 versus 3.1), and blueberries (4.6 versus 4.95; 2.92 versus 3.11). Berry consumers also had significantly lower mean AL immune scores (1.52 versus 1.56) and lower mean AL autonomic scores (2.49 versus 2.57) than nonconsumers (initial sample: n = 15,620).

CONCLUSIONS

The current study indicates that consumption of berries lowers the AL composite scores and potentially reduces stress-related disease risks in the US adult population.

Allostatic load in the US general population: Race and educational intersection

Objectives

Educational attainment is a protective factor against poor health, but high educational attainment has a weaker effect on black people than on white people; this pattern has been called marginalization-related diminished returns (MDRs). Using a national sample of white people and black people 25 years and above, this study estimates the association between high educational attainment and allostatic load between black people and white people, and within each group.

Study design

This cross-sectional study uses data from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2016, including 2761 black people and 7058 white people. The outcome variable of interest was the Allostatic Load Scale (AL). We created the allostatic load scale by using 8 biomarkers, then created a binary variable (if ALS≥4 as 1 and ALS<4 as 0) to present elevated AL.

Methods

We used several weighted modified Poisson regression models controlling for educational attainment (a predictor) and race (a moderator variable), age, sex, and marital status. We also controlled the models for smoking and drinking status as health behavior variables. As a sensitivity analysis, we ran several sets of regression analysis using the AL scale as a continuous outcome variable.

Results

We found an inverse association between AL and educational attainment. The interaction between race and education has resulted in an inverse association between AL and educational attainment, with a weaker association in black people than in white people. We found similar findings by running regression models with AL as a continuous variable.

Conclusions

We observed a weaker association between educational attainment and AL in black people than in white people, suggesting that educational attainment has more robust protection against allostatic load for white people than black people.

The Modifying Role of Resilience on Allostatic Load and Cardiovascular Disease Risk in the Jackson Heart Study

We examined whether resilience modified associations between allostatic load (AL), a physiological indicator of coping with repeated stressors, and cardiovascular disease (CVD) among 2758 African Americans in the Jackson Heart Study. Baseline AL was quantified using biological measures of metabolic, cardiovascular, and immune markers. We constructed a multidimensional resilience measure using validated questionnaires for social support, social networks, religious experiences, and optimism. Participants were followed until 2016 for stroke, coronary heart disease (CHD), and heart failure (HF). We used multivariable-adjusted, sex-stratified Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between dichotomous AL and CVD. High AL was associated with CHD among women (HR = 1.73, 95% CI = 1.00, 2.99) and HF among women (HR = 1.52, 95% CI = 0.98, 2.37) and men (HR = 2.17, 95% CI = 1.28, 3.68). Among women, resilience did not modify the AL-CVD relationship. Among men, we observed higher stroke risk among men with low resilience (HR = 2.21, 95% CI = 0.94, 5.22) and no association among those with high resilience. Counterintuitively, high AL was associated with greater HF (HR = 5.80, 95% CI = 2.32, 14.47) in the subgroup of men with high resilience. Future studies addressing different facets of resilience are needed to elucidate underlying mechanisms for CVD prevention among African Americans.

Neighborhood socioeconomic position, living arrangements, and cardiometabolic disease among older Puerto Ricans: An examination using PREHCO 2002-2007

Cardiometabolic diseases are among the leading causes of mortality worldwide and are increasingly prevalent in rapidly aging populations. Neighborhood socioeconomic position (SEP) and living arrangements are increasingly recognized as important determinants of cardiometabolic health but have not been examined within Puerto Rico. This study examined the association between neighborhood SEP, living arrangements, and incidence of cardiometabolic conditions among island-dwelling older Puerto Ricans, using longitudinal data from the Puerto Rican Elderly Health Conditions Project (Waves I 2002/03 and II 2006/07) linked with 2000 Census data for neighborhood-level conditions. Our sample consists of non-institutionalized adults aged 60 and older who remained in the same residence over both waves of data collection (N = 2,769). We used multilevel multinomial logistic regression models to examine the relationship between neighborhood SEP and the prevalence and incidence of cardiometabolic disease. Findings show that residence in a socioeconomically advantaged neighborhood was positively associated with reporting having one cardiometabolic condition at baseline, but not associated with the incidence of cardiometabolic conditions at follow-up. Living without a partner was negatively associated with reporting having cardiometabolic conditions compared to living with a partner. Similar results were found for the incidence of cardiometabolic conditions. Living arrangements significantly modified the relationship between neighborhood SEP and cardiometabolic conditions. Compared to living with a partner, living alone in a socioeconomically advantaged neighborhood was associated with a reduced risk of reporting having one condition. Living with children in a socioeconomically advantaged neighborhood was associated with a reduced risk of developing one cardiometabolic condition than living with a partner. Living arrangements are more salient to cardiometabolic health than neighborhood SEP. Social programs and services focused on household composition and familial support are needed to identify older Puerto Ricans potentially at risk of underdiagnosed chronic conditions, especially as ongoing economic, demographic, environmental, and healthcare crises potentially exacerbate social inequalities.

Investigating the Joint Effect of Allostatic Load among Lesbian, Gay, and Bisexual Adults with Risk of Cancer Mortality

Sexual minorities (SM) have higher chronic physiologic stress as indicated by allostatic load (AL), which may be explained in part by consistent experiences of discriminatory practices. This is one of the first studies to examine the joint effects of SM status and AL on the association with long-term risk for cancer death. Retrospective analyses were conducted on 12,470 participants using National Health and Nutrition Examination Survey (NHANES) from years 2001 through 2010 linked with the National Death Index through December 31, 2019. Cox proportional hazards models estimated adjusted hazard ratios (aHRs) of cancer deaths between groups of SM (those reporting as gay, lesbian, bisexual, or having same-sex sexual partners) status and AL. SM adults living with high AL (n = 326) had a 2-fold increased risk of cancer death (aHR: 2.55, 95% CI: 1.40-4.65) when compared to straight/heterosexual adults living with low AL (n = 6674). Among those living with high AL, SM (n = 326) had a 2-fold increased risk of cancer death (aHR: 2.26, 95% CI: 1.33-3.84) when compared to straight/heterosexual adults with high AL (n = 4957). SM with high AL have an increased risk of cancer mortality. These findings highlight important implications for promoting a focused agenda on cancer prevention with strategies that reduce chronic stress for SM adults.

Association between allostatic load and adverse outcomes among older patients with heart failure with preserved ejection fraction

BACKGROUND

The allostatic load (AL) refers to the cumulative weakening of multiple physiological systems caused by repeated adaptation of the body to stressors There are still no studies have focused on the association between AL and the prognosis of patients with heart failure with preserved ejection fraction (HFpEF). The present study aimed to investigate the association between AL and adverse outcomes, including mortality and HF admission, among elderly male patients with HFpEF.

METHODS

We conducted a prospective cohort study of 1111 elderly male patients with HFpEF, diagnosed between 2015 and 2019 and followed up through 2021. We constructed an AL measure using a combination of 12 biomarkers. The diagnosis of HFpEF was made according to the 2021 European Society of Cardiology guidelines. A Cox proportional hazards model was used to determine the associations between AL and adverse outcomes.

RESULTS

In multivariate analysis, AL was significantly associated with increased risk of all-cause mortality (medium AL: adjusted hazard ratio [HR] = 2.53; 95% confidence interval [CI] 1.37-4.68; high AL: HR = 4.21; 95% CI 2.27-7.83; per-score increase: HR = 1.31; 95% CI 1.18-1.46), cardiovascular mortality (medium AL: HR = 2.67; 95% CI 1.07-6.68; high AL: HR = 3.13; 95% CI 1.23-7.97; per-score increase: HR = 1.20; 95% CI 1.03-1.40), non-cardiovascular mortality (medium AL: HR = 2.45; 95% CI 1.06-5.63; high AL: HR = 5.81; 95% CI 2.55-10.28; per-score increase: HR = 1.46; 95% CI 1.26-1.69), and HF admission (medium AL: HR = 2.68; 95% CI 1.43-5.01; high AL: HR = 3.24; 95% CI 1.69-6.23; per-score increase: HR = 1.24; 95% CI 1.11-1.39). Consistent results were found in multiple subgroup analyses.

CONCLUSIONS

A higher AL was associated with poor prognosis in elderly men with HFpEF. AL relies on information that is easily obtained in physical examinations and laboratory parameters and can be assessed in various care and clinical settings to help risk stratification of HFpEF patients.

Allostatic load and risk of all-cause, cancer-specific, and cardiovascular mortality in older cancer survivors: an analysis of the National Health and Nutrition Examination Survey 1999-2010

Background

Allostatic load has been linked to an increased risk of death in various populations. However, to date, there is no research specifically investigating the effect of allostatic load on mortality in older cancer survivors.

Aims

To investigate the association between allostatic load (AL) and mortality in older cancer survivors.

Method

A total of 1,291 adults aged 60 years or older who survived for ≥1 year since cancer diagnoses were identified from the 1999-2010 National Health and Nutrition Examination Survey. AL was the exposure of interest incorporating 9 clinical measures/biomarkers; one point was added to AL if any of the measures/biomarkers exceeded the normal level. The sum of points was categorized as an ordinal variable to reflect low, moderate, and high AL. Our outcomes of interest were all-cause, cancer-specific, and cardiovascular disease (CVD)-specific mortality. Death was identified by linkage to the National Death Index. Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratio (aHR) and 95% confidence intervals (CI) of mortality by AL category.

Results

Overall, 53.6% of participants were male and 78.4% were white. The mean age of study participants at interview was 72.8 years (SD=7.1). A total of 546 participants died during the follow-up (median follow-up time: 8.0 years). Among them, 158 died of cancer and 106 died of cardiovascular events. Results from multivariable Cox proportional hazards models showed that higher ALS was positively associated with higher all-cause mortality (ALS=4-9 vs. ALS =0-1: aHR=1.52, 95% CI =1.17-1.98, p-trend<0.01) and higher cancer-specific mortality (ALS=4-9 vs. ALS =0-1: aHR=1.80, 95% CI =1.12-2.90, p-trend=0.01). The association between ALS and cardiovascular mortality was positive but non-significant (ALS=4-9 vs. ALS =0-1: aHR=1.59, 95% CI =0.86-2.94, p-trend=0.11).

Conclusions

Our study suggests that older cancer survivors can have a higher risk of death if they have a high burden of AL.

Racism: Eroding the health of Black communities

ABSTRACT

Even in the context of major advances in medicine, racial minorities continue to suffer worse medical outcomes. Although race is defined as a social, nonscientific construct, researchers have continued to use it as proxy to explain genetic and evolutionary differences among patients. Poorer health outcomes among Black Americans are known to be related to the psychosocial and physiological stress of racism. Black communities experience premature health deterioration because of the cumulative effects of social, economic, and political oppression and marginalization. Additionally, recent assertions that racism is best seen as a chronic disease has added value to understanding the effect of racism on the health of Black people. Using evidence-based information to assess the health of Black patients is a key step to assist clinicians in promptly addressing this chronic threat to the health of Black patients.

Allostatic load and physical performance in older adults: Findings from the International Mobility in Aging Study (IMIAS)

OBJECTIVE

This study aimed to evaluate the association between Allostatic Load (AL) and physical performance scores in older adults from four cities in North and South America.

METHODS

In this cross-sectional study, data from 1101 volunteers from three countries (Canada, Brazil, and Colombia) from the International Mobility in Aging Study (IMIAS) were used to evaluate the association between AL index and Short Physical Performance Battery (SPPB) scores. Three multiple linear regression models adjusted by age, Socioeconomic Status (SES), chronic conditions, depression symptoms, and Leganés Cognitive Test (LCT) were developed to estimate the independent association between SPPB and AL. Mediation analysis with 2012 LA data and covariates was performed to access the total, direct, and indirect effects of mediation on SPPB scores from 2016.

RESULTS

AL and SPPB were inversely associated, with older adults with high allostatic load scoring lower on SPPB (β: -0.234, Std: 0.033, p-value: <0.001).  Indirect effects were evidenced between age, SES and chronic conditions with AL and SPPB scores. Chronic conditions also had a total effect on SPPB scores and were also mediated by AL. However, indirect effects of depressive symptoms and LCT on SPPB scores mediated by AL were not observed.

CONCLUSIONS

Findings from this study support that increased AL index determines worse physical performance states after full adjustments. AL has a mediator role between the number of chronic diseases, depressive symptoms, cognitive status and physical performance. Socioeconomic status also influenced physical scores mediated by the AL index.

Racism, shame, and stress reactivity among young black women

Black women experience disproportional rates of cardiovascular disease (CVD) warranting further exploration of CVD risk factors. Growing evidence suggests acute stress reactivity studies may elucidate the mechanisms driving psychosocial correlates of CVD risks. Race-related stress has been identified as a CVD risk factor among Black women though recent evidence suggests emotions may facilitate these risks. Black women may be vulnerable to shame related to frequent racist experiences. Yet, no study to date has examined racism, shame, and stress reactivity in this population. The current study utilized mixed linear models to test for time and group effects of racism and shame on stress reactivity (e.g., cortisol and C-reactive protein [CRP]) among 34 Black women who completed the Trier Social Stress Test. Tests for two-way interactions (i.e., shame by racism) were also performed. Significant time and group effects were observed for shame and racism on stress reactivity. Black women who experienced greater lifetime racism, stress appraised, but lower racism during the past year, exhibited greater CRP responses. Black women who experienced high levels of shame and racism during the past year and their lifetime demonstrated greater cortisol reactivity. These results prompt further research on racism and shame as CVD risk factors among Black women.

Bearing allostatic load: insights into a more equitable future within cardio-oncology

Chronic stress is often regarded as a significant cause of morbidity and mortality; however, the mechanistic link between stress and various disease states has not yet been fully characterized. We explore the concept of allostatic load, a measurement of the physiological burden of chronic stress, as well as its potential role in disease pathogenesis as it relates to cardiovascular disease, cancer, and health-related disparities. Building from this framework, we then posit the potential implications of allostatic load on patient care and research in cardio-oncology. We identify allostatic load as a potential clinically actionable tool to improve health equity in cardio-oncology.

A predictive coding framework of allostatic-interoceptive overload in frontotemporal dementia

Recent allostatic-interoceptive explanations using predictive coding models propose that efficient regulation of the body's internal milieu is necessary to correctly anticipate environmental needs. We review this framework applied to understanding behavioral variant frontotemporal dementia (bvFTD) considering both allostatic overload and interoceptive deficits. First, we show how this framework could explain divergent deficits in bvFTD (cognitive impairments, behavioral maladjustment, brain atrophy, fronto-insular-temporal network atypicality, aberrant interoceptive electrophysiological activity, and autonomic disbalance). We develop a set of theory-driven predictions based on levels of allostatic interoception associated with bvFTD phenomenology and related physiopathological mechanisms. This approach may help further understand the disparate behavioral and physiopathological dysregulations of bvFTD, suggesting targeted interventions and strengthening clinical models of neurological and psychiatric disorders.

Associations of body mass index, fasting insulin, and inflammation with mortality: a prospective cohort study

BACKGROUND/OBJECTIVES

Obesity is often considered to increase the risk for premature mortality. Higher fasting insulin and c-reactive protein are associated with higher body mass index (BMI) and all-cause mortality, so may confound the association between obesity and mortality. Our objective was to determine the independent associations between BMI, fasting insulin, c-reactive protein, and all-cause mortality in a general population sample.

METHODS

This prospective cohort study included non-institutionalized US adults (≥20 years) from the National Health and Nutrition Examination Surveys 1999-2000 to 2013-2014. The main exposures of interest were BMI, fasting insulin, c-reactive protein. Mortality data were obtained through linking participants to the National Death Index (ending December 31, 2015).

RESULTS

There were 12,563 participants with a median age of 45 years (range 20-85) and 47.9% were male. The median BMI was 27 kg/m² (IQR 24-32), median fasting insulin was 54 pmol/L (IQR 35-87), and median c-reactive protein was 1.9 mg/L (IQR 0.8-4.4). In a Cox model adjusted for age, biological sex, cigarette smoking, and ten chronic conditions, higher BMI parameterized with quadratic and linear terms was not associated with mortality. When fasting insulin and the natural logarithm of c-reactive protein were included in the model, an inverse association between BMI and mortality was present (compared to the referent category of 5th percentile: 1st percentile, HR 1.10, 95% CI 1.06-1.13; 99th percentile, HR 0.48, 95% CI 0.34-0.69). In contrast, higher levels of fasting insulin and c-reactive protein were associated with an increased risk of mortality (for fasting insulin: 1st percentile, HR 0.98, 95% CI 0.97-0.99; 99th percentile, HR 1.83, 95% CI 1.48-2.26; for c-reactive protein, 1st percentile, HR 0.87, 95% CI 0.84-0.90; 99th percentile, HR 2.77, 95% CI 2.12-3.62).

CONCLUSIONS

Higher fasting insulin and higher c-reactive protein confound the association between BMI and the risk of all-cause mortality. The increase in mortality that has been attributed to higher BMI is more likely due to hyperinsulinemia and inflammation rather than obesity.

Allostatic load index in patients with multiple sclerosis: A case-control study

Elevated allostatic load (AL) index is a cumulative measure of biological dysregulations associated with stress exposure. It has been reported that stress plays an important role in the pathophysiology of multiple sclerosis (MS). However, the AL index has not been investigated in this population so far. Therefore, we aimed to investigate the AL index in patients with MS compared to healthy controls. A total of 90 patients with relapsing-remitting MS (76.7% females) and 47 healthy controls (76.6% females) were included in the study. The AL index was computed based on percentile distributions of 18 biomarkers. The AL index was significantly higher in patients with MS compared to healthy controls (2.74 ± 0.99 vs. 1.96 ± 0.71, p < 0.001), even after adjustment for age and education. With respect to specific AL biomarkers, individuals with MS had significantly lower resting heart rate, the levels of high-density lipoproteins and dehydroepiandrosterone sulfate as well as significantly higher level of hsCRP and albumin compared to healthy controls. There were no significant correlations of the AL index with depressive and anxiety symptoms, perceived stress, type D personality traits, insomnia, the odds of using specific coping strategies as well as MS-related clinical characteristics. These findings indicate that the AL index is increased in patients with MS. However, the exact mechanisms underlying this observation remain unknown and require additional studies.

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.

Exploring racial disparities on the association between allostatic load and cancer mortality: A retrospective cohort analysis of NHANES, 1988 through 2019

Background

Methods

Results

Conclusions

Impact

•

Allostatic load (AL) is a biologic measure for the ‘wear and tear’ of chronic stress.

•

Studies suggests that racial minorities have higher allostatic load.

•

There is limited knowledge on the association between allostatic and cancer, by race.

•

We observed that AL may increase the risk of cancer death by 14%.

•

Among those aged <40 years, high AL increased cancer death risk by more than 80%.

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.

Collecting, Using, and Reporting Race and Ethnicity Information: Implications for Research in Nutrition Education, Practice, and Policy to Promote Health Equity

This report will describe approaches for collecting, analyzing, and reporting race and ethnicity information in nutrition education and behavior research, practice, and policy to advance health equity. Race and ethnicity information is used to describe study participants and compare nutrition and health-related outcomes. Depending on the study design, race and ethnicity categories are often defined by the research question or other standardized approaches. Participant self-reported data are more acceptable than researcher adjudicated identification data, which can add bias and/or error. Valid methods to collect, use, and report race and ethnicity information are foundational to publication quality, findings of value, contribution to the knowledge base, and health equity.

Examining educational attainment and allostatic load in non-Hispanic Black women

Background

Research suggests that non-Hispanic Black (henceforth, Black) women and people with lower educational attainment have higher levels of allostatic load (AL). This study sought to determine the association between educational attainment and AL among a large sample of Black women.

Methods

We analyzed data among 4177 Black women from the National Health and Nutrition Examination Survey years 1999–2018. AL score was defined as the total for abnormal measures of eight biomarkers. We further categorized participants with AL score greater than or equal to 4 as having high AL. We calculated mean estimates of total allostatic load scores using generalized linear models. We performed modified Poisson Regression models with robust variance estimation to estimate prevalence ratios (PRs) of high allostatic load and their associated 95% confidence intervals (CIs) by educational attainment.

Results

Black women with a college degree or higher had the lowest prevalence of high allostatic load (31.8% vs. 42.7%, 36.3%, 36.6%), and age adjusted mean allostatic load scores (mean = 1.90 vs. mean = 2.34, mean = 1.99, mean = 2.05) when compared to Black women with less than a high school diploma, high school diploma or GED, and some college or associates degree respectively. Even after accounting for age, poverty-to-income ratio, smoking, congestive heart failure, and heart attack, Black college graduates had an 14.3% lower prevalence of high allostatic load (PR = 0.857, 95% CI 0.839–0.876) when compared to Black women with lower educational attainment.

Conclusions

Black women with a baccalaureate degree or higher educational attainment had lower allostatic load compared to Black women with less than a high school education. This finding further confirms higher education is a social determinant of health. Future research should explore differences in AL by more granular degree types.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01641-0.

A Landscape of Subjective and Objective Stress in African-American Dementia Family Caregivers

Stress is a significant part of daily life, and systemic social inequities, such as racism and discrimination, are well-established contributors of chronic stress for African Americans. Added exposure to the stress of caregiving may exacerbate adverse health outcomes. This secondary analysis describes subjective and objective stress in African American family caregivers, and relationships of subjective and objective stress to health outcomes. Baseline data from 142 African American dementia family caregivers from the "Great Village" study were described using means and frequencies; regression models and Pearson's correlation were used to examine associations between demographics, social determinants of health, and health outcomes. Mixed models were used to examine change and change variation in cortisol. Most caregivers had moderate degrees of stress. Stress was associated with sleep disruption and depressive symptoms, and discrimination appeared to be an independent contributor to depressive symptoms. This work provides a foundation for interpreting subjective and objective indicators of stress to tailor existing multicomponent interventions.

Allostatic Load, Income, and Race Among Black and White Men in the United States

Research indicates that income is significantly associated with allostatic load (AL) and that this association may differ between White and Black Americans. Most existing income–AL link work focuses on women and less is known about this association among men. Using data from the National Health and Nutrition Examination Survey (NHANES), we examined whether race moderates the association between income and AL among Black and White men in the United States (n = 5,685). We find that, regardless of income levels, Black men have significantly higher prevalence of being in the high-AL group compared with high-income White men. Our findings suggest that Black men do not receive the same health benefits for increased income relative to their White counterparts.

Pilot randomized controlled trial of the Yoga for HEART intervention in community-dwelling older adults

Physical activity reduces cardiovascular risk; however, many older adults do not engage in recommended levels. Theory-based interventions supporting motivation for physical activity are limited. This pilot study evaluated the feasibility of Yoga for Health Empowerment and Realizing Transformation (HEART), a theory-based intervention combining motivation and yoga-based physical activity. Feasibility was addressed as acceptability, demand, implementation fidelity, and limited efficacy in promoting physical activity, cardiovascular health, and mechanisms of action. Sedentary older adults (m = 65 years old, sd = 8.5) were randomized to Yoga for HEART (n=8) or Active Control (n=7) conditions. Yoga for HEART was: (a) acceptable, (b) retention 73%, (c) implemented as planned. A significant main effect for body mass index (BMI) was found in Yoga for HEART participants (p = .02). No significant effects were found for physical activity, other cardiovascular outcomes, or mechanisms of action. Yoga for HEART is feasible and recommended for further testing.

Social status differences in allostatic load among young adults in the United States

Allostatic load refers to wear and tear on the body due to repeated activation of the stress response and, thus, may be an early subclinical indicator of future disease and mortality risk. To date, few studies of allostatic load have focused on young adults, racial/ethnic comparisons that include Mexican Americans, or the interplay between race/ethnicity, gender, and educational attainment. To fill these gaps, we used data on non-Hispanic Black, non-Hispanic White, and Mexican-origin respondents from Waves I (1994-1995) and IV (2007-2008) of the National Longitudinal Study of Adolescent to Adult Health (Add Health; N = 11,807). We calculated allostatic load scores based on respondents' values for 10 metabolic, cardiovascular, and inflammatory biomarkers measured at Wave IV, when respondents were 24-34 years old. We then used negative binomial regression models to assess the combined effects of race/ethnicity, gender, and educational attainment on allostatic load, while controlling for key covariates. We found that Black women had significantly higher allostatic load scores than White women and Black men, net of educational attainment and other covariates. Yet, education modified the relationship between race/ethnicity, gender, and allostatic load. Obtaining a college education was protective for White males and females but no more or less protective for other women and deleterious for Black males. In other words, by the time they reach young adulthood, the cumulative physiological burden of stress on Black women and college-educated Black men is already greater than it is among their similarly or less educated White counterparts. These findings provide important information about the intermediate physiological dysregulation that underlies social inequalities in stress-related health outcomes, especially those that occur at the intersections of race/ethnicity, gender, and educational attainment. They also suggest that research on its antecedents should focus on earlier life periods.

Associations between Cumulative Biological Risk and Subclinical Atherosclerosis in Middle- and Older-Aged South Asian Immigrants in the United States

INTRODUCTION

The aim of this study was to investigate associations between cumulative biological risk and subclinical atherosclerosis in South Asian immigrants.

METHODS

Data from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study, including 858 participants at baseline (mean age = 56 [standard deviation = 9] years, 46% women). A cumulative biological risk score was derived using nine biomarkers across cardiovascular, immune, and metabolic systems with a possible score range of 0-9. Common and internal carotid artery intima media thickness (CIMT) and coronary artery calcium (CAC) were used as indicators of subclinical atherosclerosis.

RESULTS

Higher cumulative biological risk score was significantly associated with higher common and internal CIMT and higher odds of CAC at baseline. The odds of new CAC after 5 years of follow-up were 31% higher per 1-point increase in cumulative biological risk score, and the higher cumulative biological risk score was also associated with CAC progression.

CONCLUSIONS

Among South Asian immigrants, cumulative biological risk was directly associated with subclinical atherosclerosis and its progression.

Combined Effect of Lead Exposure and Allostatic Load on Cardiovascular Disease Mortality-A Preliminary Study

This study explores the combined effect of lead (Pb) exposure and an index of chronic physiological stress on cardiovascular disease mortality using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2008 linked to 1999-2014 National Death Index data. Chronic physiological stress was measured using the allostatic load (AL) index, which was formed by analyzing markers from the cardiovascular, inflammatory, and metabolic systems, with Pb levels, assessed using blood lead levels (BLL). The dataset was analyzed with statistical techniques to explore (a) the relationship between Pb exposure and AL, and (b) the combined role of Pb and AL on cardiovascular disease mortality. Results indicated that AL was more elevated in those with BLLs above the 50th percentile in the US population and that those with elevated AL were more likely to have high BLL. Finally, the interaction of AL and BLL significantly increased the likelihood of cardiovascular disease mortality. These findings highlight the need for considering the totality of exposures experienced by populations to build holistic programs to prevent Pb exposure and reduce stressors to promote optimal health outcomes and reduce cardiovascular mortality risk.

Unequal Impact of Structural Health Determinants and Comorbidity on COVID-19 Severity and Lethality in Older Mexican Adults: Considerations Beyond Chronological Aging

BACKGROUND

COVID-19 has had a disproportionate impact on older adults. Mexico's population is younger, yet COVID-19's impact on older adults is comparable to countries with older population structures. Here, we aim to identify health and structural determinants that increase susceptibility to COVID-19 in older Mexican adults beyond chronological aging.

METHODS

We analyzed confirmed COVID-19 cases in older adults using data from the General Directorate of Epidemiology of Mexican Ministry of Health. We modeled risk factors for increased COVID-19 severity and mortality, using mixed models to incorporate multilevel data concerning healthcare access and marginalization. We also evaluated structural factors and comorbidity profiles compared to chronological age for COVID-19 mortality risk prediction.

RESULTS

We analyzed 20 804 confirmed SARS-CoV-2 cases in adults aged 60 and older. Male sex, smoking, diabetes, and obesity were associated with pneumonia, hospitalization, and intensive care unit (ICU) admission in older adults, CKD and COPD were associated with hospitalization. High social lag indexes and access to private care were predictors of COVID-19 severity and mortality. Age was not a predictor of COVID-19 severity in individuals without comorbidities and combination of structural factors and comorbidities were better predictors of COVID-19 lethality and severity compared to chronological age alone. COVID-19 baseline lethality hazards were heterogeneously distributed across Mexican municipalities, particularly when comparing urban and rural areas.

CONCLUSIONS

Structural factors and comorbidity explain excess risk for COVID-19 severity and mortality over chronological age in older Mexican adults. Clinical decision-making related to COVID-19 should focus away from chronological aging onto more a comprehensive geriatric care approach.