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

Association of Allostatic Load With Depression, Anxiety, and Suicide: A Prospective Cohort Study

BACKGROUND

Allostatic load (AL) is an objective measure of the biological components of chronic stress in clinical practice, which potentially influence depression, anxiety, and suicide. In this study, we investigated the association between AL and these mental disorders.

METHODS

In this cohort study of 333,017 adults, participants without previous diagnoses of depression, anxiety, or suicide were observed from March 13, 2006, to October 31, 2022. AL was estimated using 10 biomarkers that reflect metabolic, cardiovascular, and inflammatory dysregulation. Diagnoses were based on ICD-10. We performed Cox proportional hazard models to assess the relationship between AL and these mental disorders. We also conducted subgroup analyses for sex, age, and Townsend Deprivation Index, as well as sensitivity analyses.

RESULTS

The median follow-up period was 13 years. Over the follow-up period, 13,441 (4.04%) participants developed depression, 13,903 (4.17%) developed anxiety, and 796 (0.24%) committed suicide. In the fully adjusted model, individuals with high AL had an increased risk of depression (hazard ratio = 1.389, p = 8.38 × 10-27), anxiety (hazard ratio = 1.304, p = 5.82 ×10-19), and suicide (hazard ratio = 1.433, p = 4.46 ×10-3). Women and younger individuals with high AL were vulnerable to depression and anxiety, while moderate AL levels were significantly associated with suicide in men and younger participants. Moreover, individuals with middle and high AL had an elevated risk of comorbid depression and anxiety.

CONCLUSIONS

High AL is positively associated with increased risks of depression, anxiety, and suicide, highlighting its potential as a predictive tool in mental health.

Allostatic load, genetic susceptibility, incidence risk, and all-cause mortality of colorectal cancer

BACKGROUND

Allostatic load (AL) reflects the cumulative burden of chronic stress throughout life, potentially influencing the onset and prognosis of cancer. However, the associations between AL, colorectal cancer (CRC) risk, and all-cause mortality in patients with CRC remain unclear.

METHODS

We analyzed the associations between AL and CRC risk in 304 959 adults and all-cause mortality in 1794 patients with CRC from the UK Biobank, using Cox proportional hazards regression models.

RESULTS

Compared with the AL level in the first quartile, individuals in the second to fourth quartiles had a respective 20%, 29%, and 43% increased risk of CRC; 15%, 24%, and 42% increased risk for colon cancer; and 30%, 38%, and 45% increased risk for rectal cancer. We identified a positive dose-gradient association of AL score with CRC risk, including colon and rectal cancer. Additionally, the association between AL and increased risk of CRC was observed across different strata of genetic susceptibility for CRC. Eliminating AL exposures could prevent nearly 39.24% (95% confidence interval [CI] = 36.16 to 42.32) of CRC events. Meanwhile, a statistically association between the AL and all-cause mortality in patients with CRC was found, with a hazard ratio of 1.71 (95% CI = 1.16 to 2.50) for the fourth quartile compared with the AL score in the first quartile, demonstrating a positive dose-response relationship.

CONCLUSION

High AL was associated with increased CRC risk and all-cause mortality in CRC patients. Future research should prioritize the development of cognitive or behavioral intervention strategies to mitigate the adverse effects of AL on CRC incidence and prognosis.

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.

Association of allostatic load with functional disability in the China Health and Retirement Longitudinal Study

OBJECTIVES

Allostatic load (AL) is an index that manifests as cumulative wear and tear on multiple physiological systems resulting from repeated adaptation to stressors throughout the life course. Higher AL was found to be associated with increased risk of adverse health outcomes, but studies on functional disability among large Chinese older population were limited. We aimed to investigate the associations of AL with functional disability among Chinese older adults.

RESEARCH DESIGN AND METHODS

This prospective cohort study included 5880 older adults who were at least 50 years old and participated in the CHARLS at baseline (2011 wave), with 3 follow-ups (2013, 2015 and 2018 waves). We selected 11 biomarkers from 4 physiological systems to construct AL. AL score was classified into three categories based on tertiles: 0-1 (low burden), 2-3 (medium burden) and 4-11 (high burden). Functional disability was assessed by activities of daily living (ADL) and instrumental activities of daily living (IADL). Multivariable logistic regression models examined the association between baseline AL, transitions of AL burden and incidence of functional disability.

RESULTS

In cross-sectional analyses, medium and high AL burden were associated with an increased prevalence of ADL disability, while association was only significant between high AL burden and IADL disability. During the 7-year follow-up, 1102 and 1777 participants incident ADL disability and IADL disability, respectively. Those with medium and high AL burden had an increased risk of new-onset ADL disability than those with low AL burden ("medium": OR = 1.25, 95%CI = 1.01, 1.55; "high": OR = 1.69, 95%CI = 1.32, 2.18). As for IADL disability, association was only significant in "high" group (OR = 1.50, 95% CI = 1.24, 1.83). We also found keep medium/high AL burden in 2011 and 2015 was associated with new-onset ADL (OR = 2.27, 95%CI = 1.50, 3.44) and IADL disability (OR = 1.51, 95%CI = 1.11, 2.05) in 2018.

CONCLUSION

These results show that higher AL predicts functional disability among Chinese older adults. Monitoring AL and paying close attention to those with medium/high AL burden may aid prevention of adverse health outcomes, thus giving a healthier ageing experience to a large proportion of the population.

Comparison between grip strength and relative grip strength in their relationship with allostatic load among adolescents

PURPOSE

To assess the associations of muscle strength, measure by grip strength and relative grip strength (grip strength divided by body weight), on the allostatic load (AL) index in adolescent boys and girls.

METHODS

A total of 1,323 students were recruited (boys = 776, girls = 547). Data on general demographic characteristics, anthropometric indicators, grip strength, blood pressure, pulse rate, and biological samples were collected. A 20-indicator-based AL index (using the AL1, AL2, and AL3 calculation methods) was used as the dependent variable. Multiple linear regression models were used to evaluate the association between grip strength, relative grip strength, and AL. All analyses were stratified by sex.

RESULTS

The mean age of the participants was 14.17 ± 1.45 years. Overall, the linear regression model adjusting for demografic characteristics showed that greater grip strength was associated with higher AL1 scores (R2 = 10.1%, β = 0.096, P < 0.001). Then, we further adjusted for body weight, and negative associations were observed between grip strength and AL1 (R2 = 35.3%, β = -0.027, P = 0.030). However, after sex stratification, this association was not statistically significant in girls. Moreover, relative grip strength was negatively associated with AL1 (R2 = 14.8%, β = -8.529, P < 0.001) after adjusting for demographic characteristics in the total sample. Specifically, relative grip strength was more strongly associated with the AL1 burden in boys than in girls. Finally, sensitivity analyses of AL2 and AL3 yielded similar results.

CONCLUSION

We observed that compared with grip strength, relative grip strength might be a useful indicator for the identification of AL burden in adolescents. The results suggest that strengthening relative handgrip strength in adolescents might help reduce the AL burden, especially in boys.

Allostatic Load as a Mediator and Perceived Chronic Stress as a Moderator in the Association between Maternal Mental Health and Preterm Birth: A Prospective Cohort Study of Pregnant Women in Pakistan

INTRODUCTION

The complex biopsychosocial pathways linking maternal mental health with preterm birth (PTB) are not well understood. This study aimed to explore allostatic load (AL) as a mediator and perceived chronic stress as a moderator in the pathway linking maternal mental health and PTB.

METHODS

A cohort study of pregnant women (n = 1,567) recruited at clinic visits within 10-19 weeks of gestation was assessed for maternal mental health (i.e., pregnancy-related anxiety, state anxiety, depressive symptoms) and perceived chronic stress. Blood pressure and levels of cortisol, total cholesterol, C-reactive protein, and glycosylated hemoglobin were used to create a composite measure of AL.

RESULTS

AL had the most significant effect on PTB (odds ratio (OR) = 1.84, 95% CI = 1.26-12.67, p = 0.001), while systolic blood pressure emerged as the only significant individual marker using variable selection (OR = 22%, 95% CI = 1.06-1.40, p < 0.001) in multiple logistic regression analysis. A mediation analysis revealed that maternal mental health did not have a significant direct effect on PTB (p = 0.824), but its indirect effect mediated by AL was significant (z = 2.33, p < 0.020). Low and high levels of perceived chronic stress, relative to the mean, moderated this indirect effect (z = 3.66, p < 0.001).

CONCLUSIONS

AL has a significant direct influence on PTB and mediates the effect of maternal mental health on PTB; however, the indirect effect of AL is indistinguishable between women with higher or lower levels of perceived chronic stress than normal.

Assessing the Correlation between Allostatic Load and False-Positive Image-Guided Breast Biopsies

Background: Allostatic load (AL) is the accumulation of physiological dysregulation attributed to repeated activation of the stress response over a lifetime. We assessed the utility of AL as a prognostic measure for high-risk benign breast biopsy pathology results. Method: Eligible patients were women 18 years or older, with a false-positive outpatient breast biopsy between January and December 2022 at a tertiary academic health center. AL was calculated using 12 variables representing four physiological systems: cardiovascular (pulse rate, systolic and diastolic blood pressures, total cholesterol, high-density lipoprotein, and low-density lipoprotein); metabolic (body mass index, albumin, and hemoglobin A1C); renal (creatinine and estimated glomerular filtration rate); and immune (white blood cell count). Multivariable logistic regression was used to assess the association between AL before biopsy and breast biopsy outcomes controlling for patients' sociodemographics. Results: In total, 170 women were included (mean age, 54.1 ± 12.9 years): 89.4% had benign and 10.6% had high-risk pathologies (radial scar/complex sclerosing lesion, atypical ductal or lobular hyperplasia, flat epithelial atypia, intraductal papilloma, or lobular carcinoma in-situ). A total of 56.5% were White, 24.7% Asian, and 17.1% other races. A total of 32.5% identified as Hispanic. The mean breast cancer risk score using the Tyrer-Cuzick model was 11.9 ± 7.0. In multivariable analysis, with every one unit increase in AL, the probability of high-risk pathology increased by 37% (odds ratio, 1.37; 95% confidence interval, 1.03, 1.81; p = 0.03). No significant association was seen between high-risk pathology and age, ethnicity, breast cancer risk, or area deprivation index. Conclusion: Our findings support that increased AL, a biological marker of stress, is associated with high-risk pathology among patients with false-positive breast biopsy results.

Impact of baseline and longitudinal allostatic load changes on incident cardiovascular disease and all-cause mortality: A 7-year population-based cohort study in China

BACKGROUND

We aimed to prospectively examine the association of baseline allostatic load (AL) and longitudinal AL changes with incident cardiovascular disease (CVD) and all-cause mortality among middle-aged and elderly Chinese populations and evaluate the relative contributions of each physiological system of AL.

METHODS

Data from the China Health and Retirement Longitudinal Study (CHARLS) among adults aged 45 years or older were analyzed. Cox regression models were used to estimate the hazard ratios (HRs) and 95 % confidence intervals (95 % CIs) for the associations between baseline AL/longitudinal AL changes with incident CVD and all-cause mortality.

RESULTS

Compared with adults with AL 0-1, HRs of those with baseline AL 2-3 and AL ≥ 4 were 1.24 (95 % CI: 1.06, 1.45) and 1.51 (95 % CI: 1.27, 1.80) for incident CVD, and 1.39 (95 % CI: 1.11, 1.75) and 2.02 (95 % CI: 1.60, 2.54) for all-cause mortality. Similar results were found when we treated baseline AL as a continuous variable. We also found per AL score increase during 4 years of follow-up was related to a 11 % (HR, 1.11; 95 % CI: 1.03, 1.20) and 21 % (HR, 1.21; 95 % CI: 1.10, 1.34) increase in incident CVD and all-cause mortality, respectively.

LIMITATIONS

Self-reported physician-diagnosed CVD was used to assess the incident CVD.

CONCLUSIONS

Both baseline AL and longitudinal increases in AL were positively associated with incident CVD and all-cause mortality in middle-aged and elderly adults. Individuals with high AL need to be dynamically monitored for CVD and pre-mature mortality prevention.

Lead exposure, glucocorticoids, and physiological stress across the life course: A systematic review

The biological pathways linking lead exposure to adverse outcomes are beginning to be understood. Rodent models suggest lead exposure induces dysfunction within the hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoid regulation, a primary physiological stress response system. Over time, HPA axis and glucocorticoid dysfunction has been associated with adverse neurocognitive and cardiometabolic health, much like lead exposure. This systematic review utilized PRISMA guidelines to synthesize the literature regarding associations between lead exposure and downstream effector hormones of the HPA axis, including cortisol, a glucocorticoid, and dehydroepiandrosterone (DHEA), a glucocorticoid antagonist. We additionally determined the state of the evidence regarding lead exposure and allostatic load, a measure of cumulative body burden resultant of HPA axis and glucocorticoid dysfunction. A total of 18 articles were included in the review: 16 assessed cortisol or DHEA and 3 assessed allostatic load. Generally, the few available child studies suggest a significant association between early life lead exposure and altered cortisol, potentially suggesting the impact of developmental exposure. In adulthood, only cross sectional studies were available. These reported significant associations between lead and reduced cortisol awakening response and increased cortisol reactivity, but few associations with fasting serum cortisol. Two studies reported significant associations between increasing lead exposure and allostatic load in adults and another between early life lead exposure and adolescent allostatic load. The paucity of studies examining associations between lead exposure and allostatic load or DHEA and overall heterogeneity of allostatic load measurements limit conclusions. However, these findings cautiously suggest associations between lead and dysregulation of physiological stress pathways (i.e., glucocorticoids) as seen through cortisol measurement in children and adults. Future research would help to elucidate these associations and could further examine the physiological stress pathway as a mediator between lead exposure and detrimental health outcomes.

Correlation between allostatic load index and cumulative mortality: a register-based study of Danish municipalities

OBJECTIVES

The aim of this study was to examine population-based allostatic load (AL) indices as an indicator of community health across 14 municipalities in Denmark.

DESIGN

Register-based study.

SETTING

Data derived from: the Lolland-Falster Health Study, the Copenhagen General Population Study and the Danish General Suburban Population Study. Nine biomarkers (systolic blood pressure, diastolic blood pressure, pulse rate, total serum cholesterol, high-density lipoprotein cholesterol, waist-to-hip ratio, triglycerides, C-reactive protein and serum albumin) were divided into high-risk and low-risk values based on clinically accepted criteria, and the AL index was defined as the average between the nine values. All-cause mortality data were obtained from Statistics Denmark.

PARTICIPANTS

We examined a total of 106 808 individuals aged 40-79 years.

PRIMARY OUTCOME MEASURE

Linear regression models were performed to investigate the association between mean AL index and cumulative mortality risk.

RESULTS

Mean AL index was higher in men (range 2.3-3.3) than in women (range 1.7-2.6). We found AL index to be strongly correlated with the cumulative mortality rate, correlation coefficient of 0.82. A unit increase in mean AL index corresponded to an increase in the cumulative mortality rate of 19% (95% CI 13% to 25%) for men, and 16% (95% CI 8% to 23%) for women but this difference was not statistically significant. The overall mean increase in cumulative mortality rate for both men and women was 17% (95% CI 14% to 20%).

CONCLUSIONS

Our findings indicate the population-based AL index to be a strong indicator of community health, and suggest identification of targets for reducing AL.

An expert-based system to predict population survival rate from health data

Timely detection and understanding of causes for population decline are essential for effective wildlife management and conservation. Assessing trends in population size has been the standard approach, but we propose that monitoring population health could prove more effective. We collated data from 7 bottlenose dolphin (Tursiops truncatus) populations in the southeastern United States to develop a method for estimating survival probability based on a suite of health measures identified by experts as indices for inflammatory, metabolic, pulmonary, and neuroendocrine systems. We used logistic regression to implement the veterinary expert system for outcome prediction (VESOP) within a Bayesian analysis framework. We fitted parameters with records from 5 of the sites that had a robust network of responders to marine mammal strandings and frequent photographic identification surveys that documented definitive survival outcomes. We also conducted capture-mark-recapture (CMR) analyses of photographic identification data to obtain separate estimates of population survival rates for comparison with VESOP survival estimates. The VESOP analyses showed that multiple measures of health, particularly markers of inflammation, were predictive of 1- and 2-year individual survival. The highest mortality risk 1 year following health assessment related to low alkaline phosphatase (odds ratio [OR] = 10.2 [95% CI: 3.41-26.8]), whereas 2-year mortality was most influenced by elevated globulin (OR = 9.60 [95% CI: 3.88-22.4]); both are markers of inflammation. The VESOP model predicted population-level survival rates that correlated with estimated survival rates from CMR analyses for the same populations (1-year Pearson's r = 0.99, p = 1.52 × 10-5 ; 2-year r = 0.94, p = 0.001). Although our proposed approach will not detect acute mortality threats that are largely independent of animal health, such as harmful algal blooms, it can be used to detect chronic health conditions that increase mortality risk. Random sampling of the population is important and advancement in remote sampling methods could facilitate more random selection of subjects, obtainment of larger sample sizes, and extension of the approach to other wildlife species.

Educational patterning in biological health seven years apart: Findings from the Tromsø Study

BACKGROUND

Social-to-biological processes is one set of mechanisms underlying the relationship between social position and health. However, very few studies have focused on the relationship between social factors and biology at multiple time points. This work investigates the relationship between education and the dynamic changes in a composite Biological Health Score (BHS) using two time points seven years apart in a Norwegian adult population.

METHODS

We used data from individuals aged 30 years and above who participated in Tromsø6 (2007-2008) and Tromsø7 (2015-2016) (n = 8117). BHS was defined using ten biomarkers measured from blood samples and representing three physiological systems (cardiovascular, metabolic, inflammatory). The higher the BHS, the poorer the health status.

FINDINGS

Linear regression models carried out on BHS revealed a strong educational gradient at two distinct time points but also over time. People with lower educational attainment were at higher risk of poor biological health at a given time point (βlow education Tromsø6=0.30 [95 %-CI=0.18-0.43] and βlow education Tromsø7=0.30 [95 %-CI=0.17-0.42]). They also presented higher longitudinal BHS compared to people with higher education (βlow education = 0.89 [95 %-CI=0.56-1.23]). Certain biomarkers related to the cardiovascular system and the metabolic system were strongly socially distributed, even after adjustment for sex, age, health behaviours and body mass index.

CONCLUSION

This longitudinal analysis highlights that participants with lower education had their biological health deteriorated to a greater extent over time compared to people with higher education. Our findings provide added evidence of the biological embodiment of social position, particularly with respect to dynamic aspects for which little evidence exists.

Self-Reported Health as Predictor of Allostatic Load and All-Cause Mortality: Findings From the Lolland-Falster Health Study

Objectives: The aim was to determine the association between self-reported health (SRH), allostatic load (AL) and mortality. Methods: Data derived from the Lolland-Falster Health Study undertaken in Denmark from 2016-2020 (n = 14,104). Median follow-up time for death was 4.6 years where 456 participants died. SRH was assessed with a single question and AL by an index of ten biomarkers. Multinomial regression analysis were used to examine the association between SRH and AL, and Cox regression to explore the association between SRH, AL and mortality. Results: The risk of high AL increased by decreasing level of SRH. The ratio of relative risk (RRR) of having medium vs. low AL was 1.58 (1.11-2.23) in women reporting poor/very poor SRH as compared with very good SRH. For men it was 1.84 (1.20-2.81). For high vs. low AL, the RRR was 2.43 (1.66-3.56) in women and 2.96 (1.87-4.70) in men. The hazard ratio (HR) for all-cause mortality increased by decreasing SRH. For poor/very poor vs. very good SRH, the HR was 6.31 (2.84-13.99) in women and 3.92 (2.12-7.25) in men. Conclusion: Single-item SRH was able to predict risk of high AL and all-cause mortality.

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.

The Social Context: Social and Behavioral Factors That Affect Health Outcomes

To achieve understanding and best care, screening and treating patients should consider the patient's social environment. Social and behavioral factors influence both positive and negative health behaviors that influence mental and physical health. Primary care providers continually navigate barriers faced by patients and seek solutions that take into consideration social and behavioral factors. The role of the PCP begins with an understanding of common barriers and community resources, then by assessing and responding to the patient's own challenges, and finally by advocating in the clinic and public for changes to the underlying social and structural causes of morbidity and mortality.

Allostatic load in children: The cost of empathic concern

Early-life adversity affects long-term health outcomes but there is considerable interindividual variability in susceptibility to environmental influences. We proposed that positive psychological characteristics that reflect engagement with context, such as being concerned about people or performance on tasks (i.e., empathic concern), could moderate the interindividual variation in sensitivity to the quality of the early environment. We studied 526 children of various Asian nationalities in Singapore (46.6% female, 13.4% below the poverty line) with longitudinal data on perinatal and childhood experiences, maternal report on empathic concern of the child, and a comprehensive set of physiological measures reflecting pediatric allostatic load assessed at 6 y of age. The perinatal and childhood experiences included adversities and positive experiences. We found that cumulative adverse childhood experience was positively associated with allostatic load of children at 6 y of age at higher levels of empathic concern but not significantly associated at lower levels of empathic concern. This finding reveals evidence for the importance of empathic concern as a psychological characteristic that moderates the developmental impact of environmental influences, serving as a source for vulnerability to adversities in children.

Allostatic load and incident heart failure in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study

BACKGROUND

Allostatic load (AL) is the physiologic "wear and tear" on the body from stress. Yet, despite stress being implicated in the development heart failure (HF), it is unknown whether AL is associated with incident HF events.

METHODS

We examined 16,765 participants without HF at baseline from the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. The main exposure was AL score quartile. AL was determined according to 11 physiologic parameters, whereby each parameter was assigned points (0-3) based on quartiles within the sample, and points were summed to create a total AL score ranging from 0-33. The outcome was incident HF event. We examined the association between AL quartile (Q1-Q4) and incident HF events using Cox proportional hazards models, adjusted for demographics, socioeconomic factors, and lifestyle.

RESULTS

The mean age was 64 ± 9.6 years, 61.5% were women, and 38.7% were Black participants. Over a median follow up of 11.4 years, we observed 750 incident HF events (635 HF hospitalizations and 115 HF deaths). Compared to the lowest AL quartile (Q1), the fully adjusted hazards of an incident HF event increased in a graded fashion: Q2 HR 1.49 95% CI 1.12-1.98; Q3 HR 2.47 95% CI 1.89-3.23; Q4 HR 4.28 95% CI 3.28-5.59. The HRs for incident HF event in the fully adjusted model that also adjusted for CAD were attenuated, but remained significant and increased in a similar, graded fashion by AL quartile. There was a significant age interaction (p-for-interaction < 0.001), whereby the associations were observed across each age stratum, but the HRs were highest among those aged < 65 years.

CONCLUSION

AL was associated with incident HF events, suggesting that AL could be an important risk factor and potential target for future interventions to prevent HF.

Epigenomic Links Between Social Determinants of Health and Symptoms: A Scoping Review

Social determinants of health (SDoH) impact health and wellness. The link between SDoH and adverse health outcomes, including symptom occurrence and severity, may be explained by an individual's physiologic response to one or more SDoH. One potential mechanism underlying this physiologic response linking SDoH and symptoms is the dynamic epigenome. The purpose of this scoping review of the literature was to examine differential susceptibility for symptoms by identifying and summarizing research linking SDoH and symptoms through epigenomic mechanisms. PubMed was searched to identify empirical research where at least one SDoH was an independent or dependent variable, at least one symptom was investigated, and the investigation included an epigenomic measure. Of the 484 articles initially retrieved, after thorough vetting, 41 articles met eligibility. The most studied symptom was depressive symptoms followed by anxiety, cognitive function, sleep dysfunction, and pain. The most frequently studied SDoH were: 1) stress, particularly early life stress and acculturative stress; and 2) trauma, predominantly childhood trauma. DNA methylation and telomere length were the most studied epigenomic measures. Four genes (SLC6A4, BDNF, NR3C1, OXTR) had evidence from multiple studies and across methodological approaches linking SDoH to symptoms. This review supports the inclusion of epigenomic approaches to better understand the link between SDoH and symptoms and provides evidence that SDoH impact telomere length and the methylation of genes involved in neurotransmitter signaling, neuronal survival, behavior, inflammation and stress response.

Towards a consensus definition of allostatic load: a multi-cohort, multi-system, multi-biomarker individual participant data (IPD) meta-analysis

BACKGROUND

Allostatic load (AL) is a multi-system composite index for quantifying physiological dysregulation caused by life course stressors. For over 30 years, an extensive body of research has drawn on the AL framework but has been hampered by the lack of a consistent definition.

METHODS

This study analyses data for 67,126 individuals aged 40-111 years participating in 13 different cohort studies and 40 biomarkers across 12 physiological systems: hypothalamic-pituitary-adrenal (HPA) axis, sympathetic-adrenal-medullary (SAM) axis, parasympathetic nervous system functioning, oxidative stress, immunological/inflammatory, cardiovascular, respiratory, lipidemia, anthropometric, glucose metabolism, kidney, and liver. We use individual-participant-data meta-analysis and exploit natural heterogeneity in the number and type of biomarkers that have been used across studies, but a common set of health outcomes (grip strength, walking speed, and self-rated health), to determine the optimal configuration of parameters to define the concept.

RESULTS

There was at least one biomarker within 9/12 physiological systems that was reliably and consistently associated in the hypothesised direction with the three health outcomes in the meta-analysis of these cohorts: dehydroepiandrosterone sulfate (DHEAS), low frequency-heart rate variability (LF-HRV), C-reactive protein (CRP), resting heart rate (RHR), peak expiratory flow (PEF), high density lipoprotein cholesterol (HDL-C), waist-to-height ratio (WtHR), HbA1c, and cystatin C. An index based on five biomarkers (CRP, RHR, HDL-C, WtHR and HbA1c) available in every study was found to predict an independent outcome - mortality - as well or better than more elaborate sets of biomarkers.

DISCUSSION

This study has identified a brief 5-item measure of AL that arguably represents a universal and efficient set of biomarkers for capturing physiological 'wear and tear' and a further biomarker (PEF) that could usefully be included in future data collection.

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.

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.

Latent profiles of biological dysregulation and risk of mortality: time-to-event analysis using the Midlife in the US longitudinal study

BACKGROUND

There is a well-established relationship between high allostatic load (AL) and increased risk of mortality. This study expands on the literature by combined latent profile analysis (LPA) with survival data analysis techniques to assess the degree to which AL status is associated with time to death.

METHODS

LPA was employed to identify underlying classes of biological dysregulation among a sample of 815 participants from the Midlife in the US study. Sex-stratified Cox proportional hazards regression models were used to estimate the association between class of biological dysregulation and time to death while controlling for sociodemographic covariates.

RESULTS

The LPA resulted in three classes: low dysregulation, immunometabolic dysregulation and parasympathetic reactivity. Women in the immunometabolic dysregulation group had more than three times the risk of death as compared with women in the low dysregulation group (HR=3.25, 95% CI: 1.47 to 7.07), but that there was not a statistically significant difference between the parasympathetic reactivity group and the low dysregulation group (HR=1.80, 95% CI: 0.62 to 5.23). For men, the risk of death for those in the immunometabolic dysregulation (HR=1.79, 95% CI: 0.88 to 3.65) and parasympathetic reactivity (HR=0.90, 95% CI: 0.34 to 3.65) groups did not differ from the low dysregulation group.

CONCLUSION

The findings are consistent with the previous research that demonstrates increased AL as a risk factor for mortality. Specifically, in women, that increased risk may be associated with immunometabolic dysregulation and not simply a generalised measure of cumulative risk as is typically employed in AL research.

Toward a conceptual framework of health and its operational definition: an application in the 1958 British birth cohort

BACKGROUND

Defining and measuring Health presents a challenge, partly due to its conceptual pluralism. To measure Health as an ability to adapt and self-manage, we developed an approach within the theoretical framework of resources and reserves over the life course, recently proposed in the literature. We aimed to (i) use the conceptual framework developed to identify indicators of deteriorating health reserves, (ii) construct an overall health measure from these indicators, (iii) evaluate the association between the overall health measure and subsequent health outcomes and (iv) assess the robustness of our method.

METHODS

We used data from 7,043 individuals born in 1958 in Great Britain included in the National Child Development Study. An overall health measure was constructed via the sum of three selected indicators of deteriorating health reserves in mid-life: chronic widespread pain (CWP), Clinical Interview Schedule - revised (CIS-r), and allostatic load (AL). A three-category variable was defined: impaired/medium/optimal overall health. We explored criterion validity by modelling the relationships between the overall health measure, or each reserve taken separately at 44-45 years, and self-rated health at 46 years and mortality up to 58 years, corresponding to 14 years of follow up, using Cox and logistic regressions respectively. We performed comparative analyses to assess the robustness of the method.

RESULTS

Having an impaired overall health measure was significantly associated with all-cause premature mortality (HR_impaired = 2.74 [1.86; 4.05]) and an increased risk of later fair/poor/very poor self-rated health (OR_impaired = 7.50 [6.29; 8.95]). The overall health measure had a greater effect on the self-rated health estimates than each indicator of deteriorating health reserves considered separately (OR_{AL medium} = 1.82 [1.59; 2.09]; OR_{AL high} = 2.74 [2.37; 3.16]; OR_CIS-r = 5.20 [4.45; 6.08]; OR_CWP = 2.85 [2.53; 3.21]). CIS-r and allostatic load were also associated with premature mortality contrary to chronic widespread pain (HR_{AL medium}1.82 [1.27; 2.61]; HR_{AL high} = 3.10 [2.19; 4.40]; HR_CIS-r = 1.77 [1.22; 2.56]; HR_CWP = 1.32 [0.98; 1.76]). The multiple comparative analyses conducted allowed us to assess the robustness of our method within this cohort.

CONCLUSIONS

We proposed a method for measuring Health in mid-life in line with the concept of Health as the ability to adapt and self-manage and the concept of health reserves. This method may be applied and further developed within the field of social and positive epidemiology.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Frailty: Pathophysiology, Theoretical and Operational Definition(s), Impact, Prevalence, Management and Prevention, in an Increasingly Economically Developed and Ageing World

The world's population is ageing, and most older adults experience a later life burdened with disease and disability. Frailty is a multidimensional and dynamic condition characterized by declines in reserve and function across multiple physiological systems, such that the ability to cope with every day or acute stressors becomes compromised. It is projected to become one of the most serious public health challenges economically developed societies will face in the coming century. This review provides a comprehensive overview of frailty, exploring its pathophysiology, theoretical and operational definition(s), impact, prevalence, management, and prevention, within the context of its emergence as a major public health challenge, in an increasingly economically developed and ageing world. Further, this review discusses the major limitations, deficiencies, and knowledge gaps presently within the field, and future research directions pertinent to the advancement of frailty research and the promotion of healthy longevity among the increasing global population of older adults.

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.

The Role of Epigenetic Clocks in Explaining Educational Inequalities in Mortality: A Multicohort Study and Meta-analysis

Educational inequalities in all-cause mortality have been observed for decades. However, the underlying biological mechanisms are not well known. We aimed to assess the role of DNA methylation changes in blood captured by epigenetic clocks in explaining these inequalities. Data were from 8 prospective population-based cohort studies, representing 13 021 participants. First, educational inequalities and their portion explained by Horvath DNAmAge, Hannum DNAmAge, DNAmPhenoAge, and DNAmGrimAge epigenetic clocks were assessed in each cohort via counterfactual-based mediation models, on both absolute (hazard difference) and relative (hazard ratio) scales, and by sex. Second, estimates from each cohort were pooled through a random effect meta-analysis model. Men with low education had excess mortality from all causes of 57 deaths per 10 000 person-years (95% confidence interval [CI]: 38, 76) compared with their more advantaged counterparts. For women, the excess mortality was 4 deaths per 10 000 person-years (95% CI: -11, 19). On the relative scale, educational inequalities corresponded to hazard ratios of 1.33 (95% CI: 1.12, 1.57) for men and 1.15 (95% CI: 0.96, 1.37) for women. DNAmGrimAge accounted for the largest proportion, approximately 50%, of the educational inequalities for men, while the proportion was negligible for women. Most of this mediation was explained by differential effects of unhealthy lifestyles and morbidities of the World Health Organization (WHO) risk factors for premature mortality. These results support DNA methylation-based epigenetic aging as a signature of educational inequalities in life expectancy emphasizing the need for policies to address the unequal social distribution of these WHO risk factors.

Biological aging in maltreated children followed up into middle adulthood

BACKGROUND

Childhood adversity has been linked to many indicators of shorter healthy lifespan, including earlier onset of disease and disability as well as early mortality. These observations suggest the hypothesis that childhood maltreatment may accelerate aging.

OBJECTIVE

To characterize the relationship between childhood maltreatment and accelerated biological aging in a prospective cohort of 357 individuals with documented cases of childhood maltreatment and 250 controls matched on demographic and socioeconomic factors.

METHODS

Cases were drawn from juvenile and adult court records from the years 1967 through 1971 in a large Midwest metropolitan geographic area. Cases were defined as having court-substantiated cases of childhood physical or sexual abuse, or neglect occurring at age 11 or younger. Controls were selected from the same schools and hospitals of birth and matched on age, sex, race, and approximate socioeconomic status. We compared biological aging in these two groups using two blood-chemistry algorithms, the Klemera-Doubal method Biological Age (KDM BA) and the PhenoAge. Algorithms were developed and validated in data from the National Health and Nutrition Examination Surveys (NHANES) using published methods and publicly available software.

RESULTS

Participants (55% women, 49% non-White) had mean age of 41 years (SD=4). Those with court substantiated childhood maltreatment history exhibited more advanced biological aging as compared with matched controls, although this difference was statistically different for only the KDM BA measure (KDM BA Cohen's D=0.20, 95% CI=[0.03,0.36], p = 0.02; PhenoAge Cohen's D=0.09 95% CI=[-0.08,0.25], p = 0.296). In subgroup analyses, maltreatment effect sizes were larger for women as compared to men and for White participants as compared to non-White participants, although these differences were not statistically significant at the α= 0.05 level.

CONCLUSIONS AND RELEVANCE

As of midlife, effects of childhood maltreatment on biological aging are small in magnitude but discernible. Interventions to treat psychological and behavioral sequelae of exposure to childhood maltreatment, including in midlife adults, have potential to protect survivors from excess burden of disease, disability, and mortality in later life.

The application of allostasis and allostatic load in animal species: A scoping review

Principles of allostasis and allostatic load have been widely applied in human research to assess the impacts of chronic stress on physiological dysregulation. Over the last few decades, researchers have also applied these concepts to non-human animals. However, there is a lack of uniformity in how the concept of allostasis is described and assessed in animals. The objectives of this review were to: 1) describe the extent to which the concepts of allostasis and allostatic load are applied theoretically to animals, with a focus on which taxa and species are represented; 2) identify when direct assessments of allostasis or allostatic load are made, which species and contexts are represented, what biomarkers are used, and if an allostatic load index was constructed; and 3) detect gaps in the literature and identify areas for future research. A search was conducted using CABI, PubMed, Agricola, and BIOSIS databases, in addition to a complementary hand-search of 14 peer-reviewed journals. Search results were screened, and articles that included non-human animals, as well as the terms "allostasis" or "allostatic" in the full text, were included. A total of 572 articles met the inclusion criteria (108 reviews and 464 peer-reviewed original research). Species were represented across all taxa. A subset of 63 publications made direct assessments of allostatic load. Glucocorticoids were the most commonly used biomarker, and were the only biomarker measured in 25 publications. Only six of 63 publications (9.5%) constructed an allostatic load index, which is the preferred methodology in human research. Although concepts of allostasis and allostatic load are being applied broadly across animal species, most publications use single biomarkers that are more likely indicative of short-term rather than chronic stress. Researchers are encouraged to adopt methodologies used in human research, including the construction of species-specific allostatic load indexes.

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.

Association of Allostatic Load With Overall Mortality Among Patients With Metastatic Non-Small Cell Lung Cancer

Importance

Adverse social determinants of health (SDHs) (eg, poverty) are associated with poor oncologic outcomes among patients with lung cancer. However, no studies have evaluated biological correlates of adverse SDHs, operationalized as allostatic load (AL), with mortality due to lung cancer.

Objective

To examine the association among AL, SDHs, and mortality among patients with metastatic non-small cell lung cancer (NSCLC).

Design, Setting, and Participants

This cross-sectional study of an observational cohort was performed at a National Cancer Institute-designated comprehensive cancer center with data accrued from June 1, 2017, to August 31, 2019. Patients with metastatic (stage IV) NSCLC enrolled at diagnosis into a prospective observational cohort study were included in the present analysis if they had all the biomarkers to calculate an AL score (N = 143). Follow-up was completed on August 31, 2021, and data were analyzed from July 1 to September 30, 2021.

Exposures

Social determinants of health.

Main Outcomes and Measures

Overall mortality and AL.

Results

A total of 143 patients met the study criteria with a median age of 63 (IQR, 55-71) years (89 men [62.2%] and 54 women [37.8%]). In terms of race and ethnicity, 1 patient (0.7%) was Asian, 7 (4.9%) were Black, 117 (81.8%) were White, 17 (11.9%) were of multiple races, and 1 (0.7%) was of other race or ethnicity. The mean (SD) AL was 2.90 (1.37). Elevated AL covaried with lower educational level (r = -0.26; P = .002), male sex (r = 0.19; P = .02), limited mobility (r = 0.19; P = .04), worsening self-care (r = 0.30; P < .001), problems engaging in usual activities (r = 0.21; P = .01), depressive symptoms (r = 0.23; P = .005), and a high number of stressful life events (r = 0.30; P < .001). Multivariable analysis found only increasing difficulty with mobility (r = 0.37 [95% CI, 0.13-0.60]; P = .002) and male sex (r = 0.63 [95% CI, 0.19-1.08]; P = .005) associated with higher AL. On adjusted analysis, elevated AL (hazard ratio, 1.43 [95% CI, 1.16-1.79]; P = .001) and low educational level (hazard ratio, 2.11 [95% CI, 1.03-4.34]; P = .04) were associated with worse overall mortality.

Conclusions and Relevance

The findings of this cross-sectional study suggest that higher AL was associated with adverse SDHs and worse overall mortality among patients with advanced NSCLC. These results provide a framework for replication and further studies of AL as a biological correlate for SDH and future prognostic marker.

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.

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.

Adverse childhood experiences and low socioeconomic status with respect to allostatic load in adulthood: A systematic review

Early-life psychosocial stress primes a number of health risk behaviors, and contributes to the development of various mental and somatic disorders in adulthood. It has been reported that adverse childhood experiences (ACEs) and low socioeconomic status (SES) might be associated with allostatic load (AL) in adulthood. In turn, elevated AL index has been found to predict a number of unfavorable health outcomes. Therefore, we aimed to perform a systematic review of studies investigating the association of ACEs and childhood SES with AL in adult populations. Independent online searches covered the publication period up to 20th Jun 2021. A total of 27 studies were included in qualitative synthesis. The majority of eligible studies showed that ACEs (14 out of 19 studies recording ACEs, 73.7%) and low childhood SES (11 out of 12 studies recording childhood SES, 91.7%) are associated with elevated AL in adults. However, several processes were found to mediate or moderate this association. These include educational attainments, social support, health behaviors, adult stress, post-traumatic stress disorder, coping strategies and aging. Moreover, a substantial methodological heterogeneity of approaches to calculating the AL index was observed. Apart from reports from overlapping samples, none of eligible studies used the same set of biomarkers. Findings from this systematic review imply that early-life psychosocial stress might have a lasting impact on biological dysregulations captured by the AL index. Future studies need to explore whether the association between early-life stress and the AL index accounts for the development of specific health outcomes.

Residential greenness-related DNA methylation changes

BACKGROUND

Residential greenness has been associated with health benefits, but its biological mechanism is largely unknown. Investigation of greenness-related DNA methylation profiles can contribute to mechanistic understanding of the health benefits of residential greenness.

OBJECTIVE

To identify DNA methylation profiles associated with greenness in the immediate surroundings of the residence.

METHODS

We analyzed genome-wide DNA methylation in 1938 blood samples (982 participants) from the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). We estimated residential greenness based on normalized difference vegetation index at 30 × 30 m cell (green30) and 500 m buffer (green500) around the residential address. We conducted epigenome-wide association study (EWAS) to identify differentially methylated CpGs and regions, and enrichment tests by comparing to the CpGs that previous EWAS identified as associated with allergy, physical activity, and allostatic load-relevant biomarkers.

RESULTS

We identified no genome-wide significant CpGs, but 163 and 56 differentially methylated regions for green30 and green500, respectively. Green30-related DNA methylation profiles showed enrichments in allergy, physical activity, and allostatic load, while green500-related methylation was enriched in allergy and allostatic load.

CONCLUSIONS

Residential greenness may have health impacts through allergic sensitization, stress coping, or behavioral changes. Exposure to more proximal greenness may be more health-relevant.

Role of Sex Hormones at Different Physiobiological Conditions and Therapeutic Potential in MBD2 Mediated Severe Asthma

Sex hormone has become a “hot topic” to evaluate the hormonal therapeutic potential in severe asthma. Th17 cell is one of the main influencing factors involved in the pathogenesis of severe asthma, hence also called as kernel of severe asthma, and Th17 subtype of non-T2 asthma is less responsive (resistance) to inhaled corticosteroid (ICS), so severe in nature. Methyl-CpG binding domain protein 2 (MBD2) is overexpressed and regulates the Th17 differentiation, showing the possibility of therapeutic target in treating Th17 mediated severe asthma. Sex hormone fluctuates at the different physiobiological conditions of the human body and affects the asthma pathobiology showing its role in asthma prevalence, severity, remission, and therapy. This review briefly overviews the sex hormones, their influence in asthma at the different physiobiological conditions of human body, and MBD2 severe asthma connection with the possible therapeutic potential of sex steroids in MBD2 mediated Th17 predominant severe asthma. Male sex hormone tends to show a beneficial effect and possibly downregulates the expression of Th17 cells via regulating MBD2 through a mechanism distinct from corticosteroid treatment and guides us towards discovery of new therapeutic agent, reduces the asthma-related complications, and promotes long-term survival by lowering the risk of therapy-resistant issues of old age severe asthma.

Plant-based dietary intake moderates adverse childhood experiences association with early mortality in an older Adventist cohort

BACKGROUND

Adverse Childhood Experiences (ACEs) consistently predict poor mental and physical health as well as early all-cause mortality. Much work examines health harming behaviors that may be used to cope with ACEs associated stress responses and dysregulation. Limited research has been conducted assessing plant-based dietary intake on the ACEs and mortality relationship. We investigate moderators of the ACEs and mortality association including plant-based dietary intake.

OBJECTIVE

The purpose of this study is to examine if the association between ACEs and early mortality is potentially moderated by plant-based dietary intake.

PARTICIPANTS

An observational, prospective cohort study that included 9301 Seventh-day Adventists were assessed from 2006 to 2017 in the Biopsychosocial Religion and Health Study (BRHS).

METHODS

We examined the potential impact of plant-based intake frequency on the ACEs and all-cause mortality relationship, while adjusting for potential confounders (e.g., demographics, health risks, mental and physical health) in a cox regression survival analysis.

RESULTS

ACEs were adversely associated with survival time (HR = 2.76, 95% CI: 1.15-6.64). Plant-based intake was associated with a reduction in the association of 4+ ACEs with early mortality (HR = 0.73, 95% CI: 0.59-0.90) above and beyond demographics, animal-based intake, physical health, mental health, BMI, exercise, and worship. We estimate that after 4+ ACEs, those eating high versus low plant-based dietary intake may live 5.4 years longer.

CONCLUSION

Plant-based dietary intake may potentially moderate the ACEs and early mortality relationship; however, observational studies cannot determine causality.

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.

Neighborhood poverty, allostatic load, and changes in cellular aging in African American young adults: the moderating role of attachment

Attachment experiences are thought to contribute to physical health across the lifespan. Evidence suggests that attachment style may serve as a protective factor for individuals' physical health by mitigating the negative effects of social and environmental risk factors. In the present study, we evaluated how attachment styles may moderate the link between African American adolescents' exposure to neighborhood poverty and accelerated cellular aging in young adulthood. Analyses revealed that allostatic load at age 19 mediated the association between neighborhood poverty in adolescence and changes in cellular aging from age 20 to 27. Notably, attachment avoidance (but not attachment anxiety) moderated this association, such that allostatic load was only associated with faster cellular aging for individuals who were high in avoidance. These findings suggest that allostatic load may give rise to faster cellular aging, but these detrimental effects of allostatic load can be offset by young adults' effective use of attachment figures.

Predictors of Biological Age: The Implications for Wellness and Aging Research

As healthspan and lifespan research breakthroughs have become more commonplace, the need for valid, practical markers of biological age is becoming increasingly paramount. The accessibility and affordability of biological age predictors that can reveal information about mortality and morbidity risk, as well as remaining years of life, has profound clinical and research implications. In this review, we examine 5 groups of aging biomarkers capable of providing accurate biological age estimations. The unique capabilities of these biomarkers have far reaching implications for the testing of both pharmaceutical and non-pharmaceutical interventions designed to slow or reverse biological aging. Additionally, the enhanced validity and availability of these tools may have increasingly relevant clinical value. The authors of this review explore those implications, with an emphasis on lifestyle modification research, and provide an overview of the current evidence regarding 5 biological age predictor categories: Telomere length, composite biomarkers, DNA methylation “epigenetic clocks,” transcriptional predictors of biological age, and functional age predictors.

Skin Tone, Discrimination, and Allostatic Load in Middle-Aged and Older Puerto Ricans

OBJECTIVE

A growing body of research suggests that skin tone may be a health risk indicator for Hispanics. Black and darker-skinned Hispanics have worse mental and physical outcomes than White and lighter-skinned Hispanics. Discrimination exposure has been implicated as a risk factor that may explain the association between skin tone and health. However, there is scant research examining the interrelationship between skin tone, discrimination, and health, particularly among Puerto Ricans. We examine the interrelationships between two measures of skin tone, two measures of discrimination, and allostatic load (AL) among Puerto Rican adults.

METHODS

Using cross-sectional data from wave 3 of the Boston Puerto Rican Health Study (n = 882), we examined the indirect association (IA) of skin tone on physiological dysregulated systems, also known as AL, through major discrimination and everyday discrimination. We tested these associations using two distinct measures of skin tone: interviewer-ascribed skin tone and spectrophotometer-measured skin tone.

RESULTS

Interviewer-ascribed skin tone was indirectly associated with AL through major discrimination (IA = 0.03, 95% confidence interval = 0.004 to 0.06). However, there was no evidence of an IA of interviewer-ascribed skin tone on AL through everyday discrimination (IA = -0.01, 95% confidence interval = -0.03 to 0.01). In addition, there was no evidence that spectrophotometer-measured skin tone was indirectly associated with AL through major discrimination or everyday discrimination.

CONCLUSIONS

The sociocultural significance of skin tone may affect how Puerto Ricans are perceived and treated by others, which can, in turn, have physiological health consequences. Future research is needed to replicate these findings and examine the interrelationship between skin tone, discrimination, and other health outcomes.

GrimAge Outperforms Other Epigenetic Clocks in the Prediction of Age-Related Clinical Phenotypes and All-Cause Mortality

The aging process is characterized by the presence of high interindividual variation between individuals of the same chronical age prompting a search for biomarkers that capture this heterogeneity. Epigenetic clocks measure changes in DNA methylation levels at specific CpG sites that are highly correlated with calendar age. The discrepancy resulting from the regression of DNA methylation age on calendar age is hypothesized to represent a measure of biological aging with a positive/negative residual signifying age acceleration (AA)/deceleration, respectively. The present study examines the associations of 4 epigenetic clocks-Horvath, Hannum, PhenoAge, GrimAge-with a wide range of clinical phenotypes (walking speed, grip strength, Fried frailty, polypharmacy, Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MOCA), Sustained Attention Reaction Time, 2-choice reaction time), and with all-cause mortality at up to 10-year follow-up, in a sample of 490 participants in the Irish Longitudinal Study on Ageing (TILDA). HorvathAA and HannumAA were not predictive of health; PhenoAgeAA was associated with 4/9 outcomes (walking speed, frailty MOCA, MMSE) in minimally adjusted models, but not when adjusted for other social and lifestyle factors. GrimAgeAA by contrast was associated with 8/9 outcomes (all except grip strength) in minimally adjusted models, and remained a significant predictor of walking speed, .polypharmacy, frailty, and mortality in fully adjusted models. Results indicate that the GrimAge clock represents a step-improvement in the predictive utility of the epigenetic clocks for identifying age-related decline in an array of clinical phenotypes promising to advance precision medicine.

Framework for understanding health inequalities over the life course: the embodiment dynamic and biological mechanisms of exogenous and endogenous origin

Understanding how structural, social and psychosocial factors come to affect our health resulting in health inequalities is more relevant now than ever as trends in mortality gaps between rich and poor appear to have widened over the past decades. To move beyond description, we need to hypothesise about how structural and social factors may cause health outcomes. In this paper, we examine the construction of health over the life course through the lens of influential theoretical work. Based on concepts developed by scholars from different disciplines, we propose a novel framework for research on social-to-biological processes which may be important contributors to health inequalities. We define two broad sets of mechanisms that may help understand how socially structured exposures become embodied: mechanisms of exogenous and endogenous origin. We describe the embodiment dynamic framework, its uses and how it may be combined with an intersectional approach to examine how intermeshed oppressions affect social exposures which may be expressed biologically. We explain the usefulness of this framework as a tool for carrying out research and providing scientific evidence to challenge genetic essentialism, often used to dismiss social inequalities in health.

Applying a Life Course Biological Age Framework to Improving the Care of Individuals With Adult Cancers: Review and Research Recommendations

Importance

The practice of oncology will increasingly involve the care of a growing population of individuals with midlife and late-life cancers. Managing cancer in these individuals is complex, based on differences in biological age at diagnosis. Biological age is a measure of accumulated life course damage to biological systems, loss of reserve, and vulnerability to functional deterioration and death. Biological age is important because it affects the ability to manage the rigors of cancer therapy, survivors' function, and cancer progression. However, biological age is not always clinically apparent. This review presents a conceptual framework of life course biological aging, summarizes candidate measures, and describes a research agenda to facilitate clinical translation to oncology practice.

Observations

Midlife and late-life cancers are chronic diseases that may arise from cumulative patterns of biological aging occurring over the life course. Before diagnosis, each new patient was on a distinct course of biological aging related to past exposures, life experiences, genetics, and noncancer chronic disease. Cancer and its treatments may also be associated with biological aging. Several measures of biological age, including p16INK4a, epigenetic age, telomere length, and inflammatory and body composition markers, have been used in oncology research. One or more of these measures may be useful in cancer care, either alone or in combination with clinical history and geriatric assessments. However, further research will be needed before biological age assessment can be recommended in routine practice, including determination of situations in which knowledge about biological age would change treatment, ascertaining whether treatment effects on biological aging are short-lived or persistent, and testing interventions to modify biological age, decrease treatment toxic effects, and maintain functional abilities.

Conclusions and Relevance

Understanding differences in biological aging could ultimately allow clinicians to better personalize treatment and supportive care, develop tailored survivorship care plans, and prescribe preventive or ameliorative therapies and behaviors informed by aging mechanisms.

Association between allostatic load and mortality among Chinese older adults: the Chinese Longitudinal Health and Longevity Study

BACKGROUND

Allostatic load (AL) has shown that high burden of AL is associated with increased risk of adverse outcomes, but little attention has been paid to China with largest ageing population in the world.

OBJECTIVE

This study is to examine the association between AL and all-cause mortality among Chinese adults aged at least 60 years.

DESIGN

Population-based prospective cohort study.

SETTING

In 2011-2012, an ancillary study, in which a blood test was added, including a total of 2439 participants, was conducted in eight longevity areas in the Chinese Longitudinal Healthy Longevity Survey.

PARTICIPANTS

The final analytical sample consisted of 1519 participants (mean±SD age: men 80.5±11.3 years; women 90.2±11.8 years and 53% women).

PRIMARY OUTCOME MEASURE

Cox models were used to examine the association between AL and mortality among men and women, separately. Analyses were also adjusted for potential confounders including age, ethnicity, education and marital status, smoking and exercise.

RESULTS

Male with a medium AL burden (score: 2-4) and high AL burden (score: 5-9) had a 33% and 118% higher hazard of death, respectively, than those with a low AL burden (score: 0-1). We did not find significant difference between females with different levels of AL burden.

CONCLUSION

Higher AL burden was associated with increased all-cause mortality among Chinese men aged at least 60 years. However, we did not find strong association among women. In conclusion, Intervention programmes targeting modifiable components of the AL burden may help prolong lifespan for older adults, especially men, in China.

The impact of discrimination on allostatic load in adults: An integrative review of literature

OBJECTIVE

The objective of the paper is to critically review the current state of the literature on the association between discrimination and allostatic load (AL) in adults and determine whether this association differs by sociodemographic characteristics.

METHODS

An extensive literature search was conducted in PubMed, CINAHL, PsycINFO, and Embase to identify studies that investigated the association between discrimination and AL. The search was limited to the English language, articles that were peer-reviewed and articles that were published within the last 10 years.

RESULTS

A total of 11 studies met the eligibility criteria for this review, 8 of which were cross-sectional and 3 of which were longitudinal. There was heterogeneity in the type of discrimination measured, the composition of AL summary score, and the analytic approach utilized to examine the relationship of interest. Nine studies found a significant, positive association between discrimination and AL. The types of discrimination found to be positively associated with AL included lifetime discrimination, childhood racial discrimination, everyday discrimination, and everyday weight discrimination. One study found that this association differed by educational attainment.

CONCLUSION

There is evidence that discrimination is associated with AL. Longitudinal studies with diverse samples are needed to further explore this association and how it differs based on sociodemographic characteristics.

Allostatic load, metabolic syndrome and self-rated health in overweight/obese Non-Hispanic White, non-Hispanic Black and Mexican American adults

AIM

This study examined the associations of high allostatic load (h_ALS) and metabolic syndrome (MetS) with and self-rated poor health (SRPH) in overweight/obese non-Hispanic White (NHW), non-Hispanic Black (NHB), and Mexican American (MA) adults.

METHODS

The 2015-16 and 2017-18 US National Health and Nutrition Examination Survey data (n = 4403) were used for this study.

RESULTS

Rates of h_ALS in overweight/obese NHW, NHW, and MA participants were 56.9%, 58.8%, and 51.9%, respectively (P < .05). The corresponding rates for MetS were 26.9%, 31.9%, and 46.5%, respectively. High ALS was associated with 2.19 (95% CI: 1.87-4.59), 1.82 (1.42-2.58), and 1.47 (95% CI: 1.08-1.64) increased odds of SRPH in overweight/obese NHW, NHB, and MA, respectively, after adjusting for age, education, gender, income, lifestyle behaviors, and marital status. The corresponding values for MetS were 1.86 (95% CI: 1.54-2.40), 2.77 (95% CI: 1.36-5.63), and 1.22 (95% CI: 1.06-2.32), respectively.

CONCLUSIONS

The effect of h_ALS on SRPH was much stronger in NHW, while the effect of MetS was strongest among NHB overweight/obese adults. The result of this study provides further evidence in favor of race/ethnic-tailored interventions, including education and weight control to reduced risks of bodywear and tear and SRPH.