Early life predictors of midlife allostatic load: A prospective cohort study

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.

Comparing different operationalizations of allostatic load measured in mid-life and their patterning by race and cumulative life course socioeconomic status

Since its conceptualization, there has been a lack of consensus on the best way to operationalize allostatic load (AL). As a marker of the cumulative, physiological wear and tear on the body resulting from chronic exposure to stressors, it follows that AL should be higher among people who have faced more stressful life experiences. Thus, the purpose of this study was to construct AL scores using different operationalizations and, as a measure of construct validity, compare whether each construction produced expected disparities in AL by race and a composite socioeconomic status (SES) variable which accounts for measures over the life course; we also explored differences by sex. We conducted the study in a sample of 45-52-year-old offspring from the Child Health and Development Studies, a longitudinal birth cohort established in the early 1960s. AL scores were constructed in 6 different ways and included 10 biomarkers from inflammatory, neuroendocrine, cardiovascular, and metabolic systems. Our main approach to constructing AL was to sum across high-risk biomarker quartiles, correct for medication use, and use sex-specific high-risk quartiles for specific biomarkers. Alternative constructions did not use sex-specific quartiles and/or weighted biomarkers within subsystems and/or did not correct for medication use. We estimated differences in AL scores by race, SES, sex and their pairwise interactions. All constructions of AL, including the main approach, produced expected disparities by race (higher scores for Black vs. non-Black participants) and life course SES (higher scores for low vs. high SES participants). However, disparities by sex only emerged when the AL score was constructed via approaches that did not use sex-specific high-risk quartiles; for these alternative constructions, overall, female participants had higher AL scores than male participants and Black female participants had the highest AL scores in the sample. For most constructions, the pairwise interaction between sex and SES, showed a stronger disparity in AL scores between low and high-SES female compared with low- and high-SES male participants; this suggests that, in terms of lowering AL, high life course SES may be more important for female than male participants. In conclusion, our results suggest that the basic AL concept is consistently expressed in different operationalizations, making it an especially useful and robust tool for understanding disparities by race and SES.

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.

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.

Systems of care among children and youth with special health care needs with and without adverse childhood events: National Survey of Children's Health 2016-2017

BACKGROUND

Knowledge of adverse childhood events (ACEs), the associated access to healthcare and unmet needs among children and youth with special health care needs (CYSHCN) is limited.

OBJECTIVES

Our objectives were to compare the likelihood of CYSHCN versus non-CYSHCN experiencing one or more ACEs and document differences in receipt of recommended and needed health care among CYSHCN with and without ACEs.

METHODS

We combined two years of data from the 2016 and 2017 National Survey of Children's Health (N = 71,181), providing a sample of 16,304 CYSHCN. Our primary outcome measures included eight adverse childhood events, compared to singular and aggregated ACEs among non-CYSHCN. We calculated associations between ACEs and secondary outcome measures for six components of well-functioning systems of care and unmet need for different types of health care using bivariate and multivariate analyses.

RESULTS

CYSHCN were more likely to have each of the ACEs measured and were likelier to experience aggregated levels of ACEs compared to non-CYSHCN. The likelihood of CYSHCN having a medical home with family-centered and coordinated care decreased with increased ACEs, while one or more ACES increased the likelihood of having unmet needs for mental health care.

CONCLUSION

The findings of the current study extend our understanding of the additional adverse event burden associated with special health care needs status, the accompanying limitations in access to family-centered and coordinated care in a medical home and unmet need for mental health care, indicating that much work remains in establishing appropriate care systems for this very vulnerable population.

Temporal changes in allostatic load patterns by age, race/ethnicity, and gender among the US adult population; 1988-2018

The objective of this study is to provide an assessment of allostatic load (AL) burden among US adults across race/ethnicity, gender, and age groups over a 30-year time period. We analyzed data from 50,671 participants of the National Health and Nutrition Examination Survey (NHANES) years 1988 through 2018. AL score was defined as the sum total for abnormal measures of the following components: serum albumin, body mass index, serum C - reactive protein, serum creatinine, diastolic blood pressure, glycated hemoglobin, systolic blood pressure, total cholesterol, and serum triglycerides. We performed modified Poisson regression to estimate the adjusted Relative Risks (aRRs) of allostatic load, and generalized linear models to determine adjusted mean differences accounting for NHANES sampling weights. Among US adults aged 18 or older, the prevalence of high AL increased by more than 45% from 1988 to 1991 to 2015-2018, from 33.5% to 48.6%. By the latest period, 2015-2018, Non-Hispanic Black women (aRR: 1.292; 95% CI: 1.290-1.293) and Latina women (aRR: 1.266; 95% CI: 1.265-1.267) had higher risks of AL than non-Hispanic White women. Similar trends were observed among men. Age-adjusted mean AL score among NH-Black and Latinx adults was higher than for NH-Whites of up to a decade older regardless of gender. From 1988 through 2018, Adults aged 40 years old and older had over 2-fold increased risks of high AL when compared to adults 18-29 years old. After 30-years of collective data, racial disparities in allostatic load persist for NH-Black and Latinx adults.

Association between prolonged separation from parents and allostatic load among children in China

OBJECTIVE

To capture the association of exposure to prolonged separation from both parents early in life and allostatic load (AL), a measure of biological multi-system dysregulation.

METHODS

We used data from 557 7-12-year-old children enrolled in rural area of Chizhou city, Anhui Province, China. We computed an AL score based on eleven biomarkers representing four regulatory systems: immune/inflammatory system (high sensitivity C-reactive protein); metabolic system (body mass index; high density lipoprotein; low density lipoprotein, total cholesterol; triglycerides; fasting glucose; glycated hemoglobin; insulin) and cardiovascular system (systolic and diastolic blood pressure). Child's experiences of parent-child separation were collected a brief online questionnaire by parents of children.

RESULTS

More than 1 in 3 of our participants separated with both parents at age 6 or younger and nearly 1 in 10 persistently separated from both parents after birth. The AL score was significantly higher among children separated from both parents during early childhood (3.25 ± 1.98) or persistently since birth (3.48 ± 1.92), compared with those who did not separated from both parents (2.34 ± 1.53, F = 12.992, P<0.001). After adjustment of demographic covariates, body mass index as well as parent frequency of communication and parental warmth, children who separated from both parents in early childhood (β = 0.84, 95%CI:0.40, 1.28, P < 0.001) or persistently into adolescence (β = 1.27, 95%CI:0.43, 2.12, P = 0.003) evinced the highest levels of AL.

CONCLUSION

This study is the first to show an association between prolonged parent-child separation and physiological wear-and-tear as measured by AL, which provides potential insights into the biological mechanisms underpinning long-term health outcomes in contexts of parent-child separation.

Prevalence of Parent Reported Health Conditions Among 0- to 17-Year-Olds in Rural United States: National Survey of Children's Health, 2016-2017

PURPOSE

This study's purpose was to determine the prevalence of physical, mental, and developmental health conditions among US children and assess the association with urban versus rural residence.

METHODS

Bivariate/multivariable analyses were conducted with cross-sectional data for children aged 0-17 years (N = 71,811) from the 2016-2017 National Survey of Children's Health. Prevalence estimates of excellent/very good health were derived from parents' qualitative judgments. Parent-reported health conditions were aggregated by condition type (physical, mental, developmental). Prevalence was determined for condition type and severity. Adjusted risk ratios assessed the effect of residence on having physical, mental, or developmental conditions.

RESULTS

Among rural children in the general population, we found lower crude rates of excellent/very good overall health and higher rates of ≥1 physical condition(s) and ≥1 mental condition(s), as well as these 2 conditions in combination with ≥1 developmental condition(s). Rural children in the general population were also more likely to have physical and mental conditions that parents rated as moderate/severe in unadjusted analyses. To a lesser extent, these differences held true for the children with special health care needs. Risk ratios for rural residence were largely nonsignificant in adjusted analyses.

CONCLUSIONS

While rural children had lower crude rates of parent-reported excellent/very good health and higher crude rates of parent-reported or doctor-diagnosed physical and mental health conditions compared to urban children, the same pattern of urban-rural differentials was not evident in the adjusted analyses. Compositional and contextual differences in the urban/rural populations suggest that social determinants of health may have accounted for rate disparities in child health conditions.

Stress and Depressive Symptoms Among Demographically Diverse American Pregnant Women

Pregnancy is a sensitive period of life where mental health is of utmost importance to the mother's and child's well-being peripartum and beyond. To better prevent and treat common mental health conditions such as depressive symptoms and perceived stress (defined in this study to encompass psychological and physiological (heart rate variability (HRV)) dimensions), it is crucial to examine and report differences in mental health outcomes among demographically diverse pregnant women. Therefore, the purpose of this secondary analysis (N = 79) was to determine if there are differences in mental health outcomes between pregnant women who differ across demographic factors, as well as to determine if demographic factors predict mental health outcomes when controlling for other demographic variables. Findings indicate that there were significant differences in depressive symptoms and perceived stress by all demographic factors except age. Marital status and total household income were the only significant predictors of depressive symptoms and perceived stress, respectively, when all other factors were controlled. There were no significant differences or correlations between demographic variables and HRV. Pregnant women may be predisposed to adverse mental health outcomes, illustrating the need for more refined interventions that are sensitive to pre-existing factors.

Birth weight and quality of life in midlife: a 50-year follow-up study of 2079 individuals in Denmark

PURPOSE

Low birth weight has been associated with a higher risk of reduced quality of life (QoL) in children, adolescents, and young adults, but the influence seems to diminish over time. However, previous studies have mainly focused on health-related QoL and compared individuals with low birth weight with individuals without low birth weight. The purpose of the present cohort study was to investigate the influence of the entire range of birth weights on three distinct measures of QoL in midlife.

METHODS

The study population consisted of all live-born singletons from the Copenhagen Perinatal Cohort (CPC, 1959-1961) who participated in a 50-year follow-up examination in 2009-2011 (N = 2079). Birth weight was measured by three pediatricians at birth. QoL was measured at the follow-up by the participants' scores on three QoL self-report measures: The Satisfaction With Life Scale, the Vitality Scale of the Medical Outcomes Study 36-Item Short-Form Health Survey, and a single-item QoL measure based on the question: "How is your quality of life at the moment?". General linear regression and binary logistic regression were used to estimate the association between birth weight and QoL in midlife.

RESULTS

Small, curvilinear associations of birth weight with life satisfaction, vitality, and the single-item QoL measure were found, suggesting that both low and high birth weights increase the risk of low satisfaction with life, low vitality and low QoL.

CONCLUSION

The study findings suggest that low and high-range birth weight exert a lasting influence on distinct, but complementary aspects of QoL in midlife.

Associations of early-life growth with health using an allostatic load score in young, urban African adults: Birth to Twenty Plus Cohort

Growth in early life is associated with various individual health outcomes in adulthood, but limited research has been done on associations with a more comprehensive measure of health. Combining information from multiple biological systems, allostatic load (AL) provides such a quantitative measure of overall physiological health. We used longitudinal data from the Birth to Twenty Plus cohort in South Africa to calculate an AL score at age 22 years and examined associations with birth weight and linear growth and weight gain from age 0 to 2 years and 2 to 5 years, as attenuated by trajectories of body mass index and pubertal development in later childhood and adolescence. Differences in total AL score between males and females were small, though levels of individual biological factors contributing to AL differed by sex. Increased weight gain from age 2 to 5 years among males was associated with an increased risk of high AL, but no other early-life measures were associated with AL. Increased adiposity through childhood and adolescence in females was associated with higher AL in early adulthood. These results illustrate that patterns of early-life growth are not consistently associated with higher AL. While more research is needed to link AL in young adulthood to later health outcomes, these results also suggest increased adiposity during childhood and adolescence represents a potential early sign of later physiological risk.