Associations between early life stress, self-reported traumatic experiences across the lifespan and leukocyte telomere length in elderly adults

Parent-child separation and cardiometabolic outcomes and risk factors in adulthood: A systematic review

BACKGROUND

Parent-child separation has been associated with negative mental health across childhood and adulthood, yet little is known about the long-term impacts for cardiovascular health. This systematic review synthesized and evaluated the quality of the literature examining the association between exposures to parent-child separation and cardiometabolic outcomes in adulthood.

METHODS

Following a registered protocol, online databases (Pubmed, PsycInfo, and Web of Science) were searched for relevant studies. Studies were included if they (a) defined the exposure before age 18 as institutionalization, foster care placement, parental incarceration, separation due to parents migrating for economic reasons, or asylum and war; and (b) quantified the association between parent-child separation and cardiometabolic events and diagnoses (e.g., coronary heart disease, diabetes) and risk factors (e.g., body mass index, fat distribution, serum-based metabolic markers, inflammatory markers in adulthood (≥ age 18). Studies lacking an unexposed comparison group were excluded. The risk for bias in each study was assessed with a modified Newcastle-Ottawa Scale.

RESULTS

Of the 1938 studies identified, 13 met our inclusion criteria. Two of the four studies examining associations between parent-child separation and cardiometabolic events and diagnoses found positive associations with coronary heart disease and diabetes. Amongst the 13 studies examining associations with any type of adult cardiometabolic risk factors, eight studies reported at least one positive association. Sub-analyses considering separate reasons for parent-child separation provided clearer insights: War evacuation was associated with hypertension and high blood pressure across four studies from the same cohort; out-of home care experiences largely evidenced null results across five different studies, and two studies on parental incarceration suggested positive associations with elevated inflammation, BMI and blood pressure.

CONCLUSIONS

The connections between parent-child separation and adult cardiometabolic outcomes and risk factors are currently inconsistent. The results may depend on the reason for separation, age of assessment, analytic differences and other psychosocial variables that are often unmeasured in this literature.

Early life trauma and adult leucocyte telomere length

BACKGROUND

Telomere length, a biomarker of cell division and cellular aging, has been associated with multiple chronic disease endpoints. Experienced trauma over the life course may contribute to telomere shortening via mechanisms of stress embodiment. However, it is unclear how patterns of co-occurring trauma during sensitive periods (e.g., early life) throughout the life course may influence telomere shortening. We examine the relationship between co-occurring early life trauma on adult telomere length and the extent to which adulthood trauma, socioeconomic position, and health and lifestyle factors may mediate this relationship.

METHODS

We use data from a sample of participants in the Sister Study (N = 740, analytic sample: n = 602), a prospective cohort of U.S. self-identified females aged 35-74 years at enrollment (2003-2009) for whom leukocyte telomere length was measured in baseline blood samples. Participants reported their experience of 20 different types of trauma, from which we identified patterns of co-occurring early life trauma (before age 18) using latent class analysis. We estimated the direct and indirect effects of early life trauma on leukocyte telomere length using structural equation modeling, allowing for mediating adult pathways.

RESULTS

Approximately 47 % of participants reported early life trauma. High early life trauma was associated with shorter telomere length compared to low early life trauma (β = -0.11; 95 % CI: -0.22, -0.004) after adjusting for age and childhood socioeconomic position. The inverse association between early life trauma and adult leukocyte telomere length was largely attributable to the direct effect of early life trauma on telomere length (β = -0.12; 95 %CI: -0.23, -0.01). Mediating indirect pathways via adult trauma, socioeconomic position, and health metrics did not substantively contribute the overall association.

CONCLUSIONS

These findings highlight the role of patterns of co-occurring early life trauma on shortened telomere length independent of adult pathways.

Age-related no-go P300 amplitudes are moderated by exposure to early-life stress

Deficits in inhibitory control are common with advancing age and may underlie declines in other complex cognitive functions. The inhibitory P300 event-related potential (ERP) generally decreases in amplitude with age, reflecting deficits in inhibitory performance evaluation and adaptation, with possible generators including precentral and inferior frontal gyri and midcingulate and parietal cortex. Exposure to early-life stress (ELS) is also associated with deficits in inhibitory control, smaller P300 amplitudes, and dysfunction in regions associated with P300 generation. Although biopsychosocial effects of ELS are evident in older adulthood, the influence of ELS on neural processes in later life is unknown. In the current study, 13 young adults and 21 healthy older adults completed a high-accuracy go/no-go task and the Juvenile Victimization Questionnaire (JVQ), an indicator of ELS. Regression analyses revealed significant central-parietal models, with smaller P300 amplitudes predicted by both older age and greater exposure to ELS. Age group*ELS interactions moderated P300 prediction at central and centro-parietal electrodes, such that older age predicted smaller P300 amplitudes only in those with lower to moderate ELS. Amplitudes did not significantly differ by age in those with higher ELS. Post-hoc within-age group correlations showed that greater ELS was associated with smaller P300 amplitudes in young adults. However, greater ELS was modestly associated with larger central amplitudes in older adults, potentially suggestive of anterior age-related compensatory recruitment to maintain high task performance. These findings suggest long-lasting neural implications of ELS that interact with normative neuro-cognitive aging processes, such that ELS may be an important risk factor for age-related cognitive decline.

The Association of Individual Changes in Stressful Life Events and Telomere Length Over Time in Twins 50 Years and Older

OBJECTIVE

Exposure to adverse stressors has been associated with shortening of leukocyte telomere length (LTL). The present longitudinal study investigates the time course of exposure to life events and LTL to determine whether increases in exposure to life events are related to subsequent accelerated LTL shortening.

METHODS

In the Swedish Adoption/Twin Study of Aging, we assessed late-life stressful events and LTL in 543 individual participants (mean age = 68.4 years, 40% men, including 48 complete monozygotic twin pairs and 167 complete dizygotic twin pairs) in up to five separate measurements over a period of 25 years. LTL was measured using quantitative polymerase chain reaction. Longitudinal analyses were conducted using time-varying mixed modeling, corrected for life-style factors and depressive symptoms.

RESULTS

When adjusting for differences in genetic makeup by looking only in monozygotic twins, we found that an increase in life stressors within an individual was related to decreased LTL over time (B = -0.02; 95% confidence interval = -0.04 to 0.01; p = .002). None of the findings were significant when only looking at dizygotic twins (all, p > .05).

CONCLUSIONS

Our findings in an older population show a causal relation between increase in life stress and accelerated LTL shortening by using intraindividual time-varying analysis.

Oxidative Dysregulation in Early Life Stress and Posttraumatic Stress Disorder: A Comprehensive Review

Traumatic stress may chronically affect master homeostatic systems at the crossroads of peripheral and central susceptibility pathways and lead to the biological embedment of trauma-related allostatic trajectories through neurobiological alterations even decades later. Lately, there has been an exponential knowledge growth concerning the effect of traumatic stress on oxidative components and redox-state homeostasis. This extensive review encompasses a detailed description of the oxidative cascade components along with their physiological and pathophysiological functions and a systematic presentation of both preclinical and clinical, genetic and epigenetic human findings on trauma-related oxidative stress (OXS), followed by a substantial synthesis of the involved oxidative cascades into specific and functional, trauma-related pathways. The bulk of the evidence suggests an imbalance of pro-/anti-oxidative mechanisms under conditions of traumatic stress, respectively leading to a systemic oxidative dysregulation accompanied by toxic oxidation byproducts. Yet, there is substantial heterogeneity in findings probably relative to confounding, trauma-related parameters, as well as to the equivocal directionality of not only the involved oxidative mechanisms but other homeostatic ones. Accordingly, we also discuss the trauma-related OXS findings within the broader spectrum of systemic interactions with other major influencing systems, such as inflammation, the hypothalamic-pituitary-adrenal axis, and the circadian system. We intend to demonstrate the inherent complexity of all the systems involved, but also put forth associated caveats in the implementation and interpretation of OXS findings in trauma-related research and promote their comprehension within a broader context.

The prospective association between stressful life events and inflammation among adolescents with a history of early institutional rearing

Early adversity has been shown to sensitize individuals to the effects of later stress and enhance risk of psychopathology. Using a longitudinal randomized trial of foster care as an alternative to institutional care, we extend the stress sensitization hypothesis to examine whether early institutional rearing sensitizes individuals to stressful events in adolescence engendering chronic low-grade inflammation. At baseline, institutionalized children in Romania (ages 6-31 months) were randomly assigned to foster care or to remain in usual care within institutions. A group of never-institutionalized children was recruited as an in-country comparison sample. At ages 12 and 16, participants reported stressful events. At age 16, Interleukin-6 (IL-6) and C-reactive protein (CRP) were derived from blood spots. Among children assigned to care as usual, more stressful events at age 12, but not age 16, were associated with higher IL-6. In the same group, stressful events at age 16 were associated with higher CRP, though these effects attenuated after adjusting for covariates. These associations were not observed in the foster care or never-institutionalized groups. The findings suggest that heightened inflammation following stress exposure is one pathway through which early neglect could compromise physical health. In contrast, early family care might buffer against these risks.

Prolonged Glucocorticoid Exposure Does Not Accelerate Telomere Shortening in Cultured Human Fibroblasts

Psychosocial stress, especially when chronic or excessive, can increase disease risk and accelerate biological aging. Although the underlying mechanisms are unclear, in vivo studies have associated exposure to stress and glucocorticoid stress hormones with shorter telomere length. However, the extent to which prolonged glucocorticoid exposure can shorten telomeres in controlled experimental settings remains unknown. Using a well-characterized cell line of human fibroblasts that undergo gradual telomere shortening during serial passaging in culture, we show that prolonged exposure (up to 51 days) to either naturalistic levels of the human endogenous glucocorticoid cortisol or the more potent synthetic glucocorticoid dexamethasone is not sufficient to accelerate telomere shortening. While our findings await extension in other cell types and biological contexts, they indicate that the in vivo association of psychosocial stress with telomere shortening is unlikely to be mediated by a direct and universal glucocorticoid effect on telomere length.

Potential Preventive Strategies for Amyotrophic Lateral Sclerosis

It may seem useless to propose preventive measures for a disease without established pathogenesis and successful therapy, such as amyotrophic lateral sclerosis (ALS). However, we will show that ALS shares essential molecular mechanisms with aging and that established anti-aging strategies, such as healthy diet or individually adjusted exercise, may be successfully applied to ameliorate the condition of ALS patients. These strategies might be applied for prevention if persons at ALS risk could be identified early enough. Recent research advances indicate that this may happen soon.

Psychosocial Stressors and Telomere Length: A Current Review of the Science

A growing literature suggests that exposure to adverse social conditions may accelerate biological aging, offering one mechanism through which adversity may increase risk for age-related disease. As one of the most extensively studied biological markers of aging, telomere length (TL) provides a valuable tool to understand potential influences of social adversity on the aging process. Indeed, a sizeable literature now links a wide range of stressors to TL across the life span. The aim of this article is to review and evaluate this extant literature with a focus on studies that investigate psychosocial stress exposures and experiences in early life and adulthood. We conclude by outlining potential biological and behavioral mechanisms through which psychosocial stress may influence TL, and we discuss directions for future research in this area.

Religiosity, depression and telomere length in Chinese older adults

BACKGROUND

The mechanism explaining how religiosity is linked to telomere length (TL) is unclear. The current study examines depression as a possible mediator.

METHODS

In this cross-sectional study of 1,742 community-dwelling residents aged 55 or over, the Duke University Religion Index (DUREL) and Geriatric Depression Scale (GDS) were administrated during a routine health check. Peripheral blood leukocyte TL was determined using a q-PCR procedure. The Bootstrap methods PROCESS program was used to detect mediation.

RESULTS

After controlling for sociodemographic variables, the religiosity was positively correlated with TL (p<0.05) and negatively correlated with depressive symptom (p<0.001). Depressive symptoms, in turn, was negatively correlated with TL (p<0.05) in the overall sample. Depressive symptoms significantly mediated the relationship between religiosity and TL (explaining 31.8% of the total variance) in the 65 years and older subgroup (p = 0.015). No significant mediation was found in the 55-64 age subgroup.

LIMITATIONS

The cross-sectional design prevents making causal inferences. The non-random sampling method used in selecting participants may affect the external validity of the findings in terms of generalizing to Muslims throughout China or other religious groups. Potential mediators of the relationship between religiosity and TL and confounders such as physical health status, were not assessed.

CONCLUSION

Religiosity was positively associated with TL in older mainland Chinese adults, and this association was partially mediated by depressive symptom in the 65 or older age group. This finding helps to explain why religiosity is related to cellular aging in older adults.

Holocaust history is not reflected in telomere homeostasis in survivors and their offspring

Telomeres, nucleoprotein structures at the ends of eukaryotic chromosomes, are crucial for the maintenance of genome integrity. While the lengths of telomeres at birth are determined genetically, many factors including environmental and living conditions affect the telomere lengths during a lifespan. In this context, extreme and long-term stress has been shown to negatively impact telomeres and their protective function, with even offspring being influenced by the stress experienced by parents. Using quantitative PCR, the relative lengths of telomeres of survivors of the Holocaust during World War II and two generations of their offspring were analyzed. These data were related to those of control groups, persons of comparable age without a strong life stress experience. In contrast to previous studies of other stress-exposed groups, the relative lengths of telomeres were comparable in groups of persons exposed to Holocaust-related stress and their progenies, and in control groups. Interestingly, shorter telomeres of Holocaust survivors of the age under 12 in the year 1945 compared to Holocaust survivors of the age above 12 were detected. Our results are discussed with respect to certain exceptionality of persons having been able to cope with an extreme stress more than 70 years ago and living to a very old age.

Childhood maltreatment, behavioral adjustment, and molecular markers of cellular aging in preschool-aged children: A cohort study

OBJECTIVE

Childhood maltreatment is a major risk factor for the development of behavioral problems and poor physical and mental health. Accelerated cellular aging, through reduced telomere length and mitochondrial dysfunction, may be a mechanism underlying these associations.

METHODS

Families with (n = 133) and without (n = 123) child welfare documentation of moderate-severe maltreatment in the past six months participated in this study. Children ranged in age from 3 to 5 years, were racially and ethnically diverse, and 91% qualified for public assistance. Structured record review and interviews were used to assess a history of maltreatment and other adversities. Telomere length and mitochondrial DNA copy number (mtDNAcn) were measured from saliva DNA using real-time PCR. Measures were repeated at a six-month follow-up assessment. Repeated measures general linear models were used to examine the effects of maltreatment and other adversities on telomere length and mtDNAcn over time.

RESULTS

Maltreatment and other adverse experiences were significant positive predictors of both telomere length and mtDNAcn over time. Internalizing and externalizing behavior problems were also both significantly associated with telomere length, but only internalizing symptoms were associated with mtDNAcn.

CONCLUSIONS

This is the first study to show that mtDNAcn is altered in children with stress and trauma, and the findings are consistent with recent studies of adults. Surprisingly, children who experienced moderate-severe levels of maltreatment in the prior six months had longer telomeres, possibly reflecting compensatory changes in response to recent trauma. Telomere length and mtDNAcn were also associated with behavioral problems, suggesting that these measures of cellular aging may be causally implicated in the pathophysiology of stress-related conditions.

Religiosity and Telomere Length: Moderating Effect of Religiosity on the Relationship Between High-Risk Polymorphisms of the Apolipoprotein E and TOMM40 Gene and Telomere Length

Objective: The current study seeks to examine the relationship between religiosity and telomere length (TL) in an older Chinese Muslim sample and to explore the moderating effect of religiosity on the relationship between high-risk polymorphisms and TL. Methods: A cross-sectional study of 1,692 community-dwelling adults aged 55 or older was conducted. Apolipoprotein E and TOMM40 (rs2075650) gene polymorphisms and TL were determined using standard procedures. Ordinal logistic regression was used to examine the associations. Results: Religiosity was significantly and positively related to TL. A significant interaction emerged between religiosity and the rs2075650 G polymorphism in predicting TL. Stratified multivariate analyses demonstrated that the relationship between the rs2075650 G state and TL was particularly strong among those who were more religious, as hypothesized. Conclusion: The findings revealed that religiosity may influence cellular aging in part by modifying the effect that high-risk genes have on increasing vulnerability to dementia and cognitive impairment.

Adverse Childhood Experiences and Telomere Length a Look Into the Heterogeneity of Findings-A Narrative Review

Background: Adverse childhood experiences (ACEs) have been associated with poor mental and somatic health. Accumulating evidence indicates that accelerated biological aging-indexed by altered telomere-related markers-may contribute to associations between ACEs and negative long-term health outcomes. Telomeres are repeated, non-coding deoxyribonucleic acid (DNA) sequences at the end of chromosomes. Telomeres shorten during repeated cell divisions over time and are being used as a marker of biological aging. Objectives: The aim of the current paper is to review the literature on the relationship between ACEs and telomere length (TL), with a specific focus on how the heterogeneity of sample and ACEs characteristics lead to varying associations between ACEs and TL. Methods: Multiple databases were searched for relevant English peer-reviewed articles. Thirty-eight papers were found to be eligible for inclusion in the current review. Results: Overall, the studies indicated a negative association between ACEs and TL, although many papers presented mixed findings and about a quarter of eligible studies found no association. Studies with smaller sample sizes more often reported significant associations than studies with larger samples. Also, studies reporting on non-clinical and younger samples more often found associations between ACEs and TL compared to studies with clinical and older samples. Reviewing the included studies based on the "Stressor Exposure Characteristics" recently proposed by Epel et al. (2018) revealed a lack of detailed information regarding ACEs characteristics in many studies. Conclusion: Overall, it is difficult to achieve firm conclusions about associations of ACEs with TL due to the heterogeneity of study and ACE characteristics and the heterogeneity in reported findings. The field would benefit from more detailed descriptions of study samples and measurement of ACEs.

Cold parenting is associated with cellular aging in offspring: A retrospective study

BACKGROUND

Early life stress is a known risk factor for diseases and premature death. We tested whether parenting style impacts telomere length (TL), a cellular aging biomarker.

METHODS

Information on parents' style of parenting was obtained from 199 participants in the Adventist Health Study-1 (AHS-1) who 27+ years later also enrolled in the AHS-2 where blood was collected for relative TL (rTL) assessment.

RESULTS

Subjects describing their mothers' parenting style as cold had on average 25% smaller rTL compared to subjects not reporting a cold mother (1.89 vs 2.53). This association was greatest among those with less education, and those who stayed overweight/obese or put on weight during follow-up.

CONCLUSIONS

These results support previous findings that early life stress may have health implications by promoting cellular aging, and expands these stressors to include cold parenting during an individuals' formative years. Higher education and normal weight seem to provide some resilience.

Association of psychosocial factors with leukocyte telomere length among African Americans in the Jackson Heart Study

Leukocyte telomere length (LTL) is a biomarker of cellular aging. African Americans report more stress than other groups; however, the association of psychosocial stressors with biological aging among African Americans remains unclear. The current study evaluated the association of psychosocial factors (negative affect and stressors) with LTL in a large sample of African American men and women (n = 2,516) from the Jackson Heart Study. Using multivariable linear regression, we examined the sex-specific associations of psychosocial factors (cynical distrust, anger in and out, depressive symptoms, negative affect summary scores, global stress, weekly stress, major life events, and stress summary scores) with LTL. Model 1 adjusted for demographics and education. Model 2 adjusted for model 1, smoking, alcohol intake, physical activity, diabetes, hypertension, and high-sensitivity C-reactive protein. Among women, high (vs. low) cynical distrust was associated with shorter mean LTL in model 1 (b = -0.12; p = 0.039). Additionally, high (vs. low) anger out and expressed negative affect summary scores were associated with shorter LTL among women after full adjustment (b = -0.13; p = 0.011; b = -0.12, p = 0.031, respectively). High levels of cynical distrust, anger out, and negative affect summary scores may be risk factors for shorter LTL, particularly among African-American women.

Stress and Salivary Telomere Length in the Second Half of Life: A Comparison of Life-course Models

Background

Previous research has explored the relationship between childhood and adulthood stressful life events (SLEs) and adult salivary telomere length (TL), but no research to date has tested different life-course models in which stress in adulthood may fully, partly, or not mediate the relationship between childhood stress and adult TL.

Methods

To fill this gap, we elaborate over previous work by Puterman et al. (2016) and other standard models that do not account for the temporal order of stressors in childhood and adulthood, by using structural equation modeling (SEM) for a sample of 5,754 Health and Retirement Study (HRS) participants to compare the fit of three nested life-course models-social trajectory, early critical period, and cumulative risk.

Results

Results indicated that the social trajectory model, in which the association between childhood SLEs and TL in later adulthood is fully mediated by adulthood SLEs, fit the data better than the early critical period (no mediation) and cumulative risk (partial mediation) models.

Conclusion

In the social trajectory model, childhood SLEs are related to TL in later life only through adulthood SLEs. The direct physiological effect of childhood SLEs on TL in later life would be overestimated if adulthood SLEs are overlooked.

Enhanced Molecular Appreciation of Psychiatric Disorders Through High-Dimensionality Data Acquisition and Analytics

The initial diagnosis, molecular investigation, treatment, and posttreatment care of major psychiatric disorders (schizophrenia and bipolar depression) are all still significantly hindered by the current inability to define these disorders in an explicit molecular signaling manner. High-dimensionality data analytics, using large datastreams from transcriptomic, proteomic, or metabolomic investigations, will likely advance both the appreciation of the molecular nature of major psychiatric disorders and simultaneously enhance our ability to more efficiently diagnose and treat these debilitating conditions. High-dimensionality data analysis in psychiatric research has been heterogeneous in aims and methods and limited by insufficient sample sizes, poorly defined case definitions, methodological inhomogeneity, and confounding results. All of these issues combine to constrain the conclusions that can be extracted from them. Here, we discuss possibilities for overcoming methodological challenges through the implementation of transcriptomic, proteomic, or metabolomics signatures in psychiatric diagnosis and offer an outlook for future investigations. To fulfill the promise of intelligent high-dimensionality data-based differential diagnosis in mental disease diagnosis and treatment, future research will need large, well-defined cohorts in combination with state-of-the-art technologies.

A scoping systematic review of social stressors and various measures of telomere length across the life course

Numerous studies examine the relationship between social stressors and telomere length (TL). Beyond considering methods and major findings, this scoping systematic review takes a novel approach as it groups studies according to the types of social stressor considered and by age groups. Following PRISMA guidelines, we searched PubMed, Web of Science, Embase, and Scopus. We included all English-language human subject research articles that modeled any measure of TL as a dependent variable and exposure to a social stressor as an independent variable. For the sample of 105 articles, we summarized methods and findings by type of social stressor (socioeconomic stressors, stressful life events, work-related stressors, and neighborhood stressors) and by age of the study population (infants/children, middle-aged adults, older adults, and mixed samples of middle-aged and older adults). We found more variation in TL measurement methodology in studies of infants/children and older adults than in studies focusing on middle-aged adults. The most consistent finding was a relationship between early-life stressors and shorter TL. Work and neighborhood stressors, and older populations, are currently understudied. Across all stressors, limited evidence suggests that the stress-TL relationship may be moderated by characteristics such as age, sex, and race/ethnicity. We conclude with specific suggestions for future research.

Body mass index is negatively associated with telomere length: a collaborative cross-sectional meta-analysis of 87 observational studies

Background

Even before the onset of age-related diseases, obesity might be a contributing factor to the cumulative burden of oxidative stress and chronic inflammation throughout the life course. Obesity may therefore contribute to accelerated shortening of telomeres. Consequently, obese persons are more likely to have shorter telomeres, but the association between body mass index (BMI) and leukocyte telomere length (TL) might differ across the life span and between ethnicities and sexes.

Objective

A collaborative cross-sectional meta-analysis of observational studies was conducted to investigate the associations between BMI and TL across the life span.

Design

Eighty-seven distinct study samples were included in the meta-analysis capturing data from 146,114 individuals. Study-specific age- and sex-adjusted regression coefficients were combined by using a random-effects model in which absolute [base pairs (bp)] and relative telomere to single-copy gene ratio (T/S ratio) TLs were regressed against BMI. Stratified analysis was performed by 3 age categories ("young": 18-60 y; "middle": 61-75 y; and "old": >75 y), sex, and ethnicity.

Results

Each unit increase in BMI corresponded to a -3.99 bp (95% CI: -5.17, -2.81 bp) difference in TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -7.67 bp (95% CI: -10.03, -5.31 bp) difference. Each unit increase in BMI corresponded to a -1.58 × 10(-3) unit T/S ratio (0.16% decrease; 95% CI: -2.14 × 10(-3), -1.01 × 10(-3)) difference in age- and sex-adjusted relative TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -2.58 × 10(-3) unit T/S ratio (0.26% decrease; 95% CI: -3.92 × 10(-3), -1.25 × 10(-3)). The associations were predominantly for the white pooled population. No sex differences were observed.

Conclusions

A higher BMI is associated with shorter telomeres, especially in younger individuals. The presently observed difference is not negligible. Meta-analyses of longitudinal studies evaluating change in body weight alongside change in TL are warranted.

Early life adversity and telomere length: a meta-analysis

Early adversity, in the form of abuse, neglect, socioeconomic status and other adverse experiences, is associated with poor physical and mental health outcomes. To understand the biologic mechanisms underlying these associations, studies have evaluated the relationship between early adversity and telomere length, a marker of cellular senescence. Such results have varied in regard to the size and significance of this relationship. Using meta-analytic techniques, we aimed to clarify the relationship between early adversity and telomere length while exploring factors affecting the association, including adversity type, timing and study design. A comprehensive search in July 2016 of PubMed/MEDLINE, PsycINFO and Web of Science identified 2462 studies. Multiple reviewers appraised studies for inclusion or exclusion using a priori criteria; 3.9% met inclusion criteria. Data were extracted into a structured form; the Newcastle-Ottawa Scale assessed study quality, validity and bias. Forty-one studies (N=30 773) met inclusion criteria. Early adversity and telomere length were significantly associated (Cohen's d effect size=-0.35; 95% CI, -0.46 to -0.24; P<0.0001). Sensitivity analyses revealed no outlier effects. Adversity type and timing significantly impacted the association with telomere length (P<0.0001 and P=0.0025, respectively). Subgroup and meta-regression analyses revealed that medication use, medical or psychiatric conditions, case-control vs longitudinal study design, methodological factors, age and smoking significantly affected the relationship. Comprehensive evaluations of adversity demonstrated more extensive telomere length changes. These results suggest that early adversity may have long-lasting physiological consequences contributing to disease risk and biological aging.

The fetal programming of telomere biology hypothesis: an update

Research on mechanisms underlying fetal programming of health and disease risk has focused primarily on processes that are specific to cell types, organs or phenotypes of interest. However, the observation that developmental conditions concomitantly influence a diverse set of phenotypes, the majority of which are implicated in age-related disorders, raises the possibility that such developmental conditions may additionally exert effects via a common underlying mechanism that involves cellular/molecular ageing-related processes. In this context, we submit that telomere biology represents a process of particular interest in humans because, firstly, this system represents among the most salient antecedent cellular phenotypes for common age-related disorders; secondly, its initial (newborn) setting appears to be particularly important for its long-term effects; and thirdly, its initial setting appears to be plastic and under developmental regulation. We propose that the effects of suboptimal intrauterine conditions on the initial setting of telomere length and telomerase expression/activity capacity may be mediated by the programming actions of stress-related maternal-placental-fetal oxidative, immune, endocrine and metabolic pathways in a manner that may ultimately accelerate cellular dysfunction, ageing and disease susceptibility over the lifespan. This perspectives paper provides an overview of each of the elements underlying this hypothesis, with an emphasis on recent developments, findings and future directions.This article is part of the theme issue 'Understanding diversity in telomere dynamics'.

Childhood adversity, social support, and telomere length among perinatal women

Adverse perinatal health outcomes are heightened among women with psychosocial risk factors, including childhood adversity and a lack of social support. Biological aging could be one pathway by which such outcomes occur. However, data examining links between psychosocial factors and indicators of biological aging among perinatal women are limited. The current study examined the associations of childhood socioeconomic status (SES), childhood trauma, and current social support with telomere length in peripheral blood mononuclear cells (PBMCs) in a sample of 81 women assessed in early, mid, and late pregnancy as well as 7-11 weeks postpartum. Childhood SES was defined as perceived childhood social class and parental educational attainment. Measures included the Childhood Trauma Questionnaire, Center for Epidemiologic Studies-Depression Scale, Multidimensional Scale of Perceived Social Support, and average telomere length in PBMCs. Per a linear mixed model, telomere length did not change across pregnancy and postpartum visits; thus, subsequent analyses defined telomere length as the average across all available timepoints. ANCOVAs showed group differences by perceived childhood social class, maternal and paternal educational attainment, and current family social support, with lower values corresponding with shorter telomeres, after adjustment for possible confounds. No effects of childhood trauma or social support from significant others or friends on telomere length were observed. Findings demonstrate that while current SES was not related to telomeres, low childhood SES, independent of current SES, and low family social support were distinct risk factors for cellular aging in women. These data have relevance for understanding potential mechanisms by which early life deprivation of socioeconomic and relationship resources affect maternal health. In turn, this has potential significance for intergenerational transmission of telomere length. The predictive value of markers of biological versus chronological age on birth outcomes warrants investigation.

Stress, depressive status and telomere length: Does social interaction and coping strategy play a mediating role?

BACKGROUND

Telomeres have been reported to be shorter in individuals exposed to psychosocial stress and in those with depression. Since negative environmental stress is a risk factor for depression, the present study tested whether stressors in childhood (CA) and recent adulthood (NLE) predicted telomere attrition directly and/or indirectly through individuals' depressive status 3-6 years before TL measurement; and then if social interaction and coping strategies in adulthood influenced the relationship between depressive status and TL.

METHODS

Participants were 337 individuals with a recent depression diagnosis and 574 screened controls that derived from a longitudinal population-based cohort study conducted in Stockholm, Sweden. Relative TL was determined using qPCR. Relationships between the key variables stressors, depressive status, social interaction, coping strategies and TL were explored by path analysis in males and females, adjusting for age.

RESULTS

The key variables were correlated in expected directions. In females, depressive status and age had direct negative effects on TL (p < 0.05) and both CA (p = 0.025) and NLE (p < 0.003) had indirect negative effects on TL. For males, the effects of stressors and depressive status on TL were mediated by social interaction (p = 0.005) and the coping strategy worry (p = 0.005). In females, no mediation effect of social interaction and coping strategy was detected.

LIMITATIONS

Only little of the TL variation was explained by the models. The environmental stress information was limited.

CONCLUSION

Our findings propose gender-specific paths from environmental stressors through depressive status, social interaction and coping strategy to TL.

Childhood maltreatment and HIV-associated neurocognitive disorders share similar pathophysiology: a potential sensitisation mechanism?

HIV-associated neurocognitive disorders (HAND) are increasingly prevalent despite the use of antiretroviral therapies. Previous research suggests that individual host factors play an important role in determining susceptibility to HAND. In this review, we propose that childhood trauma (CT) and HAND share several common aetiological mechanisms, namely hypothalamic-pituitary-adrenal axis dysregulation, neuroinflammation and oxidative stress. These convergent and consequent mechanisms may translate into an increased risk of developing HAND in individuals who have experienced early life stress. We provide an overview of basic and clinical research relating to these pathophysiological mechanisms and suggest that further research examine brain-derived neurotrophic factor and telomere length as common mediating factors and potential therapeutic targets for HAND and CT. Graphical abstract Both childhood trauma and HIV-associated neurocognitive disorders are associated with HPA axis dysregulation, inflammation and oxidative stress.

Association between childhood trauma and accelerated telomere erosion in adulthood: A meta-analytic study

BACKGROUND

Childhood trauma has long-term sequelae on health status and contributes to numbers of somatic and mental disorders in later life. Findings from experimental studies in animals suggest that telomere erosion may be a mediator of this relationship. However, results from human studies are heterogeneous. To address these inconsistencies, we performed a meta-analysis regarding the association between childhood trauma and telomere length in adulthood.

METHOD

Articles were identified by systematically searching the Medline, EMBASE and Web of Science databases. Twenty four studies, which include twenty six sample sets and 30,919 participants, met the inclusion criteria for meta-analyses.

RESULTS

This meta-analyses revealed that individuals experienced childhood trauma have accelerated telomere erosion in adulthood, with a small effect size (r = -0.05, 95% CI = -0.08-0.03, p < 0.001). Subgroup analyses by type of childhood trauma revealed a trend in difference between groups (Q = 5.24, p = 0.07). Analyses for individual trauma types revealed a significant association between childhood separation and telomere erosion (r = -0.09, p < 0.001), but not for physical abuse, sexual abuse and loss of a parent.

CONCLUSION

This meta-analysis demonstrated a significant association between childhood trauma and accelerated telomere erosion in adulthood, and further revealed that different trauma types have various impacts on telomere. Additional research on the mechanism that links the individual types of childhood trauma with telomere is needed in the future.

Telomere length in alcohol dependence: A role for impulsive choice and childhood maltreatment

Telomere shortening, a marker of cellular aging, has been considered to be linked with psychosocial stress as well as with chronic alcohol consumption, possibly mediated by oxidative stress and inflammatory response. Recent findings suggested that early life adversity on telomere dynamics may be related to impulsive choice. To further our understanding of the association of impulsive choice and childhood trauma on telomere length, we examined whether delayed discounting and childhood trauma or their interaction is related to leukocyte telomere length, while controlling for multiple potential confounding variables, in patients with alcohol dependence who are considered to have higher impulsive choice and shorter telomere length. We recruited 253 male patients with chronic alcohol dependence. All participants performed the delay discounting task, and the area under curve was used as a measure of delay discounting. Steeper delay discounting represents more impulsive choices. The modified Parent-Child Conflict Tactics Scale was used to measure childhood maltreatment. In addition, confounding factors, including socio-demographic characteristics, the Alcohol Use Disorders Identification Test, the Buss-Perry Aggression Questionnaire, the Resilience Quotient, the Beck Depression Inventory, and the Beck Anxiety Inventory, were also assessed. Hierarchical regression analyses showed a significant main effect of delay discounting (β=0.161, t=2.640, p=0.009), and an interaction effect between delay discounting and childhood maltreatment on leukocyte telomere length (β=0.173, t=2.138, p=0.034). In subsequent analyses stratified by childhood maltreatment, patients with alcohol dependence and high childhood trauma showed a significant relationship between delay discounting and leukocyte telomere length (β=0.279, t=3.183, p=0.002), while those with low trauma showed no association between them. Our findings suggest that higher impulsive choice is associated with shorter telomere length, and childhood trauma may exert a moderating effect in the relationship between impulsive choice and telomere length.

The effects of early life adversity on the immune system

Early life adversity (ELA) is associated with a higher risk for diseases in adulthood. Although the pathophysiological effects of ELA are varied, there may be a unifying role for the immune system in all of the long-term pathologies such as chronic inflammatory disorders (autoimmune diseases, allergy, and asthma). Recently, significant efforts have been made to elucidate the long-term effects ELA has on immune function, as well as the mechanisms underlying these immune changes. In this review, we focus on data from human studies investigating immune parameters in relation to post-natal adverse experiences. We describe the current understanding of the 'ELA immune phenotype', characterized by inflammation, impairment of the cellular immune system, and immunosenescence. However, at present, data addressing specific immune functions are limited and there is a need for high-quality, well powered, longitudinal studies to unravel cause from effect. Besides the immune system, also the stress system and health behaviors are altered in ELA. We discuss probable underlying mechanisms based on epigenetic programming that could explain the ELA immune phenotype and whether this is a direct effect of immune programming or an indirect consequence of changes in behavior or stress reactivity. Understanding the underlying mechanisms will help define effective strategies to prevent or counteract negative ELA-associated outcomes.

The Relationship Between Childhood Psychosocial Stressor Level and Telomere Length: A Meta-Analysis

This meta-analysis examined the association between the level of childhood psychosocial stressors and telomere length, an important health biomarker. The meta-analysis, including 27 samples and 16,238 participants, found a significant association of -0.08 between a higher level of childhood stressors and shorter telomere length at a mean age of 42 across studies. Moderator analyses showed a trend in the direction of effect sizes being significantly larger with shorter times between the stressors and telomere measurement. Moderator analyses showed significantly higher effect sizes for studies that used a categorical method for assessing child stressor level and for assays completed with qPCR rather than with the Southern blot method. There was no significant moderation of effect size by whether study assayed leukocytes or buccal cells, whether the study assessed child stressor level by memory-based recall versus archival records, and whether the study controlled for age, sex, or additional variables. The results, focused on childhood events, add to prior findings that perceived stress and negative emotions are associated with telomere length.

The Longitudinal Relationship Between Cortisol Responses to Mental Stress and Leukocyte Telomere Attrition

CONTEXT

Chronic psychological stress has been associated with shorter telomeres, but the underlying mechanisms are poorly understood. One possibility is that the neuroendocrine responses to stress exposure are involved.

OBJECTIVE

To test the hypothesis that greater cortisol responsivity to acute stressors predicts more rapid telomere attrition.

DESIGN

We measured salivary cortisol responses to 2 challenging behavioral tasks. Leukocyte telomere length was measured at the time of mental stress testing and 3 years later.

PARTICIPANTS

We studied 411 initially healthy men and women aged 54 to 76 years.

MAIN OUTCOME MEASURE

Leukocyte telomere length.

RESULTS

Cortisol responses to this protocol were small; we divided participants into cortisol responders (n = 156) and nonresponders (n = 255) using a criterion (≥20% increase in cortisol concentration) previously shown to predict increases in cardiovascular disease risk. There was no significant association between cortisol responsivity and baseline telomere length, although cortisol responders tended to have somewhat shorter telomeres (β = -0.061; standard error, 0.049). But cortisol responders had shorter telomeres and more rapid telomere attrition than nonresponders on follow-up, after controlling statistically for age, sex, socioeconomic status, smoking, time of day of stress , and baseline telomere length (β = -0.10; standard error, 0.046; P = 0.029). The association was maintained after additional control for cardiovascular risk factors (β = -0.11; P = 0.031). The difference between cortisol responders and nonresponders was equivalent to approximately 2 years in aging.

CONCLUSIONS

These findings suggest that cortisol responsivity may mediate, in part, the relationship between psychological stress and cellular aging.

Transcriptomic analyses and leukocyte telomere length measurement in subjects exposed to severe recent stressful life events

Stressful life events occurring in adulthood have been found able to affect mood and behavior, thus increasing the vulnerability for several stress-related psychiatric disorders. However, although there is plenty of clinical data supporting an association between stressful life events in adulthood and an enhanced vulnerability for psychopathology, the underlying molecular mechanisms are still poorly investigated. Thus, in this study we performed peripheral/whole-genome transcriptomic analyses in blood samples obtained from 53 adult subjects characterized for recent stressful life events occurred within the previous 6 months. Transcriptomic data were analyzed using Partek Genomics Suite; pathway and network analyses were performed using Ingenuity Pathway Analysis and GeneMANIA Software. We found 207 genes significantly differentially expressed in adult subjects who reported recent stressful life experiences (n=21) compared with those without such experiences (n=32). Moreover, the same subjects exposed to such stressful experiences showed a reduction in leukocyte telomere length. A correlation analyses between telomere length and transcriptomic data indicated an association between the exposures to recent stressful life events and the modulation of several pathways, mainly involved in immune-inflammatory-related processes and oxidative stress, such as natural killer cell signaling, interleukin-1 (IL-1) signaling, MIF regulation of innate immunity and IL-6 signaling. Our data suggest an association between exposures to recent stressful life events in adulthood and alterations in the immune, inflammatory and oxidative stress pathways, which could be also involved in the negative effect of stressful life events on leukocyte telomere length. The modulation of these mechanisms may underlie the clinical association between the exposure to recent Stressful life events in adulthood and an enhanced vulnerability to develop psychiatric diseases in adulthood.

Processes Linking Religious Involvement and Telomere Length

Although numerous studies suggest that religious involvement is associated with better health and longer life expectancies, it is unclear whether these general patterns extend to cellular aging. The mechanisms linking indicators of religious involvement with indicators of cellular aging are also undefined. We employed longitudinal data from the 2004 and 2008 Health and Retirement Study, a national probability sample of Americans aged 50 and older, to test whether average telomere length varied according to level of religious attendance. We also tested several potential mechanisms. Our results showed that respondents who attended religious services more frequently in 2004 also exhibited fewer stressful events, lower rates of smoking, fewer symptoms of depression, and lower levels of C-reactive protein in 2008. Respondents who increased their level of attendance from 2004 to 2008 also exhibited lower rates of smoking in 2008. Although religious attendance was not directly associated with telomere length, our mediation analyses revealed significant indirect effects through depression and smoking, but not stressful events or C-reactive protein. We conclude that religious attendance may promote telomere length indirectly by reducing symptoms of depression and the risk of smoking. There was no evidence to support stressful events or C-reactive protein as mechanisms of religious attendance.

Stressful life events and leucocyte telomere length: Do lifestyle factors, somatic and mental health, or low grade inflammation mediate this relationship? Results from a cohort of Danish men born in 1953

Exposure to psychosocial stress is associated with increased risk of a number of somatic and mental disorders with relation to immune system functioning. We aimed to explore whether stressful events in early and recent life was associated with leucocyte telomere length (TL), which is assumed to reflect the accumulated burden of inflammation and oxidative stress occurring during the life course. We specifically aimed to address whether childhood constitutes a sensitive period and how much of the relation between stressful life events and TL is mediated through somatic and mental health, lifestyle, and markers of low-grade inflammation. A cohort of Danish men born in 1953 has been followed since birth in the Metropolit Cohort. These men underwent a health examination including blood sampling in 2010 and a subset of 324 also had a quantitative PCR-based measurement of TL. The relation between stressful life events and TL was analysed using structural equation modelling, which also provided an estimate of the proportion of the total effect mediated by somatic and mental health (cardiovascular disease, body mass and depressive mood), lifestyle factors, and low grade inflammation (C-reactive protein (CRP), interleukin (IL)-6 and IL-10). Total number of stressful events experienced during the life course was not associated with TL. In terms of sensitive periods, we found that number of stressful events in childhood was associated with shorter TL (β_{per number stressful events in childhood}=-0.02(SE=-0.02); P=0.05). This relation was particularly strong for being placed away from home (β=-0.16; P<0.000). Thirty percent of the total effect of stressful events in childhood on TL was mediated by the included variables, with the largest proportion being mediated through depressive mood (16%) and CRP (9%). This study suggests that stressful events in childhood are associated with shorter TL in middle-aged men and that part of this relation is explained by depressive mood and low grade inflammation.

Life stress, glucocorticoid signaling, and the aging epigenome: Implications for aging-related diseases

Life stress has been associated with accelerated cellular aging and increased risk for developing aging-related diseases; however, the underlying molecular mechanisms remain elusive. A highly relevant process that may underlie this association is epigenetic regulation. In this review, we build upon existing evidence to propose a model whereby exposure to life stress, in part via its effects on the hypothalamic-pituitary axis and the glucocorticoid signaling system, may alter the epigenetic landscape across the lifespan and, consequently, influence genomic regulation and function in ways that are conducive to the development of aging-related diseases. This model is supported by recent studies showing that life stressors and stress-related phenotypes can accelerate epigenetic aging, a measure that is based on DNA methylation prediction of chronological age and has been associated with several aging-related disease phenotypes. We discuss the implications of this model for the prevention and treatment of aging-related diseases, as well as the challenges and limitations of this line of research.

Dimensions of religious involvement and leukocyte telomere length

Although numerous studies suggest that religious involvement is associated with a wide range of favorable health outcomes, it is unclear whether this general pattern extends to cellular aging. In this paper, we tested whether leukocyte telomere length varies according to several dimensions of religious involvement. We used cross-sectional data from the Nashville Stress and Health Study (2011-2014), a large probability sample of 1252 black and white adults aged 22 to 69 living in Davidson County, TN, USA. Leukocyte telomere length was measured using the monochrome multiplex quantitative polymerase chain reaction method with albumin as the single-copy reference sequence. Dimensions of religious involvement included religiosity, religious support, and religious coping. Our multivariate analyses showed that religiosity (an index of religious attendance, prayer frequency, and religious identity) was positively associated with leukocyte telomere length, even with adjustments for religious support, religious coping, age, gender, race, education, employment status, income, financial strain, stressful life events, marital status, family support, friend support, depressive symptoms, smoking, heavy drinking, and allostatic load. Unlike religiosity, religious support and religious coping were unrelated to leukocyte telomere length across models. Depressive symptoms, smoking, heavy drinking, and allostatic load failed to explain any of the association between religiosity and telomere length. To our knowledge, this is the first population-based study to link religious involvement and cellular aging. Although our data suggest that adults who frequently attend religious services, pray with regularity, and consider themselves to be religious tend to exhibit longer telomeres than those who attend and pray less frequently and do not consider themselves to be religious, additional research is needed to establish the mechanisms underlying this association.

Systematic review of the association between chronic social stress and telomere length: A life course perspective

Our aim was to examine whether chronic social stress is associated with telomere length throughout the life course, following our protocol published in 2014. Structured searches were conducted in MEDLINE (PubMed interface), EMBASE (OVID interface), Cochrane Central (OVID interface) and grey from their start date onwards. Reference lists of retrieved citations were hand searched for relevant studies. Eighteen studies published until May 1, 2015 investigating the association between chronic social stress (as defined by poverty, exposure to violence, or family caregiving) and telomere length in healthy or diseased adults and children were independently selected by 2 reviewers. Sixteen of those studies were cross-sectional and two had a longitudinal design. Studies differed in type of stress exposure, method to measure telomere length and cell type. As meta-analysis could not be conducted, the data were synthesized as a narrative review. Based on this comprehensive review, chronic social stress accompanies telomere shortening in both early and adult exposures, with most eligible studies showing a significant relationship. We discuss the significance of chronic stress of social origin and the potential for social interventions through public policies and we recommend methodological improvements that would allow for future meta-analysis.

Early and recent psychosocial stress and telomere length in older adults

BACKGROUND

Psychosocial stress has been associated with an increased risk for mental and somatic health problems across the life span. Some studies in younger adults linked this to accelerated cellular aging, indexed by shortened telomere length (TL). In older adults, the impact of psychosocial stress on TL may be different due to the lifetime exposure to competing causes of TL-shortening. This study aims to assess whether early and recent psychosocial stressors (childhood abuse, childhood adverse events, recent negative life events, and loneliness) were associated with TL in older adults.

METHODS

Data were from the Netherlands Study of Depression in Older Persons (NESDO) in which psychosocial stressors were measured in 496 persons aged 60 and older (mean age 70.6 (SD 7.4) years) during a face-to-face interview. Leukocyte TL was determined using fasting blood samples by performing quantitative polymerase chain reaction (qPCR) and was expressed in base pairs (bp).

RESULTS

Multiple regression analyses, adjusted for age, sex, and chronic diseases, showed that childhood abuse, recent negative life events and loneliness were unrelated to TL. Only having experienced any childhood adverse event was weakly but significantly negatively associated with TL.

CONCLUSIONS

Our findings did not consistently confirm our hypothesis that psychosocial stress is associated with shorter TL in older adults. Healthy survivorship or other TL-damaging factors such as somatic health problems seem to dominate a potential effect of psychosocial stress on TL in older adults.

Antioxidants safeguard telomeres in bold chicks

Telomeres are sensitive to damage induced by oxidative stress, and thus it is expected that dietary antioxidants may support the maintenance of telomere length in animals, particularly those with a fast rate of life (e.g. fast metabolism, activity and growth). We tested experimentally the effect of antioxidant supplements on telomere length during early development in wild gull chicks with natural individual variations in behaviour pattern and growth rate. Proactive chicks had shorter telomeres than reactive chicks, but the penalty for the bold behaviour pattern was reduced by antioxidant supplementation. Chicks growing faster had longer telomeres during early growth, suggesting that inherited quality supports a fast life history.

Alterations of Mitochondrial DNA Copy Number and Telomere Length With Early Adversity and Psychopathology

BACKGROUND

Telomere shortening and alterations of mitochondrial biogenesis are involved in cellular aging. Childhood adversity is associated with telomere shortening, and several investigations have shown short telomeres in psychiatric disorders. Recent studies have examined whether mitochondria might be involved in neuropsychiatric conditions; findings are limited and no prior work has examined this in relation to stress exposure.

METHODS

Two-hundred ninety healthy adults provided information on childhood parental loss and maltreatment and completed diagnostic interviews. Participants were categorized into four groups based upon the presence or absence of childhood adversity and the presence or absence of lifetime psychopathology (depressive, anxiety, and substance use disorders). Telomere length and mitochondrial DNA (mtDNA) copy number were measured from leukocyte DNA by quantitative polymerase chain reaction.

RESULTS

Childhood adversity and lifetime psychopathology were each associated with shorter telomeres (p < .01) and higher mtDNA copy numbers (p < .001). Significantly higher mtDNA copy numbers and shorter telomeres were seen in individuals with major depression, depressive disorders, and anxiety disorders, as well as those with parental loss and childhood maltreatment. A history of substance disorders was also associated with significantly higher mtDNA copy numbers.

CONCLUSIONS

This study provides the first evidence of an alteration of mitochondrial biogenesis with early life stress and with anxiety and substance use disorders. We replicate prior work on telomere length and psychopathology and show that this effect is not secondary to medication use or comorbid medical illness. Finally, we show that early life stress and psychopathology are each associated with these markers of cellular aging.

Posttraumatic Stress Disorder, Adverse Childhood Events, and Buccal Cell Telomere Length in Elderly Swiss Former Indentured Child Laborers

Posttraumatic stress disorder (PTSD) is associated with increased risk for age-related diseases and early mortality. Accelerated biological aging could contribute to this elevated risk. The aim of the present study was to assess buccal cell telomere length (BTL) - a proposed marker of biological age - in men and women with and without PTSD. The role of childhood trauma was assessed as a potential additional risk factor for shorter telomere length. The sample included 62 former indentured Swiss child laborers (age: M = 76.19, SD = 6.18) and 58 healthy controls (age: M = 71.85, SD = 5.97). Structured clinical interviews were conducted to screen for PTSD and other psychiatric disorders. The Childhood Trauma Questionnaire (CTQ) was used to assess childhood trauma exposure. Quantitative polymerase chain reaction was used to measure BTL. Covariates include age, sex, years of education, self-evaluated financial situation, depression, and mental and physical functioning. Forty-eight (77.42%) of the former indentured child laborers screened positive for childhood trauma, and 21 (33.87%) had partial or full-blown PTSD. Results did not support our hypotheses that PTSD and childhood trauma would be associated with shorter BTL. In fact, results revealed a trend toward longer BTL in participants with partial or full PTSD [F(2,109) = 3.27, p = 0.04, η(2) = 0.06], and longer BTL was marginally associated with higher CTQ scores (age adjusted: β = 0.17 [95% CI: -0.01 to 0.35], t = 1.90, p = 0.06). Furthermore, within-group analyses indicated no significant association between BTL and CTQ scores. To the best of our knowledge, this is the first study exploring the association between childhood trauma and BTL in older individuals with and without PTSD. Contrary to predictions, there were no significant differences in BTL between participants with and without PTSD in our adjusted analyses, and childhood adversity was not associated with BTL. Possible explanations and future research possibilities are discussed.

hTERT genetic variation in depression

BACKGROUND

Telomeres are protective DNA-protein complexes forming the chromosome ends. TL differs between tissues. Shorter telomere length (TL) in blood leukocytes (LTL) has been associated with major depression, and with previous exposure to childhood adversity. TL studies on non-invasively sampled salivary DNA are less common. Telomerase, with its catalytic subunit hTERT, counteracts telomere shortening. Reduced telomerase activity associates with depression-like behavior in mice. Recently, the minor allele of the hTERT polymorphism rs2736100 was associated with shorter LTL among primarily healthy individuals. We hypothesized that (i) TL in saliva DNA is shortened in adults with a history of depression, and that (ii) rs2736100 is implicated in depression and depressive episodes in bipolar disorder type 1 (BD1).

METHODS

Individuals with a history of depression and those without (controls) were identified using self-reported questionnaires from a well-characterized population-based cohort. Clinical BD1 patients were diagnosed by specialized psychiatrists. Saliva TL was measured in age-matched depressed individuals and controls (n=662) using qRT-PCR. rs2736100 was genotyped in 436 depressed individuals, 1590 controls, and 368 BD1 patients.

RESULTS

Saliva TL was shorter in depressed individuals compared to controls. The rs2736100 minor allele was associated with depression among those without experience of childhood adversity, and with number of depressive episodes in BD1 patients responding well to lithium.

LIMITATION

Psychopathological symptoms were recorded at two time points only, 3 and 6 years prior to DNA sampling.

CONCLUSIONS

This is the first report on hTERT genetic variation in mood disorder. It proposes that genetic variation in hTERT may influence the susceptibility to depression.

The Preeminence of Early Life Trauma as a Risk Factor for Worsened Long-Term Health Outcomes in Women

Early life trauma (ELT) comprises an array of disturbingly common distressing experiences between conception and the beginning of adulthood with numerous and significant potential long-term, even transgenerational, health consequences of great public health concern, including depression, cardiovascular disease, and other psychiatric and medical disorders, and neurobiological, psychological, and behavioral effects which are sufficiently robust to confound many types of biomedical research. The impact of ELT on a woman's health trajectory appears to vary with the specific characteristics of the ELT (e.g., type, number of different types, severity, and timing), the individual (e.g., age, genetics, epigenetics, personality, and cognitive factors), and the individual's environment (e.g., level of social support and ongoing stressors) and to be mediated to a significant extent by persistent changes in a number of biological systems, dysregulation of those governing the stress response chief among them. Growing knowledge of the risk factors and pathophysiological mechanisms by which ELT confers diathesis to various poor health outcomes and the unique treatment-response profiles of women with ELT will lead to much needed improvements in prevention, diagnostic, and therapeutic efforts, including more effective psychotherapy and pharmacotherapy approaches, hopefully making strides toward improvements in the lives of women everywhere and ending countless cycles of intergenerational trauma-associated pathology. This article attempts to broadly summarize the current state of knowledge about the long-term sequelae of ELT for women's health.

The Association of Early and Recent Psychosocial Life Stress With Leukocyte Telomere Length

OBJECTIVES

Chronic exposure to psychosocial stressors is related to worse somatic health. This association applies both to stressors early in life, such as childhood adversities, and more recent life stress, such as stressful life events. This study examined whether accelerated telomere shortening, as an indicator of cellular aging, might be an explanatory mechanism.

METHODS

We examined whether childhood adversities and recent stressful life events were associated with shorter telomeres in 2936 participants (mean [standard deviation] age = 41.8 [13.1] years, 66% women, 57% current depression) of the Netherlands Study of Depression and Anxiety. Telomeres are specialized nucleic acid-protein complexes at the ends of linear DNA that shorten with age; telomere length (TL) was measured with quantitative polymerase chain reaction.

RESULTS

Childhood life events (β = .004, p = .805) and childhood trauma (β = -.023, p = .205) were not related to shorter TL. However, we found negative associations between recent stressful life events and TL. Persons had shorter telomeres if they reported more stressful life events in the past year (β = -.039, p = .028) and 1 to 5 years ago (β = -.042, p = .018, adjusted for sociodemographics). The relationship between stressful life events and TL became borderline significant when further adjusted for smoking status. No associations with TL were found when stressful life events occurred more than 6 years ago (p > .10).

CONCLUSIONS

Results show that recent stressful life events are associated with shorter TL. This association is not observed for psychosocial stressors that occur earlier in life. Whether these results are indicative of physiological resiliency remains to be explored by future longitudinal research.

Associations between the five-factor model of personality and leukocyte telomere length in elderly men and women: The Helsinki Birth Cohort Study (HBCS)

OBJECTIVE

Personality traits have been associated with cardiometabolic diseases and mental disorders as well as with longevity. However, the underlying mechanisms are not fully understood. Accelerated cellular aging may play a role in this process. We studied whether personality traits in late adulthood, as defined in the five-factor model (FFM), were associated with a biomarker of cellular vitality, leukocyte telomere length (LTL).

METHODS

At a mean age of 63.4 (SD=2.8) years, 1671 (742 men, 929 women) participants from the Helsinki Birth Cohort Study filled in the Neuroticism, Extraversion and Openness Personality Inventory (NEO-PI). LTL was measured at a mean age of 61.5 (SD=2.9) years by using a real-time quantitative PCR method.

RESULTS

None of the FFM personality dimensions were significantly associated with the LTL in the analyses of both sexes combined. We however found interaction between sex and agreeableness (B=0.020, 95% CI=.008, 0.032, p=.001) and in the sex-specific analyses, men who scored higher on agreeableness (B=-0.086, 95% CI=-0.155, -0.016, p=.016) and women who scored lower on agreeableness (B=0.074, 95% CI=0.014, 0.134, p=.016) had shorter LTL.

CONCLUSIONS

FFM dimensions of personality were not associated with LTL in a sample of elderly individuals. The counterintuitive and sporadic sex specific finding on agreeableness requires replication. Overall our findings suggest that LTL, a biomarker of cellular aging, may not offer insight into the associations between personality, longevity and health.

Is childhood stress associated with shorter telomeres?

BACKGROUND

It has been shown that severe stress in childhood is harmful to later health. New research aims to ascertain whether – and if so, how – the telomeres, the protective caps at the end of our chromosomes, may be one of the links between this type of experience and later morbidity. Here we present an overview of studies which have examined the association between stress in childhood and length of telomeres.

METHOD

The review encompasses 26 original studies found through a literature search in PubMed. We included studies of the relationship between length of telomeres and various stress-inducing factors from conception throughout childhood and adolescence.

RESULTS

The studies were grouped into four topics. The empirical research base for mother's stress in pregnancy and parents' ability to care for their children is too small to draw any conclusions. Psychosocial stress in childhood was associated with shorter telomere length in 12 of 14 studies. Socioeconomic status in childhood was not unequivocally associated with telomere length.

INTERPRETATION

Shorter telomeres are possibly associated with psychosocial stress in childhood. This field of research is still new, and more longitudinal studies are needed with an emphasis on childhood experiences and coordination of measurement variables and results measurement in order to confirm this association.

Self Reported Childhood Difficulties, Adult Multimorbidity and Allostatic Load. A Cross-Sectional Analysis of the Norwegian HUNT Study

Background

Multimorbidity receives increasing scientific attention. So does the detrimental health impact of adverse childhood experiences (ACE). Aetiological pathways from ACE to complex disease burdens are under investigation. In this context, the concept of allostatic overload is relevant, denoting the link between chronic detrimental stress, widespread biological perturbations and disease development. This study aimed to explore associations between self-reported childhood quality, biological perturbations and multimorbidity in adulthood.

Materials and Methods

We included 37 612 participants, 30–69 years, from the Nord-Trøndelag Health Study, HUNT3 (2006–8). Twenty one chronic diseases, twelve biological parameters associated with allostatic load and four behavioural factors were analysed. Participants were categorised according to the self-reported quality of their childhood, as reflected in one question, alternatives ranging from ‘very good’ to ‘very difficult’. The association between childhood quality, behavioural patterns, allostatic load and multimorbidity was compared between groups.

Results

Overall, 85.4% of participants reported a ‘good’ or ‘very good’ childhood; 10.6% average, 3.3% ‘difficult’ and 0.8% ‘very difficult’. Childhood difficulties were reported more often among women, smokers, individuals with sleep problems, less physical activity and lower education. In total, 44.8% of participants with a very good childhood had multimorbidity compared to 77.1% of those with a very difficult childhood (Odds ratio: 5.08; 95% CI: 3.63–7.11). Prevalences of individual diseases also differed significantly according to childhood quality; all but two (cancer and hypertension) showed a significantly higher prevalence (p<0.05) as childhood was categorised as more difficult. Eight of the 12 allostatic parameters differed significantly between childhood groups.

Conclusions

We found a general, graded association between self-reported childhood difficulties on the one hand and multimorbidity, individual disease burden and biological perturbations on the other. The finding is in accordance with previous research which conceptualises allostatic overload as an important route by which childhood adversities become biologically embodied.

Childhood Physical and Sexual Abuse History and Leukocyte Telomere Length among Women in Middle Adulthood

OBJECTIVE

Abuse victimization in childhood is associated with a variety of age-related cardiometabolic diseases, but the mechanisms remain unknown. Telomeres, which form the protective caps at the ends of chromosomes, have been proposed as measures of biological age, and a growing body of research suggests that telomere attrition may help to explain relationships between stress and cardiometabolic degradation. We examined the association between childhood abuse victimization and leukocyte telomere length among 1,135 participants in the Nurses' Health Study II (NHSII).

METHODS

The NHSII ascertained physical and sexual child abuse histories in 2001. Telomere length was measured in genomic DNA extracted from peripheral blood leukocytes collected between 1996 and 1999. The ratio of telomere repeat copy number to a single gene copy number (T/S) was determined by a modified version of the quantitative real-time PCR telomere assay. Telomere length was log-transformed and corrected for assay variation across batch. We regressed telomere length on childhood abuse exposure variables and covariates using linear regression.

RESULTS

We observed a reduction in telomere length associated with moderate physical abuse versus no physical abuse, but there was no evidence of a dose-response relationship for increased severity of physical abuse. No associations were noted for sexual abuse.

CONCLUSIONS

We found no evidence of an association between severity of childhood physical or sexual abuse and leukocyte telomere length in the NHSII.

The quantified self: closing the gap between general knowledge and particular case?

RATIONALE, AIMS AND OBJECTIVES

This paper addresses the movements 'evidence-based' (EBM) and 'personalized' (PM) medicine. The former is being criticized for failing to do justice to clinical complexity and human individuality. The latter aims at tailoring medical knowledge for every patient in a personalized fashion. Instrumental to this effort is the technological development engendering unlimited amounts of data about bodily fragments. The aim of this article is to stimulate a debate about the notion of the body and knowledge in medicine.

METHODS

An authentic sickness history is used as a vantage point for a more comprehensive account of biomedicine.

RESULTS

The analysis of the sickness history demonstrates how biomedical logic guided all approaches in the care for this particular patient. Each problem was identified and treated separately, whereby neglecting the interaction between body parts and systems, and between the woman's bodily condition and her experiences. The specialists involved seemed to look for phenomena that fit categories of disorders 'belonging' to their field. These approaches engendered unintended effects: chronification, poly-pharmacy and multi-morbidity, leading to an unsustainable increase in medical costs.

CONCLUSIONS

The article elucidates how the status that professionals ascribe to the body has vital implications for what they regard as relevant and how they interpret the information they have collected. On this ground, we challenge both the prevailing and tacitly accepted separation between the physical body and human experience and the view of knowledge underpinning EBM and PM. The growing molecularization of the body veils decisive sources of human illness.