Is telomere length socially patterned? Evidence from the West of Scotland Twenty-07 Study

Parental Genetics Communicate with Intrauterine Environment to Reprogram Newborn Telomeres and Immunity

Telomeres, markers for cellular senescence, have been found substantially influenced by parental inheritance. It is well known that genomic stability is preserved by the DNA repair mechanism through telomerase. This study aimed to determine the association between parents−newborn telomere length (TL) and telomerase gene (TERT), highlighting DNA repair combined with TL/TERT polymorphism and immunosenescence of the triad. The mother−father−newborn triad blood samples (n = 312) were collected from Ziauddin Hospitals, Pakistan, between September 2021 and June 2022. The telomere length (T/S ratio) was quantified by qPCR, polymorphism was identified by Sanger sequencing, and immunosenescence by flow cytometry. The linear regression was applied to TL and gene association. The newborns had longest TL (2.51 ± 2.87) and strong positive association (R = 0.25, p ≤ 0.0001) (transgenerational health effects) with mothers’ TL (1.6 ± 2.00). Maternal demographics—socioeconomic status, education, and occupation—showed significant effects on TL of newborns (p < 0.015, 0.034, 0.04, respectively). The TERT risk genotype CC (rs2736100) was predominant in the triad (0.6, 0.5, 0.65, respectively) with a strong positive association with newborn TL (β = 2.91, <0.0011). Further analysis highlighted the expression of KLRG 1+ in T-cells with shorter TL but less frequent among newborns. The study concludes that TERT, parental TL, antenatal maternal health, and immunity have a significantly positive effect on the repair of newborn TL.

The impact of neighborhood context on telomere length: A systematic review

A growing body of research demonstrates the association between neighborhood context and health. The underlying biological mechanisms of this association are not fully understood. We conducted a systematic review of studies that investigated the association between neighborhood context and telomere length (TL), a DNA-protein complex that shortens after cell division. Short TL is linked to age-related diseases and may be impacted by chronic stress. Nineteen eligible articles identified through PubMed and Scopus met inclusion criteria. Results demonstrated inconsistent support for the relationship between neighborhood disadvantage and short TL. However, findings across several studies provide evidence for an inverse association between perceived neighborhood problems and TL, suggesting that TL may be an important factor in understanding health vulnerabilities associated specifically with negative perceptions of the neighborhood context.

Socioeconomic position links circulatory microbiota differences with biological age

Imbalanced nutrition is associated with accelerated ageing, possibly mediated by microbiota. An analysis of the circulatory microbiota obtained from the leukocytes of participants in the MRC Twenty-07 general population cohort was performed. We now report that in this cohort, the most biologically aged exhibit a significantly higher abundance of circulatory pathogenic bacteria, including Neisseria, Rothia and Porphyromonas, while those less biologically aged possess more circulatory salutogenic (defined as being supportive of human health and wellbeing) bacteria, including Lactobacillus, Lachnospiraceae UCG-004 and Kocuria. The presence of these salutogenic bactreria is consistent with a capacity to metabolise and produce Nrf2 agonists. We also demonstrate that associated one carbon metabolism, notably betaine levels, did not vary with chronological age, but displayed a difference with socioeconomic position (SEP). Those at lower SEP possessed significantly lower betaine levels indicative of a poorer diet and poorer health span and consistent with reduced global DNA methylation levels in this group. Our data suggest a clear route to improving age related health and resilience based on dietary modulation of the microbiota.

Association between socioeconomic markers and adult telomere length differs according to sex: Pro-Saúde study

Understanding the social determinants of telomere length is critical to evaluate the risk of early biological aging. We investigated sex differences on the association between socioeconomic status (SES) and demographic markers and leukocyte telomere length (LTL) in Brazilian adults. This cross-sectional study was conducted in a subsample (women=228; men=200) nested within the Pro-Saúde study, a prospective cohort study of university civil servants in Rio de Janeiro, Brazil (2012-2013). Adjusted multivariate models were used to test the relationship between SES markers (marital status, educational attainment, father's educational attainment, race/skin color, household income, and childhood experience of food deprivation) and LTL. After adjusting for age and potential health-related confounders, lower educational attainment was associated with shorter LTL among men (β=-0.05, 95% confidence interval (CI)=95%CI: -0.10, 0.00, P=0.03). In women, LTL was inversely associated with unmarried status (β=-0.05, 95%CI: -0.09, 0.00, P=0.03), lower father's educational attainment (β=-0.05, 95%CI: -0.13, 0.00, P=0.04), and childhood experience of food deprivation (β=-0.07, 95%CI: -0.13, 0.00, P=0.04). Our findings suggested that the association between SES markers and LTL differs according to sex. SES markers able to induce lifelong stress, reflected in LTL, appeared to be more related to individual factors in men, whereas in women they were family-related.

Sex-specific educational attainment is associated with telomere length in an Australian rural population

BACKGROUND

There is limited understanding on whether and how socioeconomic status (SES), particularly educational attainment and household income, impacts on telomere length in an Australian rural context. Additionally, it is unknown whether access to health services via the Australian public or private health system influences telomere length.

AIM

This study investigates whether there is a relationship between telomere length and SES indicators (income, education) as well as health insurance status in a rural Australian population.

METHODS

Samples were drawn from the Australian Rural Victoria cross-sectional Crossroads Study. Leucocyte telomere length (LTL) was measured using a multiplex quantitative polymerase chain reaction method.

RESULTS

Among 1424 participants, we did not find a significant main effect association with LTL across education, income level and health insurance. An exploratory finding was sex may influence the relationship between educational attainment and LTL (P = 0.021). In males, but not females, higher education was associated with longer LTL by 0.033 [95% confidence interval (CI) 0.002-0.063, P = 0.035]; in those with low education attainment, male participants had shorter LTL by 0.058 (95% CI -0.086 to -0.029) than female participants (P < 0.0001).

CONCLUSION

Being male and having lower education attainment was associated with shorter telomere length in our rural population. Evidence from our study supports the importance of education on LTL in males in rural Australia. Our studies also support previous findings that LTL in later life may not be closely associated with indicators of SES.

Association of Parental Socioeconomic Status and Newborn Telomere Length

IMPORTANCE

Low socioeconomic status is associated with higher all-cause mortality and risks for aging-related diseases. Biological aging is a potential process underlying health conditions related to social disadvantages, which may be present from birth onward.

OBJECTIVE

To evaluate the association of parental socioeconomic status with telomere length (TL) at birth, a marker of biological aging.

DESIGN, SETTING, AND PARTICIPANTS

This prospective birth cohort study was conducted among 1504 mother-newborn pairs in Belgium recruited between February 1, 2010, and July 1, 2017.

EXPOSURES

Parental socioeconomic measures, including maternal educational level, occupation, paternal educational level, and neighborhood income based on median annual household income.

MAIN OUTCOMES AND MEASURES

Mean relative TL was measured in cord blood and placental tissue. By constructing a principal component, an integrative socioeconomic measure was derived that integrates parental socioeconomic status and neighborhood income. Multivariable adjusted regression analyses were performed to associate the integrative socioeconomic measure and TL at birth.

RESULTS

In 1026 newborns (517 boys; mean [SD] gestational age, 39.2 [1.4] weeks), a higher socioeconomic status was associated with longer cord blood TL and placental TL. Each unit increment in the integrative socioeconomic status measure was associated with 2.1% (95% CI, 0.9%-3.4%; P < .001) longer cord blood TL in boys, while no association was observed for girls (0.5% longer cord blood TL; 95% CI, -0.9% to 1.8%; P = .50). The sex-specific socioeconomic status interaction revealed a stronger association in boys compared with newborn girls (1.6%; 95% CI, 0.02%-3.3%; P = .047 for interaction). In placental tissue, higher socioeconomic status was associated with 1.8% (95% CI, 0.3%-3.3%; P = .02) longer TL in newborn boys but not in girls (0.4% longer TL; 95% CI, -1.2% to 2.0%; P = .63). For placental tissue, no sex and socioeconomic status interaction on TL was observed (1.4%; 95% CI, -0.5% to 3.4%; P = .16 for interaction).

CONCLUSIONS AND RELEVANCE

This study suggests that parental socioeconomic status is associated with newborn TL, especially in boys. The results indicate that familial social economic factors are associated with the potential cellular longevity of the next generation, with a potential higher transgenerational vulnerability for newborn boys.

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.

More miles on the clock: Neighbourhood stressors are associated with telomere length in a longitudinal study

Background

There is a substantial gap in health and longevity between more affluent and more deprived areas, and more knowledge of the determinants of this health divide is required. Experience of the local residential environment is important for health although few studies have examined this in relation to biological markers of age such as telomere length. We sought to examine if residents’ perceptions of neighbourhood stressors over time were associated with telomere length in a community study.

Methodology/Principal findings

In a prospective cohort study of 2186 adults in the West of Scotland, we measured neighbourhood stressors at three time points over a 12-year period and telomere length at the end of the study. Using linear regression models, we found that a higher accumulation of neighbourhood stressors over time was associated with shorter telomere length, even after taking cohort, social class, health behaviours (smoking status, diet, physical activity), BMI and depression into account among females only (Beta = 0.007; 95%CI [0.001, 0.012]; P<0.014).

Conclusions/Significance

Neighborhood environments are potentially modifiable, and future efforts directed towards improving deleterious local environments may be useful to lessen telomere attrition.

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.

Selected occupational characteristics and change in leukocyte telomere length over 10 years: The Multi-Ethnic Study of Atherosclerosis (MESA)

Telomere length (TL) is considered as a marker of cell senescence, but factors influencing the rate of TL attrition are not well understood. While one previous study reported the association of occupation and TL, many subsequent studies have failed to find the association. This may be due to heterogeneity within the samples and cross-sectional designs. This longitudinal study examines two occupational characteristics, occupational complexity and hazardous conditions, as predictors of TL attrition in gender- and race/ethnicity-stratified analysis. Leukocyte TL (expressed as T/S ratio) was measured twice over a 10-year period in a multi-racial sample (n = 914). Linear mixed effect models were used to estimate TL attrition associated with occupational complexity and hazardous conditions. Analysis was stratified by gender and race/ethnicity (white, African American, and Latino) and controlled for baseline age, baseline TL, and time since baseline. Higher occupational complexity was associated with slower rates of TL attrition only among white men. Hazardous conditions were not associated with TL attrition for any gender-and-race/ethnicity stratified group. Occupational complexity may influence TL attrition, but the different findings for white men and other groups suggest that a more comprehensive framework is needed to better understand the potential link between occupational characteristics and biological aging.

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.

Lung cancer and socioeconomic status in a pooled analysis of case-control studies

BACKGROUND

An association between low socioeconomic status (SES) and lung cancer has been observed in several studies, but often without adequate control for smoking behavior. We studied the association between lung cancer and occupationally derived SES, using data from the international pooled SYNERGY study.

METHODS

Twelve case-control studies from Europe and Canada were included in the analysis. Based on occupational histories of study participants we measured SES using the International Socio-Economic Index of Occupational Status (ISEI) and the European Socio-economic Classification (ESeC). We divided the ISEI range into categories, using various criteria. Stratifying by gender, we calculated odds ratios (OR) and 95% confidence intervals (CI) by unconditional logistic regression, adjusting for age, study, and smoking behavior. We conducted analyses by histological subtypes of lung cancer and subgroup analyses by study region, birth cohort, education and occupational exposure to known lung carcinogens.

RESULTS

The analysis dataset included 17,021 cases and 20,885 controls. There was a strong elevated OR between lung cancer and low SES, which was attenuated substantially after adjustment for smoking, however a social gradient persisted. SES differences in lung cancer risk were higher among men (lowest vs. highest SES category: ISEI OR 1.84 (95% CI 1.61-2.09); ESeC OR 1.53 (95% CI 1.44-1.63)), than among women (lowest vs. highest SES category: ISEI OR 1.54 (95% CI 1.20-1.98); ESeC OR 1.34 (95% CI 1.19-1.52)).

CONCLUSION

SES remained a risk factor for lung cancer after adjustment for smoking behavior.

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.

Socioeconomic Status, Financial Strain, and Leukocyte Telomere Length in a Sample of African American Midlife Men

BACKGROUND

African American men in the USA experience poorer aging-related health outcomes compared to their White counterparts, partially due to socioeconomic disparities along racial lines. Greater exposure to socioeconomic strains among African American men may adversely impact health and aging at the cellular level, as indexed by shorter leukocyte telomere length (LTL). This study examined associations between socioeconomic factors and LTL among African American men in midlife, a life course stage when heterogeneity in both health and socioeconomic status are particularly pronounced.

METHODS

Using multinomial logistic regression, we examined associations between multiple measures of SES and tertiles of LTL in a sample of 92 African American men between 30 to 50 years of age.

RESULTS

Reports of greater financial strain were associated with higher odds of short versus medium LTL (odds ratio (OR)=2.21, p = 0.03). Higher income was associated with lower odds of short versus medium telomeres (OR=0.97, p = 0.04). Exploratory analyses revealed a significant interaction between educational attainment and employment status (χ ² = 4.07, p = 0.04), with greater education associated with lower odds of short versus long telomeres only among those not employed (OR=0.10, p = 0.040).

CONCLUSION

Cellular aging associated with multiple dimensions of socioeconomic adversity may contribute to poor aging-related health outcomes among African American men. Subjective appraisal of financial difficulty may impact LTL independently of objective dimensions of SES. Self-appraised success in fulfilling traditionally masculine gender roles, including being an economic provider, may be a particularly salient aspect of identity for African American men and have implications for cellular aging in this population.

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.

Circulating markers of ageing and allostatic load: A slow train coming

Dealing with the growing burden of age-related morbidities is one of the greatest challenges facing modern society. How we age across the lifecourse and how psychosocial and lifestyle factors interplay with the biology of ageing remains to be fully elucidated. Sensitive and specific biomarkers with which to interrogate the biology of the ageing process are sparse. Recent evidence suggests that non-coding RNAs are key determinants of such processes and that these can be used as potential circulatory bio-markers of ageing. They may also provide a mechanism which mediates the spread of allostatic load across the body over time, ultimately reflecting the immunological health and physiological status of tissues and organs. The interplay between exosomal microRNAs and ageing processes is still relatively unexplored, although circulating microRNAs have been linked to the regulation of a range of physiological and pathological processes and offer insight into mechanistic determinants of healthspan.

Association between telomere length and diabetes mellitus: A meta-analysis

Objective We investigated the relationship between diabetes and telomere length by meta-analysis. Methods We searched five popular databases for articles published between 1990 and 2015 using "diabetes" and "telomere" as search terms. Data were processed with RevMan5, and random- or fixed-effects meta-analysis was applied. The effects of geographical region, diabetes type, body mass index (BMI), age and sex were examined. Funnel plots were applied to evaluate publication bias. Results Seventeen articles were obtained from 571 references. We identified a significant association between telomere length and diabetes mellitus (standardized mean difference [SMD]: -3.41; 95% confidence interval [CI]: -4.01, -2.80; heterogeneity, I2 = 99%) by comparing 5575 patients with diabetes and 6349 healthy individuals. The pooled SMD by geographic region indicated a significant association between shortened telomere length and diabetes mellitus (SMD: -3.41; 95% CI: -4.01, -2.80; heterogeneity, I2 = 99%). In addition, telomere length was significantly associated with age (SMD: -3.41; 95% CI: -4.01, -2.80), diabetes type (SMD: -3.41; 95% CI: -4.01, -2.80), BMI (SMD: -1.61; 95% CI: -1.98, -1.23) and sex (SMD: -4.94; 95% CI: -9.47, -0.40). Conclusions The study demonstrated a close relationship between diabetes mellitus and telomere length, which was influenced by region, age, diabetes type, BMI and sex.

Air pollution, ethnicity and telomere length in east London schoolchildren: An observational study

BACKGROUND

Short telomeres are associated with chronic disease and early mortality. Recent studies in adults suggest an association between telomere length and exposure to particulate matter, and that ethnicity may modify the relationship. However associations in children are unknown.

OBJECTIVES

We examined associations between air pollution and telomere length in an ethnically diverse group of children exposed to high levels of traffic derived pollutants, particularly diesel exhaust, and to environmental tobacco smoke.

METHODS

Oral DNA from 333 children (8-9years) participating in a study on air quality and respiratory health in 23 inner city London schools was analysed for relative telomere length using monochrome multiplex qPCR. Annual, weekly and daily exposures to nitrogen oxides and particulate matter were obtained from urban dispersion models (2008-10) and tobacco smoke by urinary cotinine. Ethnicity was assessed by self-report and continental ancestry by analysis of 28 random genomic markers. We used linear mixed effects models to examine associations with telomere length.

RESULTS

Telomere length increased with increasing annual exposure to NO_x (model coefficient 0.003, [0.001, 0.005], p<0.001), NO₂ (0.009 [0.004, 0.015], p<0.001), PM_2.5 (0.041, [0.020, 0.063], p<0.001) and PM₁₀ (0.096, [0.044, 0.149], p<0.001). There was no association with environmental tobacco smoke. Telomere length was increased in children reporting black ethnicity (22% [95% CI 10%, 36%], p<0.001) CONCLUSIONS: Pollution exposure is associated with longer telomeres in children and genetic ancestry is an important determinant of telomere length. Further studies should investigate both short and long-term associations between pollutant exposure and telomeres in childhood and assess underlying mechanisms.

[DOHaD: epidemiological researches]

Epidemiological researches in the field of DOHaD are in favor of a role of early environment, including chemical (pesticides), physical (air pollution), nutritional or psychosocial environment, on child and adult health. Disentangling the different factors of environment that may affect health, especially over time, and identifying critical periods of exposure remains a major challenge. The biological mechanisms involved remain elusive in human beings. Nevertheless, it seems that whatever the nature of the exposure, epigenetic mechanisms are currently discussed to explain how the environment may alter biological systems over time.

Prenatal undernutrition and leukocyte telomere length in late adulthood: the Dutch famine birth cohort study

BACKGROUND

Energy restriction in prenatal life has detrimental effects on later life health and longevity. Studies in rats have shown that the shortening of telomeres in key tissues plays an important role in this association.

OBJECTIVE

The aim of the current study was to investigate leukocyte telomere length in relation to prenatal famine exposure.

DESIGN

The Dutch famine birth cohort consists of 2414 term singleton men and women who were born between 1943 and 1947 in Amsterdam around the time of the famine. At a mean age of 68 y, telomere length and the percentage of short telomeres was assessed in a subsample of 131 cohort members, of whom 45 were born before the famine (control), 41 were exposed to famine during early gestation, and 45 were conceived after the famine (control). Median telomere length was determined in peripheral blood leukocytes by a high-throughput quantitative fluorescent in situ hybridization-based technology.

RESULTS

Leukocyte telomere length and the percentage of short telomeres did not differ between those exposed to famine during early gestation and those unexposed during gestation. A lower socioeconomic status at birth, frequent consumption of alcohol (specifically consumption of spirits), a history of cancer, and a lower self-reported health status were significantly associated with shorter leukocyte telomere length (all P ≤ 0.03). Currently having a job was significantly associated with a smaller percentage of short telomeres (P = 0.04).

CONCLUSION

The results of the current study suggest that prenatal exposure to famine is not associated with the shortening of telomeres in peripheral blood leukocytes at age 68 y.

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.

Association between socioeconomic factors and cancer risk: a population cohort study in Scotland (1991-2006)

BACKGROUND

Lung and upper aero-digestive tract (UADT) cancer risk are associated with low socioeconomic circumstances and routinely measured using area socioeconomic indices. We investigated effect of country of birth, marital status, one area deprivation measure and individual socioeconomic variables (economic activity, education, occupational social class, car ownership, household tenure) on risk associated with lung, UADT and all cancer combined (excluding non melanoma skin cancer).

METHODS

We linked Scottish Longitudinal Study and Scottish Cancer Registry to follow 203,658 cohort members aged 15+ years from 1991-2006. Relative risks (RR) were calculated using Poisson regression models by sex offset for person-years of follow-up.

RESULTS

21,832 first primary tumours (including 3,505 lung, 1,206 UADT) were diagnosed. Regardless of cancer, economically inactivity (versus activity) was associated with increased risk (male: RR 1.14, 95% CI 1.10-1.18; female: RR 1.06, 95% CI 1.02-1.11). For lung cancer, area deprivation remained significant after full adjustment suggesting the area deprivation cannot be fully explained by individual variables. No or non degree qualification (versus degree) was associated with increased lung risk; likewise for UADT risk (females only). Occupational social class associations were most pronounced and elevated for UADT risk. No car access (versus ownership) was associated with increased risk (excluding all cancer risk, males). Renting (versus home ownership) was associated with increased lung cancer risk, UADT cancer risk (males only) and all cancer risk (females only). Regardless of cancer group, elevated risk was associated with no education and living in deprived areas.

CONCLUSIONS

Different and independent socioeconomic variables are inversely associated with different cancer risks in both sexes; no one socioeconomic variable captures all aspects of socioeconomic circumstances or life course. Association of multiple socioeconomic variables is likely to reflect the complexity and multifaceted nature of deprivation as well as the various roles of these dimensions over the life course.

Do symptoms of depression predict telomere length? Evidence from the west of Scotland twenty-07 study

OBJECTIVE

Psychological factors such as the stress of caregiving are emerging as predictors of telomere length, an index of biological aging. However, although lifetime major depressive disorder is associated with shorter telomeres, less is known about depressive symptoms. Depression and depressive symptoms are associated with a range of morbidities and mortality, but the extent to which they predict biological aging is unclear. The present study examined participants in the West of Scotland Twenty-07 Study across three age cohorts and four waves of data collection from 1992/1993 to 2007/2008.

METHODS

Participants were 37, 57, and 76 years old at final data collection. Depressive symptoms were measured using the Hospital Anxiety and Depression Scale at each time point. Telomere length was assessed from 1063 blood samples collected at the final wave in 2007/2008 for respondents who also had depression data.

RESULTS

Average depression symptoms (β= -.12, p = .047) and their change over time (β = -.12, p = .031) were negatively associated with telomere length, but only in the youngest cohort. Depressive symptoms were not cross sectionally associated with telomere length in 2007 to 2008 (β= -.03, p = .45). In the youngest cohort only, depressive symptoms assessed in 1995 to 1997 and 2000 to 2004 were associated with shorter telomere length (β = .14 [p = .046] and β = .18 [p = .012], respectively), but not 1992 to 1993 or 2007 to 2008; associations in the middle- and older-aged cohorts were nonsignificant.

CONCLUSIONS

Depressive symptoms are longitudinally associated with shorter telomere length, but only in younger adults.

Neighborhood disorder and telomeres: connecting children's exposure to community level stress and cellular response

Our objective was to explore the utility of salivary telomere length (sTL) as an early indicator of neighborhood-level social environmental risk during child development. We therefore tested the hypothesis that sTL would be associated with markers of social stress exposure in children. Children age 4-14 from 87 neighborhoods were recruited through five urban schools in New Orleans, Louisiana, U.S. Data were collected at the level of the child, family/household, and neighborhood. DNA was obtained from saliva using commercially available kits and sTL was determined for 104 children using quantitative PCR. Analysis was performed on 99 children who had complete data including sTL, social environmental stress, and additional covariates. The mean sTL value was 7.4 T/S (telomere signal/single-copy signal) ratio units (±2.4, range = 2.5-18.0), and 4.7% of the variance in sTL was attributed to differences across neighborhoods. Children living in neighborhoods characterized by high disorder had an sTL value 3.2 units lower than children not living in high disordered environments (p < 0.05) and their odds of having low relative sTL (defined as <1 standard deviation below standardized Z-score mean) values was 3.43 times that of children not living in high disorder environments (adjusted OR = 3.43, 95% CI = 1.22, 9.62). Our findings are consistent with previous studies in adults demonstrating a strong link between psychosocial stress and sTL obtained from peripheral blood, consistent with previous studies in youth demonstrating an association between early life stress and sTL obtained from buccal cell DNA and offer increased support for the hypothesis that sTL represents a non-invasive biological indicator of psychosocial stress exposure (i.e., neighborhood disorder) able to reflect differences in stress exposure levels even in young children.

Socioeconomic status, health behavior, and leukocyte telomere length in the National Health and Nutrition Examination Survey, 1999-2002

The purpose of this study was to examine the association between socioeconomic status (SES) and leukocyte telomere length (LTL) - a marker of cell aging that has been linked to stressful life circumstances - in a nationally representative, socioeconomically and ethnically diverse sample of US adults aged 20-84. Using data from the National Health and Nutrition Examination Survey (NHANES), 1999-2002, we found that respondents who completed less than a high school education had significantly shorter telomeres than those who graduated from college. Income was not associated with LTL. African-Americans had significantly longer telomeres than whites, but there were no significant racial/ethnic differences in the association between education and telomere length. Finally, we found that the association between education and LTL was partially mediated by smoking and body mass index but not by drinking or sedentary behavior.

Socioeconomic factors and leukocyte telomere length in a multi-ethnic sample: findings from the multi-ethnic study of atherosclerosis (MESA)

Previous findings have linked lower socioeconomic status (SES) with elevated morbidity and mortality. Leukocyte telomere length (LTL), which also has been associated with age-related disease morbidity and mortality, is a marker of aging at the cellular level, making it a valuable early biomarker of risk and an indicator of biological age. It is hypothesized that SES will be associated with LTL, indicating that SES influences disease risk by accelerating biological aging. In the present sample we test for associations of childhood SES and adult SES (i.e. education, income, home ownership) with LTL, and examine whether these associations vary by racial/ethnic group. Analyses on 963 subjects (18.7% White, 53% Hispanics, and 28.5% African American) from the stress ancillary study of the multi-ethnic study of atherosclerosis revealed a significant difference in LTL between home owners and renters in Hispanic and White participants (p<.05), but not amongst African Americans (p=.98). There were no linear associations of adult education or family income with LTL, however, there was an inverse association between father's education and LTL (p=.03). These findings suggest that for Whites and Hispanics renting vs. owning a home is associated with an older biological age; however we did not replicate previous findings linking education with LTL.

The association between intelligence and telomere length: a longitudinal population based study

Low intelligence has been associated with poor health and mortality, but underlying mechanisms remain obscure. We hypothesized that low intelligence is associated with accelerated biological ageing as reflected by telomere length; we suggested potential mediation of this association by unhealthy behaviors and low socioeconomic position. The study was performed in a longitudinal population-based cohort study of 895 participants (46.8% males). Intelligence was measured with the Generalized Aptitude-Test Battery at mean age 52.8 years (33–79 years, SD = 11.3). Leukocyte telomere length was measured by PCR. Lifestyle and socioeconomic factors were assessed using written self-report measures. Linear regression analyses, adjusted for age, sex, and telomere length measured at the first assessment wave (T1), showed that low intelligence was associated with shorter leukocyte telomere length at approximately 2 years follow-up (beta = .081, t = 2.160, p = .031). Nearly 40% of this association was explained by an unhealthy lifestyle, while low socioeconomic position did not add any significant mediation. Low intelligence may be a risk factor for accelerated biological ageing, thereby providing an explanation for its association with poor health and mortality.