Determinants of telomere attrition over 1 year in healthy older women: stress and health behaviors matter

The association between sleep quality and telomere attrition: A systematic review and meta-analysis comprising 400,212 participants

Psychosocial stressors accelerate telomere attrition, a biomarker of cell aging, whereas good sleep is hypothesized to be a mitigating factor. However, methodological aspects - particularly underpowered studies, inconsistent findings, and multiple approaches to assessing sleep - demonstrate the need for a meta-analysis. After PROSPERO registration, we conducted a systematical search of the following databases until June 2024 to identify studies examining the relationship between sleep quality and telomere length in adult humans: CINAHL, Cochrane Library, MEDLINE, PsychINFO, PubMed, Web of Science, and Google Scholar. In total, 29 studies met inclusion criteria for the systematic review according to the preferred reporting items for systematic reviews and meta-analysis guidelines (PRISMA), 19 of which provided data that was appropriate for meta-analytic calculations. We identified the Pittsburgh sleep quality index (PSQI) global score (odds ratio (OR) 1.24, CI 95 % [1.03; 1.50], p = 0.02), sleep-related daytime impairments (OR 1.01 [1.00; 1.02], p = 0.04), and wake after sleep onset (WASO) time (OR 1.28 [1.12; 1.47], p < 0.01) as to be significantly associated with telomere attrition. Thus, the subtle telomere attrition-mitigating role of sleep has been demonstrated based on a sufficiently large body of data and defined aspects of sleep quality.

Leukocyte telomere length and memory circuitry and cognition in early aging: Impact of sex and menopausal status

Telomere length (TL) is an important cellular marker of biological aging impacting the brain and heart. However, how it is related to the brain (e.g., cognitive function and neuroanatomic architecture), and how these relationships may vary by sex and reproductive status, is not well established. Here we assessed the association between leukocyte TL and memory circuitry regional brain volumes and memory performance in early midlife, in relation to sex and reproductive status. Participants (N = 198; 95 females, 103 males; ages 45-55) underwent structural MRI and neuropsychological assessments of verbal, associative, and working memory. Overall, shorter TL was associated with smaller white matter volume in the parahippocampal gyrus and dorsolateral prefrontal cortex. In males, shorter TL was associated with worse working memory performance and corresponding smaller white matter volumes in the parahippocampal gyrus, anterior cingulate cortex, and dorsolateral prefrontal cortex. In females, the impact of cellular aging was revealed over the menopausal transition. In postmenopausal females, shorter TL was associated with poor associative memory performance and smaller grey matter volume in the right hippocampus. In contrast, TL was not related to memory performance or grey and white matter volumes in any memory circuitry region in pre/perimenopausal females. Results demonstrated that shorter TL is associated with worse memory function and smaller volume in memory circuitry regions in early midlife, an association that differs by sex and reproductive status. Taken together, TL may serve as an early indicator of sex-dependent brain abnormalities in early midlife.

Understanding the health effects of caregiving stress: New directions in molecular aging

Dementia caregiving has been linked to multiple health risks, including infectious illness, depression, anxiety, immune dysregulation, weakened vaccine responses, slow wound healing, hypertension, cardiovascular disease, metabolic syndrome, diabetes, frailty, cognitive decline, and reduced structural and functional integrity of the brain. The sustained overproduction of proinflammatory cytokines is a key pathway behind many of these risks. However, contrasting findings suggest that some forms of caregiving may have beneficial effects, such as maintaining caregivers' health and providing a sense of meaning and purpose which, in turn, may contribute to lower rates of functional decline and mortality. The current review synthesizes these disparate literatures, identifies methodological sources of discrepancy, and integrates caregiver research with work on aging biomarkers to propose a research agenda that traces the mechanistic pathways of caregivers' health trajectories with a focus on the unique stressors facing spousal caregivers as compared to other informal caregivers. Combined with a focus on psychosocial moderators and mechanisms, studies using state-of-the-art molecular aging biomarkers such as telomere length, p16INK4a, and epigenetic age could help to reconcile mixed literature on caregiving's sequelae by determining whether and under what conditions caregiving-related experiences contribute to faster aging, in part through inflammatory biology. The biomarkers predict morbidity and mortality, and each contributes non-redundant information about age-related molecular changes -together painting a more complete picture of biological aging. Indeed, assessing changes in these biopsychosocial mechanisms over time would help to clarify the dynamic relationships between caregiving experiences, psychological states, immune function, and aging.

Burnout among high school students is linked to their telomere length and relatedness with peers

School burnout is a serious concern, as it impairs students' health and academic success. According to the Conservation of Resources Theory, burnout results from the depletion of personal coping resources and can be counteracted by supportive social relationships. However, it is not yet clear how students' relatedness with their peers is linked to their burnout. Next to students' self-reported fatigue, biomarkers such as telomere length (TL), which presents an indicator of aging, complement stress research. To identify school-related factors that may prevent students from experiencing burnout and to link TL to students' self-reported burnout, the current study investigated how relatedness with peers as well as TL at the beginning of the school year explained students' burnout at the end of the school year. The sample included 78 students (Mage = 13.7 ± 0.7 years; 48% girls). Results of multilevel analysis in Mplus indicate that, over the school year, students with higher TL and those who experienced relatedness with their peers reported lower levels of burnout. Moreover, students who felt related to their peers exhibited a longer TL. The study implies that students' relatedness with their peers may be a promising setscrew to prevent students' burnout and support their physical health. This is one of the first studies to link TL with school-related variables such as burnout and relatedness to peers in a non-clinical student sample, providing a baseline for interventions and future interdisciplinary studies in the field of education and stress.

Telomere Length Associations With Clinical Diagnosis, Age, and Polygenic Risk Scores for Anxiety Disorder, Depression, and Bipolar Disorder

Background

Accelerated biological aging might contribute to the lower life expectancy of individuals with mental disorders. The aim of this study was to characterize telomere length, a biological hallmark of aging, in individuals with mental disorders.

Methods

The UK Biobank is a multicenter community-based observational study that recruited >500,000 middle-aged and older adults. Average leukocyte telomere length (telomere repeat copy number/single-copy gene ratio) was measured using quantitative polymerase chain reaction. Polygenic risk scores (PRSs) were calculated for individuals of European ancestry. We estimated differences in telomere length between individuals with anxiety disorder, depression, or bipolar disorder and people without mental disorders and examined associations with psychotropic medication use, age, and PRSs for these 3 disorders.

Results

The analyses included up to 308,725 participants. Individuals with depression had shorter telomeres than people without mental disorders (β = -0.011, 95% CI, -0.019 to -0.004, Bonferroni-corrected p = .027). Associations between bipolar disorder and telomere length differed by lithium use. There was limited evidence that individuals with an anxiety disorder had shorter telomeres. There was no evidence that associations between age and telomere length differed between individuals with and without these disorders. PRSs for depression, but not anxiety disorder or bipolar disorder, were associated with shorter telomeres (β = -0.006, 95% CI, -0.010 to -0.003, Bonferroni-corrected p = .001).

Conclusions

Differences in telomere length were observed primarily for individuals with depression or bipolar disorder and in individuals with a higher PRS for depression. There was no evidence that the association between age and telomere length differed between individuals with and without an anxiety disorder, depression, or bipolar disorder.

Social support and telomere length: a meta-analysis

Previous studies have shown that lower social support is associated with higher all-cause mortality (Holt-Lunstad et al. in PLoS ONE Medicine 7:e1000316, 2010). While social support has been associated with system-specific biological measures (e.g., cardiovascular), there is the need to elucidate more general biological mechanisms linking social support to health risk across a number of diseases. In this meta-analytic review, the link between social support and telomere length (Cawthon et al. in Lancet 361:393-395, 2003) was conducted based on the updated PRISMA guidelines (Page et al., 2021). Across 17 studies, higher social support was not significantly related to longer telomere length (Zr = 0.010, 95% CI [- 0.028, 0.047], p > 0.05). The confidence interval indicated that the bulk of plausible values were small to null associations. Little evidence for bias was found as shown by funnel plots and Kendall's Tau. Moderator analyses focusing on the measure of support, health of sample, age, type of assay specimen, and gender were not significant. In conclusion, this review showed no significant relationship between social support and telomere length and highlights important future directions.

The association between sleep quality and telomere length: A systematic literature review

Several sleep parameters present an elevated risk for processes that contribute to cellular aging. Short sleep duration, sleep apnoea, and insomnia are significantly associated with shorter telomeres, a biological marker of cellular aging. However, there has been no review or analysis of studies that have examined the association between the psychological construct of sleep quality and telomere length. The present study aimed to provide a systematic review of the association between sleep quality and telomere length. A systematic review of English articles was conducted using MEDLINE/PubMed, PsycINFO, Google Scholar, and Web of Science electronic databases, with the final search conducted on 3rd September 2021. Search terms included sleep quality, poor sleep, insomnia, sleep difficulties, sleep issue*, non-restorative sleep, telomere*, cellular aging, and immune cell telomere length. Study eligibility criteria included human participants aged 18 years or older and a reproducible methodology. Study appraisal and synthesis were completed using a systematic search in line with a PICOS approach (P = Patient, problem, or population; I = Intervention, prognostic factor, exposure; C = Comparison, control, or comparator; O = Outcomes; S = Study designs). Twenty-two studies met review inclusion criteria. Qualitative synthesis of the literature indicated insufficient evidence overall to support a significant association between sleep quality and telomere length. Limitations across studies were addressed, such as the assessment of examined constructs. Findings highlight important targets for future research, including the standardised operationalisation of the sleep quality construct and experimental study designs. Research in this area has clinical significance by identifying possible mechanisms that increase the risk for age-related disease and mortality. PROSPERO Registration No.: CRD 42021233139.

Nutritional and lifestyle management of the aging journey: A narrative review

With age, the physiological responses to occasional or regular stressors from a broad range of functions tend to change and adjust at a different pace and restoring these functions in the normal healthy range becomes increasingly challenging. Even if this natural decline is somehow unavoidable, opportunities exist to slow down and attenuate the impact of advancing age on major physiological processes which, when weakened, constitute the hallmarks of aging. This narrative review revisits the current knowledge related to the aging process and its impact on key metabolic functions including immune, digestive, nervous, musculoskeletal, and cardiovascular functions; and revisits insights into the important biological targets that could inspire effective strategies to promote healthy aging.

Association between telomere length and insomnia: A mendelian randomization and colocalization study

BACKGROUND

Previous studies have suggested a potential association between sleep and telomere length (TL), but its genetic basis remains unclear. In this study, we aimed to explore the genetic correlation and potential causal association between TL and insomnia.

METHODS

The genome-wide association study (GWAS) datasets of TL and insomnia-related traits were used, including insomnia, snoring, daytime dozing and napping. Based on the polygenic risk scores (PRS) of TL, linear regression and linkage disequilibrium score (LDSC) regression were used to preliminarily explore the association between TL and insomnia parameters in the UK Biobank cohort. Then, we investigated the causal association between TL and insomnia by mendelian randomization (MR) analysis and colocalization analysis.

RESULTS

In the UK Biobank cohort, the association between TL and insomnia was observed in the female samples (t = 2.968, P = 3.00 × 10^-3). LDSC detected a genetic correlation between short TL and insomnia (Rg = -9.27 × 10^-2, P = 8.00 × 10^-4). We found no evidence supporting significant causal association between insomnia and TL in IVW method (b = -5.95 × 10^-3, P = 0.57), with horizontal pleiotropy and heterogeneity tests indicating the validity of our MR study. Finally, rs12638862 was classified as colocalized by COLOC (PP4 = 0.99), and TERC may be involved in regulating the association between insomnia and TL.

CONCLUSIONS

Our study found no evidence for causal association between insomnia and TL in individuals of European ancestry. We detected a candidate gene associated with both insomnia and TL, providing novel clues for understanding the roles of this association.

Effects of Chronic Burden Across Multiple Domains and Experiences of Daily Stressors on Negative Affect

BACKGROUND

Exposure to chronic psychological stress across multiple life domains (multi-domain chronic burden) is associated with poor health. This may be because multi-domain chronic burden influences daily-level emotional processes, though this hypothesis has not been thoroughly tested.

PURPOSE

The current study tested whether (a) multi-domain chronic burden is associated with greater exposure to daily stressors and (b) multi-domain chronic burden compounds negative affect on days with stressors compared to stressor-free days.

METHODS

The MIDUS Study (Wave II) and the National Study of Daily Experiences sub-study were conducted from 2004 to 2006 (N = 2,022). Participants reported on eight life domains of psychological stress used to create a multi-domain chronic burden summary score. For eight consecutive days, participants reported the daily occurrence of stressful events and daily negative affect.

RESULTS

Participants with greater multi-domain chronic burden were significantly more likely to report daily stressors. There was also a significant interaction between multi-domain chronic burden and daily stressors on negative affect: participants with higher multi-domain chronic burden had greater negative affect on stressor days than stressor-free days compared to those with lower multi-domain chronic burden.

CONCLUSION

Participants with higher multi-domain chronic burden were more likely to report daily stressors and there was a compounding effect of multi-domain chronic burden and daily stressors on negative affect. These results suggest that experiencing a greater amount of psychological stress across multiple life domains may make daily stressors more toxic for daily affect.

A multi-exposure approach to study telomere dynamics in childhood: A role for residential green space and waist circumference

BACKGROUND

Telomeres are vulnerable to various environmental exposures and lifestyle factors, encompassed in the exposome. Recent research shows that telomere length is substantially determined early in life and that exposures in childhood may have important consequences in setting later life telomere length.

OBJECTIVES

We explore in a child population the associations of 17 exposures with telomere length and longitudinal telomere change.

METHODS

Children (2.8-10.3y at baseline, 51.3% boys) were followed-up for five to seven years. Relative telomere length was measured at baseline and follow-up using quantitative real-time PCR. Exposures and lifestyle factors included: body composition (body mass index and waist circumference), dietary habits (sugar- and fat-rich food intake, vegetables and fruit intake), psychosocial stress (events, emotions, behaviour), sleep duration, physical activity, and residential environmental quality (longterm black carbon, particulate matter exposure, and residential green space). Cross-sectional (n=182) and longitudinal (n=150) analyses were assessed using linear regression models, adjusting for age, sex, socioeconomic status and multiple testing.

RESULTS

Our longitudinal analyses showed that higher residential green space at baseline was associated with (β=0.261, p=0.002) lower telomere attrition and that children with a higher waist circumference at baseline showed a higher telomere attrition (β=-0.287, p=0.001). These two predictors were confirmed via LASSO variable selection and correction for multiple testing. In addition, children with more unhealthy exposures at baseline had a significantly higher telomere attrition over the follow-up period compared to children with more healthy exposures (β=-0.200, p=0.017).

DISCUSSION

Waist circumference and residential green space were identified as predictors associated with telomere attrition in childhood. These results further support the advantages of a healthy lifestyle from early age onwards and the importance of a green environment to promote molecular longevity from childhood onwards.

Lived experience and allostatic load among transmasculine people living in the United States

BACKGROUND

Transgender and gender diverse people face significant stigma that can adversely affect their physical and mental health. However, the psychobiological link between lived experience and health has been underexplored in this population. We thus examine perceived distress, mental health, and physiological 'wear and tear' by indexing allostatic load (AL) and assess associations with a range of contextual and experiential factors from transmasculine people living in the United States.

METHODS

Sixty-five people who identified as transgender men or along a transmasculine spectrum, living in Massachusetts, Vermont, and Rhode Island participated in The Transition Experience Study (age: M=31.8, range 18-55), which examines lived experience of social and medical transition and embodied gender minority/marginalization stress among a sample of transmasculine people. Based on in-depth in-person interview and survey data and inspired by an ecological systems model, we created indices representing (1) perceived progressive geopolitical climate; (2) socio-demographic advantage; (3) social support and resources; (4) gender minority and marginalization stressors; and (5) health behaviors. The Perceived Stress Scale and psychological symptoms (depression, anxiety, insomnia) were also assessed. AL indexed 10 neuroendocrine, immune, cardiovascular, and metabolic biomarkers.

RESULTS

Regressions revealed that perceived stress and psychological symptoms were negatively correlated with progressive geopolitical climate (respectively B=-1.47, p = 0.19; B=-.77, p < .001) and positively correlated with gender minority and marginalization stressors (respectively B=1.51, p < .001; B =.38, p = .005). AL was negatively associated with perceived progressive geopolitical climate (B=-.55, p = .007) and socio-demographic advantage (B=-3.2, p = .001).

DISCUSSIONS

These findings underline the importance of assessing geopolitical context and indexing lived experiences and life domains along with biomarker sampling. Together, these enable the identification of psychobiological pathways to better nuance multi-level contributors to health and well-being and understand embodied inequalities. These analyses of embodied stigma inclusive of AL biomarkers thus provide a model to further research centering transgender people's health from youth through old age.

Relationship between Dietary Patterns and Subjectively Measured Physical Activity in Japanese Individuals 85 Years and Older: A Cross-Sectional Study

High-quality diets and regular physical activity (PA) are considered healthy behaviors (HBs). HBs are associated with many health outcomes and are expected to improve quality of life. Although implementing HBs is important, the relationship between dietary patterns (DPs) and PA has not been well investigated, especially among those aged ≥ 85. This study used data from the Tokyo Oldest Old survey on Total Health study to examine the relationship between DPs and PA in a cross-sectional study. The dietary survey used the brief self-administered diet history questionnaire to estimate the intake of 58 foods. After energy adjustment, principal component analysis was performed to identify major DPs. A validated questionnaire was used to evaluate PA, and linear regression analysis was used to investigate the association between DPs and PA, considering confounders. A total of 519 participants were included. Three major DPs (‘Various plant foods’, ‘Fish and mushrooms’, ‘Cooked rice and miso soup’) were identified. ‘Various plant foods’ was similar to DPs previously named ‘Healthy’ or ‘Prudent’, and its trend was positively associated with higher PA. This study observed the implementation of HBs even among those aged ≥ 85, suggesting that a trend toward a healthier diet is associated with higher PA.

Integrating Environment and Aging Research: Opportunities for Synergy and Acceleration

Despite significant overlaps in mission, the fields of environmental health sciences and aging biology are just beginning to intersect. It is increasingly clear that genetics alone does not predict an individual’s neurological aging and sensitivity to disease. Accordingly, aging neuroscience is a growing area of mutual interest within environmental health sciences. The impetus for this review came from a workshop hosted by the National Academies of Sciences, Engineering, and Medicine in June of 2020, which focused on integrating the science of aging and environmental health research. It is critical to bridge disciplines with multidisciplinary collaborations across toxicology, comparative biology, epidemiology to understand the impacts of environmental toxicant exposures and age-related outcomes. This scoping review aims to highlight overlaps and gaps in existing knowledge and identify essential research initiatives. It begins with an overview of aging biology and biomarkers, followed by examples of synergy with environmental health sciences. New areas for synergistic research and policy development are also discussed. Technological advances including next-generation sequencing and other-omics tools now offer new opportunities, including exposomic research, to integrate aging biomarkers into environmental health assessments and bridge disciplinary gaps. This is necessary to advance a more complete mechanistic understanding of how life-time exposures to toxicants and other physical and social stressors alter biological aging. New cumulative risk frameworks in environmental health sciences acknowledge that exposures and other external stressors can accumulate across the life course and the advancement of new biomarkers of exposure and response grounded in aging biology can support increased understanding of population vulnerability. Identifying the role of environmental stressors, broadly defined, on aging biology and neuroscience can similarly advance opportunities for intervention and translational research. Several areas of growing research interest include expanding exposomics and use of multi-omics, the microbiome as a mediator of environmental stressors, toxicant mixtures and neurobiology, and the role of structural and historical marginalization and racism in shaping persistent disparities in population aging and outcomes. Integrated foundational and translational aging biology research in environmental health sciences is needed to improve policy, reduce disparities, and enhance the quality of life for older individuals.

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.

The Impact of Exercise on Telomere Length, DNA Methylation and Metabolic Footprints

Aging as a major risk factor influences the probability of developing cancer, cardiovascular disease and diabetes, amongst others. The underlying mechanisms of disease are still not fully understood, but research suggests that delaying the aging process could ameliorate these pathologies. A key biological process in aging is cellular senescence which is associated with several stressors such as telomere shortening or enhanced DNA methylation. Telomere length as well as DNA methylation levels can be used as biological age predictors which are able to detect excessive acceleration or deceleration of aging. Analytical methods examining aging are often not suitable, expensive, time-consuming or require a high level of technical expertise. Therefore, research focusses on combining analytical methods which have the potential to simultaneously analyse epigenetic, genomic as well as metabolic changes.

Awareness of maternal stress, consequences for the offspring and the need for early interventions to increase stress resilience

Experimental and clinical studies suggest that prenatal experiences may influence health trajectories up to adulthood and high age. According to the hypothesis of developmental origins of health and disease exposure of pregnant women to stress, nutritional challenges, infection, violence, or war may "program" risks for diseases in later life. Stress and anxieties can exist or be provoked in parents after fertility treatment, after information or diagnosis of fetal abnormalities and demand simultaneous caring concepts to support the parents. In vulnerable groups, it is therefore important to increase the stress resilience to avoid harmful consequences for the growing child. "Enriched environment" defines a key paradigm to decipher how interactions between genes and environment change the structure and function of the brain. The regulation of the fetal hippocampal neurogenesis and morphology during pregnancy is one example of this complex interaction. Animal experiments have demonstrated that an enriched environment can revert consequences of stress in the offspring during critical periods of brain plasticity. Epigenetic markers of stress or wellbeing during pregnancy might even be diagnosed by fragments of placental DNA in the maternal circulation that show characteristic methylation patterns. The development of fetal senses further illustrates how external stimulation may impact individual preferences. Here, we therefore not only discuss how maternal stress influences cognitive development and resilience, but also design possibilities of non-invasive interventions for both mothers and children summarized and evaluated in the light of their potential to improve the health of future generations.

The effects of exercise intensity on the cortisol response to a subsequent acute psychosocial stressor

OBJECTIVE

The aim of this experimental study was to determine the extent to which the intensity of a single 30 min bout of exercise alters the salivary cortisol (sCort) response to a subsequently induced acute psychosocial stressor. The study further aimed to elucidate a physiological mechanism through which exercise intensity exerts stress-mitigating effects.

METHODS

Eighty-three healthy men (M_age = 21.04 SD = 2.89) were randomly assigned to exercise on a treadmill at either 30%, 50% or 70% of their heart rate reserve (HRR) for 30 min and then underwent the Trier Social Stress Test 45 min later. sCort was measured repeatedly throughout and following the exercise bout and stressor task.

RESULTS

ANCOVA and Multilevel Growth Curve Analysis determined that vigorous (70% HRR) exercise elicited dampened sCort responses to the stressor task, marked by lower total sCort levels, diminished sCort reactivity, and faster recovery to baseline values, as compared to less intense exercise. Moreover, exercise elicited a sCort response in proportion to the intensity at which it was performed, and this exercise-associated HPA-axis response was inversely proportional to the sCort response to the subsequent stressor task.

CONCLUSIONS

This study revealed that exercise-intensity dampens the HPA-axis stress response in a dose-dependent manner, with evidence that the cortisol released from exercising intensely suppresses the subsequent cortisol response to a psychosocial stressor.

Longer Leukocyte Telomere Length Predicts Stronger Response to a Workplace Sugar-Sweetened Beverage Sales Ban: An Exploratory Study

BACKGROUND

Shorter leukocyte telomere length (LTL) is associated with increased risk of a number of metabolic diseases including insulin resistance and the development of type 2 diabetes mellitus. Shorter LTL is also associated with stress reactivity suggestive of a possible role for LTL to predict response to behavioral interventions. However, few studies have evaluated how interventions, such as weight loss or dietary changes, are associated with LTL changes or whether LTL can predict behavioral responses to interventions.

OBJECTIVES

We evaluated metabolic changes in relation to LTL changes and LTL at baseline in a cohort of at-risk adults in response to a 10-mo workplace-based sugar-sweetened beverage (SSB) intervention.

METHODS

At baseline, metabolic health and LTL measurements were assessed through standard blood draws on 212 participants. Multivariable linear regression models were used to assess changes in anthropometrics, SSB consumption, and 13 blood-based metabolic risk factors, in relation to LTL at baseline and changes in LTL.

RESULTS

Longer LTL at baseline was associated with decreases in SSB consumption over the 6-mo follow-up period (B = -29.67; P = 0.04). Slower LTL attrition rates were associated with decreases in waist circumference (B = -0.27; P  = 0.03), HDL cholesterol (B = -0.20; P  = 0.05), and apoA1 (B = -0.09; P = 0.01).

CONCLUSIONS

Longer LTL at baseline predicted a favorable overall response to a behavioral intervention: decreases in SSB consumption. Abdominal adiposity losses paralleled slower declines in LTL suggestive of overall health benefits, but we found differences in the relations between metabolic changes and LTL at baseline compared with LTL attrition rates. Longer LTL may be a proxy marker of a positive behavioral response.This trial was registered at clinicaltrials.gov as NCT02585336.

Different epigenetic signatures of newborn telomere length and telomere attrition rate in early life

Telomere length (TL) and telomere shortening are biological indicators of aging, and epigenetic associates have been found for TL in adults. However, the role of epigenetic signatures in setting newborn TL and early life telomere dynamics is unknown. In the present study, based on 247 participating newborns from the ENVIRONAGE birth cohort, whole-genome DNA methylation, profiled on the Illumina MethylationEPIC BeadChip microarray, and TL were measured in cord blood. In a follow-up visit at a mean age of 4.58 years, leukocyte TL was evaluated. We combined an epigenome-wide association study and a statistical learning method with re-sampling to select CpGs and their two-way interactions to model baseline (cord blood) TL and early-life telomere attrition rate, where distinct epigenetic signatures were identified for the two outcomes. In addition, a stronger epigenetic regulation was suggested in setting newborn TL than that of telomere dynamics in early life: 47 CpGs and 7 between-CpG interactions explained 76% of the variance in baseline TLs, while 72% of the total variance in telomere attrition rate was explained by 31 CpGs and 5 interactions. Functional enrichment analysis based on the selected CpGs in the two models revealed GLUT4 translocation and immune cell signaling pathways, respectively. These CpGs and interactions, as well as the cellular pathways, are potential novel targets of further investigation of telomere biology and aging.

Minimal changes in telomere length after a 12-week dietary intervention with almonds in mid-age to older, overweight and obese Australians: results of a randomised clinical trial

Diet is a modifiable risk factor for chronic disease and a potential modulator of telomere length (TL). The study aim was to investigate associations between diet quality and TL in Australian adults after a 12-week dietary intervention with an almond-enriched diet (AED). Participants (overweight/obese, 50-80 years) were randomised to an AED (n 62) or isoenergetic nut-free diet (NFD, n 62) for 12 weeks. Diet quality was assessed using a Dietary Guideline Index (DGI), applied to weighed food records, that consists of ten components reflecting adequacy, variety and quality of core food components and discretionary choices within the diet. TL was measured by quantitative PCR in samples of lymphocytes, neutrophils, and whole blood. There were no significant associations between DGI scores and TL at baseline. Diet quality improved with AED and decreased with NFD after 12 weeks (change from baseline AED + 9·8 %, NFD - 14·3 %; P < 0·001). TL increased in neutrophils (+9·6 bp, P = 0·009) and decreased in whole blood, to a trivial extent (-12·1 bp, P = 0·001), and was unchanged in lymphocytes. Changes did not differ between intervention groups. There were no significant relationships between changes in diet quality scores and changes in lymphocyte, neutrophil or whole blood TL. The inclusion of almonds in the diet improved diet quality scores but had no impact on TL mid-age to older Australian adults. Future studies should investigate the impact of more substantial dietary changes over longer periods of time.

Focus on disability-free life expectancy: implications for health-related quality of life

BACKGROUND

Since the end of the industrial revolution, advances in public health and clinical medicine have contributed to dramatic decreases in infant and childhood mortality, improvements in health-related quality of life (HRQoL), increases in overall life expectancy (LE), and rectangularization of survival curves.

OBJECTIVES

In this article, we focus on disability that has occurred with the overall lengthening of LE in many populations and the implications this has for decreased HRQoL.

METHODS

We utilize the concept of rectangularization of population survival to depict the rising prevalence of disability associated with increased LE, especially among racial and ethnic minorities and people of low socioeconomic status (SES) and relate this to HRQoL.

RESULTS

Disability-free life expectancy (DFLE) and healthy life expectancy (HLE) are defined in terms of HRQoL. Specific attention is focused on disability experienced by disparate populations around the globe. By focusing on disparities in DFLE, and the need to expand LE to include HLE as a central component of HRQoL, this work provides an important counterpoint to the attention that has been paid to LE disparities according to race, gender, ethnicity, education, and SES.

DISCUSSION

By calling attention to those factors that appear to be the most important drivers of the differences in quality and length of DFLE between different groups (i.e., the components of the social gradient, exposure to chronic stress, systemic inflammation, and the psychological and biological mechanisms associated with the gut-brain axis) and, by logical extension, HRQoL, we hope to promote research in this arena with the ultimate goal of improving DFLE, HLE, and overall HRQoL, especially in disparate populations around the globe.

Telomere Length Change in a Multidomain Lifestyle Intervention to Prevent Cognitive Decline: A Randomized Clinical Trial

Background

Shorter leukocyte telomere length (LTL) is associated with aging and dementia. Impact of lifestyle changes on LTL, and relation to cognition and genetic susceptibility for dementia, has not been investigated in randomized controlled trials (RCTs).

Methods

Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability is a 2-year RCT enrolling 1260 participants at risk for dementia from the general population, aged 60–77 years, randomly assigned (1:1) to multidomain lifestyle intervention or control group. The primary outcome was cognitive change (Neuropsychological Test Battery z-score). Relative LTL was measured using quantitative real-time polymerase chain reaction (trial registration: NCT01041989).

Results

This exploratory LTL substudy included 756 participants (377 intervention, 379 control) with baseline and 24-month LTL measurements. The mean annual LTL change (SD) was −0.016 (0.19) in the intervention group and −0.023 (0.17) in the control group. Between-group difference was nonsignificant (unstandardized β-coefficient 0.007, 95% CI −0.015 to 0.030). Interaction analyses indicated better LTL maintenance among apolipoprotein E (APOE)-ε4 carriers versus noncarriers: 0.054 (95% CI 0.007 to 0.102); younger versus older participants: −0.005 (95% CI −0.010 to −0.001); and those with more versus less healthy lifestyle changes: 0.047 (95% CI 0.005 to 0.089). Cognitive intervention benefits were more pronounced among participants with better LTL maintenance for executive functioning (0.227, 95% CI 0.057 to 0.396) and long-term memory (0.257, 95% CI 0.024 to 0.489), with a similar trend for Neuropsychological Test Battery total score (0.127, 95% CI −0.011 to 0.264).

Conclusions

This is the first large RCT showing that a multidomain lifestyle intervention facilitated LTL maintenance among subgroups of older people at risk for dementia, including APOE-ε4 carriers. LTL maintenance was associated with more pronounced cognitive intervention benefits.

Clinical Trials Registration Number

NCT01041989

Biopsychosocial Risk Profiles among African American and Non-Hispanic White Adults: Findings from The Health and Retirement Study

BACKGROUND

Compared to Whites, African Americans have elevated risk for earlier onset fatal and non-fatal chronic conditions and accelerated aging. Despite these persistent race disparities, the causes remain poorly understood. The purpose of this study was to define a biopsychosocial risk typology that might explain accelerated aging in African Americans.

METHODS

Analyses were based on the African American and White subsample of the Health and Retirement Study (N=8,269). Latent class analysis was used to identify risk types. Chronic health conditions, salivary telomere length (STL), emotional support from family, negative interaction with family, early life adversities, and discrimination were used as class indicators. Latent class multinomial logistic regression was used to identify racial and demographic differences in risk type membership.

RESULTS

Three distinct risk types were identified: high risk, health risk, and psychosocial risk. African Americans were more likely than Whites to be assigned to the high risk type characterized by chronic health conditions, shorter STL, strained social relationships and high psychosocial stress. African Americans were less likely than Whites to be assigned to the health risk type characterized by chronic health conditions, shorter STL, optimal social relationships and low psychosocial stress.

CONCLUSIONS

The biopsychosocial risk typology accounted for population heterogeneity, identified high-risk profiles and modifiable factors within risk types that can inform current clinical interventions. The risk types also revealed different patterns of risk and resilience factors and shed light on the interplay between telomere length, stress exposure, chronic disease and accelerated aging in African Americans.

Maternal psychosocial functioning, obstetric health history, and newborn telomere length

There is growing interest in elucidating the determinants of newborn telomere length, given its potential as a biomarker of lifetime disease risk affected by prenatal exposures. There is limited evidence that increased maternal stress during pregnancy predicts shorter newborn telomere length. However, the few studies published to date have been conducted primarily with small samples utilizing inconsistent definitions of maternal stress. Moreover, the potential influence of fetal sex as a moderator of maternal stress effects on newborn telomere length has been largely ignored despite compelling evidence of likely impact. In a prospective cohort study of pregnant women seeking routine prenatal care, we tested whether a range of maternal measures of stressor exposures, subjective feelings of stress, and mental health (depression, anxiety) were associated with newborn telomere length assessed from cord blood among 146 pregnant women and their newborn infants. We further examined whether the pattern of associations differed by infant sex. Sociodemographic and maternal and newborn health indicators were considered as potential covariates. When examined within the whole sample, none of the maternal psychosocial measures were associated with newborn telomere length. Among potential covariates, maternal history of smoking and preeclampsia in a previous pregnancy were negatively associated with newborn telomere length. In adjusted linear regression analyses that considered potential sex-specific effects, maternal depression, general anxiety, and pregnancy-specific anxiety symptoms were positively associated with newborn telomere length among males. Overall, the findings provide some evidence for an association between maternal psychosocial wellbeing in pregnancy and newborn telomere length in males, although in the opposite direction than previously reported. Maternal smoking and obstetric history prior to conception may be associated with shorter offspring telomere length.

Neighborhood social environment and changes in leukocyte telomere length: The Multi-Ethnic Study of Atherosclerosis (MESA)

Given limited research on the impact of neighborhood environments on accelerated biological aging, we examined whether changes in neighborhood socioeconomic and social conditions were associated with change in leukocyte telomere length using 10 years of longitudinal data from the Multi-Ethnic Study of Atherosclerosis (years 2000-2011; N = 1031; mean age = 61, SD = 9.4). Leukocyte telomere length change was corrected for regression to the mean and neighborhood was defined as census tract. Neighborhood socioeconomic indicators (factor-based score of income, education, occupation, and wealth of neighborhood) and neighborhood social environment indicators (aesthetic quality, social cohesion, safety) were obtained from the U.S Census/American Community Survey and via study questionnaire, respectively. Results of linear mixed-effects models showed that independent of individual sociodemographic characteristics, each unit of improvement in neighborhood socioeconomic status was associated with slower telomere length attrition over 10-years (β = 0.002; 95% Confidence Interval (CI): 0.0001, 0.004); whereas each unit of increase in safety (β = -0.043; 95% CI: -0.069, -0.016) and overall neighborhood social environment score (β = -0.005; 95% CI: -0.009, -0.0004) were associated with more pronounced telomere attrition, after additionally adjusting for neighborhood socioeconomic status. This study provides support for considerations of the broader social and socioeconomic contexts in relation to biological aging. Future research should explore potential psychosocial mechanisms underlying these associations using longitudinal study designs with repeated observations.

Pathogen burden and leukocyte telomere length in the United States

BACKGROUND

Prior studies in humans have suggested that telomere shortening may be accelerated by infection, but research on multiple pathogens and use of large population-based study samples has been limited. We estimated cross-sectional associations between seropositivity to five persistent pathogens (Herpes Simplex Virus Type-1 (HSV-1), Herpes Simplex Virus Type-2 (HSV-2), cytomegalovirus (CMV), Helicobacter pylori (H.pylori), and Hepatitis B) as well as total pathogen burden and leukocyte telomere length. Data were derived from the National Health and Nutrition Examination Survey (1999-2000) for individuals 20-49 years of age, N = 1708. We analyzed the influence of each pathogen separately, a pathogen count score and a latent class model of pathogen burden on log telomere length using linear regression models, adjusted for covariates.

RESULTS

Individuals in a latent pathogen burden class characterized by high probabilities of infection with HSV-1, CMV, and H. pylori, had significantly decreased log telomere length (- 0.30 [95% CI: - 0.36, - 0.24]) compared to those in a latent class characterized by low probabilities of all five infections. There were limited significant associations using other pathogen measures.

CONCLUSIONS

These results suggest that infection with specific combinations of pathogens may be one mechanism contributing to accelerated cellular senescence with possible origins early in the life course.

Gender and palliative care: a call to arms

There has been a systematic and largely unconscious neglect of gender in palliative care research, practice and policy. This is despite significant, although previously uncollated, evidence that gender influences almost all aspects of end-of-life preferences, experiences and care. The social situations of women, transgender people and men often differ from one another while also intersecting in complex ways with sex differences rooted in biology. If palliative care is to meet its aspiration of providing universal benefit, it urgently needs to address a range of gender inequalities currently (re)produced at the level of the laboratory all the way through to government departments. In this call to arms, we spotlight specific instances where gender inequalities have been documented, for example, regarding end-of-life caregiving, end-of-life intervention and palliative care access and benefit. We highlight how gender inequalities intersect with other social determinants of health including ethnicity and economic status to exacerbate situations of marginality. We conclude by offering some practical steps that can be taken to support the discipline to adopt a more critical gender lens to support more equitable research, policy and practice.

The functional and structural connectomes of telomere length and their association with cognition in mild cognitive impairment

Previous findings on the relationship between telomere length and cognition have inconclusive, despite the relatively consistent telomere-shortening associated atrophy in the subcortical regions. Perhaps, there could be other more important telomere-associated factors in the brain, such as functional connectivity (FC) and structural connectivity (SC) that modulate cognition. The current study examined the relationship between telomere length, connectivity, and cognition. Telomere length measurements, neurocognitive scores, diffusion tensor and resting-state functional magnetic resonance imaging scans were collected from 82 older adults with mild cognitive impairment. SC and FC matrices were derived from these scans and, in various combinations, entered into connectome-based predictive models to predict telomere length. The telomere-associated features were then used to predict memory and executive functions. Leave-one-out cross-validation was performed. Predictive accuracy was assessed via the correlation between predicted and observed scores (r_{predicted-observed}). Correlation analyses were carried out between cognition and telomere length. Telomere length was significantly and negatively correlated with executive functions (EF), after controlling for demographical confounds. Telomere length was best predicted by negative SC and positive FC features (r_{predicted-observed} = .57; p < .001). The telomere-associated negative SC features significantly predicted EF scores (r_{predicted-observed} = -.26; p = .015). Telomere-shortening was associated with better EF and alterations in both FC and SC. This enhanced EF can be partly attributed to the telomere-associated changes in SC. Given that telomere is known to be a nonspecific marker of health, our findings illustrated a potential clinical use of telomere length to predict individualized health-related information from FC and SC features.

Delayed sleep-onset and biological age: late sleep-onset is associated with shorter telomere length

STUDY OBJECTIVES

We evaluated the relationship between leukocyte telomere length (LTL) and sleep duration, insomnia symptoms, and circadian rhythm, to test whether sleep and chronobiological dysregulations are associated with cellular aging.

METHODS

Data from the Netherlands Study of Depression and Anxiety (N = 2,936) were used at two waves 6 years apart, to measure LTL. Telomeres shorten during the life span and are important biomarkers for cellular aging. LTL was assessed by qualitative polymerase chain reaction and converted into base pair number. Sleep parameters were: sleep duration and insomnia symptoms from the Insomnia Rating Scale. Circadian rhythm variables were: indication of Delayed Sleep Phase Syndrome (DSPS), mid-sleep corrected for sleep debt on free days (MSFsc), sleep-onset time, and self-reported chronotype, from the Munich Chronotype Questionnaire. Generalized estimating equations analyzed the associations between LTL, sleep, and chronobiological factors, adjusted for baseline age, sex, North European ancestry, and additionally for current smoking, depression severity, obesity, and childhood trauma.

RESULTS

Indicators of delayed circadian rhythm showed a strong and consistent effect on LTL, after adjustment for sociodemographic and health indicators. Late MSFsc (B = -49.9, p = .004), late sleep-onset time (B = -32.4, p = .001), indication of DSPS (B = -73.8, p = .036), and moderately late chronotype in adulthood (B = -71.6, p = .003) were associated with significantly shorter LTL across both waves; whereas sleep duration and insomnia symptoms were not. Extremely early chronotype showed significantly less LTL shortening than intermediate chronotype (B = 161.40, p = .037). No predictors showed accelerated LTL attrition over 6 years.

CONCLUSIONS

Individuals with delayed circadian rhythm have significantly shorter LTL, but not faster LTL attrition rates.

Chronic psychosocial and financial burden accelerates 5-year telomere shortening: findings from the Coronary Artery Risk Development in Young Adults Study

Leukocyte telomere length, a marker of immune system function, is sensitive to exposures such as psychosocial stressors and health-maintaining behaviors. Past research has determined that stress experienced in adulthood is associated with shorter telomere length, but is limited to mostly cross-sectional reports. We test whether repeated reports of chronic psychosocial and financial burden is associated with telomere length change over a 5-year period (years 15 and 20) from 969 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Study, a longitudinal, population-based cohort, ages 18-30 at time of recruitment in 1985. We further examine whether multisystem resiliency, comprised of social connections, health-maintaining behaviors, and psychological resources, mitigates the effects of repeated burden on telomere attrition over 5 years. Our results indicate that adults with high chronic burden do not show decreased telomere length over the 5-year period. However, these effects do vary by level of resiliency, as regression results revealed a significant interaction between chronic burden and multisystem resiliency. For individuals with high repeated chronic burden and low multisystem resiliency (1 SD below the mean), there was a significant 5-year shortening in telomere length, whereas no significant relationships between chronic burden and attrition were evident for those at moderate and higher levels of resiliency. These effects apply similarly across the three components of resiliency. Results imply that interventions should focus on establishing strong social connections, psychological resources, and health-maintaining behaviors when attempting to ameliorate stress-related decline in telomere length among at-risk individuals.

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.

Health Behaviors and Psychological Distress Among Conscripts of the Lithuanian Military Service: A Nationally Representative Cross-Sectional Study

The decline in healthy behavior in young people is a concern for public health in general and for country's defense. The aim of this study is to identify and compare health behaviors and psychological distress between male conscripts enlisted and rejected for military service. This cross-sectional study included 1243 men aged 19-26 years (mean age 22.50 ± 2.43 years). We assessed health behaviors (physical activity, adherence to healthy eating patterns, cigarette smoking, and alcohol consumption) and psychological distress. Among all conscripts, 44.7% were physically inactive, 50.2% had low adherence to healthy nutrition, 9.6% were heavy drinkers, 62.3% were current smokers, and 9.1% had high psychological distress level. Compared with physically inactive conscripts, physically active conscripts were more likely to be enlisted (adjusted odds ratio (OR) = 1.42; 95% confidence interval (CI) 1.11-2.03). Compared with current nonsmokers, current smokers were less likely to be enlisted (OR = 0.58; CI 0.39-0.86). Compared with conscripts with a high distress level, those with a low distress level were almost four times more likely to be enlisted (OR = 0.26; 95% CI 0.12-0.55). Adherence to guidelines for healthy eating and alcohol consumption was not significantly related to enlistment. These findings suggest that health behaviors in male conscripts are unsatisfactory. That is, about half are physically inactive, have a poor diet, and smoke, and nearly one in 10 is a heavy drinker and has a high psychological distress level. The enlisted conscripts were more likely to be sufficiently physically active and less likely to be a current smoker or have a high distress level. Early intervention programs to provide a heathier population of young men for conscription should focus on mental well-being and target health-related behaviors such as physical activity and not smoking. Preferably, these should be implemented as health education programs in schools to help prevent the development of adverse health behaviors among young men. Governmental policies and strategies are required to enable intersectional collaboration and shared responsibility among the education, military and health sectors.

The impact of depression and anxiety treatment on biological aging and metabolic stress: study protocol of the MOod treatment with antidepressants or running (MOTAR) study

BACKGROUND

Depressive and anxiety disorders have shown to be associated to premature or advanced biological aging and consequently to adversely impact somatic health. Treatments with antidepressant medication or running therapy are both found to be effective for many but not all patients with mood and anxiety disorders. These interventions may, however, work through different pathophysiological mechanisms and could differ in their impact on biological aging and somatic health. This study protocol describes the design of an unique intervention study that examines whether both treatments are similarly effective in reducing or reversing biological aging (primary outcome), psychiatric status, metabolic stress and neurobiological indicators (secondary outcomes).

METHODS

The MOod Treatment with Antidepressants or Running (MOTAR) study will recruit a total of 160 patients with a current major depressive and/or anxiety disorder in a mental health care setting. Patients will receive a 16-week treatment with either antidepressant medication or running therapy (3 times/week). Patients will undergo the treatment of their preference and a subsample will be randomized (1:1) to overcome preference bias. An additional no-disease-no-treatment group of 60 healthy controls without lifetime psychopathology, will be included as comparison group for primary and secondary outcomes at baseline. Assessments are done at week 0 for patients and controls, and at week 16 and week 52 for patients only, including written questionnaires, a psychiatric and medical examination, blood, urine and saliva collection and a cycle ergometer test, to gather information about biological aging (telomere length and telomerase activity), mental health (depression and anxiety disorder characteristics), general fitness, metabolic stress-related biomarkers (inflammation, metabolic syndrome, cortisol) and genetic determinants. In addition, neurobiological alterations in brain processes will be assessed using structural and functional Magnetic Resonance Imaging (MRI) in a subsample of at least 25 patients per treatment arm and in all controls.

DISCUSSION

This intervention study aims to provide a better understanding of the impact of antidepressant medication and running therapy on biological aging, metabolic stress and neurobiological indicators in patients with depressive and anxiety disorders in order to guide a more personalized medicine treatment.

TRIAL REGISTRATION

Trialregister.nl Number of identification: NTR3460, May 2012.

Telomere regulation: lessons learnt from mice and men, potential opportunities in horses

Telomeres are genetically conserved nucleoprotein complexes located at the ends of chromosomes that preserve genomic stability. In large mammals, somatic cell telomeres shorten with age, owing to the end replication problem and lack of telomere-lengthening events (e.g. telomerase and ALT activity). Therefore, telomere length reflects cellular replicative reserve and mitotic potential. Environmental insults can accelerate telomere attrition in response to cell division and DNA damage. As such, telomere shortening is considered one of the major hallmarks of ageing. Much effort has been dedicated to understanding the environmental perturbations that accelerate telomere attrition and therapeutic strategies to preserve or extend telomeres. As telomere dynamics seem to reflect cumulative cellular stress, telomere length could serve as a biomarker of animal welfare. The assessment of telomere dynamics (i.e. rate of shortening) in conjunction with telomere-regulating genes and telomerase activity in racehorses could monitor long-term animal health, yet it could also provide some unique opportunities to address particular limitations with the use of other animal models in telomere research. Considering the ongoing efforts to optimise the health and welfare of equine athletes, the purpose of this review is to discuss the potential utility of assessing telomere length in Thoroughbred racehorses. A brief review of telomere biology in large and small mammals will be provided, followed by discussion on the biological implications of telomere length and environmental (e.g. lifestyle) factors that accelerate or attenuate telomere attrition. Finally, the utility of quantifying telomere dynamics in horses will be offered with directions for future research.

Controlling for baseline telomere length biases estimates of the rate of telomere attrition

Longitudinal studies have sought to establish whether environmental exposures such as smoking accelerate the attrition of individuals' telomeres over time. These studies typically control for baseline telomere length (TL) by including it as a covariate in statistical models. However, baseline TL also differs between smokers and non-smokers, and telomere attrition is spuriously linked to baseline TL via measurement error and regression to the mean. Using simulated datasets, we show that controlling for baseline TL overestimates the true effect of smoking on telomere attrition. This bias increases with increasing telomere measurement error and increasing difference in baseline TL between smokers and non-smokers. Using a meta-analysis of longitudinal datasets, we show that as predicted, the estimated difference in telomere attrition between smokers and non-smokers is greater when statistical models control for baseline TL than when they do not, and the size of the discrepancy is positively correlated with measurement error. The bias we describe is not specific to smoking and also applies to other exposures. We conclude that to avoid invalid inference, models of telomere attrition should not control for baseline TL by including it as a covariate. Many claims of accelerated telomere attrition in individuals exposed to adversity need to be re-assessed.

A Cross-Sectional Analysis of Telomere Length and Sleep in the Women's Health Initiative

Telomere length is a heritable marker of cellular age that is associated with morbidity and mortality. Poor sleep behaviors, which are also associated with adverse health events, may be related to leukocyte telomere length (LTL). We studied a subpopulation of 3,145 postmenopausal women (1,796 European-American (EA) and 1,349 African-American (AA)) enrolled in the Women's Health Initiative in 1993-1998 with data on Southern blot-measured LTL and self-reported usual sleep duration and sleep disturbance. LTL-sleep associations were analyzed separately for duration and disturbance using weighted and confounder-adjusted linear regression models in the entire sample (AAs + EAs; adjusted for race/ethnicity) and in racial/ethnic strata, since LTL differs by ancestry. After adjustment for covariates, each additional daily hour of sleep beyond 5 hours, approximately, was associated with a 27-base-pair (95% confidence interval (CI): 6, 48) longer LTL in the entire sample. Associations between sleep duration and LTL were strongest among AAs (adjusted β = 37, 95% CI: 4, 70); a similar, nonsignificant association was observed for EAs (adjusted β = 20, 95% CI: -7, 48). Sleep disturbance was not associated with LTL in our study. Our models did not show departure from linearity (quadratic sleep terms: P ≥ 0.55). Our results suggest that longer sleep duration is associated with longer LTL in postmenopausal women.

Telomere Biology in Mood Disorders: An Updated, Comprehensive Review of the Literature

Major psychiatric disorders are linked to early mortality and patients afflicted with these ailments demonstrate an increased risk of developing physical diseases that are characteristically seen in the elderly. Psychiatric conditions like major depressive disorder, bipolar disorder and schizophrenia may be associated with accelerated cellular aging, indicated by shortened leukocyte telomere length (LTL), which could underlie this connection. Telomere shortening occurs with repeated cell division and is reflective of a cell’s mitotic history. It is also influenced by cumulative exposure to inflammation and oxidative stress as well as the availability of telomerase, the telomere-lengthening enzyme. Precariously short telomeres can cause cells to undergo senescence, apoptosis or genomic instability; shorter LTL correlates with compromised general health and foretells mortality. Important data specify that LTL may be reduced in principal psychiatric illnesses, possibly in proportion to exposure to the ailment. Telomerase, as measured in peripheral blood monocytes, has been less well characterized in psychiatric illnesses, but a role in mood disorder has been suggested by preclinical and clinical studies. In this manuscript, the most recent studies on LTL and telomerase activity in mood disorders are comprehensively reviewed, potential mediators are discussed, and future directions are suggested. An enhanced comprehension of cellular aging in psychiatric illnesses could lead to their re-conceptualizing as systemic ailments with manifestations both inside and outside the brain. At the same time this paradigm shift could identify new treatment targets, helpful in bringing about lasting cures to innumerable sufferers across the globe.

Accelerating research on biological aging and mental health: Current challenges and future directions

Aging is associated with complex biological changes that can be accelerated, slowed, or even temporarily reversed by biological and non-biological factors. This article focuses on the link between biological aging, psychological stressors, and mental illness. Rather than comprehensively reviewing this rapidly expanding field, we highlight challenges in this area of research and propose potential strategies to accelerate progress in this field. This effort requires the interaction of scientists across disciplines - including biology, psychiatry, psychology, and epidemiology; and across levels of analysis that emphasize different outcome measures - functional capacity, physiological, cellular, and molecular. Dialogues across disciplines and levels of analysis naturally lead to new opportunities for discovery but also to stimulating challenges. Some important challenges consist of 1) establishing the best objective and predictive biological age indicators or combinations of indicators, 2) identifying the basis for inter-individual differences in the rate of biological aging, and 3) examining to what extent interventions can delay, halt or temporarily reverse aging trajectories. Discovering how psychological states influence biological aging, and vice versa, has the potential to create novel and exciting opportunities for healthcare and possibly yield insights into the fundamental mechanisms that drive human aging.

Smoking does not accelerate leucocyte telomere attrition: a meta-analysis of 18 longitudinal cohorts

Smoking is associated with shorter leucocyte telomere length (LTL), a biomarker of increased morbidity and reduced longevity. This association is widely interpreted as evidence that smoking causes accelerated LTL attrition in adulthood, but the evidence for this is inconsistent. We analysed the association between smoking and LTL dynamics in 18 longitudinal cohorts. The dataset included data from 12 579 adults (4678 current smokers and 7901 non-smokers) over a mean follow-up interval of 8.6 years. Meta-analysis confirmed a cross-sectional difference in LTL between smokers and non-smokers, with mean LTL 84.61 bp shorter in smokers (95% CI: 22.62 to 146.61). However, LTL attrition was only 0.51 bp yr-1 faster in smokers than in non-smokers (95% CI: -2.09 to 1.08), a difference that equates to only 1.32% of the estimated age-related loss of 38.33 bp yr-1. Assuming a linear effect of smoking, 167 years of smoking would be required to generate the observed cross-sectional difference in LTL. Therefore, the difference in LTL between smokers and non-smokers is extremely unlikely to be explained by a linear, causal effect of smoking. Selective adoption, whereby individuals with short telomeres are more likely to start smoking, needs to be considered as a more plausible explanation for the observed pattern of telomere dynamics.

Cumulative lifetime stress exposure and leukocyte telomere length attrition: The unique role of stressor duration and exposure timing

BACKGROUND

Stress exposure occurring across the lifespan increases risk for disease, potentially involving telomere length shortening. Stress exposure during childhood and adulthood has been cross-sectionally linked with shorter telomere length. However, few longitudinal studies have examined telomere length attrition over time, and none have investigated how stressor duration (acute life events vs. chronic difficulties), timing (childhood vs. adulthood), and perceived severity may be uniquely related to telomere length shortening.

METHODS

To address these issues, we administered a standardized instrument for assessing cumulative lifetime stress exposure (Stress and Adversity Inventory; STRAIN) to 175 mothers of children with Autism Spectrum Disorder or neurotypical children and measured their leukocyte telomere length (LTL) at baseline and 2 years later.

RESULTS

Greater count of lifetime stressors was associated with shorter LTL at baseline and greater LTL attrition over time. When separating lifetime stressors into acute life events and chronic difficulties, only greater count of chronic difficulties significantly predicted shorter baseline LTL and greater LTL attrition. Similarly, when examining timing of stressor exposure, only greater count of chronic childhood difficulties (age < 18) significantly predicted shorter baseline LTL and greater LTL attrition over the 2-year period in mid-life. Importantly, these results were robust while controlling for stressors occurring during the interim 2-year period. Post-hoc analyses suggested that chronic difficulties occurring during earlier childhood (0-12 years) were associated with greater LTL attrition. Cumulative stressor severity predicted LTL attrition in a parallel manner, but was less consistently associated with baseline LTL.

CONCLUSIONS

These data are the first to examine the effects of different aspects of cumulative lifetime stress exposure on LTL attrition over time, suggesting that accumulated chronic difficulties during childhood may play a unique role in shaping telomere shortening in midlife.

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.

Chronic stress exposure and daily stress appraisals relate to biological aging marker p16INK4a

Previous research has linked exposure to adverse social conditions with DNA damage and accelerated telomere shortening, raising the possibility that chronic stress may impact biological aging pathways, ultimately increasing risk for age-related diseases. Less clear, however, is whether these stress-related effects extend to additional hallmarks of biological aging, including cellular senescence, a stable state of cell cycle arrest. The present study aimed to investigate associations between psychosocial stress and two markers of cellular aging-leukocyte telomere length (LTL) and cellular senescence signal p16INK4a. Seventy-three adults (Mage = 43.0, SD = 7.2; 55% female) with children between 8-13 years of age completed interview-based and questionnaire measures of their exposures to and experiences of stress, as well as daily reports of stress appraisals over an 8-week diary period. Blood samples were used to assess markers of cellular aging: LTL and gene expression of senescent cell signal p16INK4a (CDKN2A). Random effects models covarying for age, sex, ethnicity/race, and BMI revealed that participants with greater chronic stress exposure over the previous 6 months (b = 0.011, p =  .04), perceived stress (b = 0.020, p <  .001), and accumulated daily stress appraisals over the 8-week period (b = 0.013, p =  .02) showed increased p16INK4a. No significant associations with LTL were found. These findings extend previous work on the impact of stress on biological aging by linking chronic stress exposure and daily stressful experiences to an accumulation of senescent cells. Findings also support the hypothesis that chronic stress is associated with accelerated aging by inducing cellular senescence, a common correlate of age-related diseases.

At the forefront of psychoneuroimmunology in pregnancy: Implications for racial disparities in birth outcomes: PART 2: Biological mechanisms

As reviewed in Part 1 of this two part review, birth prior to full term is a substantial public health issue. In the US, ˜400,000 babies per year are born preterm (< 37 weeks), while>1 million are early term (37-38^6/7 weeks) and remarkable racial disparities in shortened gestation are observed among African Americans as compared to Whites. Biomechanisms linking stressor exposures with birth outcomes are increasingly being explicated. The current paper reviews the mechanistic role of maternal biological functioning in the link between behavioral exposures and birth outcomes. These include the inter-related roles of neuroendocrine function, inflammatory regulation, biological aging, and the microbiome. An integrative approach which addresses both behavioral and biological factors within the same study, carefully considers the role of race/ethnicity, and rigorously defines birth outcomes (e.g., spontaneous versus medically-indicated and inclusive of early term birth) is needed to move research in this field toward better mechanistic understanding and clinical application.