Telomere Length and All-Cause Mortality: A Meta-analysis

Associations between epigenetic aging and diabetes mellitus in a Swedish longitudinal study

Diabetes mellitus type 2 (T2D) is associated with accelerated biological aging and the increased risk of onset of other age-related diseases. Epigenetic changes in DNA methylation levels have been found to serve as reliable biomarkers for biological aging. This study explores the relationship between various epigenetic biomarkers of aging and diabetes risk using longitudinal data. Data from the Swedish Adoption/Twin Study of Aging (SATSA) was collected from 1984 to 2014 and included 536 individuals with at least one epigenetic measurement. The following epigenetic biomarkers of aging were employed: DNAm PAI-1, DNAmTL, DunedinPACE, PCHorvath1, PCHorvath2, PCHannum, PCPhenoAge, and PCGrimAge. Firstly, longitudinal analysis of biomarker trajectories was done. Secondly, linear correlations between the biomarkers and time to diabetes were studied within individuals developing diabetes. Thirdly, Cox proportional hazards (PH) models were used to assess the associations between these biomarkers and time of diabetes diagnosis, with adjustments for chronological age, sex, education, smoking, blood glucose, and BMI. The longitudinal trajectories of the biomarkers revealed differences between individuals with and without diabetes. Smoothened average curves for DunedinPACE and DNAm PAI-1 were higher for individuals with diabetes around the age 60-70, compared to controls. Likewise, DunedinPACE and DNAm PAI-1 were higher closer to diabetes onset. However, no significant associations were found between the epigenetic biomarkers of aging and risk of diabetes in Cox PH models. Our findings suggest the potential value of developing epigenetic biomarkers specifically tailored to T2D, should we wish to model and explore the potential for predicting the disease.

Genetic and telomeric variability: Insights from a tropical avian hybrid zone

Telomere lengths and telomere dynamics can correlate with lifespan, behaviour and individual quality. Such relationships have spurred interest in understanding variation in telomere lengths and their dynamics within and between populations. Many studies have identified how environmental processes can influence telomere dynamics, but the role of genetic variation is much less well characterized. To provide a novel perspective on how telomeric variation relates to genetic variability, we longitudinally sampled individuals across a narrow hybrid zone (n = 127 samples), wherein two Manacus species characterized by contrasting genome-wide heterozygosity interbreed. We measured individual (n = 66) and population (n = 3) differences in genome-wide heterozygosity and, among hybrids, amount of genetic admixture using RADseq-generated SNPs. We tested for population differences in telomere lengths and telomere dynamics. We then examined how telomere lengths and telomere dynamics covaried with genome-wide heterozygosity within populations. Hybrid individuals exhibited longer telomeres, on average, than individuals sampled in the adjacent parental populations. No population differences in telomere dynamics were observed. Within the parental population characterized by relatively low heterozygosity, higher genome-wide heterozygosity was associated with shorter telomeres and higher rates of telomere shortening-a pattern that was less apparent in the other populations. All of these relationships were independent of sex, despite the contrasting life histories of male and female manakins. Our study highlights how population comparisons can reveal interrelationships between genetic variation and telomeres, and how naturally occurring hybridization and genome-wide heterozygosity can relate to telomere lengths and telomere dynamics.

Dynamics of Leukocyte Telomere Length in Patients with Fabry Disease

Fabry disease (FD) leads to significant morbidity and mortality, which may indicate accelerated ageing. However, it is still unclear whether there is a relationship between telomere length (TL), a marker of biological ageing, and disease outcome. We aimed to examine the relationship between leukocyte TL (LTL) dynamics and the presence of advanced disease stages and/or late complications of FD, including hypertrophic cardiomyopathy, nephropathy and stroke, both cross-sectionally and longitudinally. DNA was extracted from peripheral blood leukocytes and quantitative PCR was utilized to determine relative LTL in 99 Fabry patients. In the longitudinal analysis, we included 50 patients in whom at least three measurements were performed over a period of 5-10 years. The results showed a significant inverse correlation between LTL and age (ρ = -0.20, p = 0.05). No significant differences in LTL were found between females and males (p = 0.79) or between patients receiving disease-specific therapy and those without (p = 0.34). In a cross-sectional analysis, no association was found between the presence (p = 0.15) or number (p = 0.28) of advanced stages of the disease and/or late complications and LTL. Similarly, in a longitudinal analysis, no difference in LTL dynamics was found regarding the presence (p = 0.16) of advanced stage organ involvement and/or late complications or their number. These findings indicate that LTL dynamics in adulthood may not be a reliable indicator of disease outcomes in Fabry patients. Therefore, LTL may more accurately reflect the disease burden in early life, when TL is primarily determined.

Association of healthy and unhealthy plant-based diets with telomere length

BACKGROUND & AIMS

Previous studies have shown that plant-rich dietary patterns, such as the Mediterranean diet, are associated with longer telomeres. However, no association has been found between vegetarian diet and telomere length. We hypothesized that the quality of plant-based diets plays an important role in telomere length.

METHODS

Data were obtained from the National Health and Nutrition Examination Survey 1999-2002. Diet was assessed using a 24-h recall method. Plant-based diet quality was assessed using the overall plant-based diet index (PDI), healthy PDI (hPDI), and unhealthy PDI (uPDI). Telomere length was measured using quantitative PCR. Linear and ordinal logistic regression models were used to assess the association of PDIs with log-transformed telomere length and ordinal quintiles of telomere length in descending order, respectively.

RESULTS

In both regression models, the overall PDI was not associated with telomere length. The hPDI was associated with longer telomere length [percentage change = 2.34%, 95% confidence interval (CI): 0.42%, 4.31%, Ptrend = 0.016; odds ratio (OR) = 0.81, 95% CI: 0.69, 0.95, Ptrend = 0.013]. However, uPDI was associated with shorter telomere length (percentage change = -3.17%, 95% CI: -5.65%, -0.62%, Ptrend = 0.017; OR = 1.25, 95% CI:1.03, 1.53, Ptrend = 0.014) and this inverse association was stronger in the non-Hispanic white population (Pinteraction = 0.001 in both regression models).

CONCLUSIONS

A plant-based dietary pattern rich in healthy plant foods is associated with longer telomeres. However, plant-based dietary patterns rich in unhealthy plant-based foods are associated with shorter telomere lengths, especially in non-Hispanic white populations.

Trauma, adversity, and biological aging: behavioral mechanisms relevant to treatment and theory

Although stress and adversity are largely universal experiences, people exposed to greater hardship are at increased risk for negative health consequences. Recent studies identify accelerated biological aging as a mechanism that could explain how trauma and adversity gives rise to poor health, and advances in this area of study coincide with technological innovations in the measurement of biological aging, particularly epigenetic profiles consistent with accelerated aging derived from DNA methylation. In this review, we provide an overview of the current literature examining how adversity might accelerate biological aging, with a specific focus on social and health behaviors. The most extensive evidence in this area suggests that health-compromising behaviors, particularly smoking, may partially explain the association between adversity and accelerated aging. Although there is relatively less published support for the role of social behaviors, emerging evidence points to the importance of social connection as a mechanism for future study. Our review highlights the need to determine the extent to which the associations from adversity to accelerated aging are consistent with causal processes. As we consider these questions, the review emphasizes methodological approaches from the causal inference literature that can help deepen our understanding of how stress and trauma might result in poor health. The use of these methodologies will help provide evidence as to which behavioral interventions might slow aging and improve health, particularly among populations that more often experience adversity and trauma.

DNA methylation-based telomere length is associated with HIV infection, physical frailty, cancer, and all-cause mortality

Telomere length (TL) is an important indicator of cellular aging. Shorter TL is associated with several age-related diseases including coronary heart disease, heart failure, diabetes, osteoporosis, and cancer. Recently, a DNA methylation-based TL (DNAmTL) estimator has been developed as an alternative method for directly measuring TL. In this study, we examined the association of DNAmTL with cancer prevalence and mortality risk among people with and without HIV in the Veterans Aging Cohort Study Biomarker Cohort (VACS, N = 1917) and Women's Interagency HIV Study Cohort (WIHS, N = 481). We profiled DNAm in whole blood (VACS) or in peripheral blood mononuclear cells (WIHS) using an array-based method. Cancer prevalence was estimated from electronic medical records and cancer registry data. The VACS Index was used as a measure of physiologic frailty. Models were adjusted for self-reported race and ethnicity, batch, smoking status, alcohol consumption, and five cell types (CD4, CD8, NK, B cell, and monocyte). We found that people with HIV had shorter average DNAmTL than those without HIV infection [beta = -0.25, 95% confidence interval (-0.32, -0.18), p = 1.48E-12]. Greater value of VACS Index [beta = -0.002 (-0.003, -0.001), p = 2.82E-05] and higher cancer prevalence [beta = -0.07 (-0.10, -0.03), p = 1.37E-04 without adjusting age] were associated with shortened DNAmTL. In addition, one kilobase decrease in DNAmTL was associated with a 40% increase in mortality risk [hazard ratio: 0.60 (0.44, 0.82), p = 1.42E-03]. In summary, HIV infection, physiologic frailty, and cancer are associated with shortening DNAmTL, contributing to an increased risk of all-cause mortality.

Deep learning-based prediction of one-year mortality in Finland is an accurate but unfair aging marker

Short-term mortality risk, which is indicative of individual frailty, serves as a marker for aging. Previous age clocks focused on predicting either chronological age or longer-term mortality. Aging clocks predicting short-term mortality are lacking and their algorithmic fairness remains unexamined. We developed a deep learning model to predict 1-year mortality using nationwide longitudinal data from the Finnish population (FinRegistry; n = 5.4 million), incorporating more than 8,000 features spanning up to 50 years. We achieved an area under the curve (AUC) of 0.944, outperforming a baseline model that included only age and sex (AUC = 0.897). The model generalized well to different causes of death (AUC > 0.800 for 45 of 50 causes), including coronavirus disease 2019, which was absent in the training data. Performance varied among demographics, with young females exhibiting the best and older males the worst results. Extensive prediction fairness analyses highlighted disparities among disadvantaged groups, posing challenges to equitable integration into public health interventions. Our model accurately identified short-term mortality risk, potentially serving as a population-wide aging marker.

Telomere length and mortality in lean MAFLD: the other face of metabolic adaptation

BACKGROUND AND AIMS

Healthy weight (lean) patients with metabolic dysfunction-associated fatty liver disease (MAFLD) have a more favorable metabolic and histological profile in cross-sectional studies compared with their non-lean counterparts. Paradoxically, they also have higher overall mortality. The underpinning pathophysiology of this paradox is not understood. Telomere attrition is associated with increased mortality in various diseases.

METHODS

We investigated the role of telomere length in the pathogenesis of lean MAFLD in cohorts with biopsy-proven MAFLD (n = 303). We measured serum malondialdehyde (MDA) levels and hepatic 8-hydroxydeoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal (4-HNE) expression (reactive oxygen species (ROS) markers), growth/differentiation factor-15 (GDF-15) and tested the effect of H2O2 on telomere length and activity in hepatocyte cell lines. The association between leukocyte telomere length and mortality was examined.

RESULTS

Telomere length was significantly lower in patients with lean MAFLD (p < 0.001). They also demonstrated an increase in ROS levels and decreases in GDF-15. H2O2 induced telomere shortening and reducing telomere activity in hepatocyte cell lines. We subsequently confirmed that telomere length shortening at baseline is associated with increased hazards of all-cause mortality; the deleterious effect was more profound in lean people.

CONCLUSION

Differences in telomere length in part explain the increased mortality of lean compared to non-lean patients with MAFLD. The effect is in part mediated through ROS activation and provide opportunities for therapy.

Associations Between Early-Life Adversity, Ambient Air Pollution, and Telomere Length in Children

OBJECTIVE

Examine the independent associations and interaction between early-life adversity and residential ambient air pollution exposure on relative buccal telomere length (rBTL).

METHODS

Experiences of abuse, neglect, household challenges, and related life events were identified in a cross-sectional sample of children aged 1 to 11 years ( n = 197) using the 17-item Pediatric ACEs and Related Life Event Screener (PEARLS) tool. The PEARLS tool was analyzed both as a total score and across established domains (Maltreatment, Household Challenges, and Social Context). Ground-level fine particulate matter (PM 2.5 ) concentrations were matched to residential locations for the 1 and 12 months before biospecimen collection. We used multivariable linear regression models to examine for independent associations between continuous PM 2.5 exposure and PEARLS score/domains with rBTL. In addition, effect modification by PEARLS scores and domains on associations between PM 2.5 exposure and rBTL was examined.

RESULTS

Study participants were 47% girls, with mean (standard deviation) age of 5.9 (3.4) years, median reported PEARLS score of 2 (interquartile range [IQR], 4), median 12-month prior PM 2.5 concentrations of 11.8 μg/m 3 (IQR, 2.7 μg/m 3 ), median 1-month prior PM 2.5 concentrations of 10.9 μg/m 3 (IQR, 5.8 μg/m 3 ), and rBTL of 0.1 (IQR, 0.03). Mean 12-month prior PM 2.5 exposure was inversely associated with rBTL ( β = -0.02, 95% confidence interval = -0.04 to -0.01). Although reported PEARLS scores and domains were not independently associated with rBTL, we observed a greater decrement in rBTL with increment of average annual PM 2.5 as reported Social Context domain items increased ( p -interaction < .05).

CONCLUSIONS

Our results suggest that adverse Social Context factors may accelerate the association between chronic PM 2.5 exposure on telomere shortening during childhood.

Related risk factors for age-dependent telomere shortening change with age from the perspective of life course

BACKGROUND

Many related factors can accelerate the age-dependent telomere shortening, but some problems remain unresolved. This study aimed to assess the risk factors of telomere attrition at different age stages.

METHODS

This study was a population-based nationally representative survey study. All data were collected using a standard methodology by the national surveillance system. Quantitative polymerase chain reaction was used to measure relative leukocyte telomere length. Multiple linear regression analysis with age stratification was used to estimate the association of shortened telomere length with risk factors at the different age stages. Covariance analysis was used to compare the telomere length of category variables, and the model was adjusted for potentially confounders.

RESULTS

A total of 7,659 eligible participants aged 20 years or older with DNA specimens participated in the study. Related risk factors for age-dependent telomere shortening included gender, race-ethnicity, education levels, family income, health insurance, marital status, physical activity, smoking status, alcohol use, and self-reported greatest weight, which were associated with change in telomere length at different age stages.

CONCLUSIONS AND IMPLICATIONS

Related risk factors of telomere attrition were changed with age in life course. The evaluation of related risk factors for telomere attrition in terms of age may be a more accurate evaluation comparison with the specific age.

The influence of perceived stress and motivation on telomere length among NCAA swimmers

INTRODUCTION

Telomere length (TL) shortening is associated with increased cellular senescence and functional decline with age. Regular physical activity is posited to safeguard against TL shortening, but there is disagreement on how concurrent psychosocial stress may influence this relationship. The current analysis explored whether psychosocial stress is associated with TL differences in highly physically active individuals.

METHODS

TL was measured from capillary dried blood spots collected from Division-I (D-1) and Division-III (D-3) National Collegiate Athletics Association (NCAA) swimmers (N = 28) and non-athlete students from the same schools (N = 15). All participants completed Cohen's Perceived Stress Scale (PSS) and student-athletes completed an additional questionnaire to assess psychosocial factors associated with their lifestyle; The Student Athletes' Motivation towards Sports and Academics Questionnaire (SAMSAQ). Semi-structured interviews further contextualized how student-athletes internalize their stress.

RESULTS

There was no significant difference in TL or PSS scores between swimmers and controls. D-1 swimmers reported significantly higher career and student-athlete motivation scores compared to D-3, but non-significantly higher PSS and similar academic motivation scores. Themes from interviews with collegiate swimmers included COVID-19 stress, fear of injury, pressure from academics, expectations to perform, and financial pressures.

CONCLUSIONS

These themes may have contributed to higher PSS scores in D-1 swimmers compared to D-3 but did not appear to impact their TL. Given differences in perceived stress, sources of stress, and SAMSAQ scores, further analyses with larger sample sizes are needed to better understand how these factors influence human biology and health while engaged in intense physical activity.

Associations between weight-adjusted-waist index and telomere length: Results from NHANES: An observational study

Previous studies have demonstrated the connection between obesity and telomere length. A recently devised metric for determining obesity, the weight-adjusted-waist index (WWI), offers a distinct advantage in predicting fat and lean mass by depicting weight-independent abdominal adiposity. This article presents the results of the inaugural study on the relationship between WWI and telomere length in adult populations. The cross-sectional investigation analyzed data from 3479 participants from the National Health and Nutrition Examination Survey (NHANES) conducted from 1999 to 2000. To inspect linear and nonlinear correlations, we adopted weighted multiple logistic regression analysis and smooth curve fit, respectively. In addition, threshold effects and subgroup analyses were accomplished. In the fully adapted model, a significant adverse association of WWI with telomere length was detected [β = -0.02, 95% CI: (-0.03, -0.00), P value = 0.01]. The adverse correlation remained consistent across all subcategories. We also discovered an inverted U-shaped curve linking WWI and telomere length, with a conspicuous inflection point of 10.07 cm/√kg. For the first time, our research demonstrated strong links between WWI and telomere length. The inflection point suggests that controlling WWI within an optimum range might be essential for aging and health.

Telomeres and telomerase: active but complex players in life-history decisions

Studies on human telomeres have established that telomeres exert a significant influence on lifespan and health of organisms. However, recent research has indicated that the original idea that telomeres affect lifespan in a universal and central manner across all eukaryotic species is an oversimplification. Indeed, findings from a variety of animal species revealed that the role of telomere biology in aging is more subtle and intricate than previously recognized. Here, we show how telomere biology varies depending on the taxon. We also show how telomere biology corresponds to basic life history traits and affects the life table of a species and investments in growth, body size, reproduction, and lifespan; telomeres are hypothesized to shape evolutionary perspectives for species in an active but complex manner. Our evaluation is based on telomere biology data from many examples from throughout the animal kingdom that vary according to the degree of organismal complexity and life history strategies.

Accelerated biological aging as a potential risk factor for rheumatoid arthritis

OBJECTS

Previous studies have suggested a potential correlation between rheumatoid arthritis (RA) and biological aging, but the intricate connections and mechanisms remain elusive.

METHODS

In our study, we focused on two specific measures of biological age (PhenoAge and BioAge), which are derived from clinical biomarkers. The residuals of these measures, when compared to chronological age, are defined as biological age accelerations (BAAs). Utilizing the extensive UK Biobank dataset along with various genetic datasets, we conducted a thorough assessment of the relationship between BAAs and RA at both the individual and aggregate levels.

RESULTS

Our observational studies revealed positive correlations between the two BAAs and the risk of developing both RA and seropositive RA. Furthermore, the genetic risk score (GRS) for PhenoAgeAccel was associated with an increased risk of RA and seropositive RA. Linkage disequilibrium score regression (LDSC) analysis further supported these findings, revealing a positive genetic correlation between PhenoAgeAccel and RA. PLACO analysis identified 38 lead pleiotropic single nucleotide polymorphisms linked to 301 genes, providing valuable insights into the potential mechanisms connecting PhenoAgeAccel and RA.

CONCLUSION

In summary, our study has successfully revealed a positive correlation between accelerated biological aging, as measured by BAAs, and the susceptibility to RA.

The Relationship between Dietary Macronutrient Composition and Telomere Length Among US Adults

The role of dietary macronutrients and energy intake in the aging process has been well-established. However, previous research has mainly focused on the association between leukocyte telomere length (LTL) and individual macronutrients, while the effects of macronutrient composition on LTL remain unclear. This cross-sectional analysis involved 4130 US adults (44.8 ± 17.0 years; 51% female) from the National Health and Nutrition Examination Survey during 1999-2002. A single 24-h dietary recall is used to collect dietary data. The relationship between dietary macronutrient composition and LTL is examined using three-dimensional generalized additive models. After adjustment for age, sex, ethnicity, education, physical activity, BMI, and dietary quality, a three-dimensional association of macronutrient composition with LTL (P = 0.02) is revealed. Diets lower in protein (5-10%), higher in carbohydrates (75%), and lower in fat (15-20%) are associated with the longest LTL corresponding to 7.7 years of slower biological aging. Diets lowest in protein (5%) and carbohydrate (40%), while highest in dietary fat (55%) are associated with the shortest LTL, corresponding to accelerated biological aging of 4.4 years. The associations appeared magnified with higher energy intake. These findings support a complex relationship between dietary macronutrients and biological aging independent of diet quality.

Socioeconomic-Status-Based Disrespect, Discrimination, Exclusion, and Shaming: A Potential Source of Health Inequalities?

Observing an association between socioeconomic status (SES) and health reliably leads to the question, "What are the pathways involved?" Despite enormous investment in research on the characteristics, behaviors, and traits of people disadvantaged with respect to health inequalities, the issue remains unresolved. We turn our attention to actions of more advantaged groups by asking people to self-report their exposure to disrespect, discrimination, exclusion, and shaming (DDES) from people above them in the SES hierarchy. We developed measures of these phenomena and administered them to a cross-sectional U.S. national probability sample (N = 1,209). Consistent with the possibility that DDES represents a pathway linking SES and health, the SES→health coefficient dropped substantially when DDES variables were controlled: 112.9% for anxiety, 43.8% for self-reported health, and 49.4% for cardiovascular-related conditions. These results illustrate a need for a relational approach emphasizing the actions of more advantaged groups in shaping health inequities.

Insight into telomere regulation: road to discovery and intervention in plasma drug-protein targets

BACKGROUND

Telomere length is a critical metric linked to aging, health, and disease. Currently, the exploration of target proteins related to telomere length is usually limited to the context of aging and specific diseases, which limits the discovery of more relevant drug targets. This study integrated large-scale plasma cis-pQTLs data and telomere length GWAS datasets. We used Mendelian randomization(MR) to identify drug target proteins for telomere length, providing essential clues for future precision therapy and targeted drug development.

METHODS

Using plasma cis-pQTLs data from a previous GWAS study (3,606 Pqtls associated with 2,656 proteins) and a GWAS dataset of telomere length (sample size: 472,174; GWAS ID: ieu-b-4879) from UK Biobank, using MR, external validation, and reverse causality testing, we identified essential drug target proteins for telomere length. We also performed co-localization, Phenome-wide association studies and enrichment analysis, protein-protein interaction network construction, search for existing intervening drugs, and potential drug/compound prediction for these critical targets to strengthen and expand our findings.

RESULTS

After Bonferron correction (p < 0.05/734), RPN1 (OR: 0.96; 95%CI: (0.95, 0.97)), GDI2 (OR: 0.94; 95%CI: (0.92, 0.96)), NT5C (OR: 0.97; 95%CI: (0.95, 0.98)) had a significant negative causal association with telomere length; TYRO3 (OR: 1.11; 95%CI: (1.09, 1.15)) had a significant positive causal association with telomere length. GDI2 shared the same genetic variants with telomere length (coloc.abf-PPH 4 > 0.8).

CONCLUSION

Genetically determined plasma RPN1, GDI2, NT5C, and TYRO3 have significant causal effects on telomere length and can potentially be drug targets. Further exploration of the role and mechanism of these proteins/genes in regulating telomere length is needed.

Cross-tissue comparison of telomere length and quality metrics of DNA among individuals aged 8 to 70 years

Telomere length (TL) is an important biomarker of cellular aging, yet its links with health outcomes may be complicated by use of different tissues. We evaluated within- and between-individual variability in TL and quality metrics of DNA across five tissues using a cross-sectional dataset ranging from 8 to 70 years (N = 197). DNA was extracted from all tissue cells using the Gentra Puregene DNA Extraction Kit. Absolute TL (aTL) in kilobase pairs was measured in buccal epithelial cells, saliva, dried blood spots (DBS), buffy coat, and peripheral blood mononuclear cells (PBMCs) using qPCR. aTL significantly shortened with age for all tissues except saliva and buffy coat, although buffy coat was available for a restricted age range (8 to 15 years). aTL did not significantly differ across blood-based tissues (DBS, buffy coat, PBMC), which had significantly longer aTL than buccal cells and saliva. Additionally, aTL was significantly correlated for the majority of tissue pairs, with partial Spearman's correlations controlling for age and sex ranging from ⍴ = 0.18 to 0.51. We also measured quality metrics of DNA including integrity, purity, and quantity of extracted DNA from all tissues and explored whether controlling for DNA metrics improved predictions of aTL. We found significant tissue variation: DNA from blood-based tissues had high DNA integrity, more acceptable A260/280 and A260/230 values, and greater extracted DNA concentrations compared to buccal cells and saliva. Longer aTL was associated with lower DNA integrity, higher extracted DNA concentrations, and higher A260/230, particularly for saliva. Model comparisons suggested that incorporation of quality DNA metrics improves models of TL, although relevant metrics vary by tissue. These findings highlight the merits of using blood-based tissues and suggest that incorporation of quality DNA metrics as control variables in population-based studies can improve TL predictions, especially for more variable tissues like buccal and saliva.

Oxidation of DNA and RNA in young patients with newly diagnosed bipolar disorder and relatives

Excessive oxidative stress-generated nucleoside damage seems to play a key role in bipolar disorder (BD) and may present a trait phenomenon associated with familial risk and is one of the putative mechanisms explaining accelerated atherosclerosis and premature cardiovascular diseases (CVD) in younger patients with BD. However, oxidative stress-generated nucleoside damage has not been studied in young BD patients and their unaffected relatives (UR). Therefore, we compared oxidative stress-generated damage to DNA and RNA in young patients newly diagnosed with BD, UR, and healthy control individuals (HC). Systemic oxidative stress-generated DNA and RNA damage levels were compared by analyzing urinary levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine and 8-oxo-7,8-dihydroguanosine in participants aged 15-25 years, including 133 patients newly diagnosed with BD, 57 UR, and 83 HC. Compared with HC, damage to DNA was 21.8% higher in BD patients (B = 1.218, 95% CI = 1.111-1.335, p = <0.001) and 22.5% higher in UR (B = 1.225, 95% CI = 1.090-1.377, p = <0.002), while damage to RNA was 14.8% higher in BD patients (B = 1.148, 95% CI = 1.082-1.219, p = <0.001) and 14.0% higher in UR (B = 1.140, 95% CI = 1.055-1.230, p = < 0.001) in models adjusted for sex and age after correction for multiple comparison. Levels did not differ between patients with BD and UR. Our findings support higher oxidative stress-generated nucleoside damage being a trait phenomenon in BD associated with familial risk and highlight the importance of early diagnosis and treatment to prevent illness progression and development of premature CVD.

Association between cytomegalovirus seropositivity and all-cause mortality: An original cohort study

To examine the association between cytomegalovirus (CMV) seropositivity and all-cause mortality in a nationwide cohort of US adults. We obtained data from the National Health and Nutrition Examination Survey III (1988-1994), including 16,547 participants aged 18-90 years old with CMV serology assessments. Mortality status was ascertained until December 2019 using the National Death Index linkage data. The Cox proportional hazard model was applied to estimate the association between CMV seropositivity and mortality. During a median follow-up of 26.3 years, 6,930 deaths were recorded. CMV seropositivity was associated with a higher hazard of all-cause mortality after adjusting for attained age, sex, and ethnicity (HR: 1.22, 95% CI: 1.10, 1.36, p < 0.001). The magnitude of the association attenuated slightly after adjusting further for body mass index, family income, smoking status, diabetes, and self-reported cancer history (HR = 1.11, 95% CI: 1.00, 1.23, p = 0.04). While the association was observed for both men and women, it was only statistically significant among non-Hispanic white people (HR: 1.16, 95% CI: 1.06, 1.26, p = 0.001) but not among other ethnic populations. CMV seropositivity might be an independent risk factor for all-cause mortality among US adults. If the findings are validated in an independent population, further research is needed to unveil the biological mechanisms driving the increased mortality with CMV seropositivity.

GV1001 reduces neurodegeneration and prolongs lifespan in 3xTg-AD mouse model through anti-aging effects

GV1001, which mimics the activity of human telomerase reverse transcriptase, protects neural cells from amyloid beta (Aβ) toxicity and other stressors through extra-telomeric function, as noted in our prior in vitro studies. As per a recent phase II clinical trial, it improves cognitive function in patients with moderate to severe dementia. However, the underlying protective mechanisms remain unclear. This study aimed to investigate the effects of GV1001 on neurodegeneration, senescence, and survival in triple transgenic Alzheimer's disease (3xTg-AD) mice. GV1001 (1 mg/kg) was subcutaneously injected into old 3xTg-AD mice thrice a week until the endpoint for sacrifice, and survival was analysed. Magnetic resonance imaging (MRI) and Prussian blue staining (PBS) were performed to evaluate entry of GV1001 entrance into the brain. Diverse molecular studies were performed to investigate the effect of GV1001 on neurodegeneration and cellular senescence in AD model mice, with a particular focus on BACE, amyloid beta1-42 (Aβ1-42), phosphorylated tau, volume of dentate gyrus, β-galactosidase positive cells, telomere length, telomerase activity, and ageing-associated proteins. GV1001 crossed the blood-brain barrier, as confirmed by assessing the status of ferrocenecarboxylic acid-conjugated GV1001 using magnetic resonance imaging and PBS. GV1001 increased the survival of 3xTg-AD mice. It decreased BACE and Aβ1-42 levels, neurodegeneration (i.e., reduced CA1, CA3 and dentate gyrus volume, decreased levels of senescence-associated β-galactosidase positive cells, and increased telomere length and telomerase activity), and levels of ageing-associated proteins. We suggest that GV1001 exerts anti-ageing effects in 3xTg-AD mice by reducing neurodegeneration and senescence, which contributes to improved survival.

Unlocking longevity: the role of telomeres and its targeting interventions

Average life expectancy has been steadily increasing in developed countries worldwide. These demographic changes are associated with an ever-growing social and economic strain to healthcare systems as well as society. The aging process typically manifests as a decline in physiological and cognitive functions, accompanied by a rise in chronic diseases. Consequently, strategies that both mitigate age-related diseases and promote healthy aging are urgently needed. Telomere attrition, characterized by the shortening of telomeres with each cell division, paradoxically serves as both a protective mechanism and a contributor to tissue degeneration and age-related ailments. Based on the essential role of telomere biology in aging, research efforts aim to develop approaches designed to counteract telomere attrition, aiming to delay or reduce age-related diseases. In this review, telomere biology and its role in aging and age-related diseases is summarized along with recent approaches to interfere with telomere shortening aiming at well- and healthy-aging as well as longevity. As aging research enters a new era, this review emphasizes telomere-targeting therapeutics, including telomerase activators and tankyrase inhibitors, while also exploring the effects of antioxidative and anti-inflammatory agents, along with indirectly related approaches like statins.

Maternal psychological stress during pregnancy and newborn telomere length: a systematic review and meta-analysis

INTRODUCTION

Telomeres protect the ends of chromosomes, and shorter leukocyte telomeres are associated with major group diseases. Maternal psychological stress may be related to the shortening of telomeres in infants. This systematic review and meta-analysis set out to consolidate the varying effect sizes found in studies of maternal psychological stress and telomere length (TL) in newborns and identify moderators of the relationship between stress during pregnancy and newborn TL.

METHODS

Our systematic review was registered in Prospero. Six databases (PubMed, Scopus, Embase, PsycINFO, Web of Science, and CINAHL Complete) were searched for records in English from inception to February 10, 2023. Observational studies were included that measured the relationship of psychological stress of the mother during pregnancy on the TL of the newborn. The Newcastle-Ottawa quality assessment scale was used to assess the quality of the included studies. A random-effect model was selected. Statistical analysis performed by Stata software version 17.

RESULTS

Eight studies were included for qualitative and four for quantitative analysis. There was an inverse statistically significant relationship between maternal stress and newborn TL; A one score increase in maternal psychological stress resulted in a 0.04 decrease in the TL of the newborn (B = -0.04, 95% CI = [-0.08, 0.00], p = 0.05). Selectivity analysis showed that the pooled effect size was sensitive to one study; After removing this study, the pooled effect size remained significant (B = -0.06, 95% CI = [-0. 10, -0.02], p < 0.001).

CONCLUSION

Physiological and environmental factors can significantly affect the TL of newborns. Our results support a significant impact of maternal psychological stress on the TL of a newborn. This association demonstrates the significance of stress in influencing the telomere length, which can be a contributing factor in the infant's future. Therefore, recognizing this association is crucial for understanding and addressing potential health risks and necessitates the need for additional future studies to validate our findings.

Causal relationship between telomere length and epilepsy: A bidirectional Mendelian randomization study

OBJECTIVE

Observational studies have suggested a link between telomere length (TL) and epilepsy, but the direction of the effect and whether it is causal or not is still being debated. The objective of this study was to investigate the causal relationship between TL and epilepsy using Mendelian randomization (MR) analysis.

METHODS

We performed a bidirectional two-sample MR analysis using pooled statistics from genome-wide association studies (GWAS) of TL and epilepsy. Additionally, we conducted a replication analysis using data from another GWAS study on epilepsy to validate our findings. The final results were analyzed using five MR methods, with the inverse-variance weighted (IVW) method as the primary outcome. We applied methods such as radial MR, MR pleiotropy residual and outlier test and MR Steiger filters to exclude outliers. Sensitivity analyses were also conducted to assess heterogeneity and pleiotropy.

RESULTS

Our analysis found no evidence of a causal relationship between epilepsy and TL (all p-values >0.05). The sensitivity analysis confirms the robustness of these results.

SIGNIFICANCE

In summary, our study contradicts existing observational reports by not finding any evidence to support a causal relationship between epilepsy and TL. Further research is necessary to determine the underlying mechanism behind the association observed in observational studies.

Associations of telomere length with risk of mortality from influenza and pneumonia in US adults: a prospective cohort study of NHANES 1999-2002

BACKGROUND

Due to the ongoing Coronavirus disease 2019 (COVID-19) pandemic, interest has arisen to realize the relationship between telomere length (TL) and influenza and pneumonia mortality.

AIM

Our study attempted to investigate this correlation by analyzing information gathered from the National Health and Nutrition Examination Survey (NHANES) 1999-2002.

METHODS

A total of 7229 participants were involved in the conducted research. We utilized Cox proportional risk model analysis to determine the hazard ratio (HR) and 95% confidence interval (CI) for TL and influenza and pneumonia mortality.

RESULTS

During the average follow-up time of 204.10 ± 51.26 months, 33 (0.45%) participants died from influenza and pneumonia. After adjusting for multiple variables, shorter TL was associated with higher influenza-pneumonia mortality. In subgroup analyses stratified by sex, men exhibited stronger associations with influenza-pneumonia mortality than women (Model 1: HRmale: 0.014 vs HRfemale: 0.054; Model 2: HRmale: 0.082 vs HRfemale: 0.890; Model 3: HRmale: 0.072 vs HRfemale: 0.776). For subgroup analyses by visceral adiposity index (VAI), all statistically significant (P < 0.05) models displayed an inverse relationship between TL and influenza and pneumonia mortality.

CONCLUSIONS

Our research provides further proof for the connection between shorter telomeres and higher influenza-pneumonia mortality. Larger prospective researches are essential to support our results and explain the underlying mechanisms.

Ectoparasite presence and brood size manipulation interact to accelerate telomere shortening in nestling jackdaws

Early-life conditions impact fitness, but whether the combined effect of extrinsic stressors is additive or synergistic is not well known. This is a major knowledge gap because exposure to multiple stressors is frequent. Telomere dynamics may be instrumental when testing how stressors interact because many factors affect telomere shortening, and telomere shortening predicts survival. We evaluated the effect of manipulated brood size and natural infestation by the carnid fly Carnus hemapterus on nestling growth and telomere shortening of wild jackdaws (Corvus monedula). Telomere length, measured in blood using TRF, shortened on average by 264 bp, and on average, Carnus infection induced more telomere shortening. Further analyses showed that in enlarged broods, nestlings' telomeres shortened more when parasitized, while in reduced broods there was no effect of infection on telomere shortening. We conclude that there is a synergistic effect of number of siblings and Carnus infection on telomere shortening rate: blood-sucking parasites may negatively impact telomeres by increasing cell proliferation and/or physiological stress, and coping with infection may be less successful in enlarged broods with increased sibling competition. Larger nestlings had shorter telomeres independent of age, brood manipulation or infection. Growth was independent of infestation but in enlarged broods, nestlings were lighter at fledging. Our findings indicate that (i) evaluating consequences of early-life environmental conditions in isolation may not yield a full picture due to synergistic effects, and (ii) effects of environmental conditions may be cryptic, for example, on telomeres, with fitness consequences expressed beyond the temporal framework of the study.

The distribution and accumulation of the shortest telomeres in telomere biology disorders

Individuals with telomere biology disorders (TBDs) have very short telomeres, high risk of bone marrow failure (BMF), and reduced survival. Using data from TBD patients, a mean leukocyte Southern blot telomere length (TL) of 5 kilobases (kb) was estimated as the 'telomere brink' at which human survival is markedly reduced. However, the shortest telomere, not the mean TL, signals replicative senescence. We used the Telomere Shortest Length Assay (TeSLA) to tally TL of all 46 chromosomes in blood-derived DNA and examined its relationship with TBDs. Patients (n = 18) had much shorter mean TL (TeSmTL) (2.54 ± 0.41 kb vs. 4.48 ± 0.52 kb, p < 0.0001) and more telomeres <3 kb than controls (n = 22) (70.43 ± 8.76% vs. 33.05 ± 6.93%, p < 0.0001). The proportion of ultrashort telomeres (<1.6 kb) was also higher in patients than controls (39.29 ± 10.69% vs. 10.40 ± 4.09%, p < 0.0001). TeS <1.6 kb was associated with severe (n = 11) compared with non-severe (n = 7) BMF (p = 0.027). Patients with multi-organ manifestations (n = 10) had more telomeres <1.6 kb than those with one affected organ system (n = 8) (p = 0.029). Findings suggest that TBD clinical manifestations are associated with a disproportionately higher number of haematopoietic cell telomeres reaching a telomere brink, whose length at the single telomere level is yet to be determined.

Early origins of health and disease risk: The case for investigating adverse exposures and biological aging in utero, across childhood, and into adolescence

In this article, we suggest that aging and development are two sides of the same coin, and that developing a comprehensive understanding of health and disease risk requires examining age-related processes occurring throughout the earliest years of life. Compared to other periods in life, during this early period of acute vulnerability, when children's biological and regulatory systems are developing, biological aging occurs most rapidly. We review theory and empirical research suggesting that processes of development and aging are intricately linked, and that early adversity may program biological parameters for accelerated aging and disease risk early in life, even though clinical signs of age-related disease onset may not be evident until many years later. Following from this, we make the case for widespread incorporation of biological aging constructs into child development research.

Epigenetic age acceleration in surviving versus deceased COVID-19 patients with acute respiratory distress syndrome following hospitalization

BACKGROUND

Aging has been reported as a major risk factor for severe symptoms and higher mortality rates in COVID-19 patients. Molecular hallmarks such as epigenetic alterations and telomere attenuation reflect the biological process of aging. Epigenetic clocks have been shown to be valuable tools for measuring biological age in various tissues and samples. As such, these epigenetic clocks can determine accelerated biological aging and time-to-mortality across various tissues. Previous reports have shown accelerated biological aging and telomere attrition acceleration following SARS-CoV-2 infection. However, the effect of accelerated epigenetic aging on outcome (death/recovery) in COVID-19 patients with acute respiratory distress syndrome (ARDS) has not been well investigated.

RESULTS

In this study, we measured DNA methylation age and telomere attrition in 87 severe COVID-19 cases with ARDS under mechanical ventilation. Furthermore, we compared dynamic changes in epigenetic aging across multiple time points until recovery or death. Epigenetic age was measured using the Horvath, Hannum, DNAm skin and blood, GrimAge, and PhenoAge clocks, whereas telomere length was calculated using the surrogate marker DNAmTL. Our analysis revealed significant accelerated epigenetic aging but no telomere attrition acceleration in severe COVID-19 cases. In addition, we observed epigenetic age deceleration at inclusion versus end of follow-up in recovered but not in deceased COVID-19 cases using certain clocks. When comparing dynamic changes in epigenetic age acceleration (EAA), we detected higher EAA using both the Horvath and PhenoAge clocks in deceased versus recovered patients. The DNAmTL measurements revealed telomere attrition acceleration in deceased COVID-19 patients between inclusion and end of follow-up and a significant change in dynamic telomere attrition acceleration when comparing patients who recovered versus those who died.

CONCLUSIONS

EAA and telomere attrition acceleration were associated with treatment outcomes in hospitalized COVID-19 patients with ARDS. A better understanding of the long-term effects of EAA in COVID-19 patients and how they might contribute to long COVID symptoms in recovered individuals is urgently needed.

Association between female-specific reproductive factors and leukocyte telomere length

STUDY QUESTION

What are the associations between female-specific reproductive factors and leukocyte telomere length (LTL)?

SUMMARY ANSWER

Early menarche, early menopause, short reproductive lifespan, early age at first birth, multiparity, and use of oral contraceptives (OCs) and hormone replacement therapy (HRT) were associated with shorter LTL.

WHAT IS KNOWN ALREADY

Reproductive factors have been associated with age-related diseases, but their associations with cellular aging, as indicated by LTL, are unclear.

STUDY DESIGN, SIZE, DURATION

This population-based study included 224 965 women aged 40-69 years from the UK Biobank between 2006 and 2010.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 40-69 were included. Female-specific reproductive factors, including age at menarche, age at natural menopause, reproductive lifespan, number of live births, age at first live birth, history of stillbirth, history of miscarriage, and use of OCs and HRT were self-reported. LTL was measured using a validated polymerase chain reaction method. Multiple linear regression and restricted cubic spline models were applied to explore the association between each reproductive factor and LTL.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjustment for potential confounders, early menarche (<12 years; percent change, per unit change in LTL Z score: -1.29%, 95% CI: -2.32%, -0.26%), early menopause (<45 years; percent change: -7.18%, 95% CI: -8.87%, -5.45%), short reproductive lifespan (<30 years; percent change: -6.10%, 95% CI: -8.14%, -4.01%), multiparity (percent change: -3.38%, 95% CI: -4.38%, -2.37%), early age at first live birth (<20 years; percent change: -4.46%, 95% CI: -6.00%, -2.90%), and use of OCs (percent change: -1.10%, 95% CI: -2.18%, -0.02%) and HRT (percent change: -3.72%, 95% CI: -4.63%, -2.80%) were all significantly associated with shorter LTL. However, no significant association was found for history of miscarriage and stillbirth. We observed nonlinear relationships of age at menarche, age at natural menopause, reproductive lifespan, and age at first live birth with LTL (Pnonlinear < 0.05).

LIMITATIONS, REASONS FOR CAUTION

Considering that the participants were predominantly of European ethnicity, the findings may not be generalizable to women of other ethnic backgrounds.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that early menarche, early menopause, short reproductive lifespan, early age at first birth, multiparity, and use of OCs and HRT were associated with shorter LTL, which has been linked to various chronic diseases. The accelerated shortening of telomeres may potentially contribute to the development of chronic diseases related to reproductive factors.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the National Natural Science Foundation of China (82003479, 82073660), Hubei Provincial Natural Science Foundation of China (2023AFB663), and the China Postdoctoral Science Foundation (2019M662646, 2020T130220). The authors have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

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.

Depressive symptoms and shorter survival in lung cancer: the role of leukocyte telomere length

OBJECTIVE

To examine the association between depressive symptoms, leukocyte telomere length-a marker of cellular ageing, and survival amongst lung cancer patients.

DESIGN

Patients with non-small cell lung cancer were recruited from a university-affiliated cancer center clinic.

MAIN OUTCOME

Patients (N = 67) reported on depressive symptoms and provided a blood sample for leukocyte telomere length assessment at baseline and at a 3-month follow-up. Survival status was tracked over 3 years.

RESULTS

Age at diagnosis and depressive symptoms, as measured by the CES-D, were associated with shorter leukocyte telomere length (p < .05), although only age at diagnosis contributed statistical significance to the model. Depressive symptoms predicted shorter survival from date of diagnosis (p < .01). Patients who reported experiencing clinically meaningful levels of depressive symptoms (CES-D scores ≥ 16) demonstrated shorter survival than those who reported sub-clinical levels of depressive symptoms (p < .05). Leukocyte telomere length did not emerge as a predictor of shorter survival.

CONCLUSION

Clinically meaningful levels of depressive symptoms are associated with shorter survival amongst lung cancer patients. These findings support the on-going efforts to screen all cancer patients for low mood and to investigate mechanisms linking depressive symptoms and shorter survival in cancer contexts.

Telomere Dynamics in Livestock

Telomeres are repeated sequences of nucleotides at the end of chromosomes. They deteriorate across mitotic divisions of a cell. In Homo sapiens this process of lifetime reduction has been shown to correspond with aspects of organismal aging and exposure to stress or other insults. The early impetus to characterize telomere dynamics in livestock related to the concern that aged donor DNA would result in earlier cell senescence and overall aging in cloned animals. Telomere length investigations in dairy cows included breed effects, estimates of additive genetic control (heritability 0.12 to 0.46), and effects of external stressors on telomere degradation across animal life. Evaluation of telomeres with respect to aging has also been conducted in pigs and horses, and there are fewer reports of telomere biology in beef cattle, sheep, and goats. There were minimal associations of telomere length with animal productivity measures. Most, but not all, work in livestock has documented an inverse relationship between peripheral blood cell telomere length and age; that is, a longer telomere length was associated with younger age. Because livestock longevity affects productivity and profitability, the role of tissue-specific telomere attrition in aging may present alternative improvement strategies for genetic improvement while also providing translational biomedical knowledge.

Telomere Length, Health, and Mortality in a Cohort of Older Black South African Adults

Telomere length (TL) may be a biomarker of aging processes as well as age-related diseases. However, most studies of TL and aging are conducted in high-income countries. Less is known in low- and middle-income countries (LMICs) such as South Africa, where life expectancy remains lower despite population aging. We conducted a descriptive analysis of TL in a cohort of older adults in rural South Africa. TL was assayed from venous blood draws using quantitative polymerase chain reaction (T/S ratio). We examined the correlation between TL and biomarkers, demographic characteristics, mental/cognitive health measures, and physical performance measures in a subsample of the Wave 1 2014-2015 "Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa" (HAALSI) cohort (n = 510). We used logistic regression to measure the association between TL and mortality through Wave 3 (2021-2022). In bivariate analyses, TL was significantly correlated with age (r = -0.29, p < .0001), self-reported female sex (r = 0.13, p = .002), mortality (r = -0.1297, p = .003), diastolic blood pressure (r = 0.09, p = .037), pulse pressure (r = -0.09, p = .045), and being a grandparent (r = -0.17, p = .0001). TL was significantly associated with age (β = -0.003; 95% confidence interval [CI] = -0.005, -0.003). TL was significantly associated in unadjusted multivariate analyses with mortality, but the relationship between TL and mortality was attenuated after adjusting for age (odds ratio [OR] = 0.19; 95% CI = 0.03, 1.27) and other covariates (OR = 0.17; 95% CI = 0.02, 1.19). Our study is the first analysis of TL in an older adult South African population. Our results corroborate existing relationships between TL and age, sex, cardiometabolic disease, and mortality found in higher-income countries.

Low Antioxidant Glutathione Levels Lead to Longer Telomeres: A Sex-Specific Link to Longevity?

Telomeres are repetitive DNA sequences at the end of chromosomes that protect them from degradation. They have been the focus of intense research because short telomeres would predict accelerated ageing and reduced longevity in vertebrates. Oxidative stress is considered a physiological driver of the telomere shortening and, consequently, short lifespan. Among molecules fighting against oxidative stress, glutathione is involved in many antioxidant pathways. Literature supports that oxidative stress may trigger a compensatory "hormetic" response increasing glutathione levels and telomere length. Here, we tested the link between total glutathione concentration and telomere length in captive birds (zebra finches; Taeniopygia guttata). Total glutathione levels were experimentally decreased during birds' growth using a specific inhibitor of glutathione synthesis (buthionine sulfoximine; BSO). We monitored the birds' reproductive performance in an outdoor aviary during the first month of life, and their longevity for almost 9 years. Among control individuals, erythrocyte glutathione levels during development positively predicted erythrocyte telomere length in adulthood. However, BSO-treated females, but not males, showed longer telomeres than control females in adulthood. This counterintuitive finding suggests that females mounted a compensatory response. Such compensation agrees with precedent findings in the same population where the BSO treatment increased growth and adult body mass in females but not males. BSO did not influence longevity or reproductive output in any sex. However, early glutathione levels and adult telomere length interactively predicted longevity only among control females. Those females with "naturally" low (non-manipulated) glutathione levels at the nestling age but capable of producing longer telomeres in adulthood seem to live longer. The results suggest that the capability to mount a hormetic response triggered by low early glutathione levels can improve fitness via telomere length. Overall, the results may indicate a sex-specific link between glutathione and telomere values. Telomerase activity and sexual steroids (estrogens) are good candidates to explain the sex-biased mechanism underlying the early-life impact of oxidative stress on adult telomere length.

A Multi-Omics and Human Biomonitoring Approach to Assessing the Effectiveness of Fortified Balanced Energy-Protein Supplementation on Maternal and Newborn Health in Burkina Faso: A Study Protocol

Fortified balanced energy-protein (BEP) supplementation is a promising intervention for improving maternal health, birth outcomes and infant growth in low- and middle-income countries. This nested biospecimen sub-study aimed to evaluate the physiological effect of multi-micronutrient-fortified BEP supplementation on pregnant and lactating women and their infants. Pregnant women (15-40 years) received either fortified BEP and iron-folic acid (IFA) (intervention) or IFA only (control) throughout pregnancy. The same women were concurrently randomized to receive either a fortified BEP supplement during the first 6 months postpartum in combination with IFA for the first 6 weeks (i.e., intervention) or the postnatal standard of care, which comprised IFA alone for 6 weeks postpartum (i.e., control). Biological specimens were collected at different timepoints. Multi-omics profiles will be characterized to assess the mediating effect of BEP supplementation on the different trial arms and its effect on maternal health, as well as birth and infant growth outcomes. The mediating effect of the exposome in the relationship between BEP supplementation and maternal health, birth outcomes and infant growth were characterized via biomonitoring markers of air pollution, mycotoxins and environmental contaminants. The results will provide holistic insight into the granular physiological effects of prenatal and postnatal BEP supplementation.

The shelterin protein expansion of telomere dynamics: Linking early life adversity, life history, and the hallmarks of aging

Aging is characterized by functional decline occurring alongside changes to several hallmarks of aging. One of the hallmarks includes attrition of repeated DNA sequences found at the ends of chromosomes called telomeres. While telomere attrition is linked to morbidity and mortality, whether and how it causally contributes to lifelong rates of functional decline is unclear. In this review, we propose the shelterin-telomere hypothesis of life history, in which telomere-binding shelterin proteins translate telomere attrition into a range of physiological outcomes, the extent of which may be modulated by currently understudied variation in shelterin protein levels. Shelterin proteins may expand the breadth and timing of consequences of telomere attrition, e.g., by translating early life adversity into acceleration of the aging process. We consider how the pleiotropic roles of shelterin proteins provide novel insights into natural variation in physiology, life history, and lifespan. We highlight key open questions that encourage the integrative, organismal study of shelterin proteins that enhances our understanding of the contribution of the telomere system to aging.

Associations between klotho and telomere biology in high stress caregivers

Aging biomarkers may be related to each other through direct co-regulation and/or through being regulated by common processes associated with chronological aging or stress. Klotho is an aging regulator that acts as a circulating hormone with critical involvement in regulating insulin signaling, phosphate homeostasis, oxidative stress, and age-related inflammatory functioning. Both klotho and telomere length are biomarkers of biological aging and decrease with age; however, the relationship between them is not well understood. Here we test the association between klotho levels and the telomere length of specific sorted immune cells among a healthy sample of mothers caregiving for a child with autism spectrum disorder (ASD; i.e., experiencing higher caregiving stress) or a child without ASD, covarying age and body mass index, in order to understand if high stress associated with caregiving for a child with an ASD may be involved in any association between these aging biomarkers. In 178 caregiving women (n = 90 high-stress mothers of children with ASD, n = 88 low-stress mothers of neurotypical children), we found that klotho levels were positively associated with telomere length in PBMCs (an effect driven by CD4+ and CD8+CD28- T cells) among high-stress mothers of children with an ASD but not among low-stress mothers of neurotypical children. There were no significant associations between klotho and telomerase activity in either group, across cell types assessed here. Our results suggest that klotho levels and telomere length may be associated through a coordinated downregulation of longevity factors occurring under higher stress caregiving conditions.

Association of dietary inflammatory index with helicobacter pylori infection and mortality among US population

BACKGROUND

Limited research has been conducted on the potential relationship between the dietary inflammation index (DII) and mortality, particularly in individuals with Helicobacter pylori (H. pylori) infection. This study aimed to investigate the association between the DII and H. pylori infection, as well as their respective impacts on all-cause mortality in a cohort of individuals with or without H. pylori infection.

METHODS

Data from the 1999-2018 National Health and Nutrition Examination Survey (NHANES) were utilized for this study, with a final of 4370 participants included. Both univariable and multivariable-adjusted logistic regression analyses were employed to explore the relationship between H. pylori infection and pertinent covariates. Cox regression analysis, as well as restricted regression cubic spline analysis, were utilized to assess the association between DII and all-cause mortality among individuals with or without H. pylori infection.

RESULTS

The findings demonstrated a positive correlation between DII scores and H. pylori infection, even after adjusting for potential confounding factors. Moreover, higher DII scores were significantly associated with an elevated risk of mortality exclusively in individuals with H. pylori infection, while no such association was observed in the uninfected population. Additional analysis using restricted cubic spline modeling revealed a positive linear relationship between DII scores as a continuous variable and the adjusted risk of all-cause mortality specifically in H. pylori-infected patients.

CONCLUSION

The results of this study indicated that DII was positively correlated with an increased risk of H. pylori infection and was associated with a heightened risk of all-cause mortality solely in individuals with H. pylori infection. Consequently, DII might serve as a useful tool for risk stratification in the H. pylori-infected population among U.S. adults. Further research is warranted to elucidate the underlying mechanisms and potential clinical implications of these findings.

Impact of aging on treatment considerations for multiple sclerosis patients

With a rapidly aging global population and improvement of outcomes with newer multiple sclerosis (MS)-specific disease-modifying therapies (DMTs), the epidemiology of MS has shifted to an older than previously described population, with a peak prevalence of the disease seen in the 55-65 years age group. Changes in the pathophysiology of MS appear to be age-dependent. Several studies have identified a consistent phase of disability worsening around the fifth decade of life. The latter appears to be independent of prior disease duration and inflammatory activity and concomitant to pathological changes from acute focal active demyelination to chronic smoldering plaques, slow-expanding lesions, and compartmentalized inflammation within the central nervous system (CNS). On the other hand, decreased CNS tissue reserve and poorer remyelinating capacity with aging lead to loss of relapse recovery potential. Aging with MS may imply longer exposure to DMTs, although treatment efficacy in patients >55 years has not been evaluated in pivotal randomized controlled trials and appears to decrease with age. Older individuals are more prone to adverse effects of DMTs, an important aspect of treatment individualization. Aging with MS also implies a higher global burden of comorbid illnesses that contribute to overall impairments and represent a crucial confounder in interpreting clinical worsening. Discontinuation of DMTs after age 55, when no evidence of clinical or radiological activity is detected, is currently under the spotlight. In this review, we will discuss the impact of aging on MS pathobiology, the effect of comorbidities and other confounders on clinical worsening, and focus on current therapeutic considerations in this age group.

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

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

A review and meta-analysis: Cross-tissue telomere length correlations in healthy humans

BACKGROUND AND AIM

Tissue source has been shown to exert a significant effect on the magnitude of associations between telomere length and various health outcomes and exposures. The purpose of the present qualitative review and meta-analysis is to describe and investigate the impact of study design and methodological features on the correlation between telomere lengths measured in different tissues from the same healthy individual.

METHODS

This meta-analysis included studies published from 1988 to 2022. Databases searched included PubMed, Embase, and Web of Science and studies were identified using the keywords "telomere length" and "tissues" or "tissue." A total of 220 articles of 7856 initially identified studies met inclusion criteria for qualitative review, of which 55 met inclusion criteria for meta-analysis in R RESULTS: Studies meeting inclusion criteria for meta-analysis tended to have enhanced demographic and methodological reporting relative to studies only included in the qualitative review. A total of 463 pairwise correlations reported for 4324 unique individuals and 102 distinct tissues were extracted from the 55 studies and subject to meta-analysis, resulting in a significant effect size z = 0.66 (p < 0.0001) and meta-correlation coefficient of r = 0.58. Meta-correlations were significantly moderated by sample size and telomere length measurement methodology, with studies of smaller size and those using hybridization-based analyses exhibiting the largest meta-correlation. Tissue source also significantly moderated the meta-correlation, wherein correlations between samples of a different lineage (e.g., blood vs. non-blood) or collection method (e.g., peripheral vs. surgical) were lower than correlations between samples of the same lineage or collection method.

CONCLUSION

These results suggest that telomere lengths measured within individuals are generally correlated, but future research should be intentional in selecting a tissue for telomere length measurement that is most biologically relevant to the exposure or outcome investigated and balance this with the feasibility of obtaining the sample in sufficient numbers of individuals.

Shorter telomere length predicts poor antidepressant response and poorer cardiometabolic indices in major depression

Telomere length (TL) is a marker of biological aging, and shorter telomeres have been associated with several medical and psychiatric disorders, including cardiometabolic dysregulation and Major Depressive Disorder (MDD). In addition, studies have shown shorter TL to be associated with poorer response to certain psychotropic medications, and our previous work suggested shorter TL and higher telomerase activity (TA) predicts poorer response to Selective Serotonin Reuptake Inhibitor (SSRI) treatment. Using a new group of unmedicated medically healthy individuals with MDD (n = 48), we sought to replicate our prior findings demonstrating that peripheral blood mononuclear cell (PBMC) TL and TA predict response to SSRI treatment and to identify associations between TL and TA with biological stress mediators and cardiometabolic risk indices. Our results demonstrate that longer pre-treatment TL was associated with better response to SSRI treatment (β = .407 p = .007). Additionally, we observed that TL had a negative relationship with allostatic load (β = - .320 p = .017) and a cardiometabolic risk score (β = - .300 p = .025). Our results suggest that PBMC TL reflects, in part, the cumulative effects of physiological stress and cardiovascular risk in MDD and may be a biomarker for predicting SSRI response.

High-Intensity interval training reduces transcriptomic age: A randomized controlled trial

While the relationship between exercise and life span is well-documented, little is known about the effects of specific exercise protocols on modern measures of biological age. Transcriptomic age (TA) predictors provide an opportunity to test the effects of high-intensity interval training (HIIT) on biological age utilizing whole-genome expression data. A single-site, single-blinded, randomized controlled clinical trial design was utilized. Thirty sedentary participants (aged 40-65) were assigned to either a HIIT group or a no-exercise control group. After collecting baseline measures, HIIT participants performed three 10 × 1 HIIT sessions per week for 4 weeks. Each session lasted 23 min, and total exercise duration was 276 min over the course of the 1-month exercise protocol. TA, PSS-10 score, PSQI score, PHQ-9 score, and various measures of body composition were all measured at baseline and again following the conclusion of exercise/control protocols. Transcriptomic age reduction of 3.59 years was observed in the exercise group while a 3.29-years increase was observed in the control group. Also, PHQ-9, PSQI, BMI, body fat mass, and visceral fat measures were all improved in the exercise group. A hypothesis-generation gene expression analysis suggested exercise may modify autophagy, mTOR, AMPK, PI3K, neurotrophin signaling, insulin signaling, and other age-related pathways. A low dose of HIIT can reduce an mRNA-based measure of biological age in sedentary adults between the ages of 40 and 65 years old. Other changes in gene expression were relatively modest, which may indicate a focal effect of exercise on age-related biological processes.

Is COVID-19 severity associated with telomere length? A systematic review and meta-analysis

Telomere shortening, a marker of cellular aging, has been linked to hospitalization and the severity of COVID-19. In this systematic review and meta-analysis, the mean difference in telomere length between non-severe and severe COVID-19 individuals was pooled to determine the association between short telomeres and COVID-19 severity. Relevant studies were retrieved through searches conducted in PubMed-Medline, Scopus, EMBASE, Medrxiv, Biorxiv, EuroPMC, and SSRN databases up to November 2022. Selected studies were systematically reviewed and assessed for risk of bias using AXIS tool. The standardized mean difference in telomere length between non-severe and severe COVID-19 was pooled using random-effects model. A total of thirteen studies were included in the review, out of which seven (1332 patients with the severe COVID-19 disease and 6321 patients with non-severe COVID-19) were eligible for meta-analysis. The estimated pooled mean difference in Leukocyte telomere length between severe COVID-19 and non-severe COVID-19 was 0.39 (95% CI - 0.02 to 0.81, I² = 93.5%) with substantial heterogeneity. Our findings do not provide clear evidence for association of shorter telomere length and severe COVID-19 disease. More extensive studies measuring absolute telomere length with age and gender adjustments are needed to draw definitive conclusions on the potential causal association between telomere shortening and COVID-19 severity.

Linking Pregnancy and Long-Term Health: The Impact of Cardiovascular Risk on Telomere Shortening in Pregnant Women

Background and Objectives: Telomeres are repetitive DNA sequences located at the end of chromosomes that play a crucial role in maintaining chromosomal stability. Shortening of telomeres has been associated with an increased risk of cardiovascular disease. The aim of this study was to investigate whether the length of telomeres in pregnant women with cardiovascular risk is shorter compared to those without cardiovascular risk. Materials and Methods: A total of 68 participants were enrolled, including 30 pregnant women with cardiovascular risk and 38 without cardiovascular risk, who were followed-up during their pregnancy between 2020 and 2022 at the Obstetrical and Gynecology Department of the "Pius Brînzeu" Emergency County Clinical Hospital in Timişoara, Romania. All included women underwent delivery via cesarean section at the same medical institution. The telomere length was measured in each participant using quantitative Polymerase chain reaction (PCR). Results: The results showed that the telomere length was negatively correlated with cardiovascular risk in pregnant women, with significantly shorter telomeres observed in the cardiovascular risk group (mean telomere length = 0.3537) compared to the group without cardiovascular risk (mean telomere length = 0.5728) (p = 0.0458). Conclusions: These findings suggest that cardiovascular risk during pregnancy may be associated with accelerated telomere shortening, which could have implications for the long-term health of both the mother and the child. Further research is needed to investigate the potential mechanisms underlying this association and to identify interventions that may mitigate the negative effects of cardiovascular risk on the telomere length during pregnancy.

Stressful life events and accelerated biological aging over time in youths

Experiencing adversity in childhood and adolescence, including stressful life events (SLEs), may accelerate the pace of development, leading to adverse mental and physical health. However, most research on adverse early experiences and biological aging (BA) in youths relies on cross-sectional designs. In 171 youths followed for approximately 2 years, we examined if SLEs over follow-up predicted rate of change in two BA metrics: epigenetic age and Tanner stage. We also investigated if rate of change in BA was associated with changes in depressive symptoms over time. Youths aged 8-16 years at baseline self-reported Tanner stage and depressive symptoms at baseline and follow-up and provided saliva samples for DNA at both assessments. Horvath epigenetic age estimates were derived from DNA methylation data measured with the Illumina EPIC array. At follow-up, contextual threat interviews were administered to youths and caregivers to assess youths' experiences of past-year SLEs. Interviews were objectively coded by an independent rating team to generate a SLE impact score, reflecting the severity of all SLEs occurring over the prior year. Rate of change in BA metrics was operationalized as change in epigenetic age or Tanner stage as a function of time between assessments. Higher objective SLE impact scores over follow-up were related to a greater rate of change in epigenetic age (β = 0.21, p = .043). Additionally, among youths with lower-but not higher-Tanner stage at baseline, there was a positive association of SLE impact scores with rate of change in Tanner stage (Baseline Tanner Stage × SLE Impact Score interaction: β = - 0.21, p = .011). A greater rate of change in epigenetic age was also associated with higher depressive symptom levels at follow-up, adjusting for baseline symptoms (β = 0.15, p = .043). Associations with epigenetic age were similar, although slightly attenuated, when adjusting for epithelial (buccal) cell proportions. Whereas much research in youths has focused on severe experiences of early adversity, we demonstrate that more commonly experienced SLEs during adolescence may also contribute to accelerated BA. Further research is needed to understand the long-term consequences of changes in BA metrics for health.

Dose-response meta-analysis of ultra-processed food with the risk of cardiovascular events and all-cause mortality: evidence from prospective cohort studies

Background: Previous meta-analyses included abundant cross-sectional studies, and/or only assessed high versus low categories of UPF consumption. We conducted this meta-analysis based on prospective cohort studies to estimate the dose-response associations of UPF consumption with the risk of cardiovascular events (CVEs) and all-cause mortality among general adults. Methods: PubMed, Embase, and Web of Science were searched for relevant articles published up to August 17, 2021, and newly published articles between August 17, 2021 and July 21, 2022 were re-searched. Random-effects models were used to estimate the summary relative risks (RRs) and confidence intervals (CIs). Generalized least squares regression was used to estimate the linear dose-response associations of each additional serving of UPF. Restricted cubic splines were used to model the possible nonlinear trends. Results: Eleven eligible papers (17 analyses) were finally identified. The pooled effect size for the highest versus lowest category of UPF consumption showed positive associations with the risk of CVEs (RR = 1.35, 95% CI, 1.18-1.54) and all-cause mortality (RR = 1.21, 95% CI, 1.15-1.27). For each additional daily serving of UPF, the risk increased by 4% (RR = 1.04, 95% CI, 1.02-1.06) for CVEs and 2% (RR = 1.02, 95% CI, 1.01-1.03) for all-cause mortality. With increasing UPF intake, the risk of CVEs reflected a linear upward trend (P_nonlinearity = 0.095), while all-cause mortality reflected a nonlinear upward trend (P_nonlinearity = 0.039). Conclusion: Our findings based on prospective cohorts suggested that any increased level of UPF consumption was linked to higher CVEs and mortality risk. Thus, the recommendation is to control the intake of UPF in daily diet.

Controversies and Recent Advances in Senescence and Aging

Aging is the leading predictive factor of many chronic diseases that account for most of the morbidity and mortality worldwide, i [...]

Sedentary Behaviour and Telomere Length Shortening during Early Childhood: Evidence from the Multicentre Prospective INMA Cohort Study

Sedentary behaviour (SB) may be related to telomere length (TL) attrition due to a possible pro-inflammatory effect. This study examined the association between parent-reported sedentary behaviour (SB) and leukocyte TL at the age of 4 and telomere tracking from 4 to 8 years. In the Spanish birth cohort Infancia y Medio Ambiente (INMA) project, we analysed data from children who attended follow-up visits at age 4 (n = 669) and 8 (n = 530). Multiple robust regression models were used to explore the associations between mean daily hours of SB (screen time, other sedentary activities, and total SB) at 4 years categorised into tertiles and TL at 4 years and difference in TL rank between age 4 and 8, respectively. At the age of 4, the results showed that children with the highest screen time (1.6-5.0 h/day) had a shorter TL of -3.9% (95% CI: -7.4, -0.4; p = 0.03) compared with children in the lowest tertile (0.0-1.0 h/day). Between 4 and 8 years, a higher screen time (highest tertile group vs. lowest tertile) was associated with a decrease in the LTL rank of -1.9% (95% CI: -3.8, -0.1; p = 0.03) from 4 to 8 years. Children exposed to a higher screen time at 4 years were more prone to have shorter TL at 4 and between 4 and 8 years of age. This study supports the potential negative effect of SB during childhood on cellular longevity.