Shorter Leukocyte Telomere Length Research Articles

Investigating the impact of metabolic syndrome traits on telomere length: a Mendelian randomization study.

Observational studies have reported bidirectional associations between metabolic syndrome (MetS) traits and short leukocyte telomere length (LTL), a TL marker in somatic tissues and a proposed risk factor for age-related degenerative diseases. However, in Mendelian randomization studies, longer LTL has been paradoxically associated with higher MetS risk. This study investigated the hypothesis that shorter LTL might be a consequence of metabolic dysfunction. This study undertook univariable and multivariable Mendelian randomization. As instrumental variables for MetS traits, all of the genome-wide significant independent signals identified in genome-wide association studies for anthropometric, glycemic, lipid, and blood pressure traits conducted in European individuals were used. Summary-level data for LTL were obtained from a genome-wide association study conducted in the UK Biobank. Higher BMI was associated with shorter LTL (β = -0.039, 95% CI: -0.058 to -0.020, p = 5 × 10-5 ) equivalent to 1.70 years of age-related LTL change. In contrast, higher low-density lipoprotein cholesterol was associated with longer LTL (β = 0.022, 95% CI: 0.007 to 0.037, p = 0.003) equivalent to 0.96 years of age-related LTL change. Mechanistically, increased low-grade systemic inflammation, as measured by circulating C-reactive protein, and lower circulating linoleic acid levels might link higher BMI to shorter LTL. Overweight and obesity might promote the development of aging-related degenerative diseases by accelerating telomere shortening.

Genetic and clinical determinants of telomere length.

Many epidemiologic studies have identified important relationships between leukocyte telomere length (LTL) with genetics and health. Most of these studies have been significantly limited in scope by focusing predominantly on individual diseases or restricted to GWAS analysis. Using two large patient populations derived from Vanderbilt University and Marshfield Clinic biobanks linked to genomic and phenomic data from medical records, we investigated the inter-relationship between LTL, genomics, and human health. Our GWAS confirmed 11 genetic loci previously associated with LTL and two novel loci in SCNN1D and PITPNM1. PheWAS of LTL identified 67 distinct clinical phenotypes associated with both short and long LTL. We demonstrated that several diseases associated with LTL were related to one another but were largely independent from LTL genetics. Age of death was correlated with LTL independent of age. Those with very short LTL (<-1.5 standard deviation [SD]) died 10.4 years (p<0.0001) younger than those with average LTL (±0.5 SD; mean age of death= 74.2 years). Likewise, those with very long LTL (>1.5 SD) died 1.9 years (p= 0.0175) younger than those with average LTL. This is consistent with the PheWAS results showing diseases associating with both short and long LTL. Finally, we estimated that the genome (12.8%) and age (8.5%) explain the largest proportion of LTL variance, whereas the phenome (1.5%) and sex (0.9%) explained a smaller fraction. In total, 23.7% of LTL variance was explained. These observations provide the rationale for expanded research to understand the multifaceted correlations between TL biology and human health over time, leading to effective LTL usage in medical applications.

Leukocyte telomere length in women with multiple sclerosis: Comparison with healthy women during pregnancy and puerperium

ObjectivesSeveral studies indicated leukocyte telomere length (LTL) as a biomarker of multiple sclerosis (MS) evolution. This study aimed to investigate LTL in women with multiple sclerosis (MS) compared to that in healthy women (HW) across different reproductive phases, and to evaluate its relationship with MS activity. MethodsBlood samples were collected from women with MS and HW during the fertile phase, pregnancy, and puerperium. LTL was determined using quantitative fluorescence in situ hybridization (Q-FISH). ResultsBlood samples from 68 women with MS (22 during fertile life, 23 during pregnancy, and 23 post-partum) and 52 HW (23 during fertile life, 20 during pregnancy, and 9 post-partum) were analyzed. During pregnancy, LTL in MS women and HW was 84.7 ± 10.5 and 77.6 ± 11.5, respectively (p < 0.005). Regression analysis showed that shorter LTL was associated with pregnancy in HW (p = 0.021); this relationship was not observed in MS women, for whom shorter LTL was related to a higher EDSS (p = 0.036). A longitudinal analysis was performed in eight MS women, showing LTL shortening from pregnancy to puerperium (p = 0.003), which was related to MS reactivation (p = 0.042). ConclusionOur results highlight the possible associations between LTL, reproductive biological phases, and MS activity after delivery.

Sleep parameters might affect the attrition of leukocyte telomere length

AbstractBackgroundThe relationship between sleep parameters and longitudinal shortening of telomere length is unclear. This study aimed to investigate the relationship between sleep parameters and the shortening of leukocyte telomere length (LTL) over two years.MethodAmong the participants in the validation cohort of the Korea Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer’s Disease, participants who measured both baseline and follow‐up (two years later) of LTL were analyzed. They were dichotomized according to the degree of LTL attrition. Clinical characteristics, including sleep duration, sleep latency, Pittsburgh Sleep Quality Index (PSQI), Stanford Sleepiness Scale, and Epworth Sleepiness Scale scores were compared between the two groups.ResultA total of 238 patients were analyzed in current study. Participants with faster LTL shortening had a shorter duration of sleep (P = 0.013) and longer sleep latency (P = 0.007). Among the components of the PSQI, subjective measures of sleep quality, sleep latency, sleep duration, and sleep efficiency were significantly worse in participants with faster LTL shortening. Multivariate logistic regression analysis showed that sleep latency (odds ratio [OR] = 1.015, confidence interval [CI] = 1.001–1.029, P = 0.029), global PSQI score (OR = 1.130, CI = 1.017–1.256, P = 0.023), shortest sleep duration (OR = 5.057, CI = 1.189–21.502; P = 0.028), and lowest sleep efficiency (OR = 8.598, CI = 1.584–46.672, P = 0.013) were independently associated with faster LTL shortening.ConclusionPoor sleep quality, specifically long sleep latency, less than 5 hours of sleep, and low sleep efficiency were associated with faster longitudinal shortening of the LTL.

Association between Residential Exposure to Air Pollution and Incident Coronary Heart Disease Is Not Mediated by Leukocyte Telomere Length: A UK Biobank Study.

Higher air pollution exposure and shorter leukocyte telomere length (LTL) are both associated with increased risk of coronary heart disease (CHD), and share plausible mechanisms, including inflammation. LTL may serve as a biomarker of air pollution exposure and may be intervened with to reduce the risk of CHD. To the best of our knowledge, we are the first to test the mediation effect of LTL in the relationship between air pollution exposure and incident CHD. Using the UK Biobank (UKB) data (n = 317,601), we conducted a prospective study linking residential air pollution exposure (PM2.5, PM10, NO2, NOx) and LTL to incident CHD during a mean follow-up of 12.6 years. Cox proportional hazards models and generalized additive models with penalized spline functions were used to model the associations of pollutant concentrations and LTL with incident CHD. We found non-linear associations of air pollution exposure with LTL and CHD. Pollutant concentrations in the lower range were decreasingly associated with longer LTL and reduced risk of CHD. The associations between lower pollutant concentrations and reduced risk of CHD, however, were minimally mediated by LTL (<3%). Our findings suggest that air pollution influences CHD through pathways that do not involve LTL. Replication is needed with improved measurements of air pollution that more accurately assesses personal exposure.

Shorter leukocyte telomere length protects against NAFLD progression in children

Leukocyte telomere length (LTL) gets shorter with each cell division and is also sensitive to reactive oxygen species damage and inflammatory processes. Studies in adults with non-alcoholic fatty liver disease (NAFLD) have found that increased fibrosis but not ALT levels are associated with shorter LTL. Few pediatric studies have been conducted; as such, we sought to evaluate potential associations between LTL and liver disease and liver disease progression in pediatric patients. Using data from the Treatment of NAFLD in Children (TONIC) randomized controlled trial, we assessed the potential predictive relationship between LTL and liver disease progression based on two successive liver biopsies over 96 weeks. We assessed the potential relationship between LTL and child age, sex, and race/ethnicity and features of liver disease including components of histology. We subsequently evaluated predictors for improvement in non-alcoholic steatohepatitis (NASH) at 96 weeks including LTL. We also assessed predictors of lobular inflammation improvement at 96 weeks using multivariable models. Mean LTL at baseline was 1.33 ± 0.23 T/S. Increasing lobular and portal inflammation were associated with longer LTL. In multivariable models, greater lobular inflammation at baseline was associated with longer LTL (Coeff 0.03, 95% CI 0.006–0.13; p = 0.03). Longer LTL at baseline was associated with worsening lobular inflammation at 96 weeks (Coeff 2.41, 95% CI 0.78–4.04; p < 0.01). There was no association between liver fibrosis and LTL. The association between LTL and pediatric NASH does not parallel adults with no association between fibrosis stage and NASH. Conversely, longer LTL was associated with more lobular inflammation at baseline and increased lobular inflammation over the 96-week period. Longer LTL in children may indicate greater risk for future complications from NASH.

Leukocyte Telomere Length in Children Born Following Blastocyst-Stage Embryo Transfer

ABSTRACT Several recent studies have suggested an association between children conceived by assisted reproductive technology (ART) and a distinct growth pattern in early life, which has been linked to diseases of older age. Telomere shortening, specifically a shorter leukocyte telomere length (LTL), has also been linked to age-related diseases including cardiometabolic diseases and cancer. Initial telomere length is shaped by a telomere reset process during gamete fertilization and the early stages of preimplantation development. Given that ART involves the in vitro manipulation of oocytes and embryos, this study aimed to evaluate the association between ART-related factors and LTL in children. Whole genome-sequencing (WGS) data from the Nanjing and Suzhou centers of the China National Birth Cohort (CNBC) were obtained from 1137 individuals from 365 parent-children families, including 202 children conceived using ART and 205 conceived spontaneously. The association was determined between blastocyst-stage transfer and shorter telomere length in 180 children conceived by ART in the same centers. In addition, qPCR was used to perform validation on fingerstick blood samples from 406 children conceived using ART at 3 different centers in China. Data from qPCR were then compared with data obtained from WGS in 70 children in the discovery cohort with sufficient DNA samples. Associations between parental factors and demographics with LTL were examined in the discovery cohort. LTL attribution with aging was calculated using data from the discovery cohort, 1185 individuals aged 40–69 years from healthy controls in the Nanjing Lung Cancer Cohort with LTL measured using WGS, and 1452 East Asian adults aged 40–69 years in the UK biobank with LTL measured using qPCR. Results of association analyses found paternal LTL (β = 0.27, P = 3.26 × 10−8), maternal LTL (β = 0.26, P = 2.41 × 10−7), plurality (twins vs singletons; β = −0.34, P = 0.010), sex of children (male vs female; β = −0.22, P = 0.032), gestational age (β = 0.05, P = 0.026), and conception type (ART-conceived pregnancy vs spontaneously conceived, β = −0.35, P = 5.98 × 10−4) were all significantly associated with LTL in children. Multivariate regression analysis revealed that children conceived by ART had a significantly shorter LTL than those conceived spontaneously, even when adjusting for parental age at conception (adjusted β = −0.41, P = 3.33 × 10−4). Transfer of blastocyst-stage embryos was found to be significantly associated with shorter LTL (β = −0.54, P = 2.69 × 10−3). In addition, when LTL in children from spontaneous pregnancies was compared with LTL in children from ART pregnancies through cleavage-stage versus blastocyst-stage transfer, the LTL of the cleavage-stage group was comparable to the spontaneous pregnancy group, whereas the LTL of the blastocyst-stage group was shorter (β = −0.67, P = 7.81 × 10−8). This result suggests that the difference in LTL between transfer stages might explain the difference between the ART-conceived and spontaneous pregnancy groups. No associations between COS protocols, fertilization methods, or embryo transfer cycles on shorter LTL in children were observed. The multicenter validation cohort had similar associations between blastocyst-stage transfer and shorter LTL. Shortened LTL associated with blastocyst transfer was equivalent to 13.93 years (95% CI, 4.64–23.22 years), 13.42 years (95% CI, 4.52–22.21 years), and 10.85 years (95% CI, 1.03–20.67 years) of aging between 40–69 years in the discovery and 2 validation cohorts, respectively. The results of this study demonstrate that children conceived by ART are associated with a shorter LTL compared with those conceived spontaneously, and transfer of blastocyst-stage embryos was associated with shorter LTL in children than is the transfer of cleavage-stage embryos.

Identifying effects of genetic obesity exposure on leukocyte telomere length using Mendelian randomization.

Observational studies have shown that obesity is closely associated with leukocyte telomere length (LTL). However, the causal relationship between obesity and LTL remains unclear. This study investigated the causal relationship between obesity and LTL through the Mendelian randomization approach. The genome-wide association study (GWAS) summary data of several studies on obesity-related traits with a sample size of more than 600,000 individuals were extracted from the UK Biobank cohort. The summary-level data of LTL-related GWAS (45 6,717 individuals) was obtained from the IEU Open GWAS database. An inverse-variance-weighted (IVW) algorithm was utilized as the primary MR analysis method. Sensitivity analyses were conducted via MR-Egger regression, IVW regression, leave-one-out test, MR-pleiotropy residual sum, and outlier methods. High body mass index was correlated with a short LTL, and the odds ratio (OR) was 0.957 (95% confidence interval [CI] 0.942-0.973, p = 1.17E-07). The six body fat indexes (whole body fat mass, right leg fat mass, left leg fat mass, right arm fat mass, left arm fat mass, and trunk fat mass) were consistently inversely associated with LTL. Multiple statistical sensitive analysis approaches showed that the adverse effect of obesity on LTL was steady and dependable. The current study provided robust evidence supporting the causal assumption that genetically caused obesity is negatively associated with LTL. The findings may facilitate the formulation of persistent strategies for maintaining LTL.

Very Low and High Levels of Vitamin D Are Associated with Shorter Leukocyte Telomere Length in 148,321 UK Biobank Participants.

Background: Shorter leukocyte telomere length (LTL) is observed in multiple age-related diseases, which are also associated with vitamin D deficiency (i.e., osteosarcopenia, neurocognitive disorders, cancer, osteoarthritis, etc.), suggesting a close association between vitamin D and LTL. In this study, we examined the relationship between vitamin D levels and LTL in older participants of the UK Biobank. Methods: Data were collected from the UK Biobank. Participants aged 60 and older (n = 148,321) were included. Baseline LTL was measured using a multiplex qPCR technique and expressed as the ratio of the telomere amplification product (T) to that of a single-copy gene (S) (T/S ratio). Serum 25-hydroxyvitamin D (25OHD) was stratified by z score and linked to LTL in a linear regression model adjusting for covariates. Results: Compared to the medium level, a low (in the range of 16.6 nmol/L, 29.7 nmol/L) or extremely low (≤16.6 nmol/L) level of serum 25OHD was associated with shorter LTL: 0.018 SD (standardized β = -0.018, 95% CI -0.033 to -0.003, p = 0.022) and 0.048 SD (standardized β = -0.048, 95% CI -0.083 to -0.014, p = 0.006), respectively. Additionally, the high serum 25OHD groups (>95.9 nmol/L) had 0.038 SD (standardized β = -0.038, 95% CI -0.072 to -0.004, p = 0.030) shorter mean LTL than the group with medium 25OHD levels. The associations above were adjusted for multiple variables. Conclusions: In this population-based study, we identified an inverted U-shape relationship between LTL and vitamin D status. Our findings could be affected by unmeasured confounders. Whether high or low vitamin D-associated shorter LTL is mechanistically related to age-related conditions remains to be elucidated.

Neighbourhood residential density, urbanicity and incident dementia and Alzheimer's disease: A 12-year prospective cohort study from the UK Biobank

IntroductionAn increasing proportion of global population is exposed to urban densification in an aging society. However, little is known of the role of residential density and urbanicity on the risk of developing dementia including Alzheimer's disease. We examined long-term associations between residential density and urbanicity and risks of incident dementia and Alzheimer's disease. MethodsThis prospective cohort study included participants from the UK Biobank who lived at the same residential address, had no self-reported neurological conditions and without dementia at baseline. Residential density was measured as the number of dwelling units within 1-km street neighbourhood of participant's home address. A composite index of urbanicity was developed from neighbourhood-level z-standardized densities of housing, retail, public transport and street centrality. Hazard ratios were derived from Cox proportional hazard models adjusted for known risk factors. ResultsThe analytic sample included 239,629 participants aged 38–72 years. During a median follow-up of 12.3 years (interquartile range 11.5–13.0 years), 2,176 participants developed dementia and 1,004 Alzheimer's disease. After adjustments for potential risk factors, each 1,000 units/Km2 increment in residential density was associated with higher risks of dementia (hazard ratio [HR]=1.10, 95% confidence interval [CI]: 1.06-1.15) and Alzheimer’s disease (HR=1.10, 95% CI: 1.04-1.16). Consistently, categorical models showed that living in neighbourhoods of higher residential density and urbanicity were associated with higher risks of dementia (HR = 1.30, 95% CI: 1.12–1.51 for the highest density quintile compared to the lowest and HR = 1.21, 95% CI: 1.05–1.39 for the highest urbanicity quintile relative to the lowest). The associations were more pronounced in female, age >65 years, and among participants of the low income and those being frail and having shorter leucocyte telomere length (LTL). ConclusionsHigher residential density and urbanicity was found to be positively associated with elevated risks of dementia and Alzheimer's disease. Optimizing neighbourhood residential density maybe one of the upstream considerations for mitigating against neurodegenerative diseases.

Association of Telomere Length with Colorectal Cancer Risk and Prognosis: A Systematic Review and Meta-Analysis.

(1) Background: Colorectal cancer risk and survival have previously been associated with telomere length in peripheral blood leukocytes and tumor tissue. A systematic review and meta-analysis of the literature was conducted. The PubMed, Embase, and Web of Science databases were searched through March 2022. (2) Methods: Relevant studies were identified through database searching following PRISMA guidelines. Risk estimates were extracted from identified studies; meta-analyses were conducted using random effects models. (3) Results: Fourteen studies were identified (eight on risk; six on survival) through systematic review. While no association was observed between circulating leukocyte telomere length and the risk of colorectal cancer [overall OR (95% CI) = 1.01 (0.82-1.24)], a worse survival for those with shorter telomeres in leukocytes and longer telomeres in tumor tissues was observed [Quartile1/Quartile2-4 overall HR (95% CI) = 1.41 (0.26-7.59) and 0.82 (0.69-0.98), respectively]. (4) Conclusions: Although there was no association with colorectal cancer risk, a poorer survival was observed among those with shorter leukocyte telomere length. Future larger studies evaluating a potentially non-linear relationship between telomeres and colorectal cancer are needed.

Lower anti-Müllerian hormone levels are associated with HIV in reproductive age women and shorter leukocyte telomere length among late reproductive age women.

We sought to better understand factors associated with ovarian aging in women with HIV (WWH). HIV has been associated with diminished fertility, younger age at menopause, and shorter leukocyte telomere length (LTL), a marker of cellular aging. We herein examine cross-sectional and longitudinal associations between LTL, anti-Müllerian hormone (AMH), and HIV. We included WWH and HIV-negative women 12-50 years of age in the CARMA cohort with one or more study visit(s). LTL and AMH were measured by qPCR and ELISA, respectively. Women were analyzed in peak reproductive (<35 years) vs. late reproductive (≥35 years) life phases. Using multivariable mixed-effect linear or logistic regressions, we assessed factors associated with AMH and ΔAMH/year while adjusting for relevant confounders. WWH had shorter LTL and lower AMH levels compared to HIV-negative controls despite being of similar age. After adjusting for relevant factors, HIV was associated with 20% lower AMH levels in women under 35 years of age and shorter LTL was associated with AMH levels below 2 ng/ml among women aged 35 years or older. Longitudinally, ΔAMH/year was largely related to initial AMH level among older women, and to age in younger women. Factors associated with AMH change across women's reproductive lifespan. Lower AMH among peak reproductive aged WWH suggests that HIV may have an initial detrimental effect on ovarian reserve, an observation that may warrant counseling around pregnancy planning. In women aged 35 years or older, the association between shorter LTL and lower AMH suggests that the immune and reproductive aging connections are more important in this age group.

Causal linkage of tobacco smoking with ageing: Mendelian randomization analysis towards telomere attrition and sarcopenia.

Ageing traits and frailty are important health issues in modern medicine. Evidence supporting the causal effects of tobacco smoking on various ageing traits is required. This study performed Mendelian randomization (MR) analysis instrumenting 377 genetic variants associated with being an ever-smoker at a genome-wide significance level to test the causal estimates from tobacco smoking. The outcome data were obtained from 337 138 white British ancestry participants from the UK Biobank. Leucocyte telomere length, appendicular lean mass index, subjective walking pace, handgrip strength,and wristband accelerometry-determined physical activity degree were collected as ageing-related outcomes. Summary-level MR analysis was performed using the inverse variance-weighted method and pleiotropy-robust MR methods, including weighted median and MR-Egger. Observational association between the outcome traits and phenotypically being an ever-smoker was also investigated. Summary-level MR analysis indicated that a higher genetic predisposition for tobacco smoking was significantly associated with shorter leucocyte telomere length (twofold increase in prevalence of smoking towards standardized Z-score, -0.041 [-0.054, -0.028]), lower appendicular lean mass index (-0.007 [-0.010, -0.005]), slower walking pace (ordinal category, -0.047 [-0.054, -0.033]) and lower time spent on moderate-to-vigorous physical activity (hours per week, -0.39 [-0.56, -0.23]). The causal estimates were non-significant towards handgrip strength phenotype (kg, 0.074 [-0.055, 0.204]). Pleiotropy-robust MR results generally supported the main causal estimates. The observational findings also showed significant association between being an ever-smoker and the ageing traits. Genetically predicted and observational tobacco smoking status are significantly associated with poor ageing phenotypes. Healthcare providers may continue to reduce tobacco use, which may be helpful in reducing the burden of ageing and frailty.

Potential Antiaging and Hepatoprotective Effects of Acanthopanax senticosus Extracts in Adult Rat Models.

Data regarding plant extracts with antiaging properties, particularly through the biological process involving telomeres and telomerase, are limited. Thus, this study aimed to investigate the effects of Acanthopanax senticosus extract (ASE) supplementation on leukocyte telomere length (LTL), telomerase, and inflammatory and metabolic markers in adult animal models. A freeze-dried product of ethanol extracts was prepared using a mixture product of stem and root ASE. In a 24-week experiment that included 24-week-old Sprague Dawley male rats, experimental rats (n = 10) were administrated with 7 mg/day of ASE dissolved in saline and control rats (n = 10) with saline. All rats had access to chow and tap water ad libitum. Their LTL and plasma levels of telomerase and inflammatory and metabolic markers were assayed and compared between the two groups. The experimental rats showed significantly longer LTL (p < 0.05) and lower plasma levels of alanine aminotransferase (p < 0.05) and aspartate aminotransferase (p = 0.08) compared with the control. In addition, LTL was correlated with the aforementioned biochemical parameters of liver function test among experimental rats only. No significant differences in plasma levels of telomerase and inflammatory and metabolic markers were observed. These findings indicate that ASE supplementation may attenuate LTL shortening and reduce liver biochemical parameters, indicating its potential antiaging and hepatoprotective effects without any adverse metabolic response.

Associations of green tea, coffee, and soft drink consumption with longitudinal changes in leukocyte telomere length

Whether beverage consumption is associated with longitudinal observation of telomere length remains unclear. We evaluated the association of green tea, coffee, and soft drink consumption with 6-year changes in leukocyte telomere length (LTL). The study included 1952 participants who provided whole blood samples for LTL assays during the baseline (year 2011–2012) and follow-up (year 2017–2018) periods and reported baseline information on consumption of green tea, coffee, and soft drinks. Robust regression analysis was used to analyze the association adjusted for potential confounding variables. In the results, an inverse association between green tea consumption and LTL changes from baseline, which indicate telomere shortening, was found; regression coefficient [95% confidence interval] was − 0.097 [− 0.164, − 0.029] for participants who daily consumed at least 1 cup of green tea compared with non-consumers (p value = 0.006). This association was stronger among women (versus men) and younger participants aged 50–64 years (versus older). However, a positive association between soft drink consumption and LTL shortening was observed among women (p value < 0.05). Coffee consumption was not associated with LTL changes. These findings suggested that green tea consumption may be protective against telomere shortening reflecting biological aging whereas coffee and soft drink consumption may not.

Examining the Cross-sectional Association Between Neighborhood Conditions, Discrimination, and Telomere Length in a Predominantly African American Sample.

Disproportionate exposure to adverse neighborhood conditions and greater discrimination may contribute to health disparities among African Americans (AAs). We examined whether adverse neighborhood conditions, alone or in conjunction with discrimination, associate with shorter leukocyte telomere length among a predominantly AA cohort. The sample included 200 residents from two low-income neighborhoods (96% AA; mean age = 67years). Perceived neighborhood conditions and discrimination were surveyed in 2018, and objective neighborhood conditions (total crime rate, neighborhood walkability, ambient air pollution (PM2.5, black carbon)) were collected in 2017/2018. Relative telomere length (T/S; ratio of telomeric DNA to a single-gene copy) was assessed from blood samples. Linear regression models estimated the main effects of each neighborhood condition and discrimination and their interactions on the T/S ratio. Less walkable neighborhoods were associated with shorter telomeres. Higher air pollution (PM2.5) was associated with shorter telomeres among those experiencing greater discrimination. Findings highlight the importance of understanding the intersecting influences of historic and contemporary sources of systemic racism and how they contribute to accelerated aging among adults.

PS-B09-4: SHORTER LEUKOCYTE TELOMERE LENGTH AS AN EARLY INDICATOR FOR CHRONIC KIDNEY DISEASE IN HYPERTENSIVE PATIENTS

Objective: Essential hypertension is a major risk factor for incident chronic kidney disease (CKD). This is a main reason for preference of antihypertensive medications that provide some protection against hypertension induced renal damage. Furthermore, there is abundant evidence that hypertension and CKD comorbidity worsens cardiovascular disease prognosis with increased morbidity and mortality. Onset of CKD may not be noticeable until there is evident progressive decline in the estimated glomerular filtration rate (eGFR). For this, telomere attrition may provide some early indication. Telomeres are markers of biological aging, and telomere attrition is associated with oxidative stress and inflammation. Kidney interstitial inflammation is known to play a central role in loss of renal function progressing into CKD. This study investigated the association between telomere length and renal interstitial inflammation in hypertensive patients. Design and Methods: Our study group consisted of 200 participants from the TRANScriptome of renaL humAn TissuE (TRANSLATE) study. Interstitial inflammation in human kidney tissue samples was assessed by histology. eGFR was calculated from serum creatinine using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) FORMULA. Leukocyte telomere length (LTL) was quantified using quantitative polymerase chain reaction. Results: Mean LTL was significantly shorter in hypertensive participants (2.776 ± 0.063) compared with non-hypertensive participants (3.007 ± 0.092; P = 0.041). In hypertensive participants without CKD, renal interstitial inflammation negatively associates with leukocyte telomere length (LTL) (r = -0.483, P = 0.048), and the association remained significant after adjustment for age (r = -0.479, P = 0.041). Similar results were observed after exclusion of patients with eGFR &gt; = 60 ml/min/1.73m2. In patients with eGFR &lt; 60 ml/min/1.73m2, the association remained significant after adjusting for age, sex, BMI, diabetes mellitus and smoking status (r = -1.429, P = 0.011). These results show that telomere length associates with interstitial inflammation in hypertensive patients with no apparent decrease in eGFR. Conclusions: Hypertensive participants have shorter LTL than non-hypertensive participants, and within the hypertensive group, participants with shorter telomeres are more likely to have CKD. Telomere length may provide suitable indication to help target hypertensive patients at increased risk of developing CKD.

Leukocyte Telomeric G-Tail Length Shortening Is Associated with Esophageal Cancer Recurrence.

Despite significant advances in therapeutics for esophageal cancer (ESC) in the past decade, it remains the sixth most fatal malignancy, with a poor 5-year survival rate (approximately 10%). There is an urgent need to improve the timely diagnosis to aid the prediction of the therapeutic response and prognosis of patients with ESC. The telomeric G-tail plays an important role in the chromosome protection. However, aging and age-related diseases lead to its shortening. Therefore, the G-tail length has been proposed as a novel potential biomarker. In the present study, to examine the possibility of G-tail shortening in patients with ESC, we measured the leukocyte telomere length (LTL) and the G-tail length using a hybridization protection assay in 147 patients with ESC and 170 age-matched healthy controls. We found that the G-tail length in patients with ESC was shorter than that in the healthy controls (p = 0.02), while the LTL shortening was not correlated with the ESC incidence and recurrence. Our results suggest that the G-tail length reflects the physiological status of patients with ESC and is a promising biomarker for the diagnosis and prognosis of ESC.

Longitudinal Association of Telomere Dynamics with Obesity and Metabolic Disorders in Young Children

In adults, short leukocyte telomere length (LTL) is associated with metabolic disorders, such as obesity and diabetes mellitus type 2. These associations could stem from early life interactions between LTL and metabolic disorders. To test this hypothesis, we explored the associations between LTL and metabolic parameters as well as their evolution over time in children with or without obesity at baseline. Seventy-three (n = 73) children attending our Outpatient Clinic for the Prevention and Management of Overweight and Obesity in Childhood and Adolescence, aged 2-10 years (mean ± SD: 7.6 ± 2.0 years), were followed for 2 to 4 years. Anthropometric, clinical, and biological (including LTL by Southern blot) measurements were performed annually. Baseline LTL correlated negatively with BMI (p = 0.02), fat percentage (p = 0.01), and blood glucose (p = 0.0007). These associations persisted after adjustments for age and sex. No associations were found between LTL attrition during the follow-up period and any of the metabolic parameters. In young children, obesity and metabolic disturbances were associated with shorter telomeres but were not associated with more pronounced LTL attrition. These results suggest that short telomeres contribute to the development of obesity and metabolic disorders very early in life, which can have a major impact on health.

Shorter telomere length and suicidal ideation in familial bipolar disorder.

Bipolar Disorder (BD) has recently been related to a process of accelerated aging, with shortened leukocyte telomere length (LTL) in this population. It has also been observed that the suicide rate in BD patients is higher than in the general population, and more recently the telomere length variation has been described as shorter in suicide completers compared with control subjects. Objectives The aim of the present study was to investigate if there is an association between LTL and BD in families where two or more members have BD including clinical symptomatology variables, along with suicide behavior. Methods Telomere length and single copy gene ratio (T/S ratio) was measured using quantitative polymerase chain reaction in a sample of 143 relatives from 22 families, of which 60 had BD. The statistical analysis was performed with a polygenic mixed model. Results LTL was associated with suicidal ideation (p = 0.02) as that there is an interaction between suicidal ideation and course of the disorder (p = 0.02). The estimated heritability for LTL in these families was 0.68. In addition, covariates that relate to severity of disease, i.e. suicidal ideation and course of the disorder, showed an association with shorter LTL in BD patients. No difference in LTL between BD patients and healthy relatives was observed. Conclusion LTL are shorter in subjects with familial BD suggesting that stress related sub-phenotypes possibly accelerate the process of cellular aging and correlate with disease severity and suicidal ideation.