Shorter Leukocyte Telomere Length Research Articles

Breaking down causes, consequences, and mediating effects of telomere length variation on human health

BackgroundTelomeres form repeated DNA sequences at the ends of chromosomes, which shorten with each cell division. Yet, factors modulating telomere attrition and the health consequences thereof are not fully understood. To address this, we leveraged data from 326,363 unrelated UK Biobank participants of European ancestry.ResultsUsing linear regression and bidirectional univariable and multivariable Mendelian randomization (MR), we elucidate the relationships between leukocyte telomere length (LTL) and 142 complex traits, including diseases, biomarkers, and lifestyle factors. We confirm that telomeres shorten with age and show a stronger decline in males than in females, with these factors contributing to the majority of the 5.4% of LTL variance explained by the phenome. MR reveals 23 traits modulating LTL. Smoking cessation and high educational attainment associate with longer LTL, while weekly alcohol intake, body mass index, urate levels, and female reproductive events, such as childbirth, associate with shorter LTL. We also identify 24 traits affected by LTL, with risk for cardiovascular, pulmonary, and some autoimmune diseases being increased by short LTL, while longer LTL increased risk for other autoimmune conditions and cancers. Through multivariable MR, we show that LTL may partially mediate the impact of educational attainment, body mass index, and female age at childbirth on proxied lifespan.ConclusionsOur study sheds light on the modulators, consequences, and the mediatory role of telomeres, portraying an intricate relationship between LTL, diseases, lifestyle, and socio-economic factors.

Chronic and Latent Viral Infections and Leukocyte Telomere Length across the Lifespan of Female and Male Individuals Living with or without HIV

Background: Chronic/latent viral infections may accelerate immunological aging, particularly among people living with HIV (PLWH). We characterized chronic/latent virus infections across their lifespan and investigated their associations with leukocyte telomere length (LTL). Methods: Participants enrolled in the CARMA cohort study were randomly selected to include n = 15 for each decade of age between 0 and >60 y, for each sex, and each HIV status. Cytomegalovirus (CMV), Epstein–Barr virus (EBV), human herpesvirus 8 (HHV-8), herpes simplex virus 1 (HSV-1), and HSV-2 infection were determined serologically; HIV, hepatitis C (HCV), and hepatitis B (HBV) were self-reported. LTLs were measured using monochrome multiplex qPCR. Associations between the number of viruses, LTL, and sociodemographic factors were assessed using ordinal logistic and linear regression modeling. Results: The study included 187 PLWH (105 female/82 male) and 190 HIV-negative participants (105 female/84 male), ranging in age from 0.7 to 76.1 years. Living with HIV, being older, and being female were associated with harbouring a greater number of chronic/latent non-HIV viruses. Having more infections was in turn bivariately associated with a shorter LTL. In multivariable analyses, older age, living with HIV, and the female sex remained independently associated with having more infections, while having 3–4 viruses (vs. 0–2) was associated with a shorter LTL. Conclusions: Our results suggest that persistent viral infections are more prevalent in PLWH and females, and that these may contribute to immunological aging. Whether this is associated with comorbidities later in life remains an important question.

Causal association and shared genetics between telomere length and COVID-19 outcomes: new evidence from the latest large-scale summary statistics

BackgroundObservational studies suggested that leukocyte telomere length (LTL) is shortened in COVID-19 patients. However, the genetic association and causality remained unknown. MethodsBased on the genome-wide association of LTL (N = 472,174) and COVID-19 phenotypes (N = 1,086,211-2,597,856), LDSC and SUPERGNOVA were used to estimate the genetic correlation. Cross-trait GWAS meta-analysis, colocalization, fine-mapping analysis and transcriptome-wide association study were conducted to explore the shared genetic etiology. Mendelian randomization (MR) was utilized to infer the causality. Upstream and downstream two-step MR was performed to investigate the potential mediating effects. ResultsLDSC identified a significant genetic association between LTL and all COVID-19 phenotypes (rG < 0, p < 0.05). Six significant regions were observed for LTL and COVID-19 susceptibility and hospitalization, respectively. Colocalization analysis found rs144204502, rs34517439, and rs56255908 were shared causal variants between LTL and COVID-19 phenotypes. Numerous biological pathways associated with LTL and COVID-19 outcomes were identified, mainly involved in immune related pathways. MR showed that longer LTL was significantly associated with a lower risk of COVID-19 severity (OR [95% CI] = 0.81 [0.71-0.92], p = 1.24×10-3) and suggestively associated with lower risks of COVID-19 susceptibility (OR [95% CI] = 0.96 [0.92-1.00], p = 3.44×10-2) and COVID-19 hospitalization (OR [95% CI] = 0.89 [0.80-0.98], p = 1.89×10-2). LTL partially mediated the effects of BMI, smoking, and education on COVID-19 outcomes. Furthermore, six proteins partially mediated the causality of LTL on COVID-19 outcomes, including BNDF, QPCT, FAS, MPO, SFTPB, and APOF. ConclusionsOur findings suggested that shorter LTL was genetically associated with higher risk of COVID-19 phenotypes, with shared genetic etiology and potential causality.

Association Between Ultraprocessed Foods Consumption and Leucocyte Telomere Length: A Cross-Sectional Study of UK Biobank

Background□ ObjectivesThis study aimed to investigate the association between consumption of ultraprocessed foods and leucocyte telomere length (LTL). MethodsThis cross-sectional study utilized data from the UK Biobank, including a total of 64,690 participants. LTL was measured using qPCR with natural logarithmic conversion and z-score normalization. Dietary data were collected through a 24-h recall questionnaire from 2009 to 2010. Ultraprocessed foods (UPFs) were identified using the NOVA food classification as either a continuous or a categorical variable. Multiple linear regression models were employed to analyze the association between UPF consumption and LTL. ResultsThe included participants had an average age of 56.26 y, of whom 55.2% were female. After adjusting for demographic and health-related variables, LTL exhibited a decrease of 0.005 (95% CI: −0.007, −0.002) with 1 UPF serving increase. Compared with participants consuming ≤3.5 servings/d, those consuming 3.5 to <6 servings showed a shortening of LTL by 0.025 (95% CI: −0.046, −0.003). Participants consuming 6 to ≤8 servings/d and >8 servings/d had LTL shortening of 0.032 (95% CI: −0.054, −0.011) and 0.037 (95% CI: −0.060, −0.014), respectively (P for trend = 0.002). Subgroup analyses by UPF subclasses revealed that the consumption of ready-to-eat/heated food (β: −0.010; 95% CI: −0.016, −0.004), beans and potatoes (β: −0.027; 95% CI: −0.043, −0.012), animal-based products (β: −0.012; 95% CI: −0.020, −0.005), artificial sugar (β: −0.014; 95% CI:−0.025,−0.003), and beverages (β: −0.005; 95% CI: −0.009, −0.001) showed negative associations with LTL. Conversely, breakfast cereals (β: 0.022; 95% CI: 0.006, 0.038) and vegetarian alternatives (β: 0.056; 95% CI:0.026,0.085) showed positive correlations with LTL. ConclusionsOur study found that a higher consumption of total UPF was associated with a shorter LTL. However, some UPFs may be associated with longer LTL, depending on their nutritional composition.

Association between telomere length and Plasmodium falciparum malaria endemicity in sub-Saharan Africans

Leukocyte telomere length (LTL) varies significantly across human populations, with individuals of African ancestry having longer LTL than non-Africans. However, the genetic and environmental drivers of LTL variation in Africans remain largely unknown. We report here on the relationship between LTL, genetics, and a variety of environmental and climatic factors in ethnically diverse African adults (n= 1,818) originating from Botswana, Tanzania, Ethiopia, and Cameroon. We observe significant variation in LTL among populations, finding that the San hunter-gatherers from Botswana have the longest leukocyte telomeres and that the Fulani pastoralists from Cameroon have the shortest telomeres. Genetic factors explain ∼50% of LTL variation among individuals. Moreover, we observe a significant negative association between Plasmodium falciparum malaria endemicity and LTL while adjusting for age, sex, and genetics. Within Africa, adults from populations indigenous to areas with high malaria exposure have shorter LTL than those in populations indigenous to areas with low malaria exposure. Finally, we explore to what degree the genetic architecture underlying LTL in Africa covaries with malaria exposure.

Association between leucocyte telomere length and erectile dysfunction in US adults: a secondary study based on 2001–2002 NHANES data

ObjectiveWe aimed to explore the association between the leucocyte telomere length (LTL) and erectile dysfunction (ED) among a nationally representative sample of US adults.DesignSecondary population-based study.SettingThe National Health and Nutrition...

Evaluating Leukocyte Telomere Length and Myeloid-Derived Suppressor Cells as Biomarkers for Prostate Cancer.

Leukocyte telomere length (LTL) and myeloid-derived suppressor cells (MDSC) are associated with aging and the development and progression of cancer. However, the exact nature of this relationship remains unclear. Our study aimed to investigate the potential of LTL and MDSC as diagnostic biomarkers for prostate cancer while also seeking to deepen our understanding of the relationship of these potential biomarkers to each other. Our study involved patients undergoing a prostate biopsy. We analyzed the relative LTL in genomic DNA obtained from peripheral blood leukocytes as well as the percentage of MDSC and their subtypes in peripheral blood mononuclear cells (PBMC). Our evaluation focused on examining the relationship between LTL and MDSC and pathological diagnoses as well as investigating the correlation between LTL and MDSC levels. In our study of 102 participants, 56 were pathologically diagnosed with localized prostate cancer (cancer group), while 46 tested negative (control group). The cancer group exhibited significantly shorter LTL in comparison to the control group (p = 0.024). Additionally, the cancer group showed a tendency towards a higher percentage of monocytic MDSC (M-MDSC), although this difference did not reach statistical significance (p = 0.056). Our multivariate logistic regression analysis revealed that patients with shorter LTL and higher percentages of M-MDSC had a 2.98-fold (95% CI = 1.001-8.869, p = 0.049) and 3.03-fold (95% CI = 1.152-7.977, p = 0.025) increased risk of prostate cancer diagnosis, respectively. There was also a significant negative correlation between LTL and M-MDSC. (r = -0.347, p < 0.001). Our research has established a correlation between LTL and MDSC in patients undergoing biopsy for prostate cancer. Notably, we observed that individuals with localized prostate cancer tend to have shorter LTL and a higher percentage of M-MDSC prior to their diagnosis. These findings suggest that LTL and M-MDSC could potentially serve as adjunctive biomarkers for the early diagnosis of prostate cancer.

Abstract 3461: Shorter leukocyte telomere length and higher risk of primary liver cancer in a prospective cohort study

Abstract Background: Telomeres are conserved tandem repeats at chromosome ends that are vital to maintaining chromosomal stability and preventing degradation. Shorter telomere lengths (TL) are typically associated with older biological age or poor health status and can activate programmed cell death, whereas longer telomere lengths can be indicative of younger age or abnormal replication processes with oncogenic mutations. Previous research has identified a link between telomere length and carcinogenesis, but relatively few studies have investigated TL and primary liver cancer (PLC) risk despite it being one of the leading causes of cancer worldwide. The goal of this analysis was to study this association in a large prospective cohort. Methods: Data was extracted from the Singapore Chinese Cohort Health Study, a cohort of 63,257 men and women aged 45-74 years at enrollment during 1993-1998. Telomere length was measured in peripheral leukocytes of 26,540 participants who provided baseline blood samples, using a validated quantitative polymerase chain reaction (qPCR) method. PLC incidence and death among cohort participants was annually surveilled using the nationwide Singapore Cancer Registry and the National Birth and Death Registry from study enrollment to 2015. For statistical analysis, a t test was performed to examine the differences in TL between participants who developed incident PLC and those who remained free of PLC. Cox proportional hazard method was used to estimate the hazard ratios (HRs) and their 95% confidence interval (CI) of PLC incidence according to TL quartiles. Results: Over a 12-year follow-up, 199 participants developed incident PLC. The relative TL was significantly lower in participants with incident PLC than those without (-6.7%, p &amp;lt; 0.001). Multivariate Cox regression model showed an inverse association between TL quartile and risk of PLC (p for trend = 0.009). Compared with the lowest quartile, HRs (95% CIs) of PLC for the 2nd, 3rd, and highest quartile of TL were 0.78 (0.54-1.12), 0.75 (0.51-1.11), and 0.57 (0.37-0.88), respectively, after adjustment for age, sex, alcohol use, body mass index, and smoking status. Conclusion: The present analysis demonstrated a statistically significant association between shorter telomere length and increased risk of PLC in a large prospective cohort of Singaporean Chinese. This inverse association for PLC is different from those for other cancer types in the same cohort. These results warrant further studies such as using Mendelian randomization to quantify genetic variation in TL with PLC development. Citation Format: Sindhu Karnam, Kathryn Demanelis, Kenneth B. Beckman, Renwei Wang, Jennifer Adams-Haduch, Woon-Puay Koh, Jian-Min Yuan. Shorter leukocyte telomere length and higher risk of primary liver cancer in a prospective cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3461.

The association of sleep duration and leukocyte telomere length in middle-aged and young-old adults: A cross-sectional study of UK Biobank

BackgroundThe relationships between sleep duration and aging-associated diseases are intricate. Leukocyte telomere length (LTL) is a biomarker of aging, while the association of sleep duration and LTL is unclear. MethodsThe 310,091 study participants from UK Biobank were enrolled in this cross-sectional study. Restricted cubic splines (RCS) analysis was firstly performed to assess the nonlinear relationship between sleep duration and LTL. Sleep duration was then categorized into three groups: <7 h (short sleep duration), 7–8 h (reference group), and >8 h (long sleep duration) and multiple linear regression was applied to analyze the association of short sleep and long sleep duration with LTL. We further performed subgroup analyses stratified by sex, age, chronotype and snoring. ResultsRCS showed an inverted J-shaped relationship between sleep duration and LTL. Compared with the reference group, the inverse association of long sleep duration and LTL was statistically significant in fully-adjusted model (P = 0.001). Subgroup analyses showed that this association was more apparent in people over 50 years (51–60 y: P = 0.002; >60 y: P = 0.005), in men (P = 0.022), and in people preferred evening chronotype (P = 0.001). ConclusionCompared with participants sleeping 7–8 h, those sleep longer than 8 h had shorter LTL in middle-aged and young-old adults. The negative association between long sleep duration and LTL was more apparent in older people, in men, and in people preferred evening chronotype.

Retraction: Obesity accelerates leukocyte telomere length shortening in apparently healthy adults: a meta-analysis.

[This retracts the article DOI: 10.3389/fnut.2022.812846.].

Childhood Maltreatment and Leukocyte Telomere Length: Cardiac Vagal Activity Influences the Relation in Older Adults.

Childhood maltreatment is associated with shorter leukocyte telomere length (LTL). However, the influence of cardiac vagal control on this relation is unknown. We examined whether cardiac vagal control at rest and in response to stress moderates or cross-sectionally mediates the relationship between childhood maltreatment and LTL. Participants were 1179 men and women (aged 65 [7.2] years) suffering from coronary artery disease or non-cardiovascular chronic disease. They completed a childhood maltreatment questionnaire and underwent a stress protocol while electrocardiogram was monitored. High-frequency heart rate variability (HF-HRV) measures were obtained at rest, during stress, and after stress in absolute and normalized units (nu). LTL was measured using quantitative polymerase chain reaction. Mediation and moderation analyses were performed. HF-HRV and HF-HRV in normalized units (HFnu) measures did not mediate the childhood maltreatment-LTL relation. However, baseline HFnu ( p = .027) and HFnu reactivity ( p = .051) moderated the relation. Specifically, maltreatment was associated with significantly lower LTL among those with baseline HFnu at ( b = -0.059, p = .003) or below the mean ( b = -0.103, p < .001), but not among those with higher baseline HFnu. It was also associated with significantly lower LTL among participants who showed either blunted ( b = -0.058, p = .004) or increased HFnu ( b = -0.099, p = .001) responses to stress but not in those with large decreases in HFnu. Childhood maltreatment was associated with lower LTL in those who showed a distinct cardiac vagal profile at baseline and in response to stress. The mechanisms and implications remain to be determined.

Leukocyte Telomere Length and Cardiac Structure and Function: A Mendelian Randomization Study.

Existing research demonstrates the association of shorter leukocyte telomere length with increased risk of age-related health outcomes including cardiovascular diseases. However, the direct causality of these relationships has not been definitively established. Cardiovascular aging at an organ level may be captured using image-derived phenotypes of cardiac anatomy and function. In the current study, we use 2-sample Mendelian randomization to assess the causal link between leukocyte telomere length and 54 cardiac magnetic resonance imaging measures representing structure and function across the 4 cardiac chambers. Genetically predicted shorter leukocyte telomere length was causally linked to smaller ventricular cavity sizes including left ventricular end-systolic volume, left ventricular end-diastolic volume, lower left ventricular mass, and pulmonary artery. The association with left ventricular mass (β =0.217, Pfalse discovery rate=0.016) remained significant after multiple testing adjustment, whereas other associations were attenuated. Our findings support a causal role for shorter leukocyte telomere length and faster cardiac aging, with the most prominent relationship with left ventricular mass.

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±17.0years; 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 7.7years 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 4.4years. The associations appeared magnified with higher energy intake. These findings support a complex relationship between dietary macronutrients and biological aging independent of diet quality.

Leukocyte telomere length mediates the association between cadmium exposure and cognitive function in US older adults

BackgroundLong-term exposure to cadmium-polluted environments may lead to shortened leukocyte telomere length and cognitive decline. This study aims to investigate (1) the associations among blood cadmium levels, leukocyte telomere length, and cognitive function, and (2) the mediating role of leukocyte telomere length between blood cadmium levels and cognitive function among older adults in the United States. MethodsUsing data from the National Health and Nutrition Examination Survey (NHANES) 1999–2002. Cadmium exposure level was assessed by measuring cadmium levels in blood samples. Leukocyte telomere length was measured by quantitative polymerase chain reaction, and cognitive function was measured by the digit symbol substitution test (DSST). ResultsA total of 2185 older adults aged over 60 were included in this study, comprising 1109 (49.65%) males. Elevated blood cadmium levels were significantly associated with the risk of a decline in cognitive function (β = - 2.842, p = 0.018). Shorter leukocyte telomere lengths were significantly associated with a higher risk of a decline in cognitive function (β = 4.144, p = 0.020). The total indirect effect on the blood cadmium level and cognitive function via leukocyte telomere length was - 0.218 (p = 0.012). The mediation effect was estimated to be 0.218/2.084 × 100% = 10.46%. ConclusionThe findings suggest that cadmium exposure may increase the risk of cognitive impairment by causing shortened leukocyte telomere length.

Sub-optimal maternal gestational gain is associated with shorter leukocyte telomere length at birth in a predominantly Latinx cohort of newborns

ObjectiveTo assess in utero exposures associated with leukocyte telomere length (LTL) at birth and maternal LTL in a primarily Latinx birth cohort.Study designMothers and newborns were recruited postnatally before 24 h of life. Newborn LTL was collected via heelstick at birth and maternal LTL was collected postnatally. LTL was determined by quantitative PCR. Using a longitudinal design, we evaluated associations between neonatal and maternal LTL and appropriate maternal gestational gain as indicated by the American College of Obstetrics and Gynecology (ACOG).ResultMean infant LTL was 2.02 ± 0.30 T/S (n = 386) and maternal LTL was 1.54 ± 0.26 T/S (n = 58). Independent risk factors for shorter LTL at birth included longer gestational duration (Coeff:-0.03, 95%CI: -0.05—0.01;p < 0.01) and maternal gestational weight gain below ACOG recommendations (Coeff:-0.10, 95%CI: -0.18 – -0.02; p = 0.01).ConclusionGestational weight gain below ACOG recommendations may adversely impact neonatal health in Latinx infants as indicated by shorter LTL at birth.

Associations of measured and genetically predicted leukocyte telomere length with vascular phenotypes: a population-based study.

Shorter leukocyte telomere length (LTL) is associated with cardiovascular dysfunction. Whether this association differs between measured and genetically predicted LTL is still unclear. Moreover, the molecular processes underlying the association remain largely unknown. We used baseline data of the Rhineland Study, an ongoing population-based cohort study in Bonn, Germany [56.2% women, age: 55.5 ± 14.0years (range 30 - 95years)]. We calculated genetically predicted LTL in 4180 participants and measured LTL in a subset of 1828 participants with qPCR. Using multivariable regression, we examined the association of measured and genetically predicted LTL, and the difference between measured and genetically predicted LTL (ΔLTL), with four vascular functional domains and the overall vascular health. Moreover, we performed epigenome-wide association studies of three LTL measures. Longer measured LTL was associated with better microvascular and cardiac function. Longer predicted LTL was associated with better cardiac function. Larger ΔLTL was associated with better microvascular and cardiac function and overall vascular health, independent of genetically predicted LTL. Several CpGs were associated (p < 1e-05) with measured LTL (n = 5), genetically predicted LTL (n = 8), and ΔLTL (n = 27). Genes whose methylation status was associated with ΔLTL were enriched in vascular endothelial signaling pathways and have been linked to environmental exposures, cardiovascular diseases, and mortality. Our findings suggest that non-genetic causes of LTL contribute to microvascular and cardiac function and overall vascular health, through an effect on the vascular endothelial signaling pathway. Interventions that counteract LTL may thus improve vascular function.

The Shortening of Leukocyte Telomere Length Contributes to Alzheimer's Disease: Further Evidence from Late-Onset Familial and Sporadic Cases.

Telomeres are structures at the ends of eukaryotic chromosomes that help maintain genomic stability. During aging, telomere length gradually shortens, producing short telomeres, which are markers of premature cellular senescence. This may contribute to age-related diseases, including Alzheimer's disease (AD), and based on this, several studies have hypothesized that telomere shortening may characterize AD. Current research, however, has been inconclusive regarding the direction of the association between leukocyte telomere length (LTL) and disease risk. We assessed the association between LTL and AD in a retrospective case-control study of a sample of 255 unrelated patients with late-onset AD (LOAD), including 120 sporadic cases and 135 with positive family history for LOAD, and a group of 279 cognitively healthy unrelated controls, who were all from Calabria, a southern Italian region. Following regression analysis, telomeres were found significantly shorter in LOAD cases than in controls (48% and 41% decrease for sporadic and familial cases, respectively; p < 0.001 for both). Interestingly, LTL was associated with disease risk independently of the presence of conventional risk factors (e.g., age, sex, MMSE scores, and the presence of the APOE-ε4 allele). Altogether, our findings lend support to the notion that LTL shortening may be an indicator of the pathogenesis of LOAD.

Influence of Chromosome 9p21.3 rs1333049 Variant on Telomere Length and Their Interactive Impact on the Prognosis of Coronary Artery Disease.

Both telomere shortening and the chromosome 9p21.3 (Chr9p21) rs1333049 (G/C) variant are involved in coronary artery disease (CAD) risk, likely affecting mechanisms related to cell cycle arrest and vascular senescence. The aim of the study was to examine the link between Chr9p21 rs1333049 variant and leucocyte telomere length (LTL), as well as their interactive effect on the risk of major adverse cardiovascular events (MACEs). A cohort of 472 patients with angiographically proven and clinically stable CAD were included in the study. At baseline, the LTL, biochemical parameters, and genotype analysis of Chr9p21 rs1333049 variant were measured in all patients. The primary endpoint of this study was the occurrence of MACE defined as a composite of coronary-related death, nonfatal MI, and coronary revascularization. On multivariable linear regression analysis, age (p = 0.02) and Chr9p21 rs1333049 variant (p = 0.002) were the only independent predictors of LTL levels. Carriers of the CC genotype of this SNP had shorter telomeres than GC carriers (p = 0.02) and GG carriers (p = 0.0005). After a follow-up with a mean period of 62 ± 19 months, 90 patients (19.1%) had MACE. Short LTL was an independent prognostic factor of MACE incidence (HR:2.2; 95% CI: 1.3-3.7; p = 0.005) after adjustment for potential confounders. There was a significant interaction (p = 0.01) between the LTL and rs1333049 variant, with patients with risk-allele C and short LTL having a higher risk (HR:5.8; 95% CI: 1.8-19.2; p = 0.004). A strong relationship between LTL and Chr9p21 rs1333049 variant was identified, and they interactively affect the risk of poor prognosis in CAD patients.

Association between female-specific reproductive factors and leukocyte telomere length.

What are the associations between female-specific reproductive factors and leukocyte telomere length (LTL)? 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. Reproductive factors have been associated with age-related diseases, but their associations with cellular aging, as indicated by LTL, are unclear. This population-based study included 224 965 women aged 40-69 years from the UK Biobank between 2006 and 2010. 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. 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). Considering that the participants were predominantly of European ethnicity, the findings may not be generalizable to women of other ethnic backgrounds. 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. 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. N/A.

High Dietary Zinc Intake Is Associated with Shorter Leukocyte Telomere Length, Mediated by Tumor Necrosis Factor-α: A Study of China Adults.

Diet can influence peripheral leukocyte telomere length (LTL), and various micronutrients have been reported to correlate with it. Zinc is known for its antioxidant properties and immunomodulatory effects. However, there are few epidemiological investigations on the relationship between dietary zinc intake and LTL. This study analyzed the association between dietary zinc and LTL and the potential role of inflammation and oxidative stress among them. Cross-sectional and community-based study. 599 participants from rural communities in the Changping suburb of Beijing, China, were recruited. Serum lipid profile, glycosylated hemoglobin (HbA1c), oxidative stress marker, and inflammatory cytokines levels were measured. Detailed dietary data were obtained using a 24 h food recall. LTL was assessed using a real-time PCR assay. Spearman analysis, restricted cubic splines (RCS), and general linear regression models were used to determine the association between dietary zinc intake and LTL. Simple regulatory models were also applied to analyze the role of inflammation and oxidative stress among them. A total of 482 subjects were ultimately included in this analysis. Spearman analysis showed that dietary zinc intake and zinc intake under energy density were negatively correlated with LTL (r=-0.142 and -0.126, all P <0.05) and positively correlated with tumor necrosis factor-α (TNF-α) (r=0.138 and 0.202, all P <0.05) while only dietary zinc without energy adjustment had a positive correlation with superoxide dismutase (SOD). RCS (P for non-linearity=0.933) and multiple linear regression (B=-0.084, P=0.009) indicated a negative linear association between dietary zinc and LTL. The adjustment of TNF-α rather than SOD could abolish the relationship. The mediation model suggested that the unfavorable effect of dietary zinc on LTL was mediated by TNF-α. High dietary zinc may correlate with telomere attrition, and TNF-α can act as a mediator in this relationship. In the future, more extensive cohort studies are needed to further explore the relationship between dietary zinc and cellular aging and the specific mechanisms.