Telomere length as a biomarker for adiposity changes after a multidisciplinary intervention in overweight/obese adolescents: the EVASYON study

Joint Effects of Exercise and Ramadan Fasting on Telomere Length: Implications for Cellular Aging

Aging is a fundamental biological process that progressively impairs the functionality of the bodily systems, leading to an increased risk of diseases. Telomere length is one of the most often used biomarkers of aging. Recent research has focused on developing interventions to mitigate the effects of aging and improve the quality of life. The objective of this study was to investigate the combined effect of exercise and Ramadan fasting on telomere length. Twenty-nine young, non-obese, healthy females were randomized into two groups: the control group underwent a 4-week exercise training program, and the second group underwent a 4-week exercise training program while fasting during Ramadan. Blood samples were collected, and measurements of clinical traits, cytokines, oxidative stress, and telomere length were performed before and after intervention. Telomere length increased significantly from baseline in the exercise-while-fasting group, but showed no significant change in the exercise control group. This increase was accompanied by a reduction in TNF-α, among other cytokines. Additionally, a significant positive correlation was observed between the mean change in telomere length and HDL in the exercise-while-fasting group only. This study is the first to report an increase in telomere length after combining Ramadan fasting with training, suggesting that exercising while fasting may be an effective tool for slowing down the aging rate. Further studies using larger and more diverse cohorts are warranted.

Association of Obesity with Telomere Length in Human Sperm

Background: Telomere attrition and mitochondrial dysfunction are two fundamental aspects of aging. Calorie restriction (CR) is the best strategy to postpone aging since it can enhance telomere attrition, boost antioxidant capacity, and lower the generation of reactive oxygen species (ROS). Since ROS is produced by mitochondria and can readily travel to cell nuclei, it is thought to be a crucial molecule for information transfer between mitochondria and cell nuclei. Important variables that affect the quality and functionality of sperm and may affect male reproductive health and fertility include telomere length, mitochondrial content, and the ratio of mitochondrial DNA (mtDNA) to nuclear DNA (nDNA). Telomere damage results from mitochondrial failure, whereas nuclear DNA remains unaffected. This research aims to investigate potential associations between these three variables and how they might relate to body mass index. Methods: Data were collected from 82 men who underwent IVF/ICSI at the University Hospital of Ioannina's IVF Unit in the Obstetrics and Gynecology Department. Evaluations included sperm morphology, sperm count, sperm motility, and participant history. To address this, male participants who were categorized into three body mass index (ΒΜΙ) groups-normal, overweight, and obese-had their sperm samples tested. Results: For both the normal and overweight groups, our results show a negative connection between relative telomere length and ΒΜI. As an illustration of a potential connection between mitochondrial health and telomere maintenance, a positive correlation was found for the obese group. Only the obese group's results were statistically significant (p < 0.05). More evidence that longer telomeres are associated with lower mitochondrial content can be found in the negative connection between telomere length and mitochondrial content in both the normal and overweight groups. However, the obese group showed a positive association. The data did not reach statistical significance for any of the three groups. These associations may affect sperm quality since telomere length and mitochondrial concentration are indicators of cellular integrity and health. Moreover, the ratio of mtDNA to nDNA was positively correlated with the relative telomere lengths of the obese group, but negatively correlated with the normal and overweight groups. In every group that was studied, the results were not statistically significant. According to this, male fertility may be negatively impacted by an imbalance in the copy number of the mitochondrial genome compared to the nuclear DNA in sperm. Conclusions: Essentially, the goal of our work is to determine whether mitochondria and telomere length in human sperm interact. Understanding these connections may aid in the explanation of some male infertility causes and possibly contribute to the creation of new treatment modalities for problems pertaining to reproductive health. The functional implications of these connections and their applications in therapeutic settings require further investigation.

Changes in leukocyte telomere length among children with obesity participating in a behavioural weight control program

OBJECTIVE

To examine changes in leukocyte telomere length (LTL) during and after a behavioural weight control program for children with obesity.

METHODS

We measured LTL among a cohort of 158 children 8-12 years of age with a body mass index greater than or equal to the 95th percentile for age and sex. Children were 55% female, 29% white, 52% Latinx, 8% Asian and 11% Pacific Islander, other or multiethnic. All children participated in a 6-month, family-based, group behavioural weight control program and were assessed before treatment, after treatment and 1 year after the end of treatment. To test the sample population slope of LTL over the intervention and maintenance time periods, we fit spline mixed-effect regression models.

RESULTS

LTL increased an average of 0.09 T/S units per year (95% confidence interval [CI] 0.04 to 0.13; p = 0.0001) during the weight control program intervention period, followed by an average decline of -0.05 T/S units per year (95% CI -0.08 to -0.03; p < 0.0001) during the 1 year of follow-up after the completion of the intervention. Among 26 social, psychological, behavioural and physiological factors we examined, we did not find any predictors of these changes.

CONCLUSIONS

LTL increased in response to a behavioural weight control program among children with obesity, suggesting an impact on biological health and cellular aging from participation in a behavioural weight control intervention. LTL may be a useful biomarker for assessing changes in response to behavioural interventions.

Telomere length dynamics measured by flow-FISH in patients with obesity undergoing bariatric surgery

Obesity has negative effects on comorbidities, health-related quality of life and survival. Telomere length (TL) changes after bariatric surgery have been reported, but the studies are contradictory, and analyses using state-of-the art techniques for TL measurement, such as flow-FISH, are sparse. We measured TL dynamics via flow-FISH in patients undergoing bariatric surgery and compared their TL with 105 healthy individuals. Patients with obesity who underwent bariatric surgery were included. Lymphocyte and granulocyte absolute and age-adjusted (aa) TL were analyzed by flow-FISH before (preoperative cohort, n = 45) and after surgery (follow-up cohort, n = 35) at month 5.5 ± 3.9 (mean ± standard deviation [SD]). The initial lymphocyte aaTL was significantly shorter (-0.37 kb ± 0.18 kb, P = 0.045) in patients with obesity, while the granulocyte aaTL was not different from that in the healthy comparison population (0.28 kb ± 0.17 kb, P = 0.11). The telomere dynamics after surgery showed an increase in mean TL in both lymphocytes and granulocytes of patients with a pronounced BMI loss of ≥ 10 kg/m². We did not find any association between TL increase after surgery and age, sex or the type of procedure selected for bariatric surgery. We confirmed that patients suffering from obesity have significantly shorter lymphocyte TL using flow-FISH. Along with and dependent on the degree of weight reduction after bariatric surgery, TL significantly increased in both lymphocytes and granulocytes after a mean of 5.5 months. Our results show that bariatric surgery affects not only body weight but also biomarkers of aging, such as TL.

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.

Cellular Senescence in Obesity and Associated Complications: a New Therapeutic Target

PURPOSE OF REVIEW

Obesity has increased worldwide recently and represents a major global health challenge. This review focuses on the obesity-associated cellular senescence in various organs and the role of these senescent cells (SnCs) in driving complications associated with obesity. Also, the ability to target SnCs pharmacologically with drugs termed senotherapeutics as a therapy for these complications is discussed.

RECENT FINDINGS

Several studies have shown a positive correlation between obesity and SnC burden in organs such as adipose tissue, liver, and pancreatic-β-cells. These SnCs produce several secretory factors which affect other cells and tissues in a paracrine manner resulting in organ dysfunction. The accumulation of SnCs in adipocytes affects their lipid storage and impairs adipogenesis. The inflammatory senescence-associated secretory phenotype (SASP) of SnCs downregulates the antioxidant capacity and mitochondrial function in tissues. Senescent hepatocytes cannot oxidize fatty acids, which leads to lipid deposition and senescence in β-cells decrease function. These and other adverse effects of SnCs contribute to insulin resistance and type-2 diabetes. The reduction in the SnC burden genetically or pharmacologically improves the complications associated with obesity. The accumulation of SnCs with age and disease accelerates aging. Obesity is a key driver of SnC accumulation, and the complications associated with obesity can be controlled by reducing the SnC burden. Thus, senotherapeutic drugs have the potential to be an effective therapeutic option.

Prediction of telomere length and telomere attrition using a genetic risk score: The multi-ethnic study of atherosclerosis (MESA)

Background: Short telomere length (TL) and telomere attrition (TA) have been associated with age-related diseases. Objective: We assessed whether a genetic risk score for short TL (GRS-TL) combining seven TL-associated genetic variants identified in a European-ancestry genome-wide association study (GWAS) was associated with TL and TA over 10 years. Methods: Relative TL (T/S ratio) was measured by the quantitative polymerase chain reaction method for a sample of white, African American, and Hispanic participants, who attended Exam 1 and/or 5 of the Multi-Ethnic Study of Atherosclerosis (MESA). Our final sample included 1,227 participants for the TL analysis and 1,138 for the TA analysis. Participants were 45-84 years at Exam 1. We used a linear mixed effects model and adjusted for age, sex, and population structure. Models were stratified by race/ethnicity. Results: In the TL analysis, higher GRS-TL significantly predicted shorter TL (estimates = -0.18 [S.E. = 0.08], p = 0.02 for white; -0.18 [0.07], p < 0.01 for African American; and -0.13 [0.05], p = 0.02 for Hispanic) in fully adjusted models. In the TA analysis, no association between GRS-TL and TA over 10 years was found. Conclusion: Although GRS-TL was developed in European-ancestry populations, it was significantly associated with TL (but not TA) in all three race/ethnic groups examined.

The epigenetic aging, obesity, and lifestyle

The prevalence of obesity has dramatically increased worldwide over the past decades. Aging-related chronic conditions, such as type 2 diabetes and cardiovascular disease, are more prevalent in individuals with obesity, thus reducing their lifespan. Epigenetic clocks, the new metrics of biological age based on DNA methylation patterns, could be considered a reflection of the state of one's health. Several environmental exposures and lifestyle factors can induce epigenetic aging accelerations, including obesity, thus leading to an increased risk of age-related diseases. The insight into the complex link between obesity and aging might have significant implications for the promotion of health and the mitigation of future disease risk. The present narrative review takes into account the interaction between epigenetic aging and obesity, suggesting that epigenome may be an intriguing target for age-related physiological changes and that its modification could influence aging and prolong a healthy lifespan. Therefore, we have focused on DNA methylation age as a clinical biomarker, as well as on the potential reversal of epigenetic age using a personalized diet- and lifestyle-based intervention.

Prospective associations between leukocyte telomere length and adiposity in childhood

Leukocyte telomere length (LTL) is associated with obesity and may be involved in its aetiology, but few studies have focused on children and most have been cross-sectional. We assessed the relation of LTL with adiposity development in a prospective study of Colombian children. We quantified LTL at enrollment in 722 children aged 5-12 years and measured anthropometry annually for a median 6 years. Using mixed effects models, we estimated changes in adiposity measures including BMI and waist circumference (WC)-for-age z-scores in relation to baseline LTL z-score. In girls, longer LTL was linearly related to a lower increase in WC z-score from age 6 to 16 years. Every 1 SD LTL was associated with an adjusted 0.13 units lower increase in WC (95% CI: -0.23, -0.03; p = 0.01). In conclusion, longer LTL among girls in middle childhood is associated with smaller increases in WC, an indicator of abdominal adiposity.

Predictors of Weight Loss and Weight Loss Maintenance in Children and Adolescents With Obesity After Behavioral Weight Loss Intervention

Objective

Predictors of body weight loss (BWL) and body weight loss maintenance (BWLM) after behavioral weight loss intervention are well-investigated in adults. Less is known for children and adolescents and a systematic overview on the topic for this age group was aim of the review.

Methods

A systematic research according to PRISMA guidelines using several databases was performed. The outcome was the BMI z-Score of longitudinal studies. The extracted predictors were classified in clusters (Physiology, Behavior, Psychology, Environment) and compared with a theory-driven model based on international guidelines and known predictors for adults.

Results

Out of 2,623 articles 24 met the eligibility criteria, 23 investigating BWL and 8 BWLM. The expected key predictor in research for adults “Behavior” was hardly investigated in children. The most examined cluster was “Physiology” with the most significant predictors, in particular genetics (BWL) and blood parameters (BWLM). Factors in the cluster “Psychology” also predicted BWL and BWLM. The cluster “Environment,” which was highlighted in most intervention guidelines, was neglected in studies regarding BWLM and hardly investigated in studies with BWL.

Conclusion

The comparison with the theory-driven children model outlined research gaps and differences between predictors for adults and children providing further direction of research.

Systematic Review Registration

http://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42020200505.

Association between Telomere Length and Pediatric Obesity: A Systematic Review

Objective: Telomere length (TL) is a robust marker of biological aging, and increased telomere attrition is noted in adults with obesity. The primary objective of this systematic review was to summarize current knowledge on the effects of childhood obesity in TL. The secondary objective was to assess the effect of weight management interventions in TL. Methods: The following databases were searched: PubMed, Scopus, Web of Science and Heal-link.gr from inception to September 2021. The search was performed using the following combinations of terms: “telomer*” [All Fields] AND (“length” [All Fields] OR “lengths” [All Fields]) AND “obes*” [All Fields] AND (“child*” [All Fields] OR “adolescen*” [All Fields]). Results: A total of 16 original articles were included in this systematic review. Eleven of them were cross-sectional and five were lifestyle interventions. Conclusions: There was a tendency towards a negative association between childhood obesity and TL. Life-style interventions in children have been associated with increased TL peripherally, indicating a possible association of the redistribution of younger cells in the periphery with the favorable effect of these interventions. Further prospective studies with larger sample sizes that employ other markers of cell aging would potentially elucidate this important mechanistic relation.

Cancer-related accelerated ageing and biobehavioural modifiers: a framework for research and clinical care

A growing body of evidence indicates that patients with cancer who receive cytotoxic treatments (such as chemotherapy or radiotherapy) have an increased risk of accelerated physical and cognitive ageing. Furthermore, accelerated biological ageing is a suspected driving force behind many of these observed effects. In this Review, we describe the mechanisms of biological ageing and how they apply to patients with cancer. We highlight the important role of specific behavioural factors, namely stress, sleep and lifestyle-related factors such as physical activity, weight management, diet and substance use, in the accelerated ageing of patients with cancer and cancer survivors. We also present a framework of how modifiable behaviours could operate to either increase the risk of accelerated ageing, provide protection, or promote resilience at both the biological level and in terms of patient-reported outcomes.

Sex-Specific Association of Serum Anti-Oxidative Capacity and Leukocyte Telomere Length

Telomeres are a crucial factor in the preservation of genomic integrity, and an elevated risk for diseases such as cancer and cardiovascular events is related to shortened telomeres. However, telomere deterioration could be caused by factors such as chronic oxidative stress and inflammation, which are promoted by an imbalance among reactive oxygen species (ROS) and antioxidants. In this cross-sectional study, we investigated the relationship between telomeres and oxidative stress. The serum leucocyte telomer length (LTL), serum total antioxidant capacity (TAC) and the total serum lipid panel of 180 healthy athletic volunteers (90 males, 90 females) were measured Additionally, a questionnaire about sports behaviour and the type of training was completed. We observed a positive significant relation between serum LTL and TAC in the male group (cc = 3.4/p = 0.001) but not in females. There was no statistically significant correlation between age and physical activity and LTL in both groups. This is the first cross sectional study demonstrating an association between total serum TAC and LTL in healthy males, but interestingly, not in the females. Nevertheless, these results should be interpreted as preliminary, and further studies in independent cohorts are needed to investigate the sex-specific effects of oxidative stress on telomere length and telomerase activity.

Systematic review and meta-analysis of the association between paediatric obesity and telomere length

AIM

This systematic review and meta-analysis aimed to assess the association between paediatric obesity and telomere length.

METHODS

We conducted a comprehensive literature search for original studies assessing the associations between obesity and telomere length in children. Fixed or random effects with inverse-variance meta-analysis were used to estimate the standardised mean difference (SMD) and its 95% confidence interval (95% CI) between overweight or obese and normal-weight children. Heterogeneity was assessed using the I² statistic, and meta-regression analyses were used to evaluate the potential source of heterogeneity. Subgroup analysis was further conducted by sex.

RESULTS

A total of 11 studies were included. The meta-analysis showed that children who were overweight or obese had shorter telomere length than normal-weight children (SMD: -0.85; 95% CI: -1.42 to -0.28; p < 0.01). However, significant heterogeneity was present (I²  = 97%; p < 0.01). Study design, methods used for measuring telomere length, tissue types, mean age, and percentage of boys were not the source of heterogeneity revealed by meta-regression analysis. The inverse trend was significant only in boys, but not in girls.

CONCLUSION

There was a negative association between paediatric obesity and telomere length. Weight control in children might have beneficial effect on telomere length.

A Comprehensive, Multidisciplinary, Personalized, Lifestyle Intervention Program Is Associated with Increased Leukocyte Telomere Length in Children and Adolescents with Overweight and Obesity

Leucocyte telomere length (LTL) is a robust marker of biological aging and is associated with obesity and cardiometabolic risk factors in childhood and adolescence. We investigated the effect of a structured, comprehensive, multidisciplinary, personalized, lifestyle intervention program of healthy diet and physical exercise on LTL in 508 children and adolescents (239 males, 269 females; 282 prepubertal, 226 pubertal), aged 10.14 ± 0.13 years. Participants were classified as obese (n = 267, 52.6%), overweight (n = 174, 34.2%), or of normal BMI (n = 67, 13.2%) according to the International Obesity Task Force (IOTF) cutoff points and were studied prospectively for one year. We demonstrated that LTL increased significantly after 1 year of the lifestyle interventions, irrespective of gender, pubertal status, or body mass index (BMI). Waist circumference was the best negative predictor of LTL at initial assessment. The implementation of the lifestyle interventions also resulted in a significant improvement in clinical (BMI, BMI z-score and waist to height ratio) and body composition indices of obesity, inflammatory markers, hepatic enzymes, glycated hemoglobin (HbA1C), quantitative insulin sensitivity check index (QUICKI), and lipid profile in all participants. These findings indicate that the increased LTL may be associated with a more favorable metabolic profile and decreased morbidity later in life.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Telomere Length and Pediatric Obesity: A Review

Obesity is a chronic disease, which needs to be early detected early and treated in order prevent its complications. Changes in telomere length (TL) have been associated with obesity and its complications, such as diabetes mellitus and metabolic syndrome. Therefore, we conducted a systematic review to summarize results of studies that have measured TL in children and adolescents with obesity. Fourteen studies aiming to assess TL in pediatric patients with either obesity or who were overweight were included in this review. In conclusion, obesity and adiposity parameters are negatively associated with TL. Shorter telomeres are observed in children with obesity compared with their lean counterparts. Factors involved in obesity etiology, such as diet and physical activity, may contribute to maintenance of TL integrity. In the long term, TL change could be used as a biomarker to predict response to obesity treatment.

Conventional Risk Factors, Telomere Length, and Ischemic Heart disease: Insights into the Mediation Analysis

Telomere length is regarded as a potential biomarker of biological ageing and is associated with various age-related diseases, such as ischemic heart disease (IHD), myocardial infarction, peripheral vascular disease, and cancer. As there is a paucity of study that deals with this influence, this study aimed to assess how the cardiovascular risk factors influence the risk of IHD by performing mediation analysis. A total of 407 males were included in the study. IHD was diagnosed through echocardiography and coronary angiography by determining the number of coronary vessels involved. Demographic data, clinical history, and laboratory investigations such as random blood sugar (RBS), fasting lipid profile, serum creatinine, and serum urea levels of all the subjects were measured and recorded. Serum uric acid and blood urea nitrogen (BUN) levels were significantly higher in IHD subjects compared to non-IHD subjects (P < 0.05). Body mass index (BMI), glycosylated hemoglobin (HbA1c), RBS, serum uric acid, serum creatinine, BUN, total cholesterol, triglycerides, and telomere length significantly differed between subjects with and without IHD (P < 0.05). Further, telomere length (P < 0.001), BMI (P < 0.001), and total cholesterol level (P < 0.001) were risk factors that significantly affected the incidence of IHD, as proved by logistic regression. It indicates that shorter telomeres contribute to increased risk of IHD, influenced by BMI, HbA1c, BUN, total cholesterol levels, and RBS (P < 0.001). The study established a link between telomere shortening, conventional risk factors, and IHD; moreover, the study takes care in the role of mediation analysis which is a novel idea as little is done in this area of biostatistics with telomere length. Overall, this further establishes that telomeres length might serve as the promising biomarkers in predicting the risk of IHD.

Leukocyte telomere length is inversely associated with a metabolic risk score in Mesoamerican children

OBJECTIVE

Leukocyte telomere length (LTL) may be involved in the etiology of the metabolic syndrome (MetS). We examined the associations of LTL with MetS and its components among Mesoamerican children and their adult parents, in a region where MetS prevalence is high.

METHODS

We conducted a cross-sectional study of 151 children aged 7-12 years and 346 parents from the capitals of Belize, Honduras, Nicaragua, Costa Rica, Panama, and Chiapas State, Mexico. We quantified LTL by qPCR on DNA extracted from whole blood. In children, we created an age- and sex-standardized metabolic risk score using waist circumference (WC), the homeostasis model of insulin resistance (HOMA-IR), blood pressure, serum high-density lipoprotein (HDL) cholesterol, and serum triglycerides. In adults, MetS was defined according to the National Cholesterol Education Program's Adult Treatment Panel III definition. We estimated mean differences in metabolic risk score and prevalence ratios of MetS across quartiles of LTL using multivariable-adjusted linear and Poisson regression models, respectively.

RESULTS

In children, every 1 LTL z-score was related to an adjusted 0.05 units lower (95% CI: -0.09, -0.02, P = 0.005) MetS risk score, through WC, HOMA-IR, and HDL. Among adults, LTL was not associated with MetS prevalence; however, every 1 LTL z-score was associated with an adjusted 34% lower prevalence of high fasting glucose (95% CI: 3%, 55%, p = .03).

CONCLUSIONS

Among Mesoamerican children, LTL is associated with an improved metabolic profile; among adults, LTL is inversely associated with the prevalence of high fasting glucose.

Effects of Randomized Controlled Infancy-Onset Dietary Intervention on Leukocyte Telomere Length-The Special Turku Coronary Risk Factor Intervention Project (STRIP)

Reduced telomere length (TL) is a biological marker of aging. A high inter-individual variation in TL exists already in childhood, which is partly explained by genetics, but also by lifestyle factors. We examined the influence of a 20-year dietary/lifestyle intervention on TL attrition from childhood to early adulthood. The study comprised participants of the longitudinal randomized Special Turku Coronary Risk Factor Intervention Project (STRIP) conducted between 1990 and 2011. Healthy 7-month-old children were randomized to the intervention group (n = 540) receiving dietary counseling mainly focused on dietary fat quality and to the control group (n = 522). Leukocyte TL was measured using the Southern blot method from whole blood samples collected twice: at a mean age of 7.5 and 19.8 years (n = 232; intervention n = 108, control n = 124). Yearly TL attrition rate was calculated. The participants of the intervention group had slower yearly TL attrition rate compared to the controls (intervention: mean = −7.5 bp/year, SD = 24.4 vs. control: mean = −15.0 bp/year, SD = 30.3; age, sex and baseline TL adjusted β = 0.007, SE = 0.004, p = 0.040). The result became stronger after additional adjustments for dietary fat quality and fiber intake, serum lipid and insulin concentrations, systolic blood pressure, physical activity and smoking (β = 0.013, SE = 0.005, p = 0.009). A long-term intervention focused mainly on dietary fat quality may affect the yearly TL attrition rate in healthy children/adolescents.

Associations of telomere length with two dietary quality indices after a lifestyle intervention in children with abdominal obesity: a randomized controlled trial

BACKGROUND

Dietary factors seem to influence telomere length. Moreover, associations between changes in adiposity indices and telomere length (TL) have been found in intervention studies.

OBJECTIVE

We evaluated changes in two diet quality indices and their association with TL in children with abdominal obesity in a 12-month lifestyle intervention.

METHODS

Eighty-seven participants (7-16 years old) were assigned to the intervention (moderate hypocaloric Mediterranean diet) or usual care group (standard paediatric recommendations) for a 2-month intensive phase and a subsequent 10-month follow-up. Diet quality was assessed using the Diet Quality Index for Adolescents (DQI-A) and the Healthy Lifestyle Diet Index (HLD-I). TL was measured by monochrome multiplex real-time quantitative PCR. The intra-class correlation coefficient for TL was 0.793 (95% CI 0.707, 0.857).

RESULTS

After a 12-month lifestyle intervention, a significant reduction in BMI-SDS (-0.57 and -0.49 for the intervention and usual care groups, respectively) and fat mass was observed in all subjects without differences between groups. Changes in DQI-A (+12.36% vs +5.53%, P = .005) and HLD-I (+4.43 vs +1.09, P < .001) were higher in the intervention subjects compared with usual care subjects after 2 months. Interestingly, we observed a positive change in TL between 2 and 12 months (P = .025), which was associated with higher scores on the DQI-A (β = 0.008, R² = 0.088, P = .010) and HLD-I (β = 0.022, R² = 0.198, P = .015), in the intervention group after the 2-month intensive phase.

CONCLUSION

Favourable changes in diet quality indices could contribute to telomere integrity in children with abdominal obesity enrolled in an intensive lifestyle intervention.

Association between favourable changes in objectively measured physical activity and telomere length after a lifestyle intervention in pediatric patients with abdominal obesity

The purpose of this study was to assess the effect of physical activity (PA) changes, measured by accelerometry, on telomere length (TL) in pediatric patients with abdominal obesity after a lifestyle intervention. One hundred and twenty-one children (7-16 years old) with abdominal obesity were randomized to the intervention (a moderately hypocaloric Mediterranean diet) or the usual care group (standard pediatric recommendations) for 22 months (a 2 month intensive phase and a subsequent 20 month follow-up). Both groups were encouraged to accumulate an extra 200 min/week of PA. TL was measured by MMqPCR. Data were analyzed in 102 subjects after 2 months and 64 subjects at the first 10 months of follow-up. Light PA level decreased in both groups after 12 months of intervention. At month 2, moderate to vigorous PA (MVPA) increased in the intervention group (+5.4 min/day, p = 0.035) and so did sedentary time in the usual care group (+49.7 min/day, p = 0.010). TL changes were positively associated (p < 0.050) with metabolic equivalents (METs), MVPA level, and number of steps, and were inversely associated with sedentary and light PA levels in the intervention group after the intensive phase. In conclusion, favourable changes in PA levels in the intensive phase of a lifestyle intervention could contribute to TL maintenance in a pediatric population with abdominal obesity. Novelty Changes in physical activity levels had a direct effect on telomere length, a biomarker of cellular aging and oxidative stress. PA advice based on The American College of Sports Medicine included in this intervention is easy to implement in primary care.

Ultra-processed food consumption and the risk of short telomeres in an elderly population of the Seguimiento Universidad de Navarra (SUN) Project

BACKGROUND

Telomere length (TL) is a marker of biological age that may be affected by dietary factors through oxidation and inflammation mechanisms. In addition, ultra-processed food (UPF) consumption has increased worldwide and it has been associated with the risk of developing several diseases.

OBJECTIVES

We aimed to evaluate the association between UPF consumption and the risk of having short telomeres in an elderly population of the Seguimiento Universidad de Navarra (SUN) Project.

METHODS

This is a cross-sectional study of 886 participants (645 men and 241 women) aged 57-91 y recruited from the SUN Project (Spain, 1999-2018). TL was measured from saliva samples by real-time qPCR at baseline and UPF consumption was collected using a validated 136-item FFQ and classified according to the NOVA system. We evaluated the association between consumption of energy-adjusted UPF categorized into quartiles (low, medium-low, medium-high, and high consumption) and the risk of having short telomeres (<20th percentile) using logistic regression models.

RESULTS

Those participants with the highest UPF consumption had almost twice the odds of having short telomeres compared with those with the lowest consumption (adjusted OR: 1.82; 95% CI: 1.05, 3.22; P-trend = 0.03).

CONCLUSIONS

A higher consumption of UPF (>3 servings/d) was associated with higher risk of having shorter telomeres in an elderly Spanish population of the SUN Project.This trial was registered at clinicaltrials.gov as NCT02669602.

Associations of telomere length with anthropometric and glucose changes after a lifestyle intervention in abdominal obese children

BACKGROUND AND AIMS

In lifestyle intervention studies, we demonstrated that changes in telomere length (TL) were associated with changes in anthropometric indices. Therefore, our new hypothesis is that TL could be a predictor of changes in anthropometric or metabolic measures in children with abdominal obesity. The aim of the study was to evaluate the association between anthropometric and biochemical measurements with TL before and after an 8-week lifestyle intervention in children with abdominal obesity (7-16 years old).

METHODS AND RESULTS

We assessed anthropometric and biochemical outcomes at baseline and after 8-week lifestyle intervention in 106 children with abdominal obesity (11.30 ± 2.49 years old, 63% girls). TL was measured by monochrome multiplex real-time quantitative PCR. After the lifestyle intervention, anthropometric parameters and glucose metabolism indicators significantly improved in the participants. TL did not change after the intervention in participants. Significant negative correlations between baseline TL and anthropometric measures (BMI, body weight and waist circumference) were observed. Furthermore, baseline TL was a predictor for changes in blood glucose levels after the lifestyle intervention.

CONCLUSIONS

An inverse correlation between TL and obesity traits was observed in children with abdominal obesity. Interestingly, we found that baseline TL could predict changes in blood glucose levels.

CLINICAL TRIAL

NCT03147261. Registered 10 May 2017.

The Impact of Health Promotion Interventions on Telomere Length: A Systematic Review

Objectives:

The aim of this study was to evaluate the effectiveness of health promotion interventions in delaying telomere shortening (a biomarker for aging).

Data Source:

PubMed, PsychINFO, EMBASE, CINAHL, and Cochrane Library databases.

Study Inclusion and Exclusion Criteria:

Inclusion criteria: (1) empirical studies involving human subjects; (2) health promotion intervention studies including both randomized control trials (RCTs) and non-RCTs.; (3) measured telomere length as an intervention outcome; and (4) were written in English. Exclusion criteria: (1) observational studies without any health promotion intervention practices and (2) did not report intervention effects.

Data Extraction:

Data extraction was performed by two reviewers following the preferred reporting items for systematic reviews and meta-analysis guidelines.

Data Synthesis:

Substantial heterogeneity in intervention type and study design in the included studies precluded a meta-analysis. We conducted a narrative synthesis instead.

Results:

Thirty studies were included in the review, of which 16 were RCTs. One-third of the included studies reported significant intervention impacts in delaying telomere shortening, with relatively consistent significant results emerged from weight-loss interventions and interventions involving multiple lifestyle modification components (eg, diet and exercise). Most of supplement intervention studies observed null effects in telomere length.

Conclusions:

Weight-loss and comprehensive lifestyle intervention strategies show encouraging impacts in delaying telomere shortening. More rigorous studies targeting populations at different age stages through life span are needed.

The effects of short-term combined exercise training on telomere length in obese women: a prospective, interventional study

Background

Telomere length is inversely associated with the senescence and aging process. Parallelly, obesity can promote telomere shortening. Evidence suggests that physical activity may promote telomere elongation.

Objective

This study’s objective is to evaluate the effects of combined exercise training on telomere length in obese women.

Design and Methods

Twenty pre-menopausal women (BMI 30–40 kg/m², 20–40 years) submitted to combined training (strength and aerobic exercises), but only 13 finished the protocol. Each exercise session lasted 55 min/day, three times a week, throughout 8 weeks. Anthropometric data, body composition, physical performance (Vo_2max), and 8-h fasting blood samples were taken before and after 8 weeks of training. Leukocyte DNA was extracted for telomere length by RT-qPCR reaction, using the 2^−ΔΔCt methodology.

Results

After the training intervention, significant differences (p < 0.05) were observed in telomere length (respectively before and after, 1.03 ± 0.04 to 1.07 ± 0.04 T/S ratio), fat-free mass (46 ± 7 to 48 ± 5 kg), Vo_2max (35 ± 3 to 38 ± 3 ml/kg/min), and waist circumference (96 ± 8 to 90 ± 6 cm). In addition, an inverse correlation between waist circumference and telomere length was found, before (r = − 0.536, p = 0.017) and after (r = − 0.655, p = 0.015) exercise training.

Conclusion

Combined exercise promoted leukocyte telomere elongation in obese women. Besides, the data suggested that greater waist circumference may predict shorter telomere length.

Clinical Trial Registration

ClinicalTrails.gov, NCT03119350. Retrospectively registered on 18 April 2017

Childhood obesity and leucocyte telomere length

BACKGROUND

Obesity in adulthood is associated with decreased leucocyte telomere length (LTL), which is associated with cardiovascular disease and diabetes mellitus type 2. The aim of our study was to investigate whether increased body mass index (BMI) is associated with decreased LTL in children and adolescents, and to identify other risk factors of shorter LTL in this population.

MATERIALS AND METHODS

A cross-sectional study was conducted among 919 Greek children aged 9-13 years (The Healthy Growth Study). Participants were classified as obese (n = 124), overweight (n = 276) or of normal BMI (n = 519). LTL was determined by monochrome multiplex quantitative real-time polymerase chain reaction. Univariate and multivariable linear regression analyses were applied to determine the predictive factors of LTL.

RESULTS

Both overweight and obese children had significantly shorter LTL than their normal-BMI counterparts. Following adjustment for age, sex, total daily energy intake and average weekly physical activity (average total steps per day), increasing weight category was inversely associated with LTL in children and adolescents (β: -0.110 ± 0.035; P = .002).

CONCLUSION

Overweight and obesity in childhood and adolescence are associated with shorter LTL, even following adjustment for potential confounding effects. Therefore, the increased BMI in childhood and adolescence may be associated with accelerated biological ageing and may have an adverse impact on future health in adulthood.

Effects of Progressive Resistance Training on Obesity Indices in Polycystic Ovary Syndrome and the Relationship With Telomere Length

BACKGROUND

Physical activity is prescribed as a component of primary management for polycystic ovary syndrome (PCOS). This nonrandomized, therapeutic, open, single-arm study investigated the effects of progressive resistance training (PRT) on obesity indices in women with PCOS, and the relationship between obesity indices and telomere content.

METHODS

A total of 45 women with PCOS and 52 with non-PCOS (controls), aged 18 to 37 years, with body mass indexes of 18 to 39.9 kg/m2, performed three 1-hour sessions of PRT per week, for 16 weeks. Before and after PRT, measures included anthropometric indices and regions of interest of fat mass distribution, quantified by dual-energy X-ray absorptiometry, metabolic and hormonal parameters, and telomere content. The general linear mixed models were used to determine the effects of PRT.

RESULTS

PRT did reduce the waist-to-height ratio, waist circumference, and the index of conicity among PCOS (P < .01). However, PRT did not influence regions of interest, body mass index, and WHR. After PRT, the telomere content was associated with regions of interest and anthropometric indices in whole group independent of PCOS (P < .05).

CONCLUSION

Resistance exercise improves obesity indices in PCOS, independent of changes in body weight, and the relationship between telomeres and obesity parameters in PCOS remain to be fully clarified.

Sociodemographic correlates of change in leukocyte telomere length during mid- to late-life: The Multi-Ethnic Study of Atherosclerosis

Although epidemiologic studies of telomere length have become increasingly common, few population-based, multi-ethnic studies include data on telomere shortening, which may be a better predictor of morbidity and mortality than a single measure of telomere length. This study used stored blood samples from 1169 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) to examine age, sex, race/ethnicity, marital status, income, and education as predictors of change in telomere length over a 10-year period in linear mixed effects models. Mean age at baseline was 61 years, and the sample was 54% female, 27% white, 30% African-American, and 43% Hispanic. At baseline, 58% of the sample was married; 32% had household income below $25,000 per year, 35% had income between $25,000 and $49,999 per year, and 34% had income above $50,000 per year; 41% had a high school education or less, 30% had some college, and 29% had a college degree or more. Relative telomere length (T/S ratio) was measured by the quantitative polymerase chain reaction method. In general, ten-year telomere attrition was greater for groups that had longer telomere length at baseline, including younger people, whites, and women. After adjusting for baseline telomere length, race/ethnic differences in telomere attrition were attenuated, and age and sex differences were reversed, such that older people and men showed greater telomere shortening. There were no significant differences in telomere attrition by marital status, income, or education. There is not yet a consensus in the field regarding whether to adjust for baseline telomere length in models examining predictors of telomere attrition. To ensure comparability across studies, researchers should report results both with and without adjustment for baseline telomere length.

Childhood obesity and the associated roles of neighborhood and biologic stress

Exposure to violence and obesity continues to be growing epidemics, particularly among children. Our objective was to increase our understanding of the association between neighborhood violence exposure and children's weight and how biologic stress may mediate this relation. A matched, community-recruited cross-sectional study of 90 children, ages 5–16 years, from 52 neighborhoods took place in the greater New Orleans, LA area between 2012 and 2013. Children were matched on their propensity for living in a high violence neighborhood and previous exposure to Hurricane Katrina. Primary neighborhood exposure included violent crime, operationalized as crime rates within specific radii of children's home. Rates of exposure within 500, 1000 and 2000 meter radii from the child's home were calculated. Primary outcomes were body mass index (BMI) and waist circumference, and the primary mediator was telomere length (TL), a marker of cellular aging. Significant variation in obesity and TL was observed at the neighborhood level and violent crime was significantly associated with weight status, with an increase of 1.24 units in BMI for each additional violent crime in the child's neighborhood and a significant mediated or indirect effect of TL in the crime-BMI relation (0.32, 95% bootstrapped CI = 0.05, 0.81; 32% total mediated effect). Findings strengthen existing evidence linking neighborhood violence to childhood health and identify biologic stress, indexed by TL, as one mechanistic pathway by which neighborhood violence may influence childhood obesity. Neighborhood violence may be an important target for interventions focused on reducing obesity and other stress related health outcomes in children.

Serum Level of Total Lipids and Telomere Length in the Male Population: A Cross-Sectional Study

Telomeres contain TTAGGG (T; Thymine, A; Adenine and G; Guanine) repetitive sequences and are placed at the end of human chromosomes. Telomere dysfunction is implicated in some age-related and chronic diseases, but its association with total serum lipids and obesity is unknown. Our objective was to determine influenced of total serum lipids on leukocyte telomere lengths (TLs). Participants were selected by cluster sampling from 22 districts of Tehran. The questionnaires were completed by 500 subjects and after the initial assessment in terms of lifestyle, nutrition, home, and job, 300 healthy people, aged 25-40 years were finally selected. TLs and serum level of total lipids were measured by quantitative real-time PCR and the Phillips method, respectively. The average telomere length (T/S) and total lipids were 1.05 ± 0.3 mg/dl and 643.3 ± 70.8 mg/dl, respectively. We found that a one unit difference in the following parameters were associated with kilo base pair differences in TL: Age -0.0002 (95% CI [-0.0022, -0.0018]), BMI -0.0019 (95% CI [-0.0003, -0.0034]), TC 0.0001 (95% CI [-0.0006, -0.0007]), TG -0.0010 (95% CI [-0.0015, -0.0004]), PL 0.0001 (95% CI [-0.0005, -0.0007]), and TSL -0.0003 (95% CI [-0.0008, 0.0001]). Spearman correlation analysis revealed an inverse relationship between TC (R = -0.53; 95% CI [-0.61, -0.44]), TG (R = -0.50; 95% CI [-0.58, -0.41]), PL (R = -0.46; 95% CI [-0.54-0.36]), and TSL (R = -0.63; 95% CI [-0.69, -0.56]) with T/S. Our research suggests that the inverse relationship was found between TL and weight, BMI, age, and TSL which were associated with obesity. High serum lipids concentration may be associated with systemic inflammation and atherosclerosis and may lead to oxidative stress, resulting in telomere shortening.

Energy balance and gastrointestinal cancer: risk, interventions, outcomes and mechanisms

Obesity increases the risk of multiple gastrointestinal cancers and worsens disease outcomes. Conversely, strong inverse associations have emerged between physical activity and colon cancer and possibly other gastrointestinal malignancies. The effect of weight loss interventions - such as modifications of diet and/or physical activity or bariatric surgery - remains unclear in patients who are obese and have gastrointestinal cancer, although large clinical trials are underway. Human intervention studies have already shed light on potential mechanisms underlying the energy balance-cancer relationship, with preclinical models supporting emerging pathway effects. Central to interventions that reduce obesity or increase physical activity are pluripotent cancer-preventive effects (including reduced systemic and adipose tissue inflammation and angiogenesis, altered adipokine levels and improved insulin resistance) that directly interface with the hallmarks of cancer. Other mechanisms, such as DNA repair, oxidative stress and telomere length, immune function, effects on cancer stem cells and the microbiome, could also contribute to energy balance effects on gastrointestinal cancers. Although some mechanisms are well understood (for instance, systemic effects on inflammation and insulin signalling), other areas remain unclear. The current state of knowledge supports the need to better integrate mechanistic approaches with preclinical and human studies to develop effective, personalized diet and exercise interventions to reduce the burden of obesity on gastrointestinal cancer.

Improved Diet Quality and Nutrient Adequacy in Children and Adolescents with Abdominal Obesity after a Lifestyle Intervention

High rates of childhood obesity require integral treatment with lifestyle modifications that achieve weight loss. We evaluated a lifestyle intervention on nutrient adequacy and diet quality in children and adolescents with abdominal obesity. A randomized controlled trial was performed on 107 participants, assigned either to a usual care group or to an intensive care group that followed a moderate hypocaloric Mediterranean diet and received nutritional education. Intake adequacy was evaluated using Dietary Reference Intakes and diet quality through the Diet Quality Index for Adolescents (DQI-A), the Healthy Lifestyle Diet-Index (HLD-I) and the Mediterranean Diet Quality Index (KIDMED). Both groups achieved a significant reduction in BMI standard deviation score (BMI-SDS), glucose and total cholesterol levels. Intake of Calcium, Iodine and vitamin D were higher in the intensive care group, with enhanced compliance with recommendations. Higher dietary scores were associated with lower micronutrient inadequacy. DQI-A and HLD-I were significantly higher in the intensive care group vs. usual care group after the treatment. In conclusion, we observed that an intensive lifestyle intervention was able to reduce BMI-SDS in children with abdominal obesity. Furthermore, participants significantly improved dietary indices getting closer to the nutritional recommendations. Therefore, these diet quality indices could be a valid indicator to evaluate micronutrient adequacy.

Chronic Obesity and Incident Hypertension in Latina Women Are Associated with Accelerated Telomere Length Loss over a 1-Year Period

AIMS

Shorter telomere length is associated with increased chronic disease risk in adulthood including diabetes mellitus and cardiovascular risk. Few studies have evaluated the relationship between telomere length change and incident disease risk in populations with a high percentage of overweight and obesity.

RESULTS

In an urban Latina population recruited in San Francisco (n = 82) with a high prevalence of overweight and obesity (78.4%), we assessed leukocyte telomere length and telomere length change over a 1-year period in relation to obesity, chronicity of obesity, and incident metabolic disease risk 5-6 years later. We also assessed the relationship between telomere length change over a 1-year period and weight loss. There were no significant associations between baseline telomere length and socio-demographics including age and ethnicity, or current weight status. Telomere length change, however, was associated with being obese at baseline and previous years of chronic obesity. A high percentage of women who were obese at baseline were also obese the year before (90%) and 2 years before (85%). Obesity at baseline was an independent predictor for increased telomere length attrition (β = -346.9, -568.4 to -125.4; P < 0.01). Similarly, chronic obesity was associated with increased risk for accelerated attrition (β = -280.6, -518.4 to -42.8; P < 0.01).

INNOVATION

We speculate that accelerated attrition may be a harbinger of metabolic disease. We also found that those who had or developed hypertension had accelerated attrition [-407.4 ± 464.0 vs. -168.1 ± 643.6 (P = 0.03)].

CONCLUSION

In populations with chronic and long-standing obesity, telomere length attrition rate, rather than baseline telomere length may be a more sensitive indicator of health status including chronic disease development.

Telomere length is reduced in 9- to 16-year-old girls exposed to gestational diabetes in utero

AIMS/HYPOTHESIS

Shortened telomere length is a marker of cell damage and is associated with oxidative stress, chronic inflammation and metabolic disease. We hypothesised that the offspring of women with gestational diabetes mellitus (GDM) with increased risk of cardiovascular and metabolic diseases might exhibit shorter telomere length.

METHODS

We investigated telomere length in 439 GDM and 469 control group offspring, aged between 9 and 16 years, recruited from the Danish National Birth Cohort. Relative telomere length was measured in peripheral blood DNA (n = 908) using a quantitative PCR approach. Multivariate regression analysis was used to investigate the association between mothers' GDM status and telomere length in the offspring.

RESULTS

Female offspring had longer telomeres than males. Offspring of mothers with GDM had significantly shorter telomere length than control offspring, but this difference was observed only in girls. There was a negative association between telomere length and GDM exposure among the female offspring (14% shorter telomeres, p = 0.003) following adjustment for the age of the offspring. Telomere length in female offspring was negatively associated with fasting insulin levels and HOMA-IR (p = 0.03). Maternal age, smoking, gestational age, birthweight and the offspring's anthropometric characteristics were not associated with telomere length (p ≥ 0.1).

CONCLUSIONS/INTERPRETATION

The 9- to 16-year-old girls of mothers with GDM had shorter telomeres than those from the control population. Further studies are needed to understand the extent to which shortened telomere length predicts and/or contributes to the increased risk of disease later in life among the offspring of women with GDM.

Shorter preschool, leukocyte telomere length is associated with obesity at age 9 in Latino children

The aim of this study was to determine the potential role of leukocyte telomere length as a biomarker for development of childhood obesity in a low-income Latino population. A birth cohort of Latino children (N = 201) in San Francisco (recruited May 2006-May 2007) was followed until age 9 and assessed annually for obesity and dietary intake. Leukocyte telomere length was measured at 4 and 5 years (n = 102) and assessed as a predictor for obesity at age 9, adjusting for known risk factors. Furthermore, leukocyte telomere length at age 4 and 5 was evaluated as a possible mediator of the relationship between excessive sugar-sweetened beverage consumption and obesity at age 9. Shorter leukocyte telomere length in preschoolers was associated with obesity at age 9 (adjusted odds ratio 0.35, 95% confidence interval 0.13-0.94) after adjustment for known risk factors. Telomere length mediated 11% of the relationship between excessive sugar-sweetened beverage consumption and obesity. Shorter leukocyte telomere length may be an indicator of future obesity risk in high-risk populations as it is particularly sensitive to damage from oxidative stress exposure, including those from sugar-sweetened beverages.

Investigating the associations between adiposity, life course overweight trajectories, and telomere length

Obesity may accelerate ageing through chronic inflammation. To further examine this association, we assessed current adiposity, adiposity at early adulthood and life course overweight trajectories in relation to leukocyte telomere length (LTL). We included a total of 7,008 nationally representative U.S. residents and collected information on objectively measured body mass index (BMI), waist circumference and percent body fat. BMI at age 25 and overweight trajectories were assessed using self-reported history. Leukocyte telomere length (LTL) relative to a standard DNA reference (T/S ratio) was quantified by polymerase chain reaction (PCR). Linear regression models were used to examine the difference in LTL across adiposity measures at examination, BMI at age 25, and overweight trajectories. A 0.2% decrease in telomere length (95% CI:−0.3 to −0.07%) was observed for every kg/m2 increase in BMI, whereas a unit increase in waist circumference (cm) and percent body fat contributed to a 0.09% and 0.01% decrease in LTL, respectively. Higher BMI and being obese at age 25 contributed to lower LTL at older ages. Associations between weight loss through life course and LTL were observed, which further marked the importance of life course adiposity dynamics as a determinant of ageing.

Changes in telomere length 3-5 years after gastric bypass surgery

Increased inflammation and oxidative stress associated with obesity can accelerate aging. Telomere length (TL) has the capacity to serve as an aging indicator at the cellular level. Obesity has a known association with shorter TL. This study evaluated TL of immune cells in a population of obese individuals who underwent gastric bypass surgery. Pre and post-operative DNA samples were available for 50 subjects who had gastric bypass surgery. DNA was analyzed via quantitative polymerase chain reaction (q-PCR) to determine TL. Changes in TL were evaluated by comparing TL at baseline to TL at 3-5 years post gastric bypass surgery. Sixty percent of the individuals in the study observed an increase in TL. Significant lengthening was observed for those with the shortest baseline TL (p=0.0011), but not for those with intermediate baseline TL (p=0.411) or longest baseline TL (p=0.207). Change in TL was negatively correlated with age and triglycerides but not correlated with weight loss induced by bariatric surgery. This study confirms that TL lengthening is observed post bariatric surgery and is the first to detect TL lengthening 3-5 years after surgery.

Association of telomere length with IL-6 levels during an obesity treatment in adolescents: interaction with the-174G/C polymorphism in the IL-6gene

BACKGROUND

Shorter telomeres have been associated with elevated risk for age-related diseases. However, little is known about the biomarker role of telomere length (TL) for predicting inflammation and glucose alterations.

OBJECTIVE

The objective of this research is to evaluate the association between TL, inflammatory markers and glucose levels after a 2-month weight-loss programme in obese adolescents.

METHODS

Telomere length was measured using a quantitative polymerase chain reaction in 66 obese adolescents aged 12-17 years (51% men) from the EVASYON programme. The adolescents were genotyped for the polymorphism -174G/C (rs1800795) in the IL-6gene, and anthropometric and biochemical markers as well as inflammatory cytokines were analysed.

RESULTS

Multiple-adjusted models showed that longer telomeres at baseline were associated with a higher reduction in glucose (B = -4.08, 95% confidence interval: -6.66 to -1.50) and IL-6 (B = -1.03, 95% confidence interval: -2.01 to -0.05) serum levels after 2 months of the weight-loss treatment. The -174G/C polymorphism modulated the association between basal TL and changes in IL-6 (P interaction = 0.029). Thus, subjects with the GG + GC genotype and with longer telomeres showed a higher decrease in IL-6 levels than CC homozygotes.

CONCLUSION

Longer telomeres are associated with an improvement in glucose tolerance and inflammation after a weight-loss programme in obese adolescents. Moreover, the -174G/C polymorphism may influence the relationship between TL and IL-6 changes.

The telomere lengthening conundrum - it could be biology

Longitudinal studies of human leucocyte telomere length often report a percentage of individuals whose telomeres appear to lengthen. However, based on theoretical considerations and empirical data, Steenstrup et al. (Nucleic Acids Research, 2013, vol 41(13): e131) concluded that this lengthening is unlikely to be a real biological phenomenon and is more likely to be an artefact of measurement error. We dispute the logic underlying this claim. We argue that Steenstrup et al.'s analysis is incomplete because it failed to compare predictions derived from assuming a scenario with no true telomere lengthening with alternative scenarios in which true lengthening occurs. To address this deficit, we built a computational model of telomere dynamics that allowed us to compare the predicted percentage of observed telomere length gainers given differing assumptions about measurement error and the true underling dynamics. We modelled a set of scenarios, all assuming measurement error, but both with and without true telomere lengthening. We found a range of scenarios assuming some true telomere lengthening that yielded either similar or better quantitative fits to the empirical data on the percentage of individuals showing apparent telomere lengthening. We conclude that although measurement error contributes to the prevalence of apparent telomere lengthening, Steenstrup et al.'s conclusion was too strong, and current data do not allow us to reject the hypothesis that true telomere lengthening is a real biological phenomenon in epidemiological studies. Our analyses highlight the need for process‐level models in the analysis of telomere dynamics.

Effects of Intentional Weight Loss on Markers of Oxidative Stress, DNA Repair and Telomere Length - a Systematic Review

BACKGROUND

Altered levels of markers of oxidative stress, DNA repair, and telomere integrity have been detected in obese individuals and may underlie the pathogenesis of obesity-related diseases. However, whether or not such effects are reversed by intentional weight loss has not been systematically reviewed.

METHODS

A literature search in PubMed/Medline identified 2,388 articles of which 21 studies (randomized controlled trial (RCT) (n = 10) and non-randomized intervention studies (n = 11)) were classified as testing the effects of intentional weight loss on i) oxidative stress (n = 15), ii) DNA repair (n = 2), and iii) telomere length (n = 4).

RESULTS

Across a broad range of intervention designs, diet-, exercise-, surgery-, balloon-induced weight loss regimens decreased oxidative stress measures. Studies investigating DNA repair capacity or telomere length as endpoints after weight loss were less common in number and yielded null or inconsistent results, respectively.

CONCLUSION

While this systematic review supports a role for intentional weight loss in reducing obesity-associated oxidative stress, it is not clear whether the effects are primary outcomes or secondary to improvement in obesity-associated insulin resistance and/or chronic inflammation. Although the lack of effect of intentional weight loss on DNA repair capacity might be anticipated given that oxidative stress is reduced, additional studies are needed. The inconsistent effects of weight loss on telomere length or DNA repair suggest the need for a re-assessment of intervention designs and assay methodology to definitively address this topic.

Early exclusive breastfeeding is associated with longer telomeres in Latino preschool children

BACKGROUND

Telomere length (TL) is a marker of cellular aging, with the majority of lifetime attrition occurring during the first 4 y. Little is known about risk factors for telomere shortening in childhood.

OBJECTIVE

We evaluated the relation between early life feeding variables and preschool TL.

DESIGN

We assessed the relation between dietary, feeding, and weight-associated risk factors measured from birth and TL from blood samples taken at 4 y of age (n = 108) and 5 y of age (n = 92) in a cohort of urban, Latino children (n = 121 individual children). Feeding variables were evaluated in children with repeat measurements (n = 77).

RESULTS

Mean TL (in bp) was associated with exclusive breastfeeding at 4-6 wk of age (adjusted coefficient: 353.85; 95% CI: 72.81, 634.89; P = 0.01), maternal TL (adjusted coefficient: 0.32; 95% CI: 0.11, 0.54; P < 0.01), and older paternal age (adjusted coefficient: 33.27; 95% CI: 4.10, 62.44; P = 0.03). The introduction of other foods or drinks in addition to breast-milk or replacement-milk substitutes before 4-6 wk of age was associated with mean TL at 4 and 5 y of age (adjusted coefficient: -457.01; 95% CI: -720.50, -193.51; P < 0.01). Infant obesity at 6 mo of age and soda consumption at 4 y of age mediated the relation in part between exclusive breastfeeding at 4-6 wk of age and mean TL at 4 and 5 y of age. High soda consumption at 3 y of age was associated with an accelerated attrition from 4 to 5 y of age (adjusted coefficient: -515.14; 95% CI: -986.06, -41.22; P = 0.03).

CONCLUSION

Exclusive breastfeeding at 4-6 wk of age may have long-term effects on child health as evidenced by longer TL at 4 and 5 y of age.

Association of cadmium and arsenic exposure with salivary telomere length in adolescents in Terai, Nepal

BACKGROUND

Cadmium and arsenic are ubiquitous metals commonly found in the environment which can harm human health. A growing body of research shows telomere length as a potential biomarker of future disease risk. Few studies have examined the effects of metals on telomere length and none have focused on adolescents.

OBJECTIVES

In this study, the impact of cadmium and arsenic on salivary telomere length was studied in adolescents in Terai, Nepal.

METHODS

Adolescents aged 12-16 years old (n=351)were recruited where questionnaire interviews and both saliva and urine collection took place. Telomere length was determined by quantitative polymerase chain reaction using DNA extracted from saliva. Urinary cadmium and arsenic concentration were measured by inductively coupled plasma mass spectrometry. Multivariable linear regression was used to examine associations between urinary metals and salivary telomere length.

RESULTS

The geometric means and standard deviations of cadmium and arsenic were 0.33±0.33μg/g creatinine and 196.0±301.1μg/g creatinine, respectively. Urinary cadmium concentration was negatively associated with salivary telomere length after adjustment for confounders (β=-0.24, 95% CI -0.42,-0.07). Arsenic showed positive associations with telomere length but did not reach statistical significance.

CONCLUSIONS

This is the first study to demonstrate that cadmium may shorten adolescent telomeres, even at exposure levels that may be considered low. These results agree with prior experimental and adult epidemiological studies, and also help identify the mechanism of DNA damage by cadmium. This study expanded current evidence on the harmful effects of cadmium exposure on telomere length even to adolescents.

Telomere length elongation after weight loss intervention in obese adults

INTRODUCTION

Telomeres may be considered markers of biological aging, shorter telomere length is associated with some age-related diseases; in several studies short telomere length has also been associated to obesity in adults and adolescents. However the relationship between telomere complex functions and obesity is still not clear. Aim of the study was to assess telomere length (TL) in adults' obese subjects before and after weight loss obtained by placement of bioenteric intragastric balloon (BIB) for 6months.

METHODS

We enrolled 42 obese subjects before and after BIB placement as weight loss intervention. Blood samples were collected in order to obtain DNA from leukocyte to measure TL by quantitative PCR.

RESULTS

Data were analyzed only in 37 subjects with complete data; all presented important body weight loss (124.06±26.7 vs 105.40±23.14, p<0.001) and more interesting they presented a significant increase in TL (3.58±0.83 vs 5.61±3.29, p<0.001). Moreover we observed a significant positive correlation between TL elongation and weight loss (r=0.44, p=0.007) as well as an inverse correlation between TL at baseline and TL elongation (r=-0.35, p=0.03).The predictors of TL elongation were once again weight loss and short TL at baseline (respectively p=0.007 and p=0.003).

CONCLUSIONS

Our study shows that weight loss is associated to telomere lengthening in a positive correlation: the greater weight loss the greater telomere lengthening; moreover telomere lengthening is more significant in those subjects with shortest telomeres at baseline.

Telomere length change plateaus at 4 years of age in Latino children: associations with baseline length and maternal change

Telomeres are the protective complexes at the end of chromosomes, required for genomic stability. Little is known about predictors of attrition in young children or the relationship between parental and child patterns of telomere change. Telomere length was assessed twice over one year, at 4 and at 5 years of age, in Latino preschool children (n = 77) and their mothers (n = 70) in whole blood leukocytes. Maternal and child rates of attrition during the same time period were compared in 70 mother-child pairs. More children showed lengthened telomeres over one year compared to their mothers and very few children showed attrition (2.6 %). Approximately 31 % of children and 16 % of mothers displayed lengthening over one year while 66 % of children showed maintenance in contrast with 74 % of mothers. The strongest predictor for child telomere length change was child's baseline telomere length (r = -0.61, p < 0.01). Maternal rate of change was associated with child rate of change (r = 0.33, p < 0.01). After controlling for child baseline telomere length, the relationship between child and maternal rate of change trended towards significance (Coeff = 0.20, 95 % CI -0.03 to 0.43; p = 0.08). We found primarily maintenance and lengthening from 4 to 5 years of age in children, with minimal telomere attrition, indicating that most of the telomere loss happens in the first 4 years, plateauing by age 4. Lastly, we found close to 10 % of the variance in rate of change in children shared by mothers. While some of this shared variance is genetic, there are likely environmental factors that need to be further identified that impact rate of telomere length change.

Body weight status and telomere length in U.S. middle-aged and older adults

OBJECTIVE

Telomere length has been proposed as a biomarker of biological aging. This study examined the relationship between body weight status and telomere length in U.S. middle-aged and older adults.

METHODS

Nationally representative data (N=2749) came from the Health and Retirement Study. Linear regressions were performed to examine the relationship between baseline body weight status reported in 1992 and telomere length measured in 2008 in the overall sample and by sex and racial/ethnic groups, adjusted for individual characteristics.

RESULTS

Baseline overweight (25kg/m²≤body mass index [BMI]<30kg/m²) and obesity (BMI≥30kg/m²) status positively predicted telomere length 17 years later. Compared with their normal weight counterparts, telomere length ratio was on average 0.062 (95% confidence interval=0.016, 0.109) and 0.125 (0.048, 0.202) larger among overweight and obese adults, respectively. In comparison to women and racial/ethnic minorities, the estimated positive associations between overweight and obesity status and telomere length were more salient among men and non-Hispanic whites, respectively.

CONCLUSIONS

The positive association between body weight status and telomere length found in this study was opposite to what existing biological model predicts, and could partially relate to the nonlinear relationship between body weight status and telomere length across age cohorts, and/or the lack of reliability of BMI as an indicator for adiposity in the older population. Large-scale longitudinal studies with baseline telomere length measures are warranted to replicate this study finding and explore the potential heterogeneous relationship between body weight status and telomere length.