Telomere length loss due to smoking and metabolic traits (original) (raw)
Related papers
Obesity, cigarette smoking, and telomere length in women
The Lancet, 2005
Telomeres cap the ends of chromosomes and protect them from degradation and end-to-end fusion. Telomeres of cultured somatic cells undergo erosion with each cycle of replication, and oxidative stress enhances this process. Both obesity and cigarette smoking are important risk factors in many age-related diseases, and are associated with increased oxidative stress and inflammation. 2,3 The latter process is marked by increased white blood cell (WBC) turnover. Telomere attrition (expressed in WBCs) can serve as a marker of the cumulative oxidative stress and inflammation and, consequently, show the pace of biological ageing. We therefore expected obese individuals and smokers to have shortened telomeres. To investigate this hypothesis we studied WBC telomere length in 1122 healthy white women aged 18-72 years, examining the relations with both smoking and obesityrelated phenotypes.
Telomere shortening & metabolic/vascular diseases
The Indian journal of medical research, 2007
Telomeres are specialized DNA-protein structures located at the ends of eukaryotic chromosomes whose length is progressively reduced in most somatic cells during ageing. Over the past decade, emerging evidence has shown that the telomeres are essential regulators of cellular life span and chromosome integrity in a dynamic fashion. By inducing genomic instability, replicative senescence and apoptosis, shortening of telomeres is thought to contribute to organismal ageing. While the aetiology of cardiovascular diseases and diabetes represent a complex interaction between various risk factors overlaid on different genetic backgrounds, the conventional risk factors often did not explain the inter-individual variability related to predisposition of disease states. This underscores the need for biological indicators of ageing in evaluating the aetiology of several age-related disorders, and recent studies indicate that telomere length could qualify as an ideal marker of biological ageing. ...
Smoking does not accelerate leucocyte telomere attrition: a meta-analysis of 18 longitudinal cohorts
Royal Society Open Science
Smoking is associated with shorter leucocyte telomere length (LTL), a biomarker of increased morbidity and reduced longevity. This association is widely interpreted as evidence that smoking causes accelerated LTL attrition in adulthood, but the evidence for this is inconsistent. We analysed the association between smoking and LTL dynamics in 18 longitudinal cohorts. The dataset included data from 12 579 adults (4678 current smokers and 7901 non-smokers) over a mean follow-up interval of 8.6 years. Meta-analysis confirmed a cross-sectional difference in LTL between smokers and non-smokers, with mean LTL 84.61 bp shorter in smokers (95% CI: 22.62 to 146.61). However, LTL attrition was only 0.51 bp yr −1 faster in smokers than in non-smokers (95% CI: −2.09 to 1.08), a difference that equates to only 1.32% of the estimated age-related loss of 38.33 bp yr −1 . Assuming a linear effect of smoking, 167 years of smoking would be required to generate the observed cross-sectional difference i...
2023
Aging is considered one of the major risk factors for several human disorders. The telomere plays a crucial role in regulating cellular responsiveness to stress and growth stimuli as well as maintaining the integrity of the Deoxyribonucleic Acid (DNA), and aging leads to the progressive decline in the telomere length (TL) due to continuous cell division. The aim of this study was to determine the relationship between TL and advancing age and the impact of metabolic syndrome (MetS) on TL. Firstly, we determined the association of advancing age and TL, by measuring telomere length (T/S ratio) in healthy volunteers (n = 90). The TL was compared between normal population and patients with metabolic syndrome (n = 298). The age matched controlled and uncontrolled MetS patients (n = 149) were also compared for their TL T/S ratio. The TL showed negative correlation with advancing age, whereas the significant change was observed at the cutoffs of 40 and 70 years defining 40 with longer TL and 70 as shorter TL. The longest T/S ratio at 2.46 was measured at the age range of 1 year in healthy volunteers, while elderly population showed considerably shorter TL. The patients older than 60 years with poor or uncontrolled MetS had shorter TL, as compared to the controlled MetS. In conclusion our findings suggest that TL was negatively correlated with advancing age. Uncontrolled metabolic syndrome appeared to have worsening effects on TL. Telomere length appears to have potential to be used a parameter to determine age. However, further large scale studies are recommended to make firm guidelines. Aging is genetically characterized as the accretion due to modifications occurring over the period of time 1 , and it is also considered as one of the major risk factors for a number of human disorders 2. Globally, 150,000 individuals die daily and nearly 2/3rd of them die due to age related factors. Aging process however is not constant, but the process gets modified or expedited due to comorbidities such as, cardiovascular and metabolic disorders. Aging is a genetically controlled phenomenon, and telomeres are essential element to maintain the integrity of the genome and regulating cellular responses to stress and growth factors 3. In normal cells, under physiological conditions, the telomere length (TL) decreases with each cell division. Given that TL decreases with each cell division, it progressively shortens with advancing age, therefore can be considered a biological marker of aging. This age-related decline in TL has been associated with a number of age-related diseases, including hypertension, diabetes, cancer, Alzheimer's disease, and many others 4. In addition, there are number of factors that affect TL including oxidative stress, inflammation, and repetitive cell divisions, which correlate TL to chronological aging and age related diseases 5. The chronological age may differ from biological age due to comorbidities and other influencing factors. During normal cellular activities, free radicals and reactive oxygen species (ROS) are regularly generated. Excessive ROS formation causes oxidative damage and eventually leads to cell abnormalities and cell death. 6. Higher ROS levels, mitochondrial malfunction, additional double-strand Deoxyribonucleic Acid (DNA) breaks, and shortening of telomeres are indicators of cellular senescence 7. Furthermore, it was
Cigarette smoking and telomere length: A systematic review of 84 studies and meta-analysis
Environmental Research
Background: Cigarette smoking is a risk factor for ageing-related disease, but its association with biological ageing, indicated by telomere length, is unclear. Methods: We systematically reviewed evidence evaluating association between smoking status and telomere length. Searches were performed in MEDLINE (Ovid) and EMBASE (Ovid) databases, combining variation of keywords "smoking" and "telomere". Data was extracted for study characteristics and estimates for association between smoking and telomere length. Quality of studies was assessed with a risk of bias score, and publication bias was assessed with a funnel plot. I 2 test was used to observe heterogeneity. Meta-analysis was carried out to compare mean difference in telomere length by smoking status, and a dose-response approach was carried out for pack-years of smoking and telomere length. A sensitivity analysis was carried out to examine sources of heterogeneity. Results: A total of 84 studies were included in the review, and 30 among them were included in our metaanalysis. Potential bias was addressed in half of included studies, and there was little evidence of small study bias. Telomere length was shorter among ever smokers compared to never smokers (summary standard mean difference [SMD]: −0.11 (95% CI −0.16 to −0.07)). Similarly, shorter telomere length was found among smokers compared to non-smokers, and among current smokers compared to never or former smokers. Doseresponse meta-analysis suggested an inverse trend between pack-years of smoking and telomere length. However, heterogeneity among some analyses was observed. Conclusion: Shorter telomeres among ever smokers compared to those who never smoked may imply mechanisms linking tobacco smoke exposure to ageing-related disease.
Aging Cell, 2007
Evidence assembled over the last decade shows that average telomere length (TL) acts as a biomarker for biological aging and cardiovascular disease (CVD) in particular. Although essential for a more profound understanding of the underlying mechanisms, little reference information is available on TL. We therefore sought to provide baseline TL information and assess the association of prevalent CVD risk factors with TL in subjects free of overt CVD within a small age range. We measured mean telomere restriction fragment length of peripheral blood leukocytes in a large, representative Asklepios study cohort of 2509 community-dwelling, Caucasian female and male volunteers aged approximately 35-55 years and free of overt CVD. We found a manifest age-dependent telomere attrition, at a significantly faster rate in men as compared to women. No significant associations were established with classical CVD risk factors such as cholesterol status and blood pressure, yet shorter TL was associated with increased levels of several inflammation and oxidative stress markers. Importantly, shorter telomere length was associated with an increasingly unhealthy lifestyle, particularly in men. All findings were age and gender adjusted where appropriate. With these cross-sectional results we show that TL of peripheral blood leukocytes primarily reflects the burden of increased oxidative stress and inflammation, whether or not determined by an increasingly unhealthy lifestyle, while the association with classical CVD risk factors is limited. This further clarifies the added value of TL as a biomarker for biological aging and might improve our understanding of how TL is associated with CVD.
Metabolic Syndrome, telomere length and Aging-Review of literature
2023
Metabolic syndrome is reportedly one of the key health concerns worldwide. It is defined as a group of conditions including hypertension, dysglycemia, and abdominal obesity. The wear and tear of telomeres is known to be a major incident not only in mammalian aging, but also in distressed nutrient sensing, which may contribute to a number of metabolic dysfunctions. The metabolic syndrome was linked to the growing prevalence of obesity, which is at rise invariably in all age groups including elderly. The existing literature review focuses on the relationship of shorting of telomere and metabolic syndrome. As the shortening of telomeres influence cellular senescence and eventual stoppage of cell division. Conclusion: It is reviewed that the increasing number patients of the metabolic syndrome significantly affecting aging process by early diminishing the telomere lengthening.
Telomere length and age-dependent telomere attrition: the blood-and-muscle model
Canadian Journal of Physiology and Pharmacology
Short telomere length (TL) is associated with atherosclerotic cardiovascular disease (ACVD) and other age-related diseases. It is unclear whether these associations originate from having inherently short TL or a faster TL attrition before or during disease development. We proposed the blood-and-muscle model to assess TL dynamics throughout life course. Our objective was to measure TL in leukocytes (LTL) and in skeletal muscle (MTL), which served as a proxy of TL at birth. The delta (MTL–LTL) represented life-long telomere attrition. Blood draws and skeletal muscle biopsies were performed on 35 Lebanese individuals undergoing surgery. Following DNA extraction, LTL and MTL were measured by Southern blot. In every individual aged between 30 and 85 years, MTL was longer than LTL. With age, MTL and LTL decreased, but the delta (MTL–LTL) increased by 14 bp/year. We validated the blood-and-muscle model that allowed us to identify TL, TL at birth, and lifelong TL attrition in a cross-sectio...