Telomere, aging and age-related diseases

Association between maternal depression symptoms and child telomere length

The biological mechanisms that explain how adverse early life events influence adult disease risk are poorly understood. One proposed mechanism is via the induction of accelerated biological aging, for which telomere length is considered a biomarker. We aimed to determine if maternal depression pre- and post-partum was associated with telomere length in children at 4 years of age (n = 4299). Mothers completed structured questionnaires assessing depression during pregnancy (Edinburgh Depression Scale), at 9 months (Edinburgh Depression Scale), and at 54 months postpartum (Patient Health Questionnaire 9). Regression methods were used to investigate the relationship between telomere length (DNA from saliva) and maternal depression score recorded at each stage. Significant covariates included in the final model were: maternal age at pregnancy; child sex; child ethnicity; gestational age group, and rurality group. Child telomere length was found to be longer if their mother had a higher depression score at both postpartum time points tested (9 months of age; coefficient 0.003, SE = 0.001, P = 0.01, 54 months of age; coefficient 0.003, SE = 0.002, P = 0.02). Although these findings seem paradoxical, increased telomere length may be an adaptive response to early life stressors. We propose several testable hypotheses for these results and to determine if the positive association between depression and telomere length is a developmental adaptation or an indirect consequence of environmental factors.

Parameters and Morphological Changes of Erythrocytes and Platelets of COVID-19 Subjects: A Longitudinal Cohort Study

Purpose

Information about dynamic changes occurring in the parameters and morphology of erythrocytes and platelets during the coronavirus disease 2019 (COVID-19) infection and convalescence is scarce. To explore potential associations between dynamic erythrocyte and platelet parameters, morphological changes, and the course or severity of the disease is essential.

Patients and Methods

From January 17th, 2020, to February 20th, 2022, we followed up on 35 patients with non-severe and 11 patients with severe COVID-19 following their discharge. We collected clinical features, dynamic complete blood count (CBC), and peripheral blood smears (PBS) and analyzed parameter and morphological changes of erythrocytes and platelets depending on the course or severity of the disease. The course of the disease included four periods, namely onset (T1), discharge (T2), 1-year follow-up (T3), and 2-year follow-up (T4).

Results

Red blood cell (RBC) counts and hemoglobin were the lowest in T2, followed by T1, and lower in T1 and T2 than in T3 and T4. Inversely, the red blood cell distribution width (RDW) was the highest in T2, followed by T1, and higher than in T3 and T4. Compared to non-severe patients, the platelet of severe patients was lower in T1 and T2. In contrast, the mean platelet volume (MPV) and platelet distribution width (PDW) tended to be higher in severe patients. Similarly, anisocytosis was more common in peripheral blood smears at early stages and in severe patients. Finally, large platelets were more common in severe patients.

Conclusion

Anisocytosis of erythrocytes and large platelets are found in patients with severe COVID-19, these changes may help primary hospitals to identify patients with a high risk of severe COVID-19 at an early stage.

Pretreatment red blood cell distribution width may be a potential biomarker of prognosis in urologic cancer: a systematic review and meta-analysis

Purpose: To demonstrate the prognostic value of pretreatment red blood cell distribution width (RDW) in patients with urological cancer. Methods: We searched the relevant literature on Web of Science, Cochrane Central Register of Controlled Trials, PubMed, Embase, Sinomed databases and Chinese National Knowledge Infrastructure up to 30 March 2022, to investigate the relationship between RDW levels and the prognosis of patients with urological tumors. Results: This study comprised 15 retrospective studies involving 9492 patients. Increased pretreatment RDW was associated with poorer overall survival (hazard ratio [HR]: 1.52; 95% CI: 1.27-1.82; p < 0.001), cancer-specific survival (HR: 1.34; 95% CI: 1.15-1.57; p < 0.001) and progression-free survival (HR: 1.53; 95% CI: 1.26-1.86; p < 0.001). Conclusion: High pretreatment RDW might predict poor survival for patients with urologic cancers.

Impact of red cell distribution width and red cell distribution width/albumin ratio on all-cause mortality in patients with type 2 diabetes and foot ulcers: a retrospective cohort study

Background

Red blood cell distribution width (RDW) has emerged as a prognostic factor for mortality in various diseases. Up to now, few studies have focused on the prognostic value of RDW in patients with diabetic foot ulcers (DFUs). This retrospective cohort study aimed to investigate the impact of RDW and RDW/albumin (ALB) ratio on all-cause mortality in patients with DFUs.

Methods

This study included 860 patients with DFUs in a tertiary academic hospital. The associations of RDW and RDW/ALB with all-cause mortality were assessed by multivariable cox regression analyses. The pairwise comparisons of receiver operating characteristic (ROC) curves were performed to compare the predictive performance of RDW and RDW/ALB ratio. Harrell’s concordance index, integrated discrimination improvement, and net reclassification improvement were used to estimate the improvements in risk discrimination.

Results

Patients with high RDW and RDW/ALB had lower overall survival rates (all P < 0.001). The multivariable Cox regression revealed that high RDW [adjusted hazard ratio (HR) 2.426, 95% confidence interval (CI): 1.557–3.778, P < 0.001] and high RDW/ALB (adjusted HR 2.360, 95% CI: 1.414–3.942, P = 0.001) were independent associated with high all-cause mortality. In subgroup analyses, the comparative analysis of ROC curves revealed that the discriminating ability of the RDW/ALB ratio was significantly superior to RDW in patients with no severe DFUs or no severe peripheral artery disease, or in young and middle-aged patients (all P < 0.05). Adding RDW and RDW/ALB ratio to base models improved discrimination and risk reclassification for all-cause mortality.

Conclusions

RDW and RDW/ALB ratio are robust and independent prognostic markers in patients with DFUs. The RDW/ALB ratio appears to be of more predictive value for mortality in younger and less severely ill patients with DFUs. Both RDW and RDW/ALB ratio can provide incremental predictive value for all-cause mortality over traditional risk factors. RDW and RDW/ALB ratio can be used to identify high-risk patients with DFUs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01534-4.

Dihydro-β-agarofuran-type sesquiterpenoids from the seeds of Celastrus virens with lifespan-extending effect on the nematode Caenorhabditis elegans

Twelve dihydro-β-agarofuran-type sesquiterpenoids, including five new ones (1-5), were purified from the seeds of Celastrus virens (Wang et Tang) C. Y. Chent et T. C. Kao. Their chemical structures were characterized via comprehensive spectroscopic analysis, single-crystal X-ray diffraction analysis, and computational prediction of ECD, as well as comparison of observed and reported NMR spectral data. Among the isolates, nine abundant dihydro-β-agarofuran-type sesquiterpenoids were evaluated for their lifespan-extending activity using the nematode Caenorhabditis elegans model. As a result, compounds 1, 2, 5, 6, 8, and 9 (50 μM) significantly extended the mean survival time of C. elegans, respectively, compared with the blank control group (p < 0.05). Further Quantitative RT-PCR showed that the prolonging of lifespan mediated by compounds 1, 6, 8, and 9 were dependent on the transcription factors skn-1 and hsf-1.

Klotho: An Emerging Factor With Ergogenic Potential

Sarcopenia and impaired cardiorespiratory fitness are commonly observed in older individuals and patients with chronic kidney disease (CKD). Declines in skeletal muscle function and aerobic capacity can progress into impaired physical function and inability to perform activities of daily living. Physical function is highly associated with important clinical outcomes such as hospitalization, functional independence, quality of life, and mortality. While lifestyle modifications such as exercise and dietary interventions have been shown to prevent and reverse declines in physical function, the utility of these treatment strategies is limited by poor widespread adoption and adherence due to a wide variety of both perceived and actual barriers to exercise. Therefore, identifying novel treatment targets to manage physical function decline is critically important. Klotho, a remarkable protein with powerful anti-aging properties has recently been investigated for its role in musculoskeletal health and physical function. Klotho is involved in several key processes that regulate skeletal muscle function, such as muscle regeneration, mitochondrial biogenesis, endothelial function, oxidative stress, and inflammation. This is particularly important for older adults and patients with CKD, which are known states of Klotho deficiency. Emerging data support the existence of Klotho-related benefits to exercise and for potential Klotho-based therapeutic interventions for the treatment of sarcopenia and its progression to physical disability. However, significant gaps in our understanding of Klotho must first be overcome before we can consider its potential ergogenic benefits. These advances will be critical to establish the optimal approach to future Klotho-based interventional trials and to determine if Klotho can regulate physical dysfunction.

The Role of Red Blood Cell Distribution Width in the Severity and Prognosis of Community-Acquired Pneumonia

Objectives

The objective of this study is to unravel the correlation between RDW and the severity and prognosis of CAP, as well as exploring RDW with the inflammatory markers white blood cells (WBC), C-reactive protein (CRP), and procalcitonin (PCT).

Methods

According to the data characteristics, appropriate statistical methods were selected to analyze the relationship between RDW and the severity and prognosis of CAP patients and to determine whether RDW is associated with the inflammatory markers WBC, CRP, and PCT.

Results

The results show that with the increase of PSI and CURB-65 values, the proportion of patients with RDW ≥ 12.987% is significantly higher than that of RDW < 12.987% (P < 0.01). When RDW is combined with PSI or CURB-65 to predict the 90-day mortality of CAP patients, the area under the receiver operating characteristic (ROC) curve increased prominently, and if RDW, PSI, and CURB-65 are combined, the area under the ROC curve is maximized.

Conclusions

Our findings suggest that the higher RDW value is associated with short-term adverse outcomes in CAP patients. We also find that when RDW, PSI, and CURB-65 are combined, the best performance is achieved to predict CAP 90-day mortality risk.

Higher adherence to an empirically derived Mediterranean dietary pattern is positively associated with telomere length: the Seguimiento Universidad de Navarra (SUN) project

Telomere integrity is influenced by oxidative stress. Also, inflammation-related factors, including nutritional factors, could modulate telomere integrity. The relationship between a posteriori-derived dietary patterns and telomere length (TL) has been scarcely investigated. Thus, our objective was to examine the association between empirically derived dietary patterns ascertained through principal component analysis (PCA) and TL in an older adult Spanish population. A total of 886 older adults (>55 years old; 645 males and 241 females) from the Seguimiento Universidad de Navarra (SUN) cohort were included in the study. TL was measured by monochrome multiplex real-time quantitative PCR. Age-adjusted TL was used for all analyses. Dietary patterns were identified by PCA based on thirty predefined candidate food groups collected from a validated 136-food items frequency questionnaire. Generalised linear models were fitted to obtain β-coefficients and their 95 % CI evaluating differences in TL between each of the four upper quintiles of adherence to dietary patterns and the lowest quintile. Sensitivity analyses by rerunning all multiple linear models under different stratifications were performed to evaluate the robustness of our results. Two major dietary patterns were empirically identified, Western dietary pattern (WDP) and Mediterranean dietary pattern (MDP). After adjustment for potential confounders, longer TL was found among subjects in the highest quintile of MDP (β = 0·064; 95 % CI 0·004, 0·123). The WDP showed no significant association with TL. In conclusion, higher adherence to a posteriori-derived MDP was independently associated with longer telomeres in an older adult Spanish population of the SUN project.

Melatonin supplementation over different time periods until ageing modulates genotoxic parameters in mice

The ageing process is a multifactorial phenomenon, associated with decreased physiological and cellular functions and an increased propensity for various degenerative diseases. Studies on melatonin (N-acetyl-5-methoxytryptamine), a potent antioxidant, are gaining attention since melatonin production declines with advancing age. Hence, the aim of this study was to evaluate the effects of chronic melatonin consumption on genotoxic and mutagenic parameters of old Swiss mice. Herein, 3-month-old Swiss albino male mice (n = 240) were divided into eight groups and subdivided into two experiments: first (three groups): natural ageing experiment; second (five groups): animals that started water or melatonin supplementation at different ages (3, 6, 12 and 18 months) until 21 months. After 21 months, the animals from the second experiment were euthanized to perform the comet assay, micronucleus test and western blot analysis. The results demonstrated that melatonin prolonged the life span of the animals. Relative to genomic instability, melatonin was effective in reducing DNA damage caused by ageing, presenting antigenotoxic and antimutagenic activities, independently of initiation age. The group receiving melatonin for 18 months had high levels of APE1 and OGG1 repair enzymes. Conclusively, melatonin presents an efficient antioxidant mechanism aiding modulating genetic and physiological alterations due to ageing.

Telomeric alterations in the default mode network during the progression of Alzheimer's disease: Selective vulnerability of the precuneus

AIMS

Although telomere length (TL) and telomere maintenance proteins (shelterins) are markers of cellular senescence and peripheral blood biomarkers of Alzheimer's disease (AD), little information is available on telomeric alterations during the prodromal stage (MCI) of AD. We investigated TL in the default mode network (DMN), which underlies episodic memory deficits in AD, as well as shelterin protein and mRNA levels in the precuneus (PreC).

METHODS

Telomere length was evaluated in DMN hubs and visual cortex using quantitative PCR (qPCR). In the PreC, western blotting and NanoString nCounter expression analyses evaluated shelterin protein and mRNA levels, respectively, in cases with an antemortem clinical diagnosis of no cognitive impairment (NCI), MCI and AD.

RESULTS

TL was significantly reduced in the PreC in MCI and AD compared to NCI, but stable in frontal, inferior temporal, posterior cingulate and visual cortex. PreC TL correlated significantly with performance on cognitive tests. NCI cases with high vs low Braak scores displayed significantly shorter TL in posterior cingulate and frontal cortex, which correlated significantly with neuritic and diffuse amyloid-β plaque counts. Shelterin protein levels (TIN2, TRF1, TRF2 and POT1) declined in MCI and AD compared to NCI. The PreC displayed stable expression of shelterins TERF1, TERF2, POT1, RAP1 and TPP1, while TINF2 mRNA significantly increased in AD compared to NCI.

CONCLUSIONS

These findings indicate a selective vulnerability to telomere attrition within different nodes of the DMN in prodromal AD and in aged NCI individuals with high Braak scores highlighting a putative role in the pathogenesis of AD.

Telomere shortening is associated with poor physical performance in knee osteoarthritis

Telomere length is a hallmark characteristic of ageing and age-related diseases. Osteoarthritis (OA) is the most common cause of joint pain and physical disability in the elderly. Previous studies have revealed the role of telomere shortening in OA; however, the relationship between telomere length, muscle strength and physical performance in knee OA patients remains unknown. The aim of the present study was to investigate the association of telomere length and physical performance in patients with knee OA. A total of 202 patients with knee OA and 60 healthy controls were enrolled in the study. The quality of life was assessed using Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and Short Form Health Survey. The skeletal muscle mass was examined using bioelectrical impedance analysis, while the muscle strength was analyzed using hand grip force and isometric knee extension force. The physical performance of patients with knee OA was also investigated using gait speed, Timed up and go test (TUGT), Sit to stand test and 6-min walk test (6MWT). Blood leukocyte relative telomere length (RTL) was assessed using real time quantitative PCR. The mean blood leukocyte RTL in knee OA subjects was significantly lower compared with healthy controls (P<0.001). Knee OA patients with RTL values in the lowest quartile had a slow gait speed (P=0.006) and prolonged TUGT time (P=0.03). Multivariate regression analyses and multiple logistic regression analyses adjusted for age, sex, waist circumference, body mass index, fat mass, skeletal muscle index and the total WOMAC demonstrated that gait speed, TUGT and 6MWT were associated with longer RTL (P-trend<0.05). These findings suggested that poorer physical performance was associated with shorter RTL. Therefore, leukocyte telomere length and physical performance tests, especially gait speed, TUGT and 6MWT, could predict the health status and quality of life in patients with knee OA.

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.

D-galactose: a model of accelerated ageing sufficiently sensitive to reflect preventative efficacy of an antioxidant treatment

Considering that the phenomenon of accelerated ageing contributes to early onset of various chronic diseases, modelling of the relevant dysregulated systems or responses is vital for research aimed at identification of potential therapeutic targets. Here, we aimed to establish a model capable of simulating the redox and inflammatory changes of accelerated ageing-specifically, the aim was early phase accelerated ageing, which would allow therapeutic intervention in a preventative approach prior to clinical disease manifestation. A secondary aim was to evaluate the sensitivity of the model to reflect preventative treatment efficacy. Daily D-galactose injections (250 mg/kg body mass/day) for 8 weeks in 9-week-old male Wistar rats induced a model of early accelerated ageing (decreased plasma FRAP; P < 0.05 and altered inflammatory signalling) and an aged profile in lymph node ultrastructure, but did not yet result in telomere shortening. Preventative daily oral antioxidant administration (grape seed-derived polyphenol, 100 mg/kg body mass) prevented tissue ageing, beneficially modulated the inflammatory response, including neutrophil chemokinetic capacity, and tended to increase absolute telomere length. Data suggests that using a mild model of D-galactose administration than those employed to induce neurodegeneration, simulated the point where oxidative stress starts to overwhelm the endogenous antioxidant response and where a pro-inflammatory phenotype switch manifests. Furthermore, despite the expected small effect size, the model was sufficiently sensitive to reflect benefits of preventative antioxidant treatment in the context of ageing. This model presents a practical model for use in drug discovery, particularly in the context of preventative medicine aimed at limiting oxidative stress-associated ageing. Since this starting point of accelerated ageing as illustrated by current data, is not expected to reflect major ageing-associated changes yet, we recommend that future preventative drug discovery studies employ a longitudinal study design in order to clearly demonstrate the delay of this starting point by preventative strategies.

Prenatal second-hand smoke exposure and newborn telomere length

BACKGROUND

Cigarette smoking is associated with shorter telomere lengths in adults, but evidence on the effect of prenatal tobacco exposure is limited. We aimed to investigate the association between prenatal second-hand smoke exposure and newborn telomere length.

METHODS

We recruited 762 mother-newborn pairs from Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital) between November 2013 and March 2015. Information on second-hand smoke exposure was obtained via questionnaires. Relative telomere length was measured in DNA extracted from umbilical cord blood. We used linear regression to assess the associations between prenatal second-hand smoke exposure and newborn telomere length.

RESULTS

In the fully adjusted model, prenatal second-hand smoke exposure was associated with 9.7% shorter newborn telomere length (percent difference: -9.7%; 95% confidence interval (CI): -15.0, -4.0). The estimate for boys was lower (percent difference: -10.9%; 95% CI: -18.6, -2.5) than that for girls (percent difference: -8.5%; 95% CI: -15.8, -0.5), but the interaction term between newborn sex and prenatal second-hand smoke was not significant (P = 0.751).

CONCLUSIONS

This study demonstrated that prenatal second-hand smoke exposure may be a preventable risk factor for accelerated biological aging in the intrauterine stage, and further suggested possible sex differences in the susceptibility to prenatal second-hand smoke.

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.

Organophosphate insecticide exposure and telomere length in U.S. adults

BACKGROUND

Organophosphate insecticides have been widely used for >30 years, and are reported to be associated with various age-related chronic diseases. While shortening of telomere length has been considered as a marker of cellular aging, only a few small studies have been conducted to examine any difference of telomere length in workers exposed to organophosphates versus controls. Epidemiologic studies of the dose-response associations between environmental organophosphate exposure and telomere length in the general population are few.

OBJECTIVE

This study aimed to evaluate the association between levels of organophosphate insecticide exposure and telomere length in the general population.

METHODS

We analyzed data for 1724 participants aged 20 years or more from the National Health and Nutrition Examination Survey 1999-2002. Organophosphate insecticide exposure was estimated using measures of urinary concentrations for 3,5,6-trichloro-2-pyridinol (TCPY) and six non-specific dialkyl phosphate metabolites, e.g., diethyl thiophosphate (DETP). Multiple linear regression was conducted to assess the association between organophosphate exposure and telomere length.

RESULTS

After controlling for sociodemographic and physical factors and urinary creatinine, participants in the second quartile for urinary TCPY had 0.06 (95% CI: 0.02-0.10) T/S ratio shorter telomere length than those in the lowest quartile. By contrast, participants in the second and third tertiles of urinary DETP had 0.08 (95% CI: 0.02-0.14) and 0.06 (95% CI, 0.01-0.11) T/S ratio longer telomere length than those in the lowest tertile. For other five metabolites, there was no association with telomere length.

CONCLUSIONS

Levels of environmental exposures to certain organophosphate insecticides may be linked to altered telomere length in adults in the general population. Although our findings may need to be replicated, we provide the first evidence that environmental exposure to organophosphates may contribute to the alteration of telomere length, which is potentially related to biological aging and to the development of various chronic diseases.

Functional interaction between plasma phospholipid fatty acids and insulin resistance in leucocyte telomere length maintenance

BACKGROUND

Previous evidence suggests that plasma phospholipid fatty acids (PPFAs) and HOMA insulin resistance (HOMA-IR) are independently related to leukocyte telomere length (LTL). However, there is limited evidence of regarding the effect of their interaction on relative LTL (RLTL). Therefore, here, we aimed to determine the effect of the interaction between PPFAs and HOMA-IR on RLTL.

METHODS

We conducted a cross-sectional study, involving a total of 1246 subjects aged 25-74 years. PPFAs and RLTL were measured, and HOMA-IR was calculated. The effect of the interaction between PPFAs and HOMA-IR on RLTL was assessed by univariate analysis, adjusting for potential confounders.

RESULTS

In age-adjusted analyses, multivariate linear regression revealed a significant association of the levels of elaidic acid, HOMA-IR, monounsaturated fatty acids (MUFA) and omega-6 (n-6) polyunsaturated fatty acid (PUFA) with RLTL. After adjustment of age and gender, race, smoking, drinking, tea, and exercise, elaidic acid, and omega-3 (n-3) PUFA were negatively associated with RLTL, and HOMA-IR and n-6 PUFA were positively associated with RLTL. These associations were not significantly altered upon further adjustment for anthropometric and biochemical indicators. Meanwhile, the effect of the interaction of elaidic acid and HOMA-IR on RLTL was significant, and remained unchanged even after adjusting for the aforementioned potential confounders. Interestingly, individuals who had the lowest HOMA-IR and the highest elaidic acid levels presented the shortest RLTL.

CONCLUSIONS

Our findings indicated that shorter RLTL was associated with lower HOMA-IR and higher elaidic acid level. These findings might open a new avenue for exploring the potential role of the interaction between elaidic acid and HOMA-IR in maintaining RLTL.

Telomere length in early childhood is associated with sex and ethnicity

Telomeres are repetitive DNA sequences at the end of chromosomes that function to protect chromosomes from degradation. Throughout the life course, telomere length decreases with age and is influenced by environmental factors and health conditions. This study aimed to determine the relative telomere lengths in a diverse cohort of about 4000 four-year-old children in New Zealand. Linear regression was used to investigate the relationship between telomere length, child gender, ethnicity, paternal age and deprivation. We observed substantial variation in telomere length according to sex and self-identified ethnicity. Telomere length was longer in females compared to males (coefficient of 0.042, 95% confidence interval (CI) 0.024-0.060). European children had shorter telomere than both the indigenous Māori (coefficient of 0.03, CI 0.007-0.055) and Pacific children (coefficient of 0.15, CI 0.12-0.18). The data suggest that telomere lengths are highly variable and variability between individuals arise from early age, influenced partly by sex and ethnicity. Longer telomeres in indigenous Māori and Pacific children may reflect the heritability of telomere length in genetically less complex populations. This study increases our understanding of telomere dynamics in young children since the majority of telomere studies are conducted in adults.

Urinary metals and leukocyte telomere length in American Indian communities: The Strong Heart and the Strong Heart Family Study

INTRODUCTION

While several mechanisms may explain metal-related health effects, the exact cellular processes are not fully understood. We evaluated the association between leukocyte telomere length (LTL) and urine arsenic (ΣAs), cadmium (Cd) and tungsten (W) exposure in the Strong Heart Study (SHS, N = 1702) and in the Strong Heart Family Study (SHFS, N = 1793).

METHODS

Urine metal concentrations were measured using ICP-MS. Arsenic exposure was assessed as the sum of inorganic arsenic, monomethylarsonate and dimethylarsinate levels (ΣAs). LTL was measured by quantitative polymerase chain reaction.

RESULTS

In the SHS, median levels were 1.09 for LTL, and 8.8, 1.01 and 0.11 μg/g creatinine for ΣAs, Cd, and W, respectively. In the SHFS, median levels were 1.01 for LTL, and 4.3, 0.44, and 0.10 μg/g creatinine. Among SHS participants, increased urine ΣAs, Cd, and W was associated with shorter LTL. The adjusted geometric mean ratio (95% confidence interval) of LTL per an increase equal to the difference between the percentiles 90th and 10th in metal distributions was 0.85 (0.79, 0.92) for ΣAs, 0.91 (0.84, 1.00) for Cd and 0.93 (0.88, 0.98) for W. We observed no significant associations among SHFS participants. The findings also suggest that the association between arsenic and LTL might be differential depending on the exposure levels or age.

CONCLUSIONS

Additional research is needed to confirm the association between metal exposures and telomere length.

DNA damage in obesity: Initiator, promoter and predictor of cancer

Epidemiological evidence linking obesity with increased risk of cancer is steadily growing, although the causative aspects underpinning this association are only partially understood. Obesity leads to a physiological imbalance in the regulation of adipose tissue and its normal functioning, resulting in hyperglycaemia, dyslipidaemia and inflammation. These states promote the generation of oxidative stress, which is exacerbated in obesity by a decline in anti-oxidant defence systems. Oxidative stress can have a marked impact on DNA, producing mutagenic lesions that could prove carcinogenic. Here we review the current evidence for genomic instability, sustained DNA damage and accelerated genome ageing in obesity. We explore the notion of genotoxicity, ensuing from systemic oxidative stress, as a key oncogenic factor in obesity. Finally, we advocate for early, pre-malignant assessment of genome integrity and stability to inform surveillance strategies and interventions.

Short Telomere Length Is Related to Limitations in Physical Function in Elderly European Adults

The present study aims to explore the potential influence of leucocyte telomere length (LTL) on both a single indicator and a composite construct of physical functioning in a large European population of elderly men and women across diverse geographical locations. A total of 1,221 adults (65–79 years) were recruited from five European countries within the framework of NU-AGE study. The physical functioning construct was based on the 36-item Short Form Health Survey. Handgrip strength was used as a single indicator of muscle function and LTL was assessed using quantitative real-time PCR. Women had significantly longer (p < 0.05) LTL than men. Participants in Poland had significantly shorter LTL than in the other study centers, whereas participants in the Netherlands had significantly longer LTL than most of the other centers (p < 0.01). An analysis of LTL as a continuous outcome against physical functioning by using linear models revealed inconsistent findings. In contrast, based on an analysis of contrasting telomere lengths (first vs. fifth quintile of LTL), a significant odds ratio (OR) of 1.7 (95% CI: 1.1 – 2.6; p < 0.05) of having functional limitation was observed in those belonging to the first LTL quintile compared to the fifth. Interestingly, having the shortest LTL was still related to a higher likelihood of having physical limitation when compared to all remaining quintiles (OR: 1.5, 95% CI: 1.1 – 2.1; p < 0.05), even after adjustment by study center, age, sex, and overweight status. Collectively, our findings suggest that short LTL is an independent risk factor that accounts for functional decline in elderly European populations. The influence of LTL on functional limitation seems driven by the detrimental effect of having short telomeres rather than reflecting a linear dose-response relationship.

A review of telomere length in sarcopenia and frailty

Sarcopenia and frailty are associated with several important health-related adverse events, including disability, loss of independence, institutionalization and mortality. Sarcopenia can be considered a biological substrate of frailty, and the prevalence of both these conditions progressively increases with age. Telomeres are nucleoprotein structures located at the end of linear chromosomes and implicated in cellular ageing, shorten with age, and are associated with various age-related diseases. In addition, telomere length (TL) is widely considered a molecular/cellular hallmark of the ageing process. This narrative review summarizes the knowledge about telomeres and analyzes for the first time a possible association of TL with sarcopenia and frailty. The overview provided by the present review suggests that leukocyte TL as single measurement, calculated by quantitative real-time polymerase chain reaction (qRT-PCR), cannot be considered a meaningful biological marker for complex, multidimensional age-related conditions, such as sarcopenia and frailty. Panels of biomarkers, including TL, may provide more accurate assessment and prediction of outcomes in these geriatric syndromes in elderly people.

A reduction in DNA damage in neural tissue and peripheral blood of old mice treated with caffeine

Studies on caffeine consumption have shown a negative correlation with development of some diseases with subsequent beneficial manifestations. Our aim was to assess the effects of caffeine on peripheral blood and neural tissue DNA in young adult and aged mice. Male Swiss mice (age 2-3 or 16-18 months, respectively) were treated with a caffeine solution (0.3 g/l) for 4 weeks, while controls received water. After the treatments, blood and hippocampal cells (for a comet assay) and femurs (for a micronucleus [MN] test) were collected. The comet assay of peripheral blood and hippocampal cells demonstrated no significant differences between caffeine-treated and control young adult mice in terms of DNA damage index (DI) and frequency. In contrast, when comparing young adult with aged animals, significant differences were observed in DNA damage in blood and hippocampal cells. The differences between aged animals (with or without caffeine) consisted of a significant decrease in DNA DI in the group that received caffeine. In the MN test, an increase in frequency of micronucleated polychromatic (PCE) erythrocytes was noted in aged animals that received water compared to young adult mice. In addition, comparing treated with control aged murine groups, a decrease in frequency of MN was found in PCE erythrocytes of caffeine-treated mice. Chronic caffeine consumption was neither genotoxic nor mutagenic at the dose tested; however, it appears that caffeine actually protected mice from genotoxicity and mutagenicity, consequences attributed to aging.

Ataxia-telangiectasia (A-T): An emerging dimension of premature ageing

A-T is a prototype genome instability syndrome and a multifaceted disease. A-T leads to neurodegeneration - primarily cerebellar atrophy, immunodeficiency, oculocutaneous telangiectasia (dilated blood vessels), vestigial thymus and gonads, endocrine abnormalities, cancer predisposition and varying sensitivity to DNA damaging agents, particularly those that induce DNA double-strand breaks. With the recent increase in life expectancy of A-T patients, the premature ageing component of this disease is gaining greater awareness. The complex A-T phenotype reflects the ever growing number of functions assigned to the protein encoded by the responsible gene - the homeostatic protein kinase, ATM. The quest to thoroughly understand the complex A-T phenotype may reveal yet elusive ATM functions.

Integration of Telomere Length Dynamics into Systems Biology Framework: A Review

Telomere length dynamics plays a crucial role in regulation of cellular processes and cell fate. In contrast to epidemiological studies revealing the association of telomere length with age, age-related diseases, and cancers, the role of telomeres in regulation of transcriptome and epigenome and the role of genomic variations in telomere lengthening are not extensively analyzed. This is explained by the fact that experimental assays for telomere length measurement are resource consuming, and there are very few studies where high-throughput genomics, transcriptomics, and/or epigenomics experiments have been coupled with telomere length measurements. Recent development of computational approaches for assessment of telomere length from whole genome sequencing data pave a new perspective on integration of telomeres into high-throughput systems biology analysis framework. Herein, we review existing methodologies for telomere length measurement and compare them to computational approaches, as well as discuss their applications in large-scale studies on telomere length dynamics.

Association of Average Telomere Length with Body-Mass Index and Vitamin D Status in Juvenile Population with Type 1 Diabetes

Background

Type 1 diabetes (T1D) is an autoimmune chronic disease where hyperglycemia, increased risk of oxidative stress, advanced glycation end-products and other genetic and environmental factors lead to T1D complications. Shorter telomeres are associated with hyperglycemic levels and lower serum vitamin D levels.

Methods

Average telomere length (ATL) in whole blood DNA samples was assessed with qPCR method in 53 Slovenian T1D children/adolescents (median age 8.7 years, 1:1.3 male/female ratio). Body mass index standard deviation score (BMI-SDS), glycated haemoglobin and serum level of vitamin D metabolite (25-(OH)-D3) and the age at the onset of T1D were collected from the available medical documentation.

Results

Results indicate shorter ATL in subjects with higher BMI-SDS when compared to those with longer ATL (0.455 ± 0.438, −0.63 ± 0.295; p=0.049). Subjects with higher BMI-SDS had lower serum vitamin D levels when compared to those with lower BMI-SDS (40.66 ± 3.07 vs. 52.86 ± 4.85 nmol/L; p=0.045). Vitamin D serum levels did not significantly differ between subjects with longer/shorter ATL.

Conclusion

T1D children/adolescents with shorter ATL tend to have higher BMI-SDS. Lower serum vitamin D levels were associated with higher BMI-SDS, while associations between vitamin D serum levels, age at the onset of T1D, glycated haemoglobin and ATL were not observed. Additional studies with more participants are required to clarify the role of the telomere dynamics in T1D aetiology and development of complications.

Red blood cell distribution width: A simple parameter with multiple clinical applications

The red blood cell distribution width (RDW) is a simple and inexpensive parameter, which reflects the degree of heterogeneity of erythrocyte volume (conventionally known as anisocytosis), and is traditionally used in laboratory hematology for differential diagnosis of anemias. Nonetheless, recent evidence attests that anisocytosis is commonplace in human disorders such as cardiovascular disease, venous thromboembolism, cancer, diabetes, community-acquired pneumonia, chronic obstructive pulmonary disease, liver and kidney failure, as well as in other acute or chronic conditions. Despite some demographic and analytical issues related to the routine assessment that may impair its clinical usefulness, an increased RDW has a high negative predictive value for diagnosing a variety of disorders, but also conveys important information for short- and long-term prognosis. Even more importantly, the value of RDW is now being regarded as a strong and independent risk factor for death in the general population. Although it has not been definitely established whether an increased value of RDW is a risk factor or should only be considered an epiphenomenon of an underlying biological and metabolic imbalance, it seems reasonable to suggest that the assessment of this parameter should be broadened far beyond the differential diagnosis of anemias. An increased RDW mirrors a profound deregulation of erythrocyte homeostasis involving both impaired erythropoiesis and abnormal red blood cell survival, which may be attributed to a variety of underlying metabolic abnormalities such as shortening of telomere length, oxidative stress, inflammation, poor nutritional status, dyslipidemia, hypertension, erythrocyte fragmentation and alteration of erythropoietin function. As such, the aim of this article is to provide general information about RDW and its routine assessment, to review the most relevant implications in health and disease and give some insights about its potential clinical applications.

Knee osteoarthritis: Clinical connections to articular cartilage structure and function

Articular cartilage is a unique biphasic material that supports a lifetime of compressive and shear forces across joints. When articular cartilage deteriorates, whether due to injury, wear and tear or normal aging, osteoarthritis and resultant pain can ensue. Understanding the basic science of the structure and biomechanics of articular cartilage can help clinicians guide their patients to appropriate activity and loading choices. The purpose of this article is to examine how articular cartilage structure and mechanics, may interact with risk factors to contribute to OA and how this interaction provides guidelines for intervention choices This paper will review the microstructure of articular cartilage, its mechanical properties and link this information to clinical decision making.

Shorter telomeres in peripheral blood mononuclear cells from older persons with sarcopenia: results from an exploratory study

Background: Telomere shortening in peripheral blood mononuclear cells (PBMCs) has been associated with biological age and several chronic degenerative diseases. However, the relationship between telomere length and sarcopenia, a hallmark of the aging process, is unknown. The aim of the present study was therefore to determine whether PBMC telomeres obtained from sarcopenic older persons were shorter relative to non-sarcopenic peers. We further explored if PBMC telomere length was associated with frailty, a major clinical correlate of sarcopenia.

Methods: Analyses were conducted in 142 persons aged ≥65 years referred to a geriatric outpatient clinic (University Hospital). The presence of sarcopenia was established according to the European Working Group on Sarcopenia in Older People criteria, with bioelectrical impedance analysis used for muscle mass estimation. The frailty status was determined by both the Fried’s criteria (physical frailty, PF) and a modified Rockwood’s frailty index (FI). Telomere length was measured in PBMCs by quantitative real-time polymerase chain reaction according to the telomere/single-copy gene ratio (T/S) method.

Results: Among 142 outpatients (mean age 75.0 ± 6.5 years, 59.2% women), sarcopenia was diagnosed in 23 individuals (19.3%). The PF phenotype was detected in 74 participants (52.1%). The average FI score was 0.46 ± 0.17. PBMC telomeres were shorter in sarcopenic subjects (T/S = 0.21; 95% CI: 0.18–0.24) relative to non-sarcopenic individuals (T/S = 0.26; 95% CI: 0.24–0.28; p = 0.01), independent of age, gender, smoking habit, or comorbidity. No significant associations were determined between telomere length and either PF or the FI.

Conclusion: PBMC telomere length, expressed as T/S values, is shorter in older outpatients with sarcopenia. The cross-sectional assessment of PBMC telomere length is not sufficient at capturing the complex, multidimensional syndrome of frailty.

Telomeres are elongated in rats exposed to moderate altitude

Background

Leukocyte telomere length has been shown to be associated with life span. Hypoxia-associated changes of telomere length have been detected in cell cultures, but no in vivo studies have reported the changes of telomere length under different hypoxic conditions. This study aimed to evaluate the effects of altitude on telomere length in rat leukocytes.

Methods

One hundred and ten male Wistar rats were randomized into 3 groups and maintained at sea-level (altitude of 10 m) (SL group, n = 10), moderate altitude (2,260 m) (MA group, n = 50), or simulated high altitude (5,000 m (SHA group, n = 50). The last two groups were further divided into 5 subgroups and exposed to hypoxia for 1, 3, 7, 15, or 30 days (n = 10). The leukocyte telomere length, hemoglobin concentration, red blood cell count, hematocrit, and plasma levels of telomerase reverse transcriptase (TERT), hypoxia-inducible factor 1α (HIF-1α), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured.

Results

Leukocyte telomere length was significantly longer in the MA group than in the SL or SHA groups, and the TERT expression changed in a similar manner as the leukocyte telomere length. However, HIF-1α level was significantly higher in both MA and SHA groups than the SL group. SOD level was decreased and MDA level was elevated in SHA group.

Conclusions

The telomere length of blood leukocytes is elongated at a moderate altitude, but not at a high altitude. A mild hypoxic state may increase telomere length.