Inflammation, telomere length, and grip strength: a 10-year longitudinal study

Population-specific equations of age-related maximum handgrip force: a comprehensive review

Background

The measurement of handgrip force responses is important in many aspects, for example: to complement neurological assessments, to investigate the contribution of muscle mass in predicting functional outcomes, in setting realistic treatment goals, evaluating rehabilitation strategies. Normative data about handgrip force can assist the therapist in interpreting a patient's results compared with healthy individuals of the same age and gender and can serve as key decision criteria. In this context, establishing normative values of handgrip strength is crucial. Hence, the aim of the this study is to develop a tool that could be used both in rehabilitation and in the prevention of work-related musculoskeletal disorders. This tool takes the form of population-specific predictive equations, which express maximum handgrip force as a function of age.

Methodology

In order to collect data from studies measuring maximum handgrip force, three databases were searched. The search yielded 5,058 articles. Upon the removal of duplicates, the screening of abstracts and the full-text review of potentially relevant articles, 143 publications which focussed on experimental studies on various age groups were considered as fulfilling the eligibility criteria. A comprehensive literature review produced 1,276 mean values of maximum handgrip force.

Results

A meta-analysis resulted in gender- and world region-specific (general population, USA, Europe and Asia) equations expressing maximum force as a function of age. The equations showed quantitative differences and trends in maximum handgrip force among age, gender and national groups. They also showed that values of maximum handgrip force are about 40% higher for males than for females and that age-induced decrease in force differs between males and females, with a proved 35% difference between the ages of 35 and 75. The difference was lowest for the 60-64 year olds and highest for the 18-25 year-olds. The equations also showed that differences due to region are smaller than those due to age or gender.

Conclusions

The equations that were developed for this study can be beneficial in setting population-specific thresholds for rehabilitation programmes and workstation exposure. They can also contribute to the modification of commonly used methods for assessing musculoskeletal load and work-related risk of developing musculoskeletal disorders by scaling their limit values.

Genetic and phenotypic associations of frailty with cardiovascular indicators and behavioral characteristics

INTRODUCTION

Frailty Index (FI) is a common measure of frailty, which has been advocated as a routine clinical test by many guidelines. The genetic and phenotypic relationships of FI with cardiovascular indicators (CIs) and behavioral characteristics (BCs) are unclear, which has hampered ability to monitor FI using easily collected data.

OBJECTIVES

This study is designed to investigate the genetic and phenotypic associations of frailty with CIs and BCs, and further to construct a model to predict FI.

METHOD

Genetic relationships of FI with 288 CIs and 90 BCs were assessed by the cross-trait LD score regression (LDSC) and Mendelian randomization (MR). The phenotypic data of these CIs and BCs were integrated with a machine-learning model to predict FI of individuals in UK-biobank. The relationships of the predicted FI with risks of type 2 diabetes (T2D) and neurodegenerative diseases were tested by the Kaplan-Meier estimator and Cox proportional hazards model.

RESULTS

MR revealed putative causal effects of seven CIs and eight BCs on FI. These CIs and BCs were integrated to establish a model for predicting FI. The predicted FI is significantly correlated with the observed FI (Pearson correlation coefficient = 0.660, P-value = 4.96 × 10-62). The prediction model indicated "usual walking pace" contributes the most to prediction. Patients who were predicted with high FI are in significantly higher risk of T2D (HR = 2.635, P < 2 × 10-16) and neurodegenerative diseases (HR = 2.307, P = 1.62 × 10-3) than other patients.

CONCLUSION

This study supports associations of FI with CIs and BCs from genetic and phenotypic perspectives. The model that is developed by integrating easily collected CIs and BCs data in predicting FI has the potential to monitor disease risk.

The Relationship Between Telomeres, Cognition, Mood, and Physical Function: A Systematic Review

Background and Purpose: Cognitive, affective, and physical symptoms and alterations in their function are seen across chronic illnesses. Data suggest that environmental, psychological, and physiological factors contribute to symptom experience, potentially through loss of telomeres (telomere attrition), structures at the ends of chromosomes. Telomere length is affected by many factors including environmental (e.g., exercise, diet, smoking) and physiological (e.g., response to stress), as well as from oxidative damage and inflammation that occurs in many disease processes. Moreover, telomere attrition is associated with chronic disease (cancer, cardiovascular disease, Alzheimer's disease) and predicts higher morbidity and mortality rates. However, findings are inconsistent among telomere roles and relationships with health outcomes. This article aims to synthesize the current state-of-the-science of telomeres and their relationship with cognitive, affective, and physical function and symptoms. Method: A comprehensive literature search was performed in two databases: CINAHL and PUBMED. A total of 33 articles published between 2000 and 2022 were included in the final analysis. Results: Telomere attrition is associated with various changes in cognitive, affective, and physical function and symptoms. However, findings are inconsistent. Interventional studies (e.g., meditation and exercise) may affect telomere attrition, potentially impacting health outcomes. Conclusion: Nursing research and practice are at the forefront of furthering the understanding of telomeres and their relationships with cognitive, affective, and physical function and symptoms. Future interventions targeting modifiable risk factors may be developed to improve health outcomes across populations.

A genetic correlation and bivariate genome-wide association study of grip strength and depression

Grip strength is an important biomarker reflecting muscle strength, and depression is a psychiatric disorder all over the world. Several studies found a significant inverse association between grip strength and depression, and there is also evidence for common physiological mechanisms between them. We used twin data from Qingdao, China to calculate genetic correlations, and we performed a bivariate GWAS to explore potential SNPs, genes, and pathways in common between grip strength and depression. 139 pairs of Dizygotic twins were used for bivariate GWAS. VEAGSE2 and PASCAL software were used for gene-based analysis and pathway enrichment analysis, respectively. And the resulting SNPs were subjected to eQTL analysis and pleiotropy analysis. The genetic correlation coefficient between grip strength and depression was -0.41 (-0.96, -0.15). In SNP-based analysis, 7 SNPs exceeded the genome-wide significance level (P<5×10-8) and a total of 336 SNPs reached the level of suggestive significance (P<1×10-5). Gene-based analysis and pathway-based analysis identified genes and pathways related to muscle strength and the nervous system. The results of eQTL analysis were mainly enriched in tissues such as the brain, thyroid, and skeletal muscle. Pleiotropy analysis shows that 9 of the 15 top SNPs were associated with both grip strength and depression. In conclusion, this bivariate GWAS identified potentially common pleiotropic SNPs, genes, and pathways in grip strength and depression.

Telomere Length and Risk of Incident Fracture and Arthroplasty: Findings From UK Biobank

We investigated independent associations between telomere length and risk of fracture and arthroplasty in UK Biobank participants. Leukocyte telomere length (LTL) was measured in baseline samples using a validated polymerase chain reaction (PCR) method. We used, in men and women separately, Cox proportional hazards models to calculate the hazard ratio (HR) for incident fracture (any, osteoporotic) or arthroplasty (hip or knee) over 1,186,410 person-years of follow-up. Covariates included age, white cell count, ethnicity, smoking, alcohol, physical activity, and menopause (women). In further analyses we adjusted for either estimated bone mineral density (eBMD) from heel quantitative ultrasound, handgrip strength, gait speed, total fat mass (bioimpedance), or blood biomarkers, all measured at baseline (2006-2010). We studied 59,500 women and 51,895 men, mean ± standard deviation (SD) age 56.4 ± 8.0 and 57.0 ± 8.3 years, respectively. During follow-up there were 5619 fractures; 5285 hip and 4261 knee arthroplasties. In confounder-adjusted models, longer LTL was associated with reduced risk of incident knee arthroplasty in both men (HR/SD 0.93; 95% confidence interval [CI], 0.88-0.97) and women (0.92; 95% CI, 0.88-0.96), and hip arthroplasty in men (0.91; 95% CI, 0.87-0.95), but not women (0.98; 95% CI, 0.94-1.01). Longer LTL was weakly associated with reduced risk of any incident fracture in women (HR/SD 0.96; 95% CI, 0.93-1.00) with less evidence in men (0.98; 95% CI, 0.93-1.02). Associations with incident outcomes were not materially altered by adjustment for heel eBMD, grip strength, gait speed, fat mass, or blood biomarker measures. In this, the largest study to date, longer LTL was associated with lower risk of incident knee or hip arthroplasty, but only weakly associated with lower risk of fracture. The relative risks were low at a population level, but our findings suggest that common factors acting on the myeloid and musculoskeletal systems might influence later life musculoskeletal outcomes. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Telomere attrition and inflammation: the chicken and the egg story

The challenge to improve human life span has progressed with the advent of health care services and technologies. This improvement poses a new challenge of an associated wave of diseases and pathologies that have not been observed or experienced. This has led to rise in geriatric population who are currently facing health challenges that needs to be addressed by the research community. This review focuses primarily on two mechanisms that have contributed to aging and associated pathologies: telomere attrition and inflammatory insults. A strong interplay appears to exist between telomere attrition and inflammation, and this could be the basis of many pathologies associated with increasing age. This creates a scientific dilemma as to what comes first: telomere attrition or inflammation. This review will enthuse the reader to the underlying molecules and mechanisms associated with telomere attrition and inflammation and their contribution to aging.

A systematic review and meta-analysis of the Everyday Discrimination Scale and biomarker outcomes

Discrimination has consistently been associated with multiple adverse health outcomes. Like other psychosocial stressors, discrimination is thought to impact health through stress-related physiologic pathways including hypothalamic-pituitary-adrenal (HPA) axis activation, dysregulation of inflammation responses, and accelerated cellular aging. Given growing attention to research examining the biological pathways through which discrimination becomes embodied, this systematic review and meta-analysis synthesizes empirical evidence examining relationships between self-reported discrimination and four biomarker outcomes (i.e., cortisol, C-reactive protein (CRP), interleukin-6 (IL-6), and telomere length) among studies that have used the Everyday Discrimination Scale. We conducted a systematic review of studies discussing self-reported, everyday, or chronic discrimination in the context of health by searching Medline / PubMed (National Library of Medicine, NCBI), PsycInfo (APA, Ebsco) and Web of Science Core Collection (Clarivate). Twenty-five articles met the criteria for meta-analysis, with several reporting on multiple outcomes. Discrimination was associated with elevated CRP levels (r = 0.11; 95% CI: 0.01, 0.20, k = 10), though not cortisol (r = 0.05; 95% CI: -0.06, 0.16, k = 9), IL-6 (r = 0.05; 95% CI: -0.32, 0.42, k = 5), or telomere length (r = 0.03; 95% CI: -0.01, 0.07, k = 6). We identify several points of consideration for future research including addressing heterogeneity in assessment of biomarker outcomes and the need for longitudinal assessments of relationships between discrimination and biomarker outcomes.

A complex systems approach to aging biology

Having made substantial progress understanding molecules, cells, genes and pathways, aging biology research is now moving toward integration of these parts, attempting to understand how their joint dynamics may contribute to aging. Such a shift of perspective requires the adoption of a formal complex systems framework, a transition being facilitated by large-scale data collection and new analytical tools. Here, we provide a theoretical framework to orient researchers around key concepts for this transition, notably emergence, interaction networks and resilience. Drawing on evolutionary theory, network theory and principles of homeostasis, we propose that organismal function is accomplished by the integration of regulatory mechanisms at multiple hierarchical scales, and that the disruption of this ensemble causes the phenotypic and functional manifestations of aging. We present key examples at scales ranging from sub-organismal biology to clinical geriatrics, outlining how this approach can potentially enrich our understanding of aging.

Adverse childhood experiences and handgrip strength among middle-aged and older adults: a cross-sectional study in China

BACKGROUND

Evidence on the association between adverse childhood experiences (ACEs) and handgrip strength (HGS) in later life was limited and inconclusive. We aimed to explore the impact of ACEs on HGS among middle-aged and older Chinese adults.

METHODS

We conducted a cross-sectional study with data extracted from the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative survey with respondents recruited from 450 villages/urban communities of 28 provinces. Participants aged 45 years or older were drawn from the CHARLS 2014 life history survey and the 2015 health survey. Twelve ACE indicators before the age of 17 years were collected. HGS was measured with a dynamometer and the maximum value of HGS obtained from both hands was used in the analyses. Low muscle strength (LMS) was defined according to the recommendation of European Working Group on Sarcopenia in Older People (EWGSOP). Multivariate linear and logistic regression models were constructed to evaluate the association of ACEs with continuous HGS and LMS, with adjustment for age, sex, marital status, ethnicity, area of residence, smoking and drinking status, body mass index, hypertension, dyslipidaemia, diabetes mellitus, cardiovascular disease, arthritis, hip fracture, and memory-related disease.

RESULTS

Of the 7209 eligible participants, 2258 (31.3%) had experienced three or more ACEs. Compared to individuals without ACEs, exposure to ≥ 3 ACEs was negatively associated with continuous HGS in kilogram (β = -0.93, 95% CI: -1.37, -0.49) and positively associated with the risk of LMS (OR = 1.34, 95% CI: 1.12, 1.61). Such associations were consistently found both in men and women who had experienced three or more ACEs. Significant dose-response relationship between the number of ACEs and outcomes was also observed in the overall population and different sex groups.

CONCLUSION

Exposure to ACEs was associated with lower HGS and increased risk of LMS among middle-aged and older Chinese adults, indicating the importance of intervention in individuals with experience of ACEs in order to mitigate its detrimental impact on HGS and promote healthy ageing.

Heterogeneous trajectories in schizophrenia: insights from neurodevelopment and neuroprogression models

OBJECTIVES

The notion that schizophrenia is a neuroprogressive disorder is based on clinical perception of cumulative impairments over time and is supported by neuroimaging and biomarker research. Nevertheless, increasing evidence has indicated that schizophrenia first emerges as a neurodevelopmental disorder that could follow various pathways, some of them neuroprogressive. The objective of this review is to revisit basic research on cognitive processes and neuroimaging findings in a search for candidate keys to the intricate connections between neurodevelopment and neuroprogression in schizophrenia. In the complete panorama, schizophrenia is a neurodevelopmental disorder, possibly associated with an additional burden over the course of the disease through pathologically accelerated aging, and cognitive heterogeneity may explain the different trajectories of each patient.

Intra-uterine effects on adult muscle strength

BACKGROUND

Maternal behaviors and exposures affect fetal growth and development. Smoking, malnutrition, sedentary behavior, and stress can each lead to fetal programming and intra-uterine growth restriction. As a result, tissue development may be impaired. Problems with muscle formation can lead to reductions in muscle performance throughout life. The purpose of this study was to determine if in utero effects on muscle mass, muscle function, or both are responsible for the relationship between size at birth and adult muscle strength.

STUDY DESIGN

One hundred adults (ages 18-40), who were singletons born at term (37-42 weeks), participated. Birth weight was adjusted for gestational age using neonatal growth reference data. Maximal voluntary contractions (MVC) of dominant and non-dominant handgrip, and right and left leg extension were measured. Linear regression analysis was used to determine the association between adjusted birth weight and muscle strength. Sex and lean body mass were covariates.

RESULTS

Dominant handgrip MVC increased by 1.533 kg per 1 SD increase in adjusted birth weight (p = 0.004). Lean body mass had a significant indirect effect on this relationship. The relationship between handgrip strength and adjusted birth weight was strongest among female subjects. No other muscle strength measures were significantly associated with adjusted birth weight.

CONCLUSIONS

Birth size was a significant predictor of handgrip strength in adulthood. Including lean body mass attenuated, but did not remove, the association. Thus, among individuals born to term, having a smaller-than-predicted birth size likely causes both reductions in muscle mass formation and decreased muscle function, ultimately impacting muscle strength in adulthood.

Sex, Age, BMI, and C-Reactive Protein Impact the Odds of Developing Hypertension-Findings Based on Data From the Health and Retirement Study (HRS)

BACKGROUND

Hypertension is a major contributor to cardiovascular diseases and premature death, therefore determining factors that contribute to such a high burden of disease is critically important. This study examined anthropometric and physical measurements, as well as blood and saliva biomarkers, as predictors for hypertension using datasets from the 2008 Health and Retirement Study.

METHODS

A total of 2,924 participants (aged 74.84 ± 6.45 years) were included. Binary logistic regression was performed to ascertain the effects of sex, age, telomere length, C-reactive protein (CRP), body mass index (BMI), and additional markers on the odds of developing hypertension.

RESULTS

Males had 2.3 times the odds (odds ratio (OR) = 2.313, confidence interval (CI) 95% (1.391, 3.845); P = 0.001) of being hypertensive if they were obese, females had 1.7 times the odds (OR = 1.788, CI 95% (1.260, 2.536); P = 0.001) if overweight, and 2.4 times (OR = 2.479, CI 95% (1.693, 3.630); P < 0.001) if obese. Age in females was an independent predictor where every 1-year increase in age was tied to a 5.1% increase in being hypertensive (OR = 1.051, CI 95% (1.027, 1.075); P <0.001), and CRP (>3 mg/l) had 1.4 times the odds (OR = 1.447, CI 95% (1.079, 1.942); P = 0.014).

CONCLUSIONS

This study provides verification for BMI as a predictor for hypertension and proposes age and CRP as predictors for females. Specific sex differences and life stage should be considered when evaluating hypertension risk to improve clinical outcomes and promote healthy aging.

Association of Serum Total Bilirubin Concentration with Telomere Length: The National Health and Nutrition Examination Survey

Introduction

Mildly increased bilirubin concentration has a protective effect on oxidative stress–related diseases. However, it remains unknown whether elevated circulating bilirubin is associated with longer telomere length. The aim of this cross-sectional study was to examine the association between total bilirubin concentration and telomere length.

Methods

We used the data from the National Health and Nutrition Examination Survey (NHANES) 1999-2002. The multivariable linear regression model was used to examine the association between total bilirubin concentration and telomere length. The nonlinear relationship was analyzed using a generalized additive model with the smoothing plot.

Results

A total of 7818 participants with a mean age of 49.20 ± 18.82 years were included. Compared with the lowest concentration of total bilirubin (Q1), the highest quartile of total bilirubin concentration was associated with longer telomere length in male (β = 0.04, 95 CI%: 0.00, 0.07, P = 0.024) and female (β = 0.04, 95 CI%: 0.02, 0.04, P = 0.002). Furthermore, an inverted U-shaped relationship between total bilirubin and telomere length was found. On the left of turning points (total bilirubin < 0.5 mg/dL), total bilirubin concentration was positively associated with telomere length (β = 0.23, 95 CI%: 0.14, 0.32, P < 0.001). However, the association between total bilirubin concentration and telomere length was not significant (β = 0.01, 95% CI: -0.01, 0.04, P = 0.346) above the turning point.

Conclusion

This is the first evidence based on a nationally representative survey demonstrating a positive and nonlinear association between total bilirubin concentration and telomere length. Future large-scale prospective studies are warranted to confirm our findings.

A Systematic Review of the Association Between Muscular Fitness and Telomere Length Across the Adult Lifespan

This study aimed to systematically review the association between telomere length (TL) and muscular fitness. In October 2020, an articles search was applied to PubMed, Scopus, and Web of Science. Eligibility criteria included: cross-sectional, prospective, and experimental study design; outcomes included TL; results expressed the relationship between muscular fitness and TL; studies published in English, Portuguese, or Spanish. Nine studies were included in the review. Results from the four prospective studies are mixed. In one study, the changes in TL were associated with grip strength. Another study concluded that longer mid-life TL was associated with increased grip strength later in life. However, in the other two studies, the association between TL and sarcopenia was not strong. Nevertheless, longer TL was associated with a slower decline in grip strength in older people. From the four cross-sectional studies, three indicated that TL was associated with muscular fitness. On the other hand, in a study with powerlifters, TL remained within the range of values found in subjects with no history of regular strength training, supporting the notion that muscular fitness was not associated with TL. The cross-sectional and prospective studies showed that the relationship between TL and muscular fitness is not conclusive. It seems that there is a positive association between TL and muscular fitness in middle-aged and older adults. However, among younger adults, this relationship was not observed.

Midlife Leukocyte Telomere Length as an Indicator for Handgrip Strength in Late Life

BACKGROUND

Telomere attrition has been proposed as a hallmark of aging. We previously reported on the association between blood leukocyte telomere length (LTL) at midlife and risk of chronic diseases and mortality.

METHODS

In this study, we investigated the effect of midlife LTL and genetic proxies on 5 markers of aging outcomes, namely handgrip strength, timed up-and-go (TUG), Singapore-modified Mini-Mental State Examination (SM-MMSE) scores, anxiety, and depression indices, measured after a median 20-year follow-up in the Singapore Chinese Health Study (N = 9581).

RESULTS

We observed a significant association between midlife LTL and handgrip strength later in life (p = .004, padjust = .020), as well as a nominal significant association between midlife LTL and TUG later in life (p = .036, padjust = .180). The weighted Genetic Risk Score (wGRS) comprising 15 previously reported LTL reducing loci in East Asians was not significantly associated with handgrip strength. However, results from Structural Equation Modeling showed that the effect of this wGRS on handgrip strength was mediated through LTL (proportion of wGRS effect on handgrip strength mediated through LTL = 33.3%, p = .010).

CONCLUSIONS

Longer midlife LTL was associated with increased handgrip strength later in life.

Muscle weakness is a prognostic indicator of disability and chronic disease multimorbidity

BACKGROUND

The objective of this study was to use nationally-representative data on Americans greater than 50 years of age to determine the association between grip strength and inflammation as independent predictors of incident disability, chronic multimorbidity and dementia.

METHODS

Middle age and older adults (n = 12,618) from the 2006-2008 waves of the Health and Retirement Study with 8-years of follow-up were included. Longitudinal modeling was performed to examine the association between baseline grip strength (normalized to body mass: NGS) and high sensitivity C-reactive protein (hs-CRP) (≥3.0 mg/L) with incident physical disabilities (i.e., ≥2 limitations to activities of daily living), chronic multimorbidity (≥2 of chronic conditions), and dementia.

RESULTS

The odds of incident disability were 1.25 (95% CI: 1.20-1.30) and 1.31 (95% CI: 1.26-1.36) for men and women respectively, for each 0.05-unit lower NGS. The odds of incident chronic multimorbidity were 1.14 (95% CI: 1.08-1.20) and 1.14 (95% CI: 1.07-1.21) for men and women respectively for each 0.05-unit lower NGS. The odds of incident dementia were 1.10 for men (95% CI: 1.02-1.20) for each 0.05-unit lower NGS, but there was no significant association for women. Elevated hs-CRP was only associated with chronic multimorbidity among men (OR = 1.29; 95% CI: 1.00-1.73) and women (OR = 1.60; 95% CI: 1.26-2.02).

CONCLUSIONS

Our findings indicate a robust inverse association between NGS and disability and chronic, multimorbidity in older men and women, and dementia in men. Elevated hs-CRP was only associated with chronic multimorbidity in men and women. Healthcare providers should implement measures of grip strength in routine health assessments and discuss the potential dangers of weakness as well as interventions to improve strength with their patients.

Black Older Adults in the Age of Biomarkers, Physical Functioning, and Genomics: Heterogeneity, Community Engagement, and Bioethics

There are persistent disparities in all-cause mortality between Blacks and Whites in the United States. Black Americans also carry the greatest burden of morbidity from different diseases of aging including heart disease, stroke, hypertension, type 2 diabetes, and certain types of cancer. Health disparities research, and particularly race/ethnic comparison studies of physical health and aging, have consistently positioned Black health in frameworks of disadvantage, suggesting that regardless of the outcome, Black people are in worse states of health and well-being relative to Whites. Yet, extensive evidence suggests that there is significant within-group variability in the aging process among Black older adults. The use of biological, physical performance, and genomic data in survey settings offer new tools and insights to interrogate heterogeneity in Black health. This chapter examines indicators of biological, physical performance, and genetic markers of aging among a national sample of Black Americans ages 54+ years with the aim of addressing two questions about heterogeneity among Black older adults: (a) How do these measures vary by age and gender among Black older adults? (b) Which indicators predict health and mortality among Black older adults? The results indicate that biological, physical performance, and genomic measures of health, generally, have more variation than simple yes or no measures of a disease, condition, or diagnosis among Black older adults, providing counternarratives to the disadvantage frameworks that dominate characterizations of Black health and aging. However, bioethical challenges limit the utility of biomarkers, physical performance, and genomics measures for Black populations.

The effect of a 12-week resistance training intervention on leukocyte telomere length

Telomere dynamics are an active biological process and positive lifestyle factors such as exercise are proposed to potentiate their length. The aim of this study was to investigate the effect of a low-resistance, high-repetition resistance training intervention on leukocyte telomere length (LTL) and associated health parameters. 23 sedentary middle-aged adults volunteered for this study (16 female/7 male; age = 51.5 ± 4.9 years) and performed two one-hour sessions of Les Mills BODYPUMP™ per week for 12 weeks. Outcome measures were taken at baseline, after the training intervention and at 12-month follow-up. LTL remained unchanged following the training intervention (pre 0.819 ± 0.121 vs post 0.812 ± 0.114, p = 0.420), despite a borderline significant increase in hTERT expression (p = 0.050). Circulating levels of tumour necrosis factor alpha were reduced after the intervention (p = 0.001). At 12-month follow-up, subjects who returned to a sedentary lifestyle (n = 10) displayed shorter telomeres compared to their pre (p = 0.036) values. In conclusion, no changes were observed in LTL following the 12-week training intervention, despite improvements in molecular parameters associated with telomere dynamics. It appears continued long-term exercise (>12 months) is necessary to preserve LTL in previously sedentary individuals.

The role of cellular senescence in ageing and endocrine disease

With the ageing of the global population, interest is growing in the 'geroscience hypothesis', which posits that manipulation of fundamental ageing mechanisms will delay (in parallel) the appearance or severity of multiple chronic, non-communicable diseases, as these diseases share the same underlying risk factor - namely, ageing. In this context, cellular senescence has received considerable attention as a potential target in preventing or treating multiple age-related diseases and increasing healthspan. Here we review mechanisms of cellular senescence and approaches to target this pathway therapeutically using 'senolytic' drugs that kill senescent cells or inhibitors of the senescence-associated secretory phenotype (SASP). Furthermore, we highlight the evidence that cellular senescence has a causative role in multiple diseases associated with ageing. Finally, we focus on the role of cellular senescence in a number of endocrine diseases, including osteoporosis, metabolic syndrome and type 2 diabetes mellitus, as well as other endocrine conditions. Although much remains to be done, considerable preclinical evidence is now leading to the initiation of proof-of-concept clinical trials using senolytics for several endocrine and non-endocrine diseases.

Resistance Training for Older Adults: Position Statement From the National Strength and Conditioning Association

Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res 33(8): 2019-2052, 2019-Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being of older adults. The purpose of this Position Statement is to provide an overview of the current and relevant literature and provide evidence-based recommendations for resistance training for older adults. As presented in this Position Statement, current research has demonstrated that countering muscle disuse through resistance training is a powerful intervention to combat the loss of muscle strength and muscle mass, physiological vulnerability, and their debilitating consequences on physical functioning, mobility, independence, chronic disease management, psychological well-being, quality of life, and healthy life expectancy. This Position Statement provides evidence to support recommendations for successful resistance training in older adults related to 4 parts: (a) program design variables, (b) physiological adaptations, (c) functional benefits, and (d) considerations for frailty, sarcopenia, and other chronic conditions. The goal of this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults.

Nutrition and Muscle Strength, As the Key Component of Sarcopenia: An Overview of Current Evidence

Much has been achieved by recent research to increase understanding of the links between nutrition and muscle health. Focusing on muscle strength as the key component of sarcopenia, the aim of this overview was to evaluate its links to nutrition, both to variation in habitual diets in older populations, as well as considering supplementation effects in trials. A main message from the reviewed studies is that while many provide suggestive evidence of benefits of higher nutrient intakes and diets of higher quality, findings are inconsistent, and data on muscle strength are often lacking. To assess the potential of optimising diets as a strategy to promote and maintain muscle strength, gaps in current evidence need to be addressed. These include the need for (i) better understanding of individual differences in responsiveness to dietary change, and the need for targeted nutritional support; (ii) clearer distinction between protective and therapeutic actions of diet; and (iii) definition of the role of dietary patterns and their influence on muscle strength, to allow effects of changes in food consumption to be evaluated—particularly when combined with physical activity. Development of this evidence is needed to enable translation into appropriate dietary recommendations for older populations.

Meta-inflammaging at the crossroad of geroscience

Geroscience posits that selected fundamental biological processes are the foundation of age-related chronic diseases and are responsible for the decline in physical and mental function in old age. Late-life chronic low-grade inflammation ("inflammaging") and altered signal transduction pathways in metabolism have been identified as two of the key themes in the aging process. Age-related changes in the immune and metabolic responses are also recognized as playing a critical pathogenic role in most common chronic medical conditions that plague the elderly. Emerging investigations emphasize the interconnectedness of the immune and metabolic responses in aging, an area of gerontological research that can be termed "meta-inflammaging."

Acute inflammation is associated with lower muscle strength, muscle mass and functional dependency in male hospitalised older patients

Background

Hospitalisation is associated with adverse health outcomes including loss of muscle strength, muscle mass and functional decline, which might be further aggravated by acute inflammation. This study aimed to determine whether acute inflammation, as denoted by C-reactive protein (CRP), is associated with muscle strength, muscle mass and functional dependency in hospitalised older patients.

Methods

The observational, prospective EMPOWER study included 378 hospitalised patients aged 70 years and older. As part of the hospital assessment, 191 patients (50.5%) had CRP measured. Muscle strength and mass were measured using handheld dynamometry and bioelectrical impedance analysis respectively. Activities of Daily Living (ADL) were assessed using Katz score and Instrumental ADL (IADL) by Lawton and Brody score. Linear regression analyses and logistic regression analyses were performed stratified by sex and adjusted for age and comorbidities.

Results

Mean age was 79.7 years (SD 6.4) and 50.8% were males. On admission and discharge, males with elevated CRP had significantly lower handgrip strength and lower absolute muscle mass compared with males with normal CRP and those with no CRP measured. At three months post-discharge, males with elevated CRP were more likely to be ADL dependent than those with normal CRP and with no CRP measured. In females, no associations were found between CRP and muscle strength, muscle mass, ADL or IADL.

Conclusions

Hospitalised older male patients with acute inflammation had lower muscle strength at admission and discharge and lower absolute muscle mass at admission and higher ADL dependency at three months post-discharge.

Major trauma and acceleration of the ageing process

It is well established that numerous factors can affect the rate at which we age biologically. Diet, physical activity, lifestyle and our genes all play a major role in influencing the ageing trajectory and longevity. Major trauma affects millions globally, is the major cause of death in young adults and could influence ageing processes but has largely been ignored by biogenterologists. The long-term health consequences of physical trauma are well known in the medical community, how trauma effects the ageing process at a molecular level is not. It has long been difficult to assess ageing trajectories due to the absence of a biomarker of biological rather than chronological age. Recent advances in epigenetics have helped by identifying specific DNA methylation sites as good indicators of biological age. Recent investigations into the impact of psychological trauma and the associated physical stress on accelerating ageing as measured by epigenetic drift are promising. The physical and metabolic stress which is synonymous with physical trauma may also accelerate the ageing process. We suggest that long term epigenetic profiling is required to understand to what degree the ageing trajectory is altered by trauma, which will in turn add support for the development of novel therapies to improve health outcomes for survivors of traumatic injury.

The association of sarcopenia, telomere length, and mortality: data from the NHANES 1999-2002

BACKGROUND/OBJECTIVES

Sarcopenia is defined as the loss of muscle mass or function with aging and is associated with adverse outcomes. Telomere shortening is associated with mortality, yet its relationship with sarcopenia is unknown.

SUBJECTS/METHODS

Adults ≥60 years from the 1999-2002 NHANES with body composition measures were identified. Sarcopenia was defined using the two Foundation for the National Institute of Health definitions: appendicular lean mass (ALM) (men <19.75; women <15.02 kg); or ALM divided by body mass index (BMI) (ALM:BMI, men <0.789; women <0.512). Telomere length was assessed using quantitative PCR. Regression models predicted telomere length with sarcopenia (referent = no sarcopenia).

RESULTS

We identified 2672 subjects. Mean age was 70.9 years (55.5% female). Prevalence of ALM and ALM:BMI sarcopenia was 29.2 and 22.1%. Deaths were higher in persons with sarcopenia as compared to those without sarcopenia (ALM: 46.4 vs. 33.4%, p < 0.001; ALM:BMI: 46.7 vs. 33.2%, p < 0.001). No adjusted differences were observed in telomere length in those with/without sarcopenia (ALM: 0.90 vs. 0.92, p = 0.74, ALM:BMI 0.89 vs. 0.92, p = 0.24). In men with ALM:BMI-defined sarcopenia, adjusted telomere length was significantly lower compared to men without sarcopenia (0.85 vs. 0.91, p = 0.013). With sarcopenia, we did not observe a significant association between telomere length and mortality (ALM: HR 1.11 [0.64,1.82], p = 0.68; ALM:BMI: HR 0.97 [0.53,1.77], p = 0.91), but noted significance in those without sarcopenia with mortality (ALM: HR 0.59 [0.40,0.86], p = 0.007; ALM:BMI: HR 0.62 [0.42,0.91]; p = 0.01).

CONCLUSIONS

We observed a potentially inverse relationship between telomere length and mortality in those without sarcopenia but did not observe a significant relationship between telomere length and mortality in the presence of sarcopenia.

Systems Biology in Aging Research

Systems biology is an approach to collect high-dimensional data and analyze in an integrated manner. As aging is a complicated physiological functional decline in biological system, the methods in systems biology could be utilized in aging studies. Here we reviewed recent advances in systems biology in aging research and divide them into two major parts. One is the data resource, which includes omics data from DNA, RNA, proteins, epigenetic changes, metabolisms, and recently single-cell-level variations. The other is the data analysis methods consisting of network and modeling approaches. With all the data and the tools to analyze them, we could further promote our understanding of the systematic aging.

Telomere Length and CCL11 Levels are Associated With Gray Matter Volume and Episodic Memory Performance in Schizophrenia: Evidence of Pathological Accelerated Aging

Schizophrenia (SZ) is associated with increased somatic morbidity and mortality, in addition to cognitive impairments similar to those seen in normal aging, which may suggest that pathological accelerated aging occurs in SZ. Therefore, we aim to evaluate the relationships of age, telomere length (TL), and CCL11 (aging and inflammatory biomarkers, respectively), gray matter (GM) volume and episodic memory performance in individuals with SZ compared to healthy controls (HC). One hundred twelve participants (48 SZ and 64 HC) underwent clinical and memory assessments, structural MRI, and had their peripheral blood drawn for biomarkers analysis. Comparisons of group means and correlations were performed. Participants with SZ had decreased TL and GM volume, increased CCL11, and worse memory performance compared to HC. In SZ, shorter TL was related to increased CCL11, and both biomarkers were related to reduced GM volume, all of which were related to worse memory performance. Older age was only associated with reduced GM, but longer duration of illness was related with all the aforementioned variables. Younger age of disease onset was associated with increased CCL11 levels and worse memory performance. In HC, there were no significant correlations except between memory and GM. Our results are consistent with the hypothesis of accelerated aging in SZ. These results may indicate that it is not age itself, but the impact of the disease associated with a pathological accelerated aging that leads to impaired outcomes in SZ.

Nutritional habits, risk, and progression of Parkinson disease

Parkinson disease (PD) is a multifactorial disease, where a genetic predisposition combines with putative environmental risk factors. Mounting evidence suggests that the initial PD pathological manifestations may be located in the gut to subsequently affect brain areas. Moreover, several lines of research demonstrated that there are bidirectional connections between the central nervous system and the gut, the "gut-brain axis" that influences both brain and gastrointestinal function. This opens a potential therapeutic window suggesting that specific dietary strategies may interact with the disease process and influence the risk of PD or modify its course. Dietary components can also theoretically modulate the chronic activation of the inflammatory response that is associated with aging, the strongest risk factor for PD, that has been suggested to hasten the underlying neurodegenerative process in PD. Here, we reviewed the evidence supporting an association between certain dietary compound and either the risk or progression of PD and have provided an overview of the possible pathomechanisms linking nutrition and neurodegeneration. The results of our review would not support a clear role for any dietary components in reducing the risk or progression of PD. However, the evidence favouring a connection between gut abnormalities, inflammation, and neurodegeneration in PD have become too compelling to be ignored, so that further research, also in the field of nutritional genomics, is highly warranted.

Does nutrition play a role in the prevention and management of sarcopenia?

There is a growing body of evidence that links nutrition to muscle mass, strength and function in older adults, suggesting that it has an important role to play both in the prevention and management of sarcopenia. This review summarises the discussions of a working group [ESCEO working group meeting 8th September 2016] that met to review current evidence and to consider its implications for preventive and treatment strategies. The review points to the importance of 'healthier' dietary patterns that are adequate in quality in older age, to ensure sufficient intakes of protein, vitamin D, antioxidant nutrients and long-chain polyunsaturated fatty acids. In particular, there is substantial evidence to support the roles of dietary protein and physical activity as key anabolic stimuli for muscle protein synthesis. However, much of the evidence is observational and from high-income countries. Further high-quality trials, particularly from more diverse populations, are needed to enable an understanding of dose and duration effects of individual nutrients on function, to elucidate mechanistic links, and to define optimal profiles and patterns of nutrient intake for older adults.

Telomere Shortening, Inflammatory Cytokines, and Anti-Cytomegalovirus Antibody Follow Distinct Age-Associated Trajectories in Humans

A number of biological parameters have been cited as hallmarks of immune aging. However, it is not clear whether these multiple biological changes are the result of common underlying aging processes and follow correlated trajectories, or whether the patterns of change for multiple parameters vary across individuals and reflect heterogeneity in the aging process. Here, we have studied parameters of immune system aging through longitudinal analysis of telomere length, inflammatory cytokines, and antibody titer to cytomegalovirus (CMV) in 465 subjects ranging in age from 21 to 88 years at the first visit, with an average of 13 years (7-19 years) follow-up. We observed a highly variable rate of change in telomere length of PBMCs with a relatively slow average rate of telomere shortening (-16 bp/year). Similarly, there were significant increases with age in vivo in three inflammation-related cytokines (interferon gamma, IL-6, and IL-10) and in anti-CMV IgG titer, which varied widely across individuals as well. We further observed positive correlative changes among different inflammatory cytokines. However, we did not find significant correlations among the rate of changes in telomere length, inflammatory cytokines, and anti-CMV IgG titers. Our findings thus reveal that age-related trajectories of telomere attrition, elevated circulating inflammatory cytokines, and anti-CMV IgG are independent and that aging individuals do not show a uniform pattern of change in these variables. Immune aging processes are complex and vary across individuals, and the use of multiple biomarkers is essential to evaluation of biological aging of the immune system.

Neutrophil and Monocyte Bactericidal Responses to 10 Weeks of Low-Volume High-Intensity Interval or Moderate-Intensity Continuous Training in Sedentary Adults

Neutrophils and monocytes are key components of the innate immune system that undergo age-associated declines in function. This study compared the impact of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on immune function in sedentary adults. Twenty-seven (43 ± 11 years) healthy sedentary adults were randomized into ten weeks of either a HIIT (>90% maximum heart rate) or MICT (70% maximum heart rate) group training program. Aerobic capacity (VO_2peak), neutrophil and monocyte bacterial phagocytosis and oxidative burst, cell surface receptor expression, and systemic inflammation were measured before and after the training. Total exercise time commitment was 57% less for HIIT compared to that for MICT while both significantly improved VO_2peak similarly. Neutrophil phagocytosis and oxidative burst and monocyte phagocytosis and percentage of monocytes producing an oxidative burst were improved by training similarly in both groups. Expression of monocyte but not neutrophil CD16, TLR2, and TLR4 was reduced by training similarly in both groups. No differences in systemic inflammation were observed for training; however, leptin was reduced in the MICT group only. With similar immune-enhancing effects for HIIT compared to those for MICT at 50% of the time commitment, our results support HIIT as a time efficient exercise option to improve neutrophil and monocyte function.

Inflammatory markers, sarcopenia and its diagnostic criteria among the elderly: a systematic review

Abstract Objective: To identify the relationship between inflammatory markers and sarcopenia, and the diagnostic criteria of the condition among the elderly. Methods: A systematic review was performed based on the consultation of the PubMed and LILACS databases. Eligible original articles were those involving individuals aged 60 years or more, which investigated sarcopenia [low muscle mass (MM) associated with poor muscle strength and/or reduced physical performance, according to the European Working Group on Sarcopenia in Older People consensus (EWGSOP)] or its diagnostic criteria, published in English or Portuguese, between 2010-2015. Results: Four articles were included in the review, the principle results of which were: the growth differentiation factor (GDF-15) exhibited a negative correlation with MM, handgrip strength and gait speed; the insulin-like growth factor-1 (IGF-1) correlated positively with MM; follistatin exhibited a weak correlation with physical performance; activin A and myostatin did not correlate with the diagnostic criteria; the highest tercile of extracellular heat shock protein 72 (eHsp72) was associated with lower median levels of MM, handgrip strength and gait speed; elderly persons with low MM had higher serum ferritin concentrations; women with low MM exhibited lower serum concentration levels of C-reactive protein (CRP). Conclusion: the six investigated inflammatory markers (GDF-15, IGF-1, follistatin, eHsp72, ferritin and CRP) were associated with the diagnostic criteria for sarcopenia, but not with sarcopenia itself. As research in this area is still developing, additional studies are required to broaden knowledge and eventually establish the role of these markers in the diagnosis and management of sarcopenia.

Associations of Leukocyte Telomere Length With Aerobic and Muscular Fitness in Young Adults

Decline in both telomere length and physical fitness over the life course may contribute to increased risk of several chronic diseases. The relationship between telomere length and aerobic and muscular fitness is not well characterized. We examined whether there are cross-sectional associations of mean relative leukocyte telomere length (LTL) with objective measures of aerobic fitness, muscle strength, and muscle endurance, using data on 31-year-old participants of the Northern Finland Birth Cohort 1966 (n = 4,952–5,205, varying by exposure-outcome analysis). Aerobic fitness was assessed by means of heart rate measurement following a standardized submaximal step test; muscular fitness was assessed by means of a maximal isometric handgrip strength test and a test of lower-back trunk muscle endurance. Longer LTL was associated with higher aerobic fitness and better trunk muscle endurance in models including adjustment for age, sex, body mass index, socioeconomic position, diet, smoking, alcohol consumption, physical activity level, and C-reactive protein. In a sex-stratified analysis, LTL was not associated with handgrip strength in either men or women. LTL may relate to aspects of physical fitness in young adulthood, but replication of these findings is required, along with further studies to help assess directions and causality in these associations.

Depressive and anxiety disorders and short leukocyte telomere length: mediating effects of metabolic stress and lifestyle factors

BACKGROUND

Depressive and anxiety disorders are associated with shorter leukocyte telomere length (LTL), an indicator of cellular aging. It is, however, unknown which pathways underlie this association. This study examined the extent to which lifestyle factors and physiological changes such as inflammatory or metabolic alterations mediate the relationship.

METHOD

We applied mediation analysis techniques to data from 2750 participants of the Netherlands Study of Depression and Anxiety. LTL was assessed using quantitative polymerase chain reaction. Independent variables were current depressive (30-item Inventory of Depressive Symptoms - Self Report) and anxiety (21-item Beck's Anxiety Inventory) symptoms and presence of a depressive or anxiety disorder diagnosis based on DSM-IV; mediator variables included physiological stress systems, metabolic syndrome components and lifestyle factors.

RESULTS

Short LTL was associated with higher symptom severity (B = -2.4, p = 0.002) and current psychiatric diagnosis (B = -63.3, p = 0.024). C-reactive protein, interleukin-6, waist circumference, triglycerides, high-density lipoprotein cholesterol and cigarette smoking were significant mediators in the relationship between psychopathology and LTL. When all significant mediators were included in one model, the effect sizes of the relationships between LTL and symptom severity and current diagnosis were reduced by 36.7 and 32.7%, respectively, and the remaining direct effects were no longer significant.

CONCLUSIONS

Pro-inflammatory cytokines, metabolic alterations and cigarette smoking are important mediators of the association between depressive and anxiety disorders and LTL. This calls for future research on intervention programs that take into account lifestyle changes in mental health care settings.

Higher Daily Physical Activities Continue to Preserve Muscle Strength After Mid-Life, But Not Muscle Mass After Age of 75

The objective of this study is to explore the impact of aging and daily physical activities (PA) on muscle mass and muscle strength among community-dwelling people in Taiwan.The design is a cross-sectional study. Setting is a population-based community study.One thousand eight hundred thirty-nine community-dwelling people aged 50 years and older in Taiwan participated in the study.Measurements include demographic characteristics, Charlson Comorbidity Index (CCI) for multimorbidity, mini-nutritional assessment (MNA) for nutritional evaluation, functional autonomy measurement system (SMAF) for functional capacity, Chinese version mini mental state examination (MMSE), 5-item Taiwan Geriatric Depression Scale (TGDS-5), Chinese version of International Physical Activity Questionnaire (IPAQ), height-adjusted skeletal muscle index (SMI) by dual-energy X-ray absorptiometry, handgrip strength, timed 6-m walking test for usual gait speed. Laboratory measurements include testosterone, sex-hormone binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEA-S), insulin-like growth factor-1 (IGF-1), high-sensitivity C-reactive protein (hsCRP), 25-OH vitamin D, and insulin resistance.After adjusted for age, the lowest PA tertile was associated with multimorbidity, poorer functional capacity and nutritional status, more depressive symptoms, lower SMI and lower handgrip strength, and lower free androgen index (FAI) in men. The negative association between PA and low SMI was more significant among subjects aged younger than 65 and the association decreased with older age. For subjects aged younger than 65, moderate daily PA (Q2) group had lower risk of low SMI compared with Q1 participants (OR: 0.62, 95% CI = 0.39-0.98, P = 0.040). For muscle strength, higher daily PA was associated with lower risk of low handgrip strength after age of 65 and the effect was dose-dependent. The effect was attenuated by potential confounders during age 65 to 74, while after age 75, the result was almost unchanged in fully adjusted model (OR = 0.37, 95% CI = 0.18-0.79, P = 0.010).Older age may attenuate the protective effects of higher daily PA on preventing muscle loss, but higher daily PA continues to preserve muscle strength at different age groups, even after the age of 75. The prognostic role of daily PA may be mediated by muscle strength instead of muscle mass among people aged 75 years and older.

Baseline biopsychosocial determinants of telomere length and 6-year attrition rate

BACKGROUND

Short leukocyte telomere length (TL) and accelerated telomere attrition have been associated with various deleterious health outcomes, although their determinants have not been explored collectively in a large-scale study.

MATERIAL AND METHODS

Leukocyte TL was measured (baseline N=2936; 6-year follow-up N=1860) in participants (18-65 years) from the NESDA study. Baseline determinants of TL included sociodemographics, lifestyle, chronic diseases, psychosocial stressors, and metabolic and physiological stress markers. Multivariate linear regression models were used to examine the associations between these determinants and (1) baseline TL, and (2) 6-year TL change. Multinomial logistic regression analyses were used to examine the predictors of telomere attrition and lengthening, as compared to stable TL.

RESULTS

Short baseline TL was associated with older age, male sex, non-European ethnicity, cigarette smoking, recent life events, and higher triglycerides, glucose and pre-ejection period (R(2)=11.3%). The 6-year telomere attrition was inversely associated with baseline TL (R(2)=51.6%); also older age, long sleep, not having a partner, high childhood trauma index, and gastrointestinal disease were associated with 6-year TL attrition (additional R(2)=3.7%). Telomere attrition seemed to have slightly more predictors than lengthening.

CONCLUSIONS

Sociodemographic, lifestyle, psychosocial stress and metabolic and physiological stress factors are cross-sectionally linked with TL. Telomere attrition over six years was strongly associated with baseline TL, suggesting an internal homeostatic influence. Modulation of the identified determinants may become target of future studies to promote telomere maintenance and healthy aging.

Nutrition and Inflammation in Older Individuals: Focus on Vitamin D, n-3 Polyunsaturated Fatty Acids and Whey Proteins

Chronic activation of the inflammatory response, defined as inflammaging, is the key physio-pathological substrate for anabolic resistance, sarcopenia and frailty in older individuals. Nutrients can theoretically modulate this phenomenon. The underlying molecular mechanisms reducing the synthesis of pro-inflammatory mediators have been elucidated, particularly for vitamin D, n-3 polyunsaturated fatty acids (PUFA) and whey proteins. In this paper, we review the current evidence emerging from observational and intervention studies, performed in older individuals, either community-dwelling or hospitalized with acute disease, and evaluating the effects of intake of vitamin D, n-3 PUFA and whey proteins on inflammatory markers, such as C-Reactive Protein (CRP), interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α). After the analysis, we conclude that there is sufficient evidence for an anti-inflammatory effect in aging only for n-3 PUFA intake, while the few existing intervention studies do not support a similar activity for vitamin D and whey supplements. There is need in the future of large, high-quality studies testing the effects of combined dietary interventions including the above mentioned nutrients on inflammation and health-related outcomes.

Longitudinal telomere length shortening and cognitive and physical decline in later life: The Lothian Birth Cohorts 1936 and 1921

Telomere length is hypothesised to be a biological marker of both cognitive and physical ageing. Here we measure telomere length, and cognitive and physical abilities at mean ages 70, 73 and 76 years in the Lothian Birth Cohort 1936 (LBC1936), and at mean ages 79, 87, 90 and 92 years in the Lothian Birth Cohort 1921 (LBC1921). We investigate whether telomere length change predicts change in cognitive and physical abilities. In LBC1936 telomere length decreased by an average of 65 base pairs per year and in LBC1921 by 69 base pairs per year. However, change in telomere length did not predict change in cognitive or physical abilities. This study shows that, although cognitive ability, walking speed, lung function and grip strength all decline with age, they do so independently of telomere length shortening.

Longer telomeres in chronic, moderate, unconjugated hyperbilirubinaemia: insights from a human study on Gilbert's Syndrome

Bilirubin (BR) is a natural endogenous compound with a potent bioactivity. Gilbert’s Syndrome (GS) is a benign hereditary condition of increased unconjugated bilirubin (UCB) in serum and serves as a convenient model for studying the effects of BR in humans. In absence of liver disease, increased UCB levels are inversely associated to all-cause mortality risk, especially from cardiovascular diseases (CVDs). On the other hand, telomere malfunction is linked to a higher risk of CVDs. To our knowledge, there is no data on whether UCB is linked to telomere length in healthy or diseased individuals In the present study we have observed a relationship between mildly increased serum UCB and telomere length. We used an in vivo approach, assessing telomere length in PBMCs from individuals with GS (n = 60) and matched healthy controls (n = 60). An occurrence of longer telomeres was observed in male individuals chronically exposed to increased UCB, as well as in Gunn rats, an animal model of unconjugated hyperbilirubinaemia. Previously identified differences in immunomodulation and redox parameters in individuals with GS, such as IL-6, IL-1β and ferric reducing ability of plasma, were confirmed and proposed as possible contributors to the occurrence of longer telomeres in GS.

Gene transcripts associated with muscle strength: a CHARGE meta-analysis of 7,781 persons

Lower muscle strength in midlife predicts disability and mortality in later life. Blood-borne factors, including growth differentiation factor 11 (GDF11), have been linked to muscle regeneration in animal models. We aimed to identify gene transcripts associated with muscle strength in adults. Meta-analysis of whole blood gene expression (overall 17,534 unique genes measured by microarray) and hand-grip strength in four independent cohorts (n = 7,781, ages: 20-104 yr, weighted mean = 56), adjusted for age, sex, height, weight, and leukocyte subtypes. Separate analyses were performed in subsets (older/younger than 60, men/women). Expression levels of 221 genes were associated with strength after adjustment for cofactors and for multiple statistical testing, including ALAS2 (rate-limiting enzyme in heme synthesis), PRF1 (perforin, a cytotoxic protein associated with inflammation), IGF1R, and IGF2BP2 (both insulin like growth factor related). We identified statistical enrichment for hemoglobin biosynthesis, innate immune activation, and the stress response. Ten genes were associated only in younger individuals, four in men only and one in women only. For example, PIK3R2 (a negative regulator of PI3K/AKT growth pathway) was negatively associated with muscle strength in younger (<60 yr) individuals but not older (≥ 60 yr). We also show that 115 genes (52%) have not previously been linked to muscle in NCBI PubMed abstracts. This first large-scale transcriptome study of muscle strength in human adults confirmed associations with known pathways and provides new evidence for over half of the genes identified. There may be age- and sex-specific gene expression signatures in blood for muscle strength.

Leukocyte telomere length is related to appendicular lean mass: cross-sectional data from the Berlin Aging Study II (BASE-II)

BACKGROUND

Age-related progressive loss of muscle mass is an increasing problem in our aging society, affecting physical ability, risk of falls, and need for health care. Telomere length has been recognized as a marker of biological age on the population level. The relation between muscle mass in advanced age and telomere length, however, has rarely been examined.

OBJECTIVE

We evaluated the relation between appendicular lean mass (ALM) and relative leukocyte telomere length (rLTL) in 1398 participants of the Berlin Aging Study II (mean ± SD age: 68.2 ± 3.7 y; 49.6% men).

DESIGN

rLTL was determined by real-time polymerase chain reaction. Lean mass was estimated by dual X-ray absorptiometry and examined as leg lean mass (LLM), ALM, and the ratio of ALM to body mass index (ALMBMI).

RESULTS

Weak, but highly significant (P < 0.001), correlations of rLTL with ALM (r = 0.248), ALMBMI (r = 0.254), and LLM (r = 0.263) were found. In the fully adjusted model that included age, BMI, low-grade inflammation, lifestyle factors, and morbidities as potential confounders, rLTL was associated with ALM (β = 1.11, SEM = 0.46, P = 0.017), LLM (β = 1.20, SEM = 0.36, P = 0.001), and ALMBMI (β = 0.04, SEM = 0.02, P = 0.013) in men and with LLM in women (β = 0.78, SEM = 0.35, P = 0.026).

CONCLUSIONS

Our results suggest that short telomeres may be a risk factor for lower ALM, particularly for low LLM. To confirm the association between telomere attrition and loss of LLM and ALMBMI, which are highly relevant for physical ability, further research in a longitudinal context is needed. The medical portion of this trial was registered in the German Clinical Trials Registry (http://drks-neu.uniklinik-freiburg.de/drks_web/navigate.do?navigationId=start) as DRKS00009277.

Integration of 'omics' data in aging research: from biomarkers to systems biology

Age is the strongest risk factor for many diseases including neurodegenerative disorders, coronary heart disease, type 2 diabetes and cancer. Due to increasing life expectancy and low birth rates, the incidence of age-related diseases is increasing in industrialized countries. Therefore, understanding the relationship between diseases and aging and facilitating healthy aging are major goals in medical research. In the last decades, the dimension of biological data has drastically increased with high-throughput technologies now measuring thousands of (epi) genetic, expression and metabolic variables. The most common and so far successful approach to the analysis of these data is the so-called reductionist approach. It consists of separately testing each variable for association with the phenotype of interest such as age or age-related disease. However, a large portion of the observed phenotypic variance remains unexplained and a comprehensive understanding of most complex phenotypes is lacking. Systems biology aims to integrate data from different experiments to gain an understanding of the system as a whole rather than focusing on individual factors. It thus allows deeper insights into the mechanisms of complex traits, which are caused by the joint influence of several, interacting changes in the biological system. In this review, we look at the current progress of applying omics technologies to identify biomarkers of aging. We then survey existing systems biology approaches that allow for an integration of different types of data and highlight the need for further developments in this area to improve epidemiologic investigations.

No strong correlations between serum cytokine levels, CMV serostatus and hand-grip strength in older subjects in the Berlin BASE-II cohort

Hand-grip strength is strongly correlated with measures of muscle mass and can be taken to predict morbidity and mortality. The aim of this study was to investigate the relationship between hand-grip strength and other markers associated with immune ageing, such as Cytomegalovirus (CMV) infection, leukocyte telomere length and serum levels of inflammatory and anti-inflammatory markers in the elderly. We have assessed grip strength with the Smedley Dynamometer in younger (22-37 years) and older (60-85 years) men and women in a sample of people living in Berlin (the BASE-II study). Serum cytokine levels were determined by flow-cytometry, CMV serostatus via ELISA and leukocyte telomere length by quantitative PCR. IL-1β levels tended to be negatively associated with grip strength, but we did not find a significant association with IL-6 levels. CMV-seropositivity was not associated with higher levels of IL-1β, IL-6 or TNF, nor with weaker grip strength in men or women at any age. A putative general measure of organismal ageing, overall leukocyte telomere length, was also found not to be associated with lower grip strength in the elderly. Hand-grip strength remains an important biomarker independent of CMV infection or shorter telomere lengths, and poorly reflected in peripheral pro-inflammatory cytokine levels, all of which have been associated in some studies with frailty and mortality.