Adiponectin levels and genotype: a potential regulator of life span in humans

Effects of obesogenic diet and 17β-estradiol in female mice with APOE 3/3, 3/4, and 4/4 genotypes

The main genetic risk factor for Alzheimer's disease (AD) is the apolipoprotein E ε4 allele (APOE4). AD risk associated with APOE4 disproportionately affects women. Furthermore, human and rodent studies indicate that the cognitive deficits associated with APOE4 are greater in females. One modifiable AD risk factor is obesity during middle age. Given that approximately two-thirds of US adults are overweight, it is important to understand how obesity affects AD risk, how it interacts with APOE4, and the extent to which its detrimental effects can be mitigated with therapeutics. One intervention study for women is estrogen-based hormone therapy, which can exert numerous health benefits when administered in early middle age. No experimental studies have examined the interactions among APOE4, obesity, and hormone therapy in aging females. To begin to explore these issues, we considered how obesity outcomes are affected by treatment with estradiol at the onset of middle age in female mice with human APOE3 and APOE4. Furthermore, to explore how gene dosage affects outcomes, we compared mice homozygous for APOE3 (3/3) and homozygous (4/4) or hemizygous (3/4) for APOE4. Mice were examined over a 4-month period that spans the transition into reproductive senescence, a normal age-related change that models many aspects of human perimenopause. Beginning at 5 months of age, mice were maintained on a control diet (10% fat) or high-fat diet (HFD; 60% fat). After 8 weeks, by which time obesity was present in all HFD groups, mice were implanted with an estradiol or vehicle capsule that was maintained for the final 8 weeks. Animals were assessed on a range of metabolic and neural measures. Overall, APOE4 was associated with poorer metabolic function and cognitive performance. However, an obesogenic diet induced relatively greater impairments in metabolic function and cognitive performance in APOE3/3 mice. Estradiol treatment improved metabolic and cognitive outcomes across all HFD groups, with APOE4/4 generally exhibiting the greatest benefit. APOE3/4 mice were intermediate to the homozygous genotypes on many measures but also exhibited unique profiles. Together, these findings highlight the importance of the APOE genotype as a modulator of the risks associated with obesity and the beneficial outcomes of estradiol.

Oxidative stress and regulation of adipogenic differentiation capacity by sirtuins in adipose stem cells derived from female patients of advancing age

Patient age is critical for mesenchymal stem cell quality and differentiation capacity. We demonstrate that proliferation and adipogenic capacity of subcutaneous adipose stem cells (ASCs) from female patients declined with advanced age, associated with reduction in cell nucleus size, increase in nuclear lamina protein lamin B1/B2, and lamin A, upregulation of senescence marker p16INK4a and senescence-associated β-galactosidase activity. Adipogenic induction resulted in differentiation of adipocytes and upregulation of adipogenic genes CCAAT enhancer binding protein alpha, fatty acid binding protein 4, lipoprotein lipase, and peroxisome proliferator-activated receptor-γ, which was not affected by the Sirt-1 activator YK-3-237 or the Sirt-1 inhibitor EX-527. Protein expression of the stem cell markers Oct4 and Sox2 was not significantly downregulated with advanced patient age. Mitochondrial reactive oxygen species were increased in ASCs from old-aged patients, whereas protein expression of NADPH oxidases NOX1 and NOX4 was downregulated, and dual oxidase isoforms remained unchanged. Generation of nitric oxide and iNOS expression was downregulated. Protein expression of Sirt-1 and Sirt-3 decreased with patient age, whereas Sirt-2 and Sirt-5 remained unchanged. Induction of adipogenesis stimulated protein expression of Sirt-1 and Sirt-3, which was not affected upon pre-incubation with the Sirt-1-activator YK-3-237 or the Sirt-1-inhibitor EX-527. The Sirt-1 inhibitor Sirtinol downregulated adiponectin protein expression and the number of adipocytes, whereas YK-3-237 exerted stimulatory effects. In summary, our data demonstrate increased oxidative stress in ASCs of aging patients, and decline of adipogenic capacity due to Sirt-1- mediated adiponectin downregulation in elderly patients.

AMPK: The energy sensor at the crossroads of aging and cancer

AMP-activated protein kinase (AMPK) is a protein kinase that plays versatile roles in response to a variety of physiological stresses, including glucose deprivation, hypoxia, and ischemia. As a kinase with pleiotropic functions, it plays a complex role in tumor progression, exhibiting both tumor-promoting and tumor-suppressing activities. On one hand, AMPK enhances cancer cell proliferation and survival, promotes cancer metastasis, and impairs anti-tumor immunity. On the other hand, AMPK inhibits cancer cell growth and survival and stimulates immune responses in a context-dependent manner. Apart from these functions, AMPK plays a key role in orchestrating aging and aging-related disorders, including cardiovascular diseases (CVD), Osteoarthritis (OA), and Diabetes. In this review article, we summarized the functions of AMPK pathway based on its oncogenic and tumor-suppressive roles and highlighted the importance of AMPK pathway in regulating cellular aging. We also spotlighted the significant role of various signaling pathways, activators, and inhibitors of AMPK in serving as therapeutic strategies for anti-cancer and anti-aging therapy.

Inflammation-mediated metabolic regulation in adipose tissue

Chronic inflammation of adipose tissue is a prominent characteristic of many metabolic diseases. Lipid metabolism in adipose tissue is consistently dysregulated during inflammation, which is characterized by substantial infiltration by proinflammatory cells and high cytokine concentrations. Adipose tissue inflammation is caused by a variety of endogenous factors, such as mitochondrial dysfunction, reactive oxygen species (ROS) production, endoplasmic reticulum (ER) stress, cellular senescence, ceramides biosynthesis and mediators of lipopolysaccharides (LPS) signaling. Additionally, the gut microbiota also plays a crucial role in regulating adipose tissue inflammation. Essentially, adipose tissue inflammation arises from an imbalance in adipocyte metabolism and the regulation of immune cells. Specific inflammatory signals, including nuclear factor-κB (NF-κB) signaling, inflammasome signaling and inflammation-mediated autophagy, have been shown to be involved in the metabolic regulation. The pathogenesis of metabolic diseases characterized by chronic inflammation (obesity, insulin resistance, atherosclerosis and nonalcoholic fatty liver disease [NAFLD]) and recent research regarding potential therapeutic targets for these conditions are also discussed in this review.

Reevaluating Adiponectin's impact on obesity hypertension: a Chinese case-control study

BACKGROUND

Obesity and hypertension are major risk factors for cardiovascular diseases that affect millions of people worldwide. Both conditions are associated with chronic low-grade inflammation, which is mediated by adipokines such as adiponectin. Adiponectin is the most abundant adipokine that has a beneficial impact on metabolic and vascular biology, while high serum concentrations are associated with some syndromes. This "adiponectin paradox" still needs to be clarified in obesity-associated hypertension. The aim of this study was to investigate how adiponectin affects blood pressure, inflammation, and metabolic function in obesity hypertension using a Chinese adult case-control study.

METHODS

A case-control study that had finished recruiting 153 subjects divided as four characteristic groups. Adiponectin serum levels were tested by ELISA in these subjects among these four characteristic Chinese adult physical examination groups. Waist circumference (WC), body mass index (BMI), systolic blood pressure (SB), diastolic blood pressure (DB), and other clinical laboratory data were collected. Analyzation of correlations between the research index and differences between groups was done by SPSS.

RESULTS

Serum adiponectin levels in the| normal healthy group (NH group) were significantly higher than those in the newly diagnosed untreated just-obesity group (JO group), and negatively correlated with the visceral adiposity index. With multiple linear egression analysis, it was found that, for serum adiponectin, gender, serum albumin (ALB), alanine aminotransferase (ALT) and high-density lipoprotein cholesterol (HDLC) were the significant independent correlates, and for SB, age and HDLC were the significant independent correlates, and for DB, alkaline phosphatase (ALP) was the significant independent correlate. The other variables did not reach significance in the model.

CONCLUSIONS

Our study reveals that adiponectin's role in obesity-hypertension is multifaceted and is influenced by the systemic metabolic homeostasis signaling axis. In obesity-related hypertension, compensatory effects, adiponectin resistance, and reduced adiponectin clearance from impaired kidneys and liver all contribute to the "adiponectin paradox".

Association between serum Klotho concentration and hyperlipidemia in adults: a cross-sectional study from NHANES 2007-2016

Objective

The Klotho protein is a well-documented anti-aging protein known for its diverse biological functions. Hyperlipidemia is an established independent risk factor for various chronic diseases. However, there is limited understanding of the connection between Klotho and hyperlipidemia. The aim was to assess the association between serum Klotho levels and hyperlipidemia among adults.

Methods

The study included 11,618 individuals from the NHANES database from 2006 to 2017. Hyperlipidemia was diagnosed following the National Cholesterol Education Program guidelines. Serum Klotho concentration was measured by an enzyme-linked immunosorbent assay kit, and the association between Klotho and hyperlipidemia was assessed by a multivariable logistic regression model. Fitted smoothing curves and threshold-effect analysis were employed to describe nonlinear relationships.

Results

In our multiple logistic regression models, serum Klotho concentration was significantly associated with hyperlipidemia after adjusting for comprehensive confounders (per SD increment odds ratio (OR): 0.91; 95% confidence interval (CI): 0.86-0.97). Compared to individuals in the lowest Klotho quartile, those in the highest quartile exhibited a substantially decreased prevalence of hyperlipidemia (OR: 0.72; 95% CI: 0.58-0.90). Using a two-segment logistic regression model, we identified a U-shaped relationship between serum Klotho concentration and hyperlipidemia, with an inflection point at 1,365.5 pg/mL. Subgroup analysis did not reveal any potential moderating effects.

Conclusion

This study revealed an inverse relationship between Klotho levels and hyperlipidemia. Further investigation is warranted to explore the underlying mechanism between serum Klotho and hyperlipidemia.

Discovering Biological Mechanisms of Exceptional Human Health Span and Life Span

Humans age at different rates and families with exceptional longevity provide an opportunity to understand why some people age slower than others. Unique features exhibited by centenarians include a family history of extended life span, compression of morbidity with resultant extension of health span, and longevity-associated biomarker profiles. These biomarkers, including low-circulating insulin-like growth factor 1 (IGF-1) and elevated high-density lipoprotein (HDL) cholesterol levels, are associated with functional genotypes that are enriched in centenarians, suggesting that they may be causative for longevity. While not all genetic discoveries from centenarians have been validated, in part due to exceptional life span being a rare phenotype in the general population, the APOE2 and FOXO3a genotypes have been confirmed in a number of populations with exceptional longevity. However, life span is now recognized as a complex trait and genetic research methods to study longevity are rapidly extending beyond classical Mendelian genetics to polygenic inheritance methodologies. Moreover, newer approaches are suggesting that pathways that have been recognized for decades to control life span in animals may also regulate life span in humans. These discoveries led to strategic development of therapeutics that may delay aging and prolong health span.

Mechanism associated with changes in male reproductive functions during ageing process

Ageing is a natural process with physiological changes in different body parts and has been associated with decreased reproductive capacity. Factors such as imbalance in the antioxidant defence system, vascular diseases, diabetes mellitus, accessory reproductive glands infection, obesity as well as buildup of toxic substances play a role in age-related male reproductive malfunction. Age is inversely proportional to volume of semen, sperm count, sperm progressive motility, sperm viability, normal sperm morphology. The observed negative correlation between ageing and semen indices contributes to male infertility and reproductive decline. Normal levels of ROS, plays crucial role in facilitating sperm function, such as capacitation, hyper-activation, acrosome reaction as well as sperm-oocyte fusion; however, a substantial elevation in the endogenous level of ROS, especially in reproductive tissues, usually instigates destruction of sperm cells and heightened male infertility. Contrarily, antioxidants, such as vitamins C and E, beta-carotene, and micronutrients like zinc and folate, have been found by researchers to facilitate normal semen quality and male reproductive function. Furthermore, the role of hormonal imbalance as a result of the compromised hypothalamic-pituitary-gonadal axis, Sertoli and Leydig cells disorder, and nitric oxide-medicated erectile dysfunction during ageing cannot be undermined.

The Transcriptomic Landscape of Age-Induced Changes in Human Visceral Fat and the Predicted Omentum-Liver Connectome in Males

Aging causes alterations in body composition. Specifically, visceral fat mass increases with age and is associated with age-related diseases. The pathogenic potential of visceral fat accumulation has been associated with its anatomical location and metabolic activity. Visceral fat may control systemic metabolism by secreting molecules that act in distal tissues, mainly the liver, through the portal vein. Currently, little is known about age-related changes in visceral fat in humans. Aiming to identify molecular and cellular changes occurring with aging in the visceral fat of humans, we analyzed publicly available transcriptomic data of 355 omentum samples from the Genotype-Tissue Expression portal (GTEx) of 20-79-year-old males and females. We identified the functional enrichment of genes associated with aging, inferred age-related changes in visceral fat cellularity by deconvolution analysis, profiled the senescence-associated secretory phenotype of visceral adipose tissue, and predicted the connectivity of the age-induced visceral fat secretome with the liver. We demonstrate that age induces alterations in visceral fat cellularity, synchronous to changes in metabolic pathways and a shift toward a pro-inflammatory secretory phenotype. Furthermore, our approach identified candidates such as ADIPOQ-ADIPOR1/ADIPOR2, FCN2-LPR1, and TF-TFR2 to mediate visceral fat-liver crosstalk in the context of aging. These findings cast light on how alterations in visceral fat with aging contribute to liver dysfunction and age-related disease etiology.

Brown adipose tissue is not associated with cachexia or increased mortality in a retrospective study of patients with cancer

Although brown fat is strongly associated with a constellation of cardiometabolic benefits in animal models and humans, it has also been tied to cancer cachexia. In humans, cancer-associated cachexia increases mortality, raising the possibility that brown fat in this context may be associated with increased cancer death. However, the effect of brown fat on cancer-associated cachexia and survival in humans remains unclear. Here, we retrospectively identify patients with and without brown fat on fluorodeoxyglucose (18F-FDG) positron-emission tomography (PET) scans obtained as part of routine cancer care and assemble a cohort to address these questions. We did not find an association between brown fat status and cachexia. Furthermore, we did not observe an association between brown fat and increased mortality in patients with cachexia. Our analyses controlled for confounding factors including age at cancer diagnosis, sex, body mass index, cancer site, cancer stage, outdoor temperature, comorbid conditions (heart failure, type 2 diabetes mellitus, coronary artery disease, hypertension, dyslipidemia, cerebrovascular disease), and β-blocker use. Taken together, our results suggest that brown fat is not linked to cancer-associated cachexia and does not worsen overall survival in patients with cachexia.NEW & NOTEWORTHY This study finds that brown fat is not linked to cancer-associated cachexia. Moreover, this work shows that brown fat does not worsen overall survival in patients with cachexia.

Biochemical Markers of Musculoskeletal Health and Aging to be Assessed in Clinical Trials of Drugs Aiming at the Treatment of Sarcopenia: Consensus Paper from an Expert Group Meeting Organized by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) and the Centre Académique de Recherche et d'Expérimentation en Santé (CARES SPRL), Under the Auspices of the World Health Organization Collaborating Center for the Epidemiology of Musculoskeletal Conditions and Aging

In clinical trials, biochemical markers provide useful information on the drug's mode of action, therapeutic response and side effect monitoring and can act as surrogate endpoints. In pharmacological intervention development for sarcopenia management, there is an urgent need to identify biomarkers to measure in clinical trials and that could be used in the future in clinical practice. The objective of the current consensus paper is to provide a clear list of biochemical markers of musculoskeletal health and aging that can be recommended to be measured in Phase II and Phase III clinical trials evaluating new chemical entities for sarcopenia treatment. A working group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) proposed classifying biochemical markers into 2 series: biochemical markers evaluating musculoskeletal status and biochemical markers evaluating causal factors. For series 1, the group agreed on 4 biochemical markers that should be assessed in Phase II or Phase III trials (i.e., Myostatin-Follistatin, Brain Derived Neurotrophic Factor, N-terminal Type III Procollagen and Serum Creatinine to Serum Cystatin C Ratio - or the Sarcopenia Index). For series 2, the group agreed on 6 biochemical markers that should be assessed in Phase II trials (i.e., the hormones insulin-like growth factor-1 (IGF-I), dehydroepiandrosterone sulphate, and cortisol, and the inflammatory markers C-reactive protein (CRP), interleukin-6 and tumor necrosis factor-α), and 2 in Phase III trials (i.e., IGF-I and CRP). The group also proposed optional biochemical markers that may provide insights into the mode of action of pharmacological therapies. Further research and development of new methods for biochemical marker assays may lead to the evolution of these recommendations.

High polygenic risk score for exceptional longevity is associated with a healthy metabolic profile

Healthy metabolic measures in humans are associated with longevity. Dysregulation leads to metabolic syndrome (MetS) and negative health outcomes. Recent exceptional longevity (EL) genome wide association studies have facilitated estimation of an individual's polygenic risk score (PRS) for EL. We tested the hypothesis that individuals with high ELPRS have a low prevalence of MetS. Participants were from five cohorts of middle-aged to older adults. The primary analyses were performed in the UK Biobank (UKBB) (n = 407,800, 40-69 years). Replication analyses were undertaken using three Australian studies: Hunter Community Study (n = 2122, 55-85 years), Older Australian Twins Study (n = 539, 65-90 years) and Sydney Memory and Ageing Study (n = 925, 70-90 years), as well as the Swedish Gothenburg H70 Birth Cohort Studies (n = 2273, 70-93 years). MetS was defined using established criteria. Regressions and meta-analyses were performed with the ELPRS and MetS and its components. Generally, MetS prevalence (22-30%) was higher in the older cohorts. In the UKBB, high EL polygenic risk was associated with lower MetS prevalence (OR = 0.94, p = 1.84 × 10^-42) and its components (p < 2.30 × 10^-8). Meta-analyses of the replication cohorts showed nominal associations with MetS (p = 0.028) and 3 MetS components (p < 0.05). This work suggests individuals with a high polygenic risk for EL have a healthy metabolic profile promoting longevity.

Health effects of voluntary exposure to cold water - a continuing subject of debate

This review is based on a multiple database survey on published literature to determine the effects on health following voluntary exposure to cold-water immersion (CWI) in humans. After a filtering process 104 studies were regarded relevant. Many studies demonstrated significant effects of CWI on various physiological and biochemical parameters. Although some studies were based on established winter swimmers, many were performed on subjects with no previous winter swimming experience or in subjects not involving cold-water swimming, for example, CWI as a post-exercise treatment. Clear conclusions from most studies were hampered by the fact that they were carried out in small groups, often of one gender and with differences in exposure temperature and salt composition of the water. CWI seems to reduce and/or transform body adipose tissue, as well as reduce insulin resistance and improve insulin sensitivity. This may have a protective effect against cardiovascular, obesity and other metabolic diseases and could have prophylactic health effects. Whether winter swimmers as a group are naturally healthier is unclear. Some of the studies indicate that voluntary exposure to cold water has some beneficial health effects. However, without further conclusive studies, the topic will continue to be a subject of debate.

Adipose Tissue Plasticity in Aging

As a dynamic endocrine organ, white adipose tissue (WAT) stores lipids and plays a critical role in maintaining whole-body energy homeostasis and insulin sensitivity. A large group of the population over 65 years old suffer from increased WAT mass, especially in the visceral location. Visceral adiposity accelerates aging through promoting age-associated chronic conditions, significantly shortening life expectancy. Unlike WAT, brown adipose tissue (BAT) functions as an effective energy sink that burns and disposes of excess lipids and glucose upon activation of thermogenesis. Unfortunately, the thermogenic activity of BAT declines during aging. New appreciation of cellular and functional remodeling of WAT and BAT during aging has emerged in recent years. Efforts are underway to explore the potential underlying mechanisms behind these age-associated alterations in WAT and BAT and the impact of these alterations on whole-body metabolism. Lastly, it is intriguing to translate our knowledge obtained from animal models to the clinic to prevent and treat age-associated metabolic disorders. © 2022 American Physiological Society. Compr Physiol 12: 4119-4132, 2022.

Metabolic changes in aging humans: current evidence and therapeutic strategies

Aging and metabolism are inextricably linked, and many age-related changes in body composition, including increased central adiposity and sarcopenia, have underpinnings in fundamental aging processes. These age-related changes are further exacerbated by a sedentary lifestyle and can be in part prevented by maintenance of activity with aging. Here we explore the age-related changes seen in individual metabolic tissues - adipose, muscle, and liver - as well as globally in older adults. We also discuss the available evidence for therapeutic interventions such as caloric restriction, resistance training, and senolytic and senomorphic drugs to maintain healthy metabolism with aging, focusing on data from human studies.

Ageing male (part I): Pathophysiology and diagnosis of functional hypogonadism

This narrative review summarizes key points of the pathogenesis and diagnosis of the ageing-related decline of testosterone (T) in men. The condition is commonly termed late-onset hypogonadism (LOH), but because it is more often caused by other factors than chronological ageing (obesity and other comorbidities), a more appropriate term is functional hypogonadism (FH). Unlike the classical organic hypogonadism, no anatomical or genetic aberrations are found in FH, and the suppression of T is milder. Moreover, FH can be reversible if the underlying cause (e.g. obesity, chronic disease) is removed/treated. Low serum total T in connection with more specific hypogonadism-associated symptoms (primarily sexual) form the basis of the diagnosis of FH. When T concentrations are borderline, the accuracy of diagnosis can be improved by assessment of free or calculated free T, especially when suppressed SHBG levels (usually related to obesity) are likely. Current data indicate that FH (low T and sexual symptoms) is not a common condition, and it is detectable in about 2% of community-dwelling men aged 40-80 years.

Ceramides are early responders in metabolic syndrome development in rhesus monkeys

Metabolic syndrome increases risk of complicating co-morbidities. Current clinical indicators reflect established metabolic impairment, preventing earlier intervention strategies. Here we show that circulating sphingolipids are altered in the very early stages of insulin resistance development. The study involved 16 paired overweight but healthy monkeys, one-half of which spontaneously developed metabolic syndrome over the course of 2 years. Importantly, animals did not differ in adiposity and were euglycemic throughout the study period. Using mass spectrometry, circulating sphingolipids, including ceramides and sphingomyelins, were detected and quantified for healthy and impaired animals at both time points. At time of diagnosis, several ceramides were significantly different between healthy and impaired animals. Correlation analysis revealed differences in the interactions among ceramides in impaired animals at diagnosis and pre-diagnosis when animals were clinically indistinguishable from controls. Furthermore, correlations between ceramides and early-stage markers of insulin resistance, diacylglycerols and non-esterified fatty acids, were distinct for healthy and impaired states. Regression analysis identifies coordinated changes in lipid handling across lipid classes as animals progress from healthy to insulin resistant. Correlations between ceramides and the adipose-derived adipokine adiponectin were apparent in healthy animals but not in the metabolically impaired animals, even in advance of loss in insulin sensitivity. These data suggest that circulating ceramides are clinically relevant in identifying disease risk independent of differences in adiposity, and may be important in devising preventative strategies.

Cardiovascular Aging and Longevity: JACC State-of-the-Art Review

Cardiovascular aging and longevity are interrelated through many pathophysiological mechanisms. Many factors that promote atherosclerotic cardiovascular disease are also implicated in the aging process and vice versa. Indeed, cardiometabolic disorders such as hyperglycemia, insulin resistance, dyslipidemia, and arterial hypertension share common pathophysiological mechanisms with aging and longevity. Moreover, genetic modulators of longevity have a significant impact on cardiovascular aging. The current knowledge of genetic, molecular, and biochemical pathways of aging may serve as a substrate to introduce interventions that might delay cardiovascular aging, thus approaching the goal of longevity. In the present review, the authors describe pathophysiological links between cardiovascular aging and longevity and translate these mechanisms into clinical data by reporting genetic, dietary, and environmental characteristics from long-living populations.

Adiponectin preserves metabolic fitness during aging

Adiponectin is essential for the regulation of tissue substrate utilization and systemic insulin sensitivity. Clinical studies have suggested a positive association of circulating adiponectin with healthspan and lifespan. However, the direct effects of adiponectin on promoting healthspan and lifespan remain unexplored. Here, we are using an adiponectin null mouse and a transgenic adiponectin overexpression model. We directly assessed the effects of circulating adiponectin on the aging process and found that adiponectin null mice display exacerbated age-related glucose and lipid metabolism disorders. Moreover, adiponectin null mice have a significantly shortened lifespan on both chow and high-fat diet. In contrast, a transgenic mouse model with elevated circulating adiponectin levels has a dramatically improved systemic insulin sensitivity, reduced age-related tissue inflammation and fibrosis, and a prolonged healthspan and median lifespan. These results support a role of adiponectin as an essential regulator for healthspan and lifespan.

Divergent immunometabolic changes in adipose tissue and skeletal muscle with ageing in healthy humans

KEY POINTS

Ageing is associated with increased systemic inflammation and metabolic dysfunction that contributes to the development of age-associated diseases. The role of adipose tissue in immunometabolic alterations that take place with ageing is unknown in humans. We show, in healthy, active and lean older adults, that adipose tissue, but not skeletal muscle, displays considerable pro-inflammatory transcriptomic, cellular and secretory changes, as well as a reduction in insulin signalling proteins compared to younger adults. These findings indicate that adipose tissue undergoes substantial immunometabolic alterations with ageing, and that these changes are tissue-specific and more profound than those observed in skeletal muscle or in the circulation. These results identify adipose tissue as an important tissue in the biological ageing process in humans, which may exhibit signs of immunometabolic dysfunction prior to systemic manifestation.

ABSTRACT

Ageing and obesity are both characterized by inflammation and a deterioration in metabolic health. It is now clear that adipose tissue plays a major role in inflammation and metabolic control in obesity, although little is known about the role of adipose tissue in human ageing. To understand how ageing impacts adipose tissue, we characterized subcutaneous adipose tissue and skeletal muscle samples from twelve younger (27 ± 4 years [Young]) and twelve older (66 ± 5 years [Old]) active/non-obese males. We performed a wide-range of whole-body and tissue measures, including RNA-sequencing and multicolour flow cytometry. We also measured a range of inflammatory and metabolic proteins in the circulation and their release by adipose tissue, ex vivo. Both adipose tissue and muscle had ∼2-fold more immune cells per gram of tissue with ageing. In adipose tissue, this immune cell infiltration was driven by increased memory/effector T-cells, whereas, in muscle, the accumulation was driven by memory/effector T-cells and macrophages. Transcriptomic analysis revealed that, with ageing, adipose tissue, but not muscle, was enriched for inflammatory transcripts/pathways related to acquired and innate immunity. Ageing also increased the adipose tissue pro-inflammatory secretory profile. Insulin signalling protein content was reduced in adipose tissue, but not muscle. Our findings indicate that adipose tissue undergoes substantial immunometabolic changes with ageing in humans, and that these changes are tissue-specific and more profound than those observed in the circulation and skeletal muscle.

Advances in Understanding of the Role of Lipid Metabolism in Aging

During aging, body adiposity increases with changes in the metabolism of lipids and their metabolite levels. Considering lipid metabolism, excess adiposity with increased lipotoxicity leads to various age-related diseases, including cardiovascular disease, cancer, arthritis, type 2 diabetes, and Alzheimer's disease. However, the multifaceted nature and complexities of lipid metabolism make it difficult to delineate its exact mechanism and role during aging. With advances in genetic engineering techniques, recent studies have demonstrated that changes in lipid metabolism are associated with aging and age-related diseases. Lipid accumulation and impaired fatty acid utilization in organs are associated with pathophysiological phenotypes of aging. Changes in adipokine levels contribute to aging by modulating changes in systemic metabolism and inflammation. Advances in lipidomic techniques have identified changes in lipid profiles that are associated with aging. Although it remains unclear how lipid metabolism is regulated during aging, or how lipid metabolites impact aging, evidence suggests a dynamic role for lipid metabolism and its metabolites as active participants of signaling pathways and regulators of gene expression. This review describes recent advances in our understanding of lipid metabolism in aging, including established findings and recent approaches.

Mouse models of growth hormone insensitivity

Growth hormone (GH) induces pleiotropic effects on growth and metabolism via binding and subsequent activation of the growth hormone receptor (GHR) and its downstream signaling pathways. Growth hormone insensitivity (GHI) describes a group of disorders in which there is resistance to the action of GH and resultant insulin-like growth factor I (IGF-I) deficiency. GHI is commonly due to genetic disorders of the GH receptor causing GH receptor deficiency (e.g. Laron Syndrome (LS)), decreased activation of GHR, or defects in post-receptor signaling molecules. Genetically altered mouse lines have been invaluable to better understand the physiological impact of GHI due to the ability to do invasive and longitudinal measures of metabolism, growth, and health on a whole animal or in individual tissues/cells. In the current review, the phenotype of mouse lines with GHI will be reviewed. Mouse lines to be discussed include: 1) GHR-/- mice with a gene disruption in the GHR that results in no functional GHR throughout life, also referred to as the Laron mouse, 2) mice with temporal loss of GHR (aGHRKO) starting at 6 weeks of age, 3) mice transgenic for a GHR antagonist (GHA mice), 4) mice with GHI in select tissues or cells generated via Cre-lox or related technology, and 5) assorted mice with defects in post-receptor signaling molecules. Collectively, these mouse lines have revealed an intriguing role of GH action in health, disease, and aging.

Is Adipose Tissue the Fountain of Youth? The Impact of Adipose Stem Cell Aging on Metabolic Homeostasis, Longevity, and Cell-Based Therapies

Aging is driven by four interlinked processes: (1) low-grade sterile inflammation; (2) macromolecular and organelle dysfunction, including DNA damage, telomere erosion, and mitochondrial dysfunction; (3) stem cell dysfunction; and (4) an accumulation of senescent cells in tissues. Adipose tissue is not immune to the effects of time, and all four of these processes contribute to a decline of adipose tissue function with advanced age. This decline is associated with an increase in metabolic disorders. Conversely, optimally functioning adipose tissue generates signals that promote longevity. As tissue-resident progenitor cells that actively participate in adipose tissue homeostasis and dysregulation, adipose stem cells (ASCs) have emerged as a key feature in the relationship between age and adipose tissue function. This review will give a mechanistic overview of the myriad ways in which age affects ASC function and, conversely, how ASC function contribute to healthspan and lifespan. A central mediator in this relationship is the degree of resilience of ASCs to maintain stemness into advanced age and the consequent preservation of adipose tissue function, in particular subcutaneous fat. The last sections of this review will discuss therapeutic options that target senescent ASCs to extend healthspan and lifespan, as well as ASC-based therapies that can be used to treat age-related pathologies, and collectively, these therapeutic applications may transform the way we age.

The Combination of High Levels of Adiponectin and Insulin Resistance Are Affected by Aging in Non-Obese Old Peoples

BACKGROUND

Adipokine dysregulation is a key feature of insulin resistance and a metabolic syndrome associated with obesity. Low adiponectin levels are associated with higher risks of cardiovascular diseases (CVD). However, high adiponectin levels have also been associated with increased all-cause and cardiovascular mortality in the elderly. This adiponectin paradox has yet to be clarified, which has hindered our understanding of the biological role of adiponectin. Adipokine dysregulation and insulin resistance are also associated with energy-deprivation conditions, such as frailty in old age. The objective of this study was to investigate the association between plasma adiponectin and insulin resistance using the homeostasis model assessment for insulin resistance (HOMA-IR) classified by age. In particular, we sought to determine the factors of the subjects associated with both high adiponectin levels and HOMA-IR (H-adiponectin/H-HOMA) and high adiponectin levels and low HOMA-IR (H-adiponectin/L-HOMA).

METHODS

The eligible subjects in this cross-sectional study were 33,216 individuals who had undergone health checkups at the Physical Checkup Center of Sumitomo Hospital between April 2008 and December 2018. After excluding 26,371 individuals who were under 60 years old, 529 who had been taking medications for diabetes mellitus, and 690 with missing data, the present study included 5,673 (3,467 males, 2,206 females) subjects with no missing data. The relationship between serum adiponectin levels and HOMA-IR was assessed using logistic regression models adjusted by clinically relevant factors.

RESULTS

In the multivariable logistic regression analysis, age and low BMI were shown to positively correlate with the characteristics of H-adiponectin/H-HOMA. In females, systolic blood pressure was also shown to be an associated factor.

CONCLUSION

In conclusion, this study showed that aging or a low BMI may contribute to high adiponectin levels and insulin resistance.

Adiponectin and Sarcopenia: A Systematic Review With Meta-Analysis

BACKGROUND

Sarcopenia is a progressive loss of skeletal muscle mass whose pathophysiology has been proposed to possibly involve mechanisms of altered inflammatory status and endocrine function. Adiponectin has been shown to modulate inflammatory status and muscle metabolism. However, the possible association between adiponectin levels and sarcopenia is poorly understood. In order to fill this gap, in the present manuscript we aimed to summarize the current evidence with a systematic review and a meta-analysis of studies reporting serum adiponectin levels in patients with sarcopenia compared to non-sarcopenic controls.

METHODS

An electronic search through Medline/PubMed, Cochrane Library, and Science Direct was performed till March 1, 2020. From the included papers, meta-analysis of cross-sectional studies comparing serum levels of adiponectin between patients with sarcopenia and controls was performed.

RESULTS

Out of 1,370 initial studies, seven studies were meta-analyzed. Sarcopenic participants had significantly higher levels of adiponectin Hedges' g with 95% confidence interval (CI): 1.20 (0.19-2.22), p = 0.02 than controls. Subgroup analysis, performed in Asian population and focused on identification of the condition based on AWGS criteria, reported higher adiponectin levels in sarcopenic population (2.1 (0.17-4.03), p = 0.03 and I2 = 98.98%. Meta-regression analysis revealed female gender to significantly influence the results as demonstrated by beta = 0.14 (95% CI (0.010-0.280), p = 0.040).

CONCLUSIONS

Our meta-analysis found evidence that sarcopenia is associated with higher adiponectin levels. However, caution is warranted on the interpretation of these findings, and future longitudinal research is required to disentangle and better understand the topic.

How does adipose tissue contribute to inflammageing?

Across aging, white adipose tissue (WAT) undergoes significant changes in quantity and distribution, with an increase in visceral adipose tissue, ectopic fat deposition and a decline in gluteofemoral subcutaneous depot. In particular, WAT becomes dysfunctional with an increase in production of inflammatory peptides and a decline of those with anti-inflammatory activity and infiltration of inflammatory cells. Moreover, dysfunction of WAT is characterized by preadipocyte differentiation decline, increased oxidative stress and mitochondrial dysfunction, reduction in vascularization and hypoxia, increased fibrosis and senescent cell accumulation. WAT changes represent an important hallmark of the aging process and may be responsible for the systemic pro-inflammatory state ("inflammageing") typical of aging itself, leading to age-related metabolic alterations. This review focuses on mechanisms linking age-related WAT changes to inflammageing.

Regulation of aging and cancer by enhanced environmental activation of a hypothalamic-sympathoneural-adipocyte axis

Social and environmental factors impact cancer and energy balance profoundly. Years ago, our lab established the existence of a novel brain-fat interaction we termed the "hypothalamic-sympathoneural-adipocyte (HSA) axis", through which complex environmental stimuli provided by an enriched environment regulate body composition, energy balance, and development of cancer. We have spent a significant portion of the past decade to further characterize the broad health benefits of an enriched environment (for example, leanness, enhanced immune function, and cancer resistance), and to identify mediators in the brain and periphery along the HSA axis. This review summarizes our recent work regarding the interface between endocrinology, immunology, cancer biology, aging, and neuroscience. We will discuss the interplay between these systemic phenomena and how the HSA axis can be targeted for regulation of cancer and aging.

Adipose tissue, immune aging, and cellular senescence

Obesity represents a serious health problem as it is rapidly increasing worldwide. Obesity is associated with reduced healthspan and lifespan, decreased responses to infections and vaccination, and increased frequency of inflammatory conditions typical of old age. Obesity is characterized by increased fat mass and remodeling of the adipose tissue (AT). In this review, we summarize published data on the different types of AT present in mice and humans, and their roles as fat storage as well as endocrine and immune tissues. We review the age-induced changes, including those in the distribution of fat in the body, in abundance and function of adipocytes and their precursors, and in the infiltration of immune cells from the peripheral blood. We also show that cells with a senescent-associated secretory phenotype accumulate in the AT of mice and humans with age, where they secrete several factors involved in the establishment and maintenance of local inflammation, oxidative stress, cell death, tissue remodeling, and infiltration of pro-inflammatory immune cells. Not only adipocytes and pre-adipocytes but also immune cells show a senescent phenotype in the AT. With the increase in human lifespan, it is crucial to identify strategies of intervention and target senescent cells in the AT to reduce local and systemic inflammation and the development of age-associated diseases. Several studies have indeed shown that senescent cells can be effectively targeted in the AT by selectively removing them or by inhibiting the pathways that lead to the secretion of pro-inflammatory factors.

Interplay between hormones and exercise on hippocampal plasticity across the lifespan

The hippocampus is a brain structure known to play a central role in cognitive function (namely learning and memory) as well as mood regulation and affective behaviors due in part to its ability to undergo structural and functional changes in response to intrinsic and extrinsic stimuli. While structural changes are achieved through modulation of hippocampal neurogenesis as well as alterations in dendritic morphology and spine remodeling, functional (i.e., synaptic) changes can be noted through the strengthening (i.e., long-term potentiation) or weakening (i.e., long-term depression) of the synapses. While age, hormone homeostasis, and levels of physical activity are some of the factors known to module these forms of hippocampal plasticity, the exact mechanisms through which these factors interact with each other at a given moment in time are not completely understood. It is well known that hormonal levels vary throughout the lifespan of an individual and it is also known that physical exercise can impact hormonal homeostasis. Thus, it is reasonable to speculate that hormone modulation might be one of the various mechanisms through which physical exercise differently impacts hippocampal plasticity throughout distinct periods of an individual's life. The present review summarizes the potential relationship between physical exercise and different types of hormones (namely sex, metabolic, and stress hormones) and how this relationship may mediate the effects of physical activity during three distinct life periods, adolescence, adulthood, and senescence. Overall, the vast majority of studies support a beneficial role of exercise in maintaining hippocampal hormonal levels and consequently, hippocampal plasticity, cognition, and mood regulation.

Improvements to Healthspan Through Environmental Enrichment and Lifestyle Interventions: Where Are We Now?

Environmental enrichment (EE) is an experimental paradigm that is used to explore how a complex, stimulating environment can impact overall health. In laboratory animal experiments, EE housing conditions typically include larger-than-standard cages, abundant bedding, running wheels, mazes, toys, and shelters which are rearranged regularly to further increase stimulation. EE has been shown to improve multiple aspects of health, including but not limited to metabolism, learning and cognition, anxiety and depression, and immunocompetence. Recent advances in lifespan have led some researchers to consider aging as a risk factor for disease. As such, there is a pressing need to understand the processes by which healthspan can be increased. The natural and predictable changes during aging can be reversed or decreased through EE and its underlying mechanisms. Here, we review the use of EE in laboratory animals to understand mechanisms involved in aging, and comment on relative areas of strength and weakness in the current literature. We additionally address current efforts toward applying EE-like lifestyle interventions to human health to extend healthspan. Although increasing lifespan is a clear goal of medical research, improving the quality of this added time also deserves significant attention. Despite hurdles in translating experimental results toward clinical application, we argue there is great potential in using features of EE toward improving human healthy life expectancy or healthspan, especially in the context of increased global longevity.

Running wheel access fails to resolve impaired sustainable health in mice feeding a high fat sucrose diet

Diet and physical activity are thought to affect sustainable metabolic health and survival. To improve understanding, we studied survival of mice feeding a low-fat (LF) or high-saturated fat/high sugar (HFS) diet, each with or without free running wheel (RW) access. Additionally several endocrine and metabolic health indices were assessed at 6, 12, 18 and 24 months of age. As expected, HFS feeding left-shifted survival curve of mice compared to LF feeding, and this was associated with increased energy intake and increased (visceral/total) adiposity, liver triglycerides, and increased plasma cholesterol, corticosterone, HOMA-IR, and lowered adiponectin levels. Several of these health parameters improved (transiently) by RW access in HFS and LF fed mice (i.e., HOMA-IR, plasma corticosterone), others however deteriorated (transiently) by RW access only in HFS-fed mice (i.e., body adiposity, plasma resistin, and free cholesterol levels). Apart from these multiple and sometimes diverging health effects of RW access, RW access did not affect survival curves. Important to note, voluntary RW activity declined with age, but this effect was most pronounced in the HFS fed mice. These results thus challenge the hypothesis that voluntary wheel running can counteract HFS-induced deterioration of survival and metabolic health.

Aging and the Male Reproductive System

This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.

Serum adiponectin is associated with body composition and cognitive and psychological status in older adults living in long-term nursing homes

Frailty is a geriatric syndrome characterized by decreasing functional reserves and increasing vulnerability to falls, injuries and declining health, leading to dependence upon caregivers. Frailty is associated not only with physical decline, but also with cognitive and psychological impairments in aging people. Higher serum adiponectin concentration has been linked to better performance on frailty measures but also to worse cognitive status. Nonetheless, several studies have proposed adiponectin as a frailty biomarker. To further delineate the relationship between adiponectin serum levels and frailty-related parameters, we studied a population of 112 long-term nursing home residents (aged 84.9 ± 6.7) and analyzed their serum adiponectin levels in conjunction with frailty-related parameters including body composition, physical fitness, cognitive function, psychological parameters and quality of life. Frailty was assessed following the Fried Frailty Criteria, the Clinical Frailty Scale and the Tilburg Frailty Indicator. In women, higher serum adiponectin levels were associated with lower body weight, body mass index, body fat mass, fat mass/height², lean mass, lean mass/height² and smaller waist circumference and hip circumference (p < 0.05). In men, the association was positive (p < 0.05) between serum adiponectin and percentage of fat mass and negative between serum adiponectin and percentage of lean mass. Interestingly, in men, better cognitive function was inversely related to adiponectin (p < 0.05) while decreased anxiety was linked to a higher concentration of adiponectin in women (p < 0.05). According to the Tilburg Frailty Indicator, frail men had lower levels of adiponectin than those who were not frail (p < 0.05). Variables that predicted adiponectin concentration in multiple regression models were different for women and men. In women, lean mass and anxiety were independent negative predictors of blood adiponectin (β = -0.363, p = 0.002; β = -0.204, p = 0.067, respectively). In men, the Montreal Cognitive Assessment (MOCA) test was the only parameter to remain significant in the regression model (β = -439, p = 0.015). The results of our study show that adiponectin is linked to body composition, cognitive function and anxiety in long-term nursing home residents with differential relationships by sex. Further studies should be conducted to determine whether adiponectin is a valid and reliable frailty biomarker.

Adipokines and Aging: Findings From Centenarians and the Very Old

Adipose tissue, which was once considered as a simple energy storage depot, is now recognized as an active endocrine organ that regulates the whole-body energy homeostasis by secreting hundreds of bioactive substances termed adipokines. Dysregulation of adipokines is a key feature of insulin resistance and a metabolic syndrome associated with obesity. Adipokine dysregulation and insulin resistance are also associated with energy-deprivation conditions, such as frailty in old age. Previous studies have demonstrated that preserved insulin sensitivity and low prevalence of diabetes are the metabolic peculiarities of centenarians, suggesting the possible role of adipokine homeostasis in healthy longevity. Among the numerous adipokines, adiponectin is regarded as unique and salutary, showing negative correlations with several age- and obesity-related metabolic disturbances and a positive correlation with longevity and insulin sensitivity among centenarians. However, large-scale epidemiological studies have implied the opposite aspect of this adipokine as a prognostic factor for all-cause and cardiovascular mortality in patients with heart failure or kidney disease. In this review, the clinical significance of adiponectin was comparatively addressed in centenarians and the very old, in terms of frailty, cardiovascular risk, and mortality.

ROLE of IGF-1 System in the Modulation of Longevity: Controversies and New Insights From a Centenarians' Perspective

Human aging is currently defined as a physiological decline of biological functions in the body with a continual adaptation to internal and external damaging. The endocrine system plays a major role in orchestrating cellular interactions, metabolism, growth, and aging. Several in vivo studies from worms to mice showed that downregulated activity of the GH/IGF-1/insulin pathway could be beneficial for the extension of human life span, whereas results are contradictory in humans. In the present review, we discuss the potential role of the IGF-1 system in modulation of longevity, hypothesizing that the endocrine and metabolic adaptation observed in centenarians and in mammals during caloric restriction may be a physiological strategy for extending lifespan through a slower cell growing/metabolism, a better physiologic reserve capacity, a shift of cellular metabolism from cell proliferation to repair activities and a decrease in accumulation of senescent cells. Therefore, understanding of the link between IGF-1/insulin system and longevity may have future clinical applications in promoting healthy aging and in Rehabilitation Medicine.

The Dual Role of the Pervasive "Fattish" Tissue Remodeling With Age

Human aging is characterized by dramatic changes in body mass composition that include a general increase of the total fat mass. Within the fat mass, a change in the proportions of adipose tissues also occurs with aging, affecting body metabolism, and playing a central role in many chronic diseases, including insulin resistance, obesity, cardiovascular diseases, and type II diabetes. In mammals, fat accumulates as white (WAT) and brown (BAT) adipose tissue, which differ both in morphology and function. While WAT is involved in lipid storage and immuno-endocrine responses, BAT is aimed at generating heat. With advancing age BAT declines, while WAT increases reaching the maximum peak by early old age and changes its distribution toward a higher proportion of visceral WAT. However, lipids tend to accumulate also within lipid droplets (LDs) in non-adipose tissues, including muscle, liver, and heart. The excess of such ectopic lipid deposition and the alteration of LD homeostasis contribute to the pathogenesis of the above-mentioned age-related diseases. It is not clear why age-associated tissue remodeling seems to lean toward lipid deposition as a "default program." However, it can be noted that such remodeling is not inevitably detrimental. In fact, such a programmed redistribution of fat throughout life could be considered physiological and even protective, in particular at extreme old age. In this regard, it has to be considered that an excessive decrease of subcutaneous peripheral fat is associated with a pro-inflammatory status, and a decrease of LD is associated with lipotoxicity leading to an increased risk of insulin resistance, type II diabetes and cardiovascular diseases. At variance, a balanced rate of fat content and distribution has beneficial effects for health and metabolic homeostasis, positively affecting longevity. In this review, we will summarize the present knowledge on the mechanisms of the age-related changes in lipid distribution and we will discuss how fat mass negatively or positively impacts on human health and longevity.

Relationship between inflammatory parameters and cardiovascular and lifestyle factors in the Mugello study oldest old

AIM

To explore possible inter-relationships of various biomarkers of inflammation and lifestyle and other cardiovascular risk factors (age, gender, smoking history, hypertension, Type 2 diabetes, dyslipidemia, alteration of circadian rhythms, body mass index, calf circumference, thigh circumference, abdominal circumference) in the Mugello study oldest old.

METHODS

In 399 noninstitutionalized nonagenarians (291 women), whole blood cells, mean platelet volume, C-reactive protein, uric acid, gamma-glutamyl transferase were assessed.

RESULTS

Aging resulted as the only independent determinant for uric acid (<0.05), and abdominal circumference for C-reactive protein. Female gender (<0.01), and thigh circumference (<0.05) remained as determinants for mean platelet volume, age (<0.01), and male gender (<0.01) for gamma-glutamyl transferase, and Type 2 diabetes (≤0.01) and alteration of circadian rhythms (<0.05) for whole blood cells.

CONCLUSION

Several inflammatory parameters remain associated with adverse lifestyle and cardiovascular risk factors even among nonagenarians.

Biomarkers and Gene Polymorphisms in Members of Long- and Short-lived Families: A Longevity Study

Background

The influence of biomarkers in human lifespan has been investigated but with no clear results yet.

Materials and methods

Lipids, Uric Acid (UA), Adiponectin (ADIPOQ), Insulin-like Growth Factor (IGF-1), cholesteryl ester transfer protein (CETP) and angiotensin-converting enzyme (ACE) proteins, as well as CETP, ADIPOQ, insulin-like growth factor binding protein-3 (IGFBP3) and ACE-gene polymorphisms were evaluated in 149 Greek individuals. The Long-Lived Families (LON) (n=84) comprised of 3 generations: long-lived aged ≥90 years (P), offspring (FL1) and their grandchildren (FL2), while the Short-Lived Families (EAD) (n=65) where both parents died <75 years, comprised of 2 generations: middle-aged (FD1) and children (FD2).

Results

Serum CETP and IGF-1 levels were lower, whereas AdipoQ concentrations were higher in P compared with FL1 and FL2 members (CETP: p = 0.03 for both comparisons; IGF-1 p < 0.001 for both comparisons and ADIPOQ: p = 0.001 and p = 0.004, respectively). Furthermore, serum triglycerides, UA and glucose concentrations were higher in FD1 compared with FD2 subjects (p=0.001, 0.02 and ≤0.001, respectively). In FD2 and FL2, CETP levels were lower in individuals with B2B2 compared with B1B1 genotype (p=0.007). Additionally, ACE concentrations were higher in individuals with DD compared with II genotype in both Families (p=0.001). After adjustment for age and gender, CETP levels were lower in P and FL2 individuals with B2B2 compared with the B1B1 genotype (p=0.004 and 0.007, respectively).

Conclusion

Increase serum TGs, UA and GL concentrations were higher in the middle-aged individuals compared with their children in families independently of their lifespan. The serum adiponectin concentration was the highest in the oldest old individuals implying beneficial influence on lifespan. Independently of family's lifespan history, the youngest individuals with CETPB2B2 genotype, compared with individuals with CETPB1B1 genotypes, had lower serum CETP concentrations. The knowledge of the unfavourable gene(s)influencing human lifespan may be helpful in encouraging individuals to follow healthier lifestyle habits and better control their high-risk biomarkers.

Parallels in Immunometabolic Adipose Tissue Dysfunction with Ageing and Obesity

Ageing, like obesity, is often associated with alterations in metabolic and inflammatory processes resulting in morbidity from diseases characterised by poor metabolic control, insulin insensitivity, and inflammation. Ageing populations also exhibit a decline in immune competence referred to as immunosenescence, which contributes to, or might be driven by chronic, low-grade inflammation termed "inflammageing". In recent years, animal and human studies have started to uncover a role for immune cells within the stromal fraction of adipose tissue in driving the health complications that come with obesity, but relatively little work has been conducted in the context of immunometabolic adipose function in ageing. It is now clear that aberrant immune function within adipose tissue in obesity-including an accumulation of pro-inflammatory immune cell populations-plays a major role in the development of systemic chronic, low-grade inflammation, and limiting the function of adipocytes leading to an impaired fat handling capacity. As a consequence, these changes increase the chance of multiorgan dysfunction and disease onset. Considering the important role of the immune system in obesity-associated metabolic and inflammatory diseases, it is critically important to further understand the interplay between immunological processes and adipose tissue function, establishing whether this interaction contributes to age-associated immunometabolic dysfunction and inflammation. Therefore, the aim of this article is to summarise how the interaction between adipose tissue and the immune system changes with ageing, likely contributing to the age-associated increase in inflammatory activity and loss of metabolic control. To understand the potential mechanisms involved, parallels will be drawn to the current knowledge derived from investigations in obesity. We also highlight gaps in research and propose potential future directions based on the current evidence.

The role of dietary patterns and exceptional parental longevity in healthy aging

BACKGROUND

Individuals with exceptional longevity and their offspring manifest a lower prevalence of age-related diseases than families without longevity. However, the contribution of dietary habits to protection from disease has not been systematically assessed in families with exceptional longevity.

OBJECTIVE

The aim of this study is to compare dietary patterns between individuals with parental longevity and individals without parental longevity.

METHODS

Dietary intake was evaluated using the Block Brief Food Frequency Questionnaire in 234 community dwelling Ashkenazi Jewish adults aged 65 years and older who were participants of the LonGenity study, which enrolls the offspring of parents with exceptional longevity (OPEL) and offspring of parents with usual survival (OPUS).

RESULTS

OPEL constituted 38% of the subjects. The two groups had similar daily intake of total calories (1119 vs. 1218 kcal, p = 0.83), grams of cholesterol (141 g vs. 143 g, p = 0.19), and grams of sodium (1324 g vs.1475 g, p = 0.45), in OPEL vs. OPUS respectively. There were also no significant differences in the intake of other macronutrients, micronutrients, nutritional supplements and consumption of various food groups between OPEL and OPUS after adjustment for age and sex.

DISCUSSION

A healthy diet is associated with a lower risk of several chronic diseases. Our study revealed that dietary intake did not differ between OPEL and OPUS; thus, pointing to the role of longevity genes in protecting from disease among individuals with familial longevity.

CONCLUSION

The offspring of long-lived parents do not differ in their dietary patterns compared to individuals without parental longevity.

Hepatic lipid metabolism and non-alcoholic fatty liver disease in aging

Aging is associated with dysregulation of glucose and lipid metabolism. Various factors that contribute to the dysregulation include both modifiable (e.g. obesity, insulin resistance) and non-modifiable risk factors (age-associated physiologic changes). Although there is no linear relationship between aging and prevalence of non-alcoholic fatty liver disease, current data strongly suggests that advanced age leads to more severe histological changes and poorer clinical outcomes. Hepatic lipid accumulation could lead to significant hepatic and systemic consequences including steatohepatitis, cirrhosis, impairment of systemic glucose metabolism and metabolic syndrome, thereby contributing to age-related diseases. Insulin, leptin and adiponectin are key regulators of the various physiologic processes that regulate hepatic lipid metabolism. Recent advances have expanded our understanding in this field, highlighting the role of novel mediators such as FGF 21, and mitochondria derived peptides. In this review, we will summarize the mediators of hepatic lipid metabolism and how they are altered in aging.

Health Benefits of Fasting and Caloric Restriction

PURPOSE OF REVIEW

Obesity and obesity-related diseases, largely resulting from urbanization and behavioral changes, are now of global importance. Energy restriction, though, is associated with health improvements and increased longevity. We review some important mechanisms related to calorie limitation aimed at controlling of metabolic diseases, particularly diabetes.

RECENT FINDINGS

Calorie restriction triggers a complex series of intricate events, including activation of cellular stress response elements, improved autophagy, modification of apoptosis, and alteration in hormonal balance. Intermittent fasting is not only more acceptable to patients, but it also prevents some of the adverse effects of chronic calorie restriction, especially malnutrition. There are many somatic and potentially psychologic benefits of fasting or intermittent calorie restriction. However, some behavioral modifications related to abstinence of binge eating following a fasting period are crucial in maintaining the desired favorable outcomes.

Association Between Peripheral Adipokines and Inflammation Markers: A Systematic Review and Meta-Analysis

OBJECTIVE

Obesity-induced inflammation potentially promotes a variety of chronic conditions. This study aimed to summarize cross-sectional associations between adipose tissue-derived hormones (leptin and adiponectin) and inflammatory biomarkers (C-reactive protein [CRP], interleukin [IL]-6, and tumor necrosis factor [TNF]-α) by means of meta-analysis.

METHODS

A systematic search of the databases EMBASE and MEDLINE (PubMed) up to January 2017 was conducted. Data were independently extracted and evaluated by two reviewers. Pooled effect sizes and 95% confidence intervals were calculated using random-effects models.

RESULTS

After the initial search, 5,907 publications were retrieved; of these, an overall 60 studies with 45,210 participants were deemed eligible for inclusion in the meta-analysis. Positive correlations with inflammatory biomarkers were observed for leptin (pooled R_ho  = 0.35, 0.20, and 0.20 for CRP, IL-6, and TNF-α, respectively), whereas the respective correlations with adiponectin were negative (pooled R_ho  = -0.18, -0.14, and -0.12 for CRP, IL-6, and TNF-α, respectively). Stratification by age showed that the observed correlations tended to be weaker with the increasing age of participants. No apparent differences were observed by sex and adiposity status.

CONCLUSIONS

This is the first quantitative synthesis of human studies on the association between circulating adipokines and inflammation biomarkers. Potential influence of age on these associations requires further evaluation.

Lipid and Alzheimer's disease genes associated with healthy aging and longevity in healthy oldest-old

Several studies have found that long-lived individuals do not appear to carry lower numbers of common disease-associated variants than ordinary people; it has been hypothesized that they may instead carry protective variants. An intriguing type of protective variant is buffering variants that protect against variants that have deleterious effects. We genotyped 18 variants in 15 genes related to longevity or healthy aging that had been previously reported as having a gene-gene interaction or buffering effect. We compared a group of 446 healthy oldest-old ‘Super-Seniors’ (individuals 85 or older who have never been diagnosed with cancer, cardiovascular disease, dementia, diabetes or major pulmonary disease) to 421 random population-based midlife controls. Cases and controls were of European ancestry. Association tests of individual SNPs showed that Super-Seniors were less likely than controls to carry an APOEε4 allele or a haptoglobin HP2 allele. Interactions between APOE/FOXO3, APOE/CRYL1, and LPA/CRYL1 did not remain significant after multiple testing correction. In a network analysis of the candidate genes, lipid and cholesterol metabolism was a common theme. APOE, HP, and CRYL1 have all been associated with Alzheimer’s Disease, the pathology of which involves lipid and cholesterol pathways. Age-related changes in lipid and cholesterol maintenance, particularly in the brain, may be central to healthy aging and longevity.

Phenome and genome based studies into human ageing and longevity: An overview

Human ageing is an extremely personal process leading across the life course of individuals to large population heterogeneity in the decline of functional capacity, health and lifespan. The extremes of this process are witnessed by the healthy vital 100-year-olds on one end and the 60-year-olds suffering from multiple morbid conditions on the other end of the spectrum. Molecular studies into the basis of this heterogeneity have focused on a range of endpoints and methodological approaches. The phenotype definitions most prominently investigated in these studies are either lifespan-related or biomarker based indices of the biological ageing rate of individuals and their tissues. Unlike for many complex, age-related diseases, consensus on the ultimate set of multi-biomarker ageing or lifespan-related phenotypes for genetic and genomic studies has not been reached yet. Comparable to animal models, hallmarks of age-related disease risk, healthy ageing and longevity include immune and metabolic pathways. Potentially novel genomic regions and pathways have been identified among many (epi)genomic studies into chronological age and studies into human lifespan regulation, with APOE and FOXO3A representing yet the most robust loci. Functional analysis of a handful of genes in cell-based and animal models is ongoing. The way forward in human ageing and longevity studies seems through improvements in the interpretation of the biology of the genome, in application of computational and systems biology, integration with animal models and by harmonization of repeated phenotypic and omics measures in longitudinal and intervention studies. This article is part of a Special Issue entitled: Model Systems of Aging - edited by "Houtkooper Riekelt".

Five gene variants in nonagenarians, centenarians and average individuals

INTRODUCTION

Genetic factors contribute to the variation of human life span which is believed to be more profound after 85 years of age. The aim of the present study was to evaluate the frequency of 5 gene polymorphisms between nonagenarians, centenarians and average individuals.

MATERIAL AND METHODS

Single nucleotide polymorphisms (SNPs) of telomerase reverse transcriptase (TERT; rs2736098), insulin-like growth factor-1 binding protein-3 (IGFBP3; A-202C, rs2857744), fork-head box O3A (FOXO3A; rs13217795 and rs2764264) factor and adiponectin (ADIPOQ; rs2241766) were evaluated in 405 individuals: n = 256 nonagenarians and centenarians (study group) and n = 149 average lifespan individuals (control group aged 18 - < 80 years).

RESULTS

The frequency of women was significantly higher in the study group than the control group (64.5 vs. 49.7%, p = 0.004). Genotypic and allele frequencies did not differ between groups according to gender. However, in men, the frequency of TT genotype of FOXO3A; rs2764264 was higher in the study group than the control group (45.6 vs. 28.0%, p = 0.05). Overall, the frequency of the C allele of FOXO3A; rs2764264 was significantly lower in the study group than the control group (3.9 vs. 9.5%, respectively, p = 0.023). Furthermore, in the study group, the T allele was significantly more frequent in the nonagenarians (n = 239) than the centenarians (n = 17) in both FOXO3A; rs13217795 and rs2764264 (64.4 vs. 44.1%, p = 0.018 and 69.7 vs. 50.0%, p = 0.017, respectively).

CONCLUSIONS

According to survival status, there is differentiation in the prevalence of both studied FOXO3A gene polymorphisms. The study group had half of the C alleles compared with the control group and centenarians less frequently had the T allele of both FOXO3A gene polymorphisms compared with nonagenarians. No difference was found between groups according to TERT, IGFBP3 and ADIPOQ gene polymorphisms. It seems that some polymorphisms may be significant in prolonging our lifespan. Nevertheless, confirmation in additional study populations is needed.