Obesity and aging: Molecular mechanisms and therapeutic approaches

Skeletal Muscle as a Mediator of Interorgan Crosstalk During Exercise: Implications for Aging and Obesity

Physical exercise is critical for preventing and managing chronic conditions, such as cardiovascular disease, type 2 diabetes, hypertension, and sarcopenia. Regular physical activity significantly reduces cardiovascular and all-cause mortality. Exercise also enhances metabolic health by promoting muscle growth, mitochondrial biogenesis, and improved nutrient storage while preventing age-related muscle dysfunction. Key metabolic benefits include increased glucose uptake, enhanced fat oxidation, and the release of exercise-induced molecules called myokines, which mediate interorgan communication and improve overall metabolic function. These myokines and other exercise-induced signaling molecules hold promise as therapeutic targets for aging and obesity-related conditions.

Regulation of Metabolic Aging Through Adenosine Mono Phosphate-Activated Protein Kinase and Mammalian Target of Rapamycin: A Comparative Study of Intermittent Fasting Variations in Obese Young Women

Background/Objectives: Obesity accelerates metabolic aging through oxidative stress, inflammation, and mitochondrial dysfunction. AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) are nutrient-sensing pathways regulating metabolism. AMPK promotes energy metabolism and autophagy, while excessive mTOR activity contributes to aging. Intermittent fasting (IF), including time-restricted feeding (TRF)-limiting food intake to a 6 h window (18:6)-and alternate-day modified fasting (ADMF)-alternating 24 h fasting (≤25% daily caloric intake) with unrestricted feeding-may improve metabolic regulation. However, their effects on AMPK, mTOR, and metabolic age remain unclear. Methods: This quasi-experimental pre-test-post-test control group study compared the TRF and ADMF on metabolic age, AMPK, and mTOR in young obese women. Twenty-four participants (mean age: 21.29 ± 1.76 years; body fat: 36.92 ± 3.18%; BMI: 29.68 ± 3.70 kg/m2) were initially matched by BMI and assigned to Control, TRF, and ADMF groups. A total of 4 participants (1 Control, 3 ADMF) were excluded due to outlier values, yielding final group sizes: Control (n = 7), TRF (n = 8), and ADMF (n = 5). The intervention lasted 20 days. Results: A significant decrease in AMPK levels was observed in the ADMF group (p = 0.043), while changes in the TRF and Control groups were not significant. mTOR levels showed a decreasing trend but were not statistically significant. No significant changes were found in metabolic age. Conclusions: Twenty days of intermittent fasting intervention did not significantly affect AMPK, mTOR, or metabolic age in young obese women. TRF may more effectively enhance AMPK and reduce mTOR, while ADMF may better reduce metabolic age.

Associations of weight-adjusted-waist index and systemic immune-inflammatory index with sKlotho: evidence from the NHANES 2007-2016

Background

Klotho is an anti-aging protein, and obesity and inflammation have been identified as having a relationship with Klotho. This study investigated the correlation between weight-adjusted-waist index(WWI), systemic inflammation index(SII) and soluble Klotho (sKlotho) and explored the potential mediating role of SII.

Methods

The association between WWI, SII, and sKlotho was investigated using weighted multivariate linear regression, subgroup analysis, and smoothed curve fitting in this cross-sectional study, which was based on NHANES data. The Bootstrap method was used to test for mediation effects. Covariate selection was validated using the variance inflation factor (VIF).

Results

The study involved a total of 9,506 participants. The results showed that WWI (β=-0.03; 95%CI:-0.04,-0.01; p<0.0001) was associated with SII (β=-0.00, 95%CI:-0.00,-0.00:p<0.001) and Ln-sKlotho.There was a negative correlation between both WWI and SII and sKlotho. Subgroup analysis showed that gender, age, education, marital status, family income, HEI, PA, hypertension, diabetes, CKD, alcohol use, smoking, and SII did not affect the negative correlation between WWI and sKlotho (FDR-corrected p>0.1). The mediation analysis showed that SII played a significant mediating effect in the role of WWI on sKlotho, with SII mediating 6.78% of the relationship between WWI and sKlotho.

Conclusion

There is a negative correlation between WWI and sKlotho, and SII may be an important mediator between WWI and sKlotho. Reducing inflammatory conditions in obese populations may increase sKlotho levels, which in turn may delay organismal aging in middle-aged and elderly people.

Association of longitudinal body mass index trajectories with phenotypic age acceleration: a cross-sectional study based on growth mixture modeling

To examine the association between body mass index (BMI) trajectories, early and recent BMI changes, and phenotypic age acceleration (PhenoAgeAccel), addressing inconsistent findings in previous studies on weight change and aging. Data from the National Health and Nutrition Examination Survey from 2005 to 2018 were used, selecting participants aged 50 years and older. A growth mixture model was employed to identify BMI trajectories. The association between different BMI trajectories and PhenoAgeAccel was assessed using linear and multinomial logistic regression models. The nonlinear effects of BMI changes were identified through threshold effect analysis. Among 5404 participants, the four BMI trajectories identified were as follows: stable weight (29.07%), midlife weight gain (24.31%), late-life weight gain (32.22%), and chronic obesity (14.41%). The chronic obesity group exhibited the most significant elevations in PhenoAgeAccel, indicating they were phenotypically older compared to other groups (β = 4.34, 95% confidence interval 3.67-5.02). Early BMI changes of less than 6% were associated with being phenotypically younger (β =  - 5.06, P = 0.029), whereas increases exceeding 6% were linked to being phenotypically older (β = 2.83, P < 0.001). The key threshold for recent BMI changes was 2%; changes below this level were associated with being phenotypically younger, while those exceeding this threshold were linked to being phenotypically older (P < 0.001). This cross-sectional study suggests that individuals with long-term chronic obesity tend to be phenotypically older, whereas those with stable body weight are more likely to be phenotypically younger.

Prevalence of overweight and obesity in adults from the Middle East: A large-scale population-based study

AIMS

Although there are population-level estimates of the prevalence of overweight and obesity (OAO), there are few direct epidemiological surveys of OAO prevalence at scale.

MATERIALS AND METHODS

This was a cross-sectional, multi-centre, population-based study of all adults aged >18 years attending the Dubai Academic Health Corporation (DAHC) between January 2018 and August 2023. OAO was defined according to WHO standards or modified WHO cut points for individuals from WHO South-East Asian Region (SEAR) countries. Clinical obesity, defined according to new Lancet Commission diagnostic criteria, was estimated using ICD-10 codes corresponding to end-organ dysfunction.

RESULTS

Of 440 590 participants, 48.5% were female, 52% were aged 19-39 years and 37.1% were UAE nationals. 63.4% of the population were living with OAO. Significantly more UAE nationals (68.3%) were living with OAO than nationals from SEAR countries (59.7%, p < 0.001) or elsewhere (63.6%, respectively, p < 0.001). Significantly more females than males were living with obesity (30.4% vs. 25.9%, p < 0.001). About a half of female UAE nationals aged ≥40 years were living with obesity, about one in five of whom had class 2 or class 3 obesity. Using modified ethnicity-specific thresholds increased the overall proportion of people living with obesity in the UAE from 28.0% to 35.8%. About a third of individuals with a body mass index ≥40 kg/m2 also had signs or symptoms of ongoing organ dysfunction classifiable as clinical obesity.

CONCLUSIONS

This is the largest epidemiological study to provide direct prevalence data on OAO at this scale in the region and one of the largest globally. Using standard WHO cut points to define OAO may severely underestimate the prevalence of clinically actionable obesity in individuals of Southeast Asian ethnicity. This first application of new diagnostic criteria of clinical obesity suggests that some individuals may be disqualified from therapy who might otherwise benefit from a patient-centric approach.

High-fat diet induces sarcopenic obesity in natural aging rats through the gut-trimethylamine N-oxide-muscle axis

INTRODUCTION

The lack of suitable animal models for sarcopenic obesity (SO) limits in-depth research into the disease. Emerging studies have demonstrated that gut dysbiosis is involved in the development of SO. As the importance of microbial metabolites is starting to unveil, it is necessary to comprehend the specific metabolites associated with gut microbiota and SO.

OBJECTIVES

We aimed to investigate whether high-fat diet (HFD) causes SO in natural aging animal models and specific microbial metabolites that are involved in linking HFD and SO.

METHODS

Young rats received HFD or control diet for 80 weeks, and obesity-related metabolic disorders and sarcopenia were measured. 16S rRNA sequencing and non-targeted and targeted metabolomics methods were used to detect fecal gut microbiota and serum metabolites. Gut barrier function was evaluated by intestinal barrier integrity and intestinal permeability. Trimethylamine N-oxide (TMAO) treatment was further conducted for verification.

RESULTS

HFD resulted in body weight gain, dyslipidemia, impaired glucose tolerance, insulin resistance, and systemic inflammation in natural aging rats. HFD also caused decreases in muscle mass, strength, function, and fiber cross-sectional area and increase in muscle fatty infiltration in natural aging rats. 16S rRNA sequencing and nontargeted and targeted metabolomics analysis indicated that HFD contributed to gut dysbiosis, mainly characterized by increases in deleterious bacteria and TMAO. HFD destroyed intestinal barrier integrity and increased intestinal permeability, as evaluated by reducing levels of colonic mucin-2, tight junction proteins, goblet cells and elevating serum level of fluorescein isothiocyanate-dextran 4. Correlation analysis showed a positive association between TMAO and SO. In addition, TMAO treatment aggravated the development of SO in HFD-fed aged rats through regulating the ROS-AKT/mTOR signaling pathway.

CONCLUSION

HFD leads to SO in natural aging rats, partially through the gut-microbiota-TMAO-muscle axis.

Association of metabolomic aging acceleration and body mass index phenotypes with mortality and obesity-related morbidities

This study aims to investigate the association between metabolomic aging acceleration and body mass index (BMI) phenotypes with mortality and obesity-related morbidities (ORMs). 85,458 participants were included from the UK Biobank. Metabolomic age was determined using 168 metabolites. The Chronological Age-Adjusted Gap was used to define metabolomically younger (MY) or older (MO) status. BMI categories were defined as normal weight, overweight, and obese. Participants were categorized into MY normal weight (MY-NW, reference), MY overweight (MY-OW), MY obesity (MY-OB), MO normal weight (MO-NW), MO overweight (MO-OW), and MO obesity (MO-OB). Mortality and 43 ORMs were identified through death registries and hospitalization records. Compared with MY-NW phenotype, MO-OB phenotype yielded increased risk of mortality and 32 ORMs, followed by MO-OW with mortality and 27 ORMs, MY-OB with mortality and 26 ORMs, MY-OW with 21 ORMs, and MO-NW with mortality and 14 ORMs. Consistently, MO-OB phenotype showed the highest risk of developing obesity-related multimorbidities, followed by MY-OB phenotype, MO-OW phenotype, MY-OW phenotype, and MO-NW phenotype. Additive interactions were found between metabolomic aging acceleration and obesity on CVD-specific mortality and 10 ORMs. Additionally, individuals with metabolomic aging acceleration had higher mortality and cardiovascular risk, even within the same BMI category. These findings suggest that metabolomic aging acceleration could help stratify mortality and ORMs risk across different BMI categories. Weight management should also be extended to individuals with overweight or obesity even in the absence of accelerated metabolomic aging, as they face increased healthy risk compared with MY-NW individuals. Additionally, delaying metabolic aging acceleration is needed for all metabolomically older groups, including those with normal weight.

Epigenetic Aging Acceleration in Obesity Is Slowed Down by Nutritional Ketosis Following Very Low-Calorie Ketogenic Diet (VLCKD): A New Perspective to Reverse Biological Age

Background/Objectives: Epigenetic clocks have emerged as a tool to quantify biological age, providing a more accurate estimate of an individual's health status than chronological age, helping to identify risk factors for accelerated aging and evaluating the reversibility of therapeutic strategies. This study aimed to evaluate the potential association between epigenetic acceleration of biological age and obesity, as well as to determine whether nutritional interventions for body weight loss could slow down this acceleration. Methods: Biological age was estimated using three epigenetic clocks (Horvath (Hv), Hannum (Hn), and Levine (Lv)) based on the leukocyte methylome analysis of individuals with normal weight (n = 20), obesity (n = 24), and patients with obesity following a VLCKD (n = 10). We analyzed differences in biological age estimates, the relationship between age acceleration and obesity, and the impact of VLCKD. Correlations were assessed between age acceleration, BMI, and various metabolic parameters. Results: Analysis of the epigenetic clocks revealed an acceleration of biological age in individuals with obesity (Hv = +3.4(2.5), Hn = +5.7(3.2), Lv = +3.9(2.7)) compared to a slight deceleration in individuals with normal weight. This epigenetic acceleration correlated with BMI (p < 0.0001). Interestingly, patients with obesity following a VLCKD showed a deceleration in estimated biological age, both in nutritional ketosis (Hv = -3.3(4.0), Hn = -6.3(5.3), Lv = -8.8(4.5)) and at endpoint (Hv = -1.1(4.3), Hn = -7.4(5.6), Lv = -8.2(5.3)). Relevantly, this slowdown in age is associated with BMI (p < 0.0001), ketonemia (p ≤ 0.001), and metabolic parameters (p < 0.05). Conclusions: Our findings highlight the applicability of epigenetic clocks to monitor obesity-related biological aging in precision medicine and show the potential efficacy of the VLCKD in slowing obesity-related epigenetic aging.

The association between gut microbiota and accelerated aging and frailty: a Mendelian randomization study

BACKGROUND

The recent observational studies have unveiled the correlation between the composition and dynamic alterations of the gut microbiome and aging; however, the causal relationship remains uncertain.

AIMS

The objective of this study is to investigate the causal relationship between the gut microbiome and accelerated aging as well as frailty, from a genetic perspective.

METHODS

We obtained data on the gut microbiome, intrinsic epigenetic age acceleration, and Frailty Index from published large-scale genome-wide association studies. A two-sample Mendelian randomization analysis was conducted primarily using inverse variance weighting model. We utilized the MR-Egger intercept analysis, IVW method, the Cochran Q test, and the leave-one-out analysis to assess the robustness of the results.

RESULTS

IVW analysis indicated a potential association between Peptococcus (OR: 1.231, 95% CI 1.013-1.497, P = 0.037), Dialister (OR: 1.447, 95% CI 1.078-1.941, P = 0.014) and Subdoligranulum (OR: 1.538, 95% CI 1.047-2.257, P = 0.028) with intrinsic epigenetic age acceleration; while Prevotella 7 (OR: 0.792, 95% CI 0.672-0.935, P = 0.006) was associated with a potential protective effect. Allisonella (OR: 1.033, 95% CI 1.005-1.063, P = 0.022), Howardella (OR: 1.026, 95% CI 1.002-1.050, P = 0.031) and Eubacterium coprostanoligenes (OR: 1.037, 95% CI 1.001-1.073, P = 0.042) were associated with an increased risk of frailty; conversely, Flavonifractor (OR: 0.954, 95% CI 0.920-0.990, P = 0.012) and Victivallis (OR: 0.984, 95% CI 0.968-1.000, P = 0.049) appeared to exhibit a potential protective effect against frailty.

CONCLUSION

The findings of this study provide further evidence for the genetic correlation between gut microbiota and accelerated aging as well as frailty, enhancing the understanding of the role of gut microbiota in aging-related processes. However, the underlying mechanisms and potential clinical applications require further investigation before any targeted interventions can be developed.

Antiageing strategy for neurodegenerative diseases: from mechanisms to clinical advances

In the context of global ageing, the prevalence of neurodegenerative diseases and dementia, such as Alzheimer's disease (AD), is increasing. However, the current symptomatic and disease-modifying therapies have achieved limited benefits for neurodegenerative diseases in clinical settings. Halting the progress of neurodegeneration and cognitive decline or even improving impaired cognition and function are the clinically meaningful goals of treatments for neurodegenerative diseases. Ageing is the primary risk factor for neurodegenerative diseases and their associated comorbidities, such as vascular pathologies, in elderly individuals. Thus, we aim to elucidate the role of ageing in neurodegenerative diseases from the perspective of a complex system, in which the brain is the core and peripheral organs and tissues form a holistic network to support brain functions. During ageing, the progressive deterioration of the structure and function of the entire body hampers its active and adaptive responses to various stimuli, thereby rendering individuals more vulnerable to neurodegenerative diseases. Consequently, we propose that the prevention and treatment of neurodegenerative diseases should be grounded in holistic antiageing and rejuvenation means complemented by interventions targeting disease-specific pathogenic events. This integrated approach is a promising strategy to effectively prevent, pause or slow down the progression of neurodegenerative diseases.

Association between body roundness index and stroke results from the 1999-2018 NHANES

IMPORTANCE

Obesity, especially visceral obesity, is a controllable risk factor associated with the incidence of stroke. The body roundness index (BRI) bridges the gap between traditional anthropometric methods of assessing fat distribution to predict the percentage of body fat and visceral adipose tissue, which can be used to decipher its population-based characteristics and potential association with stroke.

OBJECTIVE

The negative impact of accumulated visceral obesity on cerebrovascular health has been widely documented. However, the association between BRI and stroke has never been reported before. The purpose of this study was to elucidate the connection between BRI and the general incidence of stroke in the US population.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study extracted cross-sectional data from 39,454 U.S. adults (aged ≥20 years) from documents related to the National Health and Nutrition Examination Survey (NHANES) from 1999 through 2018.

METHODS

We evaluated the relationship between BRI and stroke using weighted logistic regression analysis, and we looked at any possible nonlinear relationships using restricted cubic spline (RCS) regression. Additionally, subgroup analysis and interaction tests were carried out.

RESULTS

The study involved 39,454 participants, of whom 1,427 (3.6 %) had a stroke. Fully adjusted logistic regression models showed that BRI was positively associated with stroke, with a 5.7 % increase in stroke incidence per unit increase in BRI (OR = 1.057, 95 % CI = 1.009,1.108, P = 0.020). RCS analysis revealed a nonlinear association, suggesting an elevated risk of stroke before the inflection point of 8.489. This positive correlation was consistent across settings, according to subgroup analyses and interaction tests (P > 0.05 for all interactions).

CONCLUSIONS AND RELEVANCE

There is a nonlinear positive correlation between BRI and stroke, according to this national cohort study. These results support the use of the BRI as a screening tool for assessing stroke risk; yet, because cross-sectional studies have inherent limitations, more thorough research is required until the BRI has been consistently validated in additional independent cohorts.

Obesity and overweight are common among hospitalized patients and are associated with specific causes of admission to an internal medicine department: a cross-sectional study

PURPOSE

Data on the prevalence of obesity among hospitalized patients are limited. Our objective was to capture the rates of overweight and obesity among people admitted to an internal medicine department and to explore a potential association between body mass index (BMI) and causes of hospitalization.

METHODS

Demographic and anthropometric parameters and cause of admission were recorded in all patients admitted to our department over a 30-day period.

RESULTS

One hundred and eighteen patients with a mean age of 71.84 years and a mean BMI of 26.85 kg/m2 were included in the analysis. Among study participants, 53.25% were living with overweight and obesity. Patients admitted for hepatobiliary disease had a higher BMI compared to those admitted for other diseases of the gastrointestinal tract (P < 0.001).

CONCLUSIONS

More than half of patients admitted to an internal medicine department live with obesity or overweight, the specific reasons for admission being associated with a higher BMI.

Adiponectin signaling regulates urinary bladder function by blunting smooth muscle purinergic contractility

Lower urinary tract symptoms (LUTS) affect approximately 50% of the population over 40 years of age and are strongly associated with obesity and metabolic syndrome. Adipose tissue plays a key role in obesity/metabolic syndrome by releasing adipokines that regulate systemic energy/lipid metabolism, insulin resistance, and inflammation. Adiponectin (ADPN), the most abundant adipokine, modulates energy/metabolism homeostasis through its insulin-sensitizing and antiinflammatory effects. Human plasma ADPN levels are inversely associated with obesity and diabetes. To the best of our knowledge, the role of adipokines such as ADPN in the LUTS associated with obesity/metabolic syndrome remains unknown. We have tested such a possible role in a global ADPN-knockout (Adpn-/-) mouse model. Adpn-/- mice exhibited increased voiding frequency, small voids, and reduced bladder smooth muscle (BSM) contractility, with absence of purinergic contraction. Molecular examination indicated significantly altered metabolic and purinergic pathways. The ADPN receptor agonist AdipoRon was found to abolish acute BSM contraction. Intriguingly, both AMPK activators and inhibitors also abolished BSM purinergic contraction. These data indicate the important contribution of what we believe is a novel ADPN signaling pathway to the regulation of BSM contractility. Dysregulation of this ADPN signaling pathway might be an important mechanism leading to LUTS associated with obesity/metabolic syndrome.

Biomonitoring of Serum Inorganic Element Concentrations in Morbidly Obese Patients: Impact of Bariatric Surgery

Adipose tissue, in addition to serving as energy storage, can store lipophilic substances, some of which may pose a health risk if massively mobilized during rapid weight loss. This study aimed to biomonitor inorganic elements in obese patients undergoing bariatric surgery and analyze the role of sociodemographic factors. ICP-MS was employed to quantify 55 elements, including elements identified from the ATSDR's Substance Priority List and rare-earth elements, in serum samples of 58 obese patients before and after bariatric surgery. A total of 39 out of 55 elements were detected, either before or after surgery, in at least one patient. Serum concentrations of gold, copper, mercury, platinum, and selenium significantly decreased after surgery. Serum concentrations of iron and zinc were significantly lower before surgery. Age, sex, diabetes status, arterial hypertension, and family history of obesity were demographic factors associated with the concentration of elements. Correlation analyses showed significant associations between elements and total lipid concentration or body mass index. Our findings indicate a complex interplay between inorganic elements and body fat and provide relevant information regarding the biomonitoring of these chemical elements in a specific and understudied population.

The Anti-Aging Mechanism of Metformin: From Molecular Insights to Clinical Applications

Aging represents a complex biological phenomenon marked by the progressive deterioration of physiological functions over time, reduced resilience, and increased vulnerability to age-related diseases, ultimately culminating in mortality. Recent research has uncovered diverse molecular mechanisms through which metformin extends its benefits beyond glycemic control, presenting it as a promising intervention against aging. This review delves into the anti-aging properties of metformin, highlighting its role in mitochondrial energy modulation, activation of the AMPK-mTOR signaling pathway, stimulation of autophagy, and mitigation of inflammation linked to cellular aging. Furthermore, we discuss its influence on epigenetic modifications that underpin genomic stability and cellular homeostasis. Metformin's potential in addressing age-associated disorders including metabolic, cardiovascular, and neurodegenerative diseases is also explored. The Targeting Aging with Metformin (TAME) trial aims to provide key evidence on its efficacy in delaying aging in humans. Despite these promising insights, significant challenges persist in gaining a more comprehensive understanding into its underlying mechanisms, determining optimal dosing strategies, and evaluating long-term safety in non-diabetic populations. Addressing these challenges is crucial to fully realizing metformin's potential as an anti-aging therapeutic.

Challenges in the diagnosis of heart failure with preserved ejection fraction in individuals with obesity

The rising prevalence of obesity and its association with heart failure with preserved ejection fraction (HFpEF) highlight an urgent need for a diagnostic approach tailored to this population. Diagnosing HFpEF is hampered by the lack of a single non-invasive diagnostic criterion. While this makes a firm diagnosis of HFpEF already notoriously difficult in the general population, it is even more challenging in individuals with obesity. The challenges stem from a range of factors, including the use of body mass index as a conceptually suboptimal indicator of health risks associated with increased body mass, symptom overlap between HFpEF and obesity, limitations in physical examination, difficulties in electrocardiographic and echocardiographic evaluation, and reduced diagnostic sensitivity of natriuretic peptides in individuals with obesity. In this review, we examine these diagnostic challenges and propose a diagnostic algorithm specifically tailored to improve the accuracy and reliability of HFpEF diagnosis in this growing patient demographic.

Recent Advances in the Anti-Obesity Benefits of Phytoconstituents: From Phytochemistry to Targeting Novel-Systems

Obesity is a metabolic disorder that has become a global health concern. The existing pharmaceutical drugs for treating obesity have some side effects. Compounds from natural sources are prospective substitutes for treating chronic diseases such as obesity, with the added advantages of being safe and cost-effective. However, due to factors such as poor solubility, low bioavailability, and instability in the physiological environment, the therapeutic efficacy of phytoconstituents is limited. Nowadays, developing nanoscaled systems has emerged as a vital strategy for enhancing the delivery and therapeutic effect of phytoconstituents. The present study discusses and categorizes phytoconstituents with anti-obesity effects and concludes the main mechanisms underlying their effects. Importantly, strategies used to develop phytoconstituent-based nano-drug delivery systems (NDDS) for obesity treatment that show improved efficacy relative to traditional administration routes are reviewed. Finally, the progress of research on phytoconstituent-based NDDS for obesity treatment is summarized to provide a reference for the development of safe and effective treatment strategies for obesity.

Exploring the global impact of obesity and diet on dementia burden: the role of national policies and sex differences

Obesity is a significant modifiable risk factor for dementia. This study aims to quantify the global impact of obesity on dementia burden and examine how national strategies for managing overweight/obesity and dietary factors influence dementia prevalence and mortality, with a focus on sex-specific differences. We used data from the Global Burden of Disease (GBD) and World Health Organization (WHO) to evaluate the association between obesity age-standardized prevalence rate (ASPR) and dementia age-standardized mortality rate (ASMR) and ASPR across 161 countries. A two-step multivariate analysis adjusted for socioeconomic and lifestyle factors was performed. Temporal trends in dementia were analyzed based on the presence of national obesity management strategies and varying dietary scores. A 1% increase in national obesity prevalence was associated with a 0.36% increase in dementia mortality (OR: 1.0036; 95% CI: 1.0028-1.0045) in males and 0.12% in females (OR: 1.0012; 95% CI: 1.0007-1.0018). A 1% increase in national obesity ASPR was associated with an increase in ASPR of dementia by 0.26% for males (OR: 1.0026, 95% CI: 1.0024-1.0028) and 0.05% for females (OR: 1.0005, 95% CI: 1.0004-1.0006). Males exhibited a higher susceptibility to obesity-related dementia. Countries with national obesity management strategies showed a significantly greater reduction in dementia mortality, particularly among females (P = 0.025). Higher dietary scores were associated with a more significant decrease in dementia prevalence across both sexes. Rising obesity prevalence is linked to increased dementia burden globally, with males being more vulnerable to this relationship. National management of overweight/obesity and healthier dietary habits may help mitigate the dementia burden, emphasizing the need for integrated public health interventions.

Immunometabolic Changes Following Gastric Bypass and Sleeve Gastrectomy: A Comparative Study

BACKGROUND

Immunometabolism is the interaction between immune system and nutrient metabolism. Severe obesity is considered a state of meta-inflammation associated with obesity that influences the development of chronic-degenerative diseases.

OBJECTIVE

We aimed to establish the immunometabolic differences in bariatric patients and to determine whether cellular immunity is associated with metabolic changes.

METHODOLOGY

We conducted an observational study in patients who underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB). We explored the differences in the immunometabolic profile before and after surgery in the study group, by surgical technique, and we evaluated the changes in immunological variables as a function of metabolic variables with correlation analysis.

RESULTS

The follow-up rate was 88.7%. After the intervention, there were changes in cellular immunity, with a decrease in effector T lymphocytes (CD8+CD28-) and an increase in B lymphocytes, memory helper T cells, and cytotoxic T lymphocytes. LSG resulted in a greater decrease in (CD4+CD62-) T lymphocytes compared with LRYGB. Patients who underwent surgery with LRYGB presented greater clinical and metabolic improvements, as well as improvement of obesity-associated medical problems. Women who underwent LRYGB showed a greater reduction in fat-free mass compared with women who underwent LSG.

CONCLUSION

Bariatric surgery, mainly LRYGB, leads to immunometabolic changes and improves associated medical problems.

Tissue-specific effects of dietary protein on cellular senescence are mediated by branched-chain amino acids

Dietary protein is a key regulator of healthy aging in both mice and humans. In mice, reducing dietary levels of the branched-chain amino acids (BCAAs) recapitulates many of the benefits of a low protein diet; BCAA-restricted diets extend lifespan, reduce frailty, and improve metabolic health, while BCAA supplementation shortens lifespan, promotes obesity, and impairs glycemic control. Recently, high protein diets have been shown to promote cellular senescence, a hallmark of aging implicated in many age-related diseases, in the liver of mice. Here, we test the hypothesis that the effects of high protein diets on metabolic health and on cell senescence are mediated by BCAAs. We find that reducing dietary levels of BCAAs protects male and female mice from the negative metabolic consequences of both normal and high protein diets. Further, we identify tissue-specific effects of BCAAs on cellular senescence, with restriction of all three BCAAs - but not individual BCAAs - protecting from hepatic cellular senescence while potentiating cell senescence in white adipose tissue. We find that the effects of BCAAs on hepatic cellular senescence are cell-autonomous, with lower levels of BCAAs protecting cultured cells from antimycin-A induced senescence. Our results demonstrate a direct effect of a specific dietary component on a hallmark of aging and suggest that cellular senescence may be highly susceptible to dietary interventions.

The associations between the energy and timing of sugar-sweetened beverage intake and phenotypic age acceleration in U.S. adults: a cross-sectional survey of NHANES 2007-2010

OBJECTIVES

The relationship between sugar-sweetened beverage (SSB) intake and phenotypic age acceleration (PhenoAgeAccel) is unclear. The aim of this study was to explore the associations between the energy and timing of SSB intake and PhenoAgeAccel in adults.

METHODS

A cross-sectional analysis was conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010, which involved U.S. adults aged 20 to 79 years. The assessment and estimation of SSB intake were conducted through 24-hour dietary recall interviews, categorizing participants into three groups: non-intake, low moderate-intake, and moderate-high-intake. Furthermore, SSB consumers were divided into three time intervals based on intake timing: dawn-to-forenoon (5:00 a.m. to 11:59 a.m.), noon-to-afternoon (12:00 p.m. to 17:59 p.m.), and dusk-to-night (18:00 p.m. to 4:59 a.m.). Multivariable linear regression models were employed to evaluate the associations between SSB intake (energy and timing) and PhenoAgeAccel. Additionally, stratified analyses and interaction analyses were conducted. Furthermore, obesity was assessed via two distinct metrics: the body roundness index (BRI) and the body mass index (BMI). Mediation analysis was conducted to investigate the mediating effect of obesity on the relationship between the energy of SSB intake and PhenoAgeAccel.

RESULTS

After controlling for covariates, SSB intake (per 100 kcal/day) was positively correlated with PhenoAgeAccel (β = 0.179, 95% confidence interval [CI]: 0.086-0.271). The moderate-high-intake group presented a significantly greater PhenoAgeAccel than the non-intake group (β = 1.023, 95% CI: 0.414-1.632). This relationship remained stable across stratified analyses. Compared with those who abstained from SSB, those who consumed SSB during the dusk-to-night period exhibited notably elevated PhenoAgeAccel (β = 0.915, 95% CI: 0.316-1.514). A significant interactive effect of smoking on the SSB intake timing-PhenoAgeAccel association was observed (P for interaction = 0.002). Mediation analysis revealed that both BRI and BMI significantly mediated the relationship between energy intake from SSB and PhenoAgeAccel, with mediation proportions of 16.29% and 16.21%, respectively.

CONCLUSION

Our study revealed a positive correlation between SSB energy intake and PhenoAgeAccel, which may be partially mediated by obesity. Moreover, consuming SSB during the dusk-to-night period may increase PhenoAgeAccel.

Flll32, a curcumin analog, improves adipose tissue thermogenesis

Adipose tissue is a key regulator of systemic energy homeostasis and improving adipose tissue function provides a brand-new theoretical reference for the prevention and treatment of obesity. FLLL32, a curcumin analog, can hinder various carcinogenic processes, however, its role in adipose tissue has not been fully elucidated. In this study, we observed that FLLL32 treatment significantly improved cold intolerance and reduced white adipose tissue (WAT) adipocyte size in mice, but had no effect on body weight and adipose tissues weight. Furthermore, FLLL32 treatment upregulated the expression level of uncoupling protein 1 and downregulated the expression level of peroxisome proliferator-activated receptor gamma in adipose tissue. Additionally, FLLL32 promoted the mRNA level of transferrin receptor protein 1, a key iron transporter on the cell membrane, and the lipid peroxidation in inguinal WAT. Finally, FLLL32 significantly inhibited the differentiation and maturation of preadipocytes. In summary, our results demonstrated that FLLL32 plays a crucial role in regulating adipose tissue function.

Correlation between lipid accumulation product and epigenetic age acceleration in American adults: a cross-sectional analysis using NHANES data

BACKGROUND

The risks of obesity and epigenetic age acceleration (EAA) have drawn widespread attention. Lipid accumulation product (LAP) is a simple and reliable indicator of obesity; however, the relationship between LAP and EAA remains unclear.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2002 were used. The EAA was assessed using a self-administered questionnaire in the database. LAP was calculated based on triglycerides and waist circumference. The association between LAP and EAA was analyzed using logistic regression models, subgroup analysis, and smooth curve fitting.

RESULTS

A total of 1796 participants were included in the study, of whom 1055 had EAA. After adjusting for relevant covariates, participants with EAA generally had higher LAP levels than those without EAA (258.1 vs. 244.6). Logistic regression analysis showed that individuals in the highest LAP quartile (Q4) were more likely to have EAA than those in the lowest quartile (Q1) (OR = 1.77; 95% CI 1.31-2.39; P < 0.001). The area under the curve of the adjusted logistic regression analysis was 0.706.

CONCLUSION

This research indicates that elevated LAP levels are independently linked to an increased risk of EAA, and early intervention to reduce high LAP levels is necessary to mitigate the progression of EAA.

ANGPTL4-mediated microglial lipid droplet accumulation: Bridging Alzheimer's disease and obesity

Increasing evidence suggests that metabolic disorders such as obesity are implicated in the development of Alzheimer's disease (AD). The pathological buildup of lipids in microglia is regarded as a key indicator in brain aging and the progression of AD, yet the mechanisms behind this process remain uncertain. The adipokine ANGPTL4 is strongly associated with obesity and is thought to play a role in the advancement of neurodegenerative diseases. This study utilized RNA sequencing to identify differential expression in lipid-accumulating BV2 microglia and investigated the potential mechanism through ANGPTL4 overexpression in BV2. Subsequently, animal models and clinical data were employed to further explore alterations in circulating ANGPTL4 levels in AD. RNA sequencing results indicated a correlation between ANGPTL4 and microglial lipid accumulation. The overexpression of ANGPTL4 in microglia resulted in increased secretion of inflammatory factors, elevated oxidative stress levels, and diminished antiviral capacity. Furthermore, when simulating the coexistence of AD and obesity through combined treatment with Amyloid-Beta 1-42 peptide (Aβ) and Free Fatty Acids (FFA) in vitro, we observed a notable upregulation of ANGPTL4 expression, highlighting its potential role in the interplay between AD and obesity. In vivo experiments, we also observed a significant increase in ANGPTL4 expression in the hippocampus and plasma of APP/PS1 mice compared to wild-type controls. This was accompanied by heightened microglial activation and reduced expression of longevity-related genes in the hippocampus. Clinical data from the UK Biobank indicated that plasma ANGPTL4 levels are elevated in patients with AD when compared to healthy controls. Moreover, significantly higher ANGPTL4 levels were observed in obese AD patients relative to their non-obese counterparts. Our findings suggest that ANGPTL4-mediated microglial aging may serve as a crucial link between AD and obesity, proposing ANGPTL4 as a potential biomarker for AD.

Associations of accelerated biological aging and metabolic heterogeneity of obesity with rheumatoid arthritis: a prospective cohort study

OBJECTIVE

To evaluate the associations between biological aging, metabolic heterogeneity of obesity, and rheumatoid arthritis (RA).

METHODS

This prospective cohort study analyzed 268,184 individuals from the UK Biobank. Biological age was estimated using phenotypic age (PhenoAge), Klemera-Doubal methods (KDM-BA), and telomere length. We calculated KDM-BA acceleration and PhenoAge acceleration after subtracting the effect of chronological age by regression residual. The metabolic heterogeneity of obesity can be evaluated by four BMI metabolic phenotypes, namely metabolically unhealthy normal weight (MUNW), metabolically healthy normal weight (MHNW), metabolically unhealthy overweight/obesity (MUOO), and metabolically healthy overweight/obesity (MHOO). Cox models were employed to estimate the associations between biological aging, metabolic heterogeneity of obesity, and RA risk.

RESULTS

A total of 2842 patients experienced RA during a mean follow-up time of 12.21 years. A standard deviation (SD) increase in KDM-BA acceleration and PhenoAge acceleration was associated with an increased risk of RA by 13% (hazard ratio = 1.13; 95% CI, 1.09-1.17) and 39% (HR = 1.39; 95% CI, 1.34-1.44), respectively. A SD increase in telomere length was associated with a reduced risk of RA by 5% (HR = 0.95; 95% CI, 0.91-0.98). Compared to the MHNW group, the MUOO group was associated with a 51% increase in the risk of incident RA. In the joint effect analysis, compared to the MHNW + KDM-BA younger subgroup, the HR (95% CI) for RA was 1.68 (1.48, 1.90) in the MUOO + KDM-BA older subgroup.

CONCLUSION

Accelerated biological aging may heighten the susceptibility to RA, particularly in individuals with obesity or metabolic dysfunction. Key Points •Accelerated biological aging increases the risk of developing RA. •Overweight/obese people with a healthy metabolism have a higher risk of RA than those with normal weight and healthy metabolism. •The BMI metabolic phenotype has a strong modifying effect on the association between KDM-BA/PhenoAge and RA risk.

Association between inflammatory markers, body composition and frailty in home-dwelling elderly: an 8-year follow-up study

Frailty has been linked to inflammation and changes in body composition, but the findings are inconsistent. To explore this, we used the Frailty Index (FI) definition to (1) investigate the association between levels of inflammatory markers (baseline) and change in FI score after 8 years of follow-up and (2) investigate the longitudinal associations between inflammatory markers, body composition, and frailty. Home-dwelling elderly (≥ 70 years) were invited to participate in the study and re-invited to a follow-up visit 8 years later. This study includes a total of 133 participants. The inflammatory markers included were high-sensitive C-reactive protein (hs-CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and glycoprotein acetyls (Gp-acetyls). We used the body composition markers fat mass, fat-free mass, and waist circumference. The FI score consisted of 38 variables. Additional clinical assessments such as blood pressure and body mass index (BMI), as well as information about daily medications, were collected at both visits. Linear regression model and Spearman's rank correlation were used to investigate associations. We showed that the FI score increased after 8 years, and participants with higher hs-CRP levels at baseline had the largest change in the FI score. Changes in fat mass were significantly correlated with changes in hs-CRP and IL-6, and changes in waist circumference were significantly correlated with changes in TNF-α. The use of drugs increased during the 8 years of follow-up, which may have attenuated the associations between inflammation and frailty. However, elevated concentrations of hs-CRP in the elderly may be associated with an increased risk of frailty in subsequent years.

Self-rated health, epigenetic ageing, and long-term mortality in older Australians

Self-rated health (SRH) is a subjective indicator of overall health based on a single questionnaire item. Previous evidence found that it is a strong predictor of mortality, although the underlying mechanism is poorly understood. Epigenetic age is an objective, emerging biomarker of health, estimated using DNA methylation data at hundreds of sites across the genome. This study aimed to assess the overlap and interaction between SRH and epigenetic ageing in predicting mortality risk. We used DNA methylation data from 1059 participants in the Melbourne Collaborative Cohort Study (mean age: 69 years) to calculate three age-adjusted measures of epigenetic ageing: GrimAge, PhenoAge, and DunedinPACE. SRH was assessed using a five-category questionnaire item ("excellent, very good, good, fair, poor"). Cox models were used to assess the associations of SRH, epigenetic ageing, and their interaction, with all-cause mortality over up to 17 years of follow-up (Ndeaths = 345). The association of SRH with mortality per category increase was HR = 1.29; 95%CI: 1.14-1.46. The association was slightly attenuated after adjusting for all three epigenetic ageing measures (HR = 1.25, 95%CI: 1.10-1.41). A strong gradient was observed in the association of GrimAge (Pinteraction = 0.006) and DunedinPACE (Pinteraction = 0.002) with mortality across worsening SRH strata. For example, the association between DunedinPACE and mortality in participants with "excellent" SRH was HR = 1.02, 95%CI: 0.73-1.43 and for "fair/poor" HR = 1.72, 95%CI: 1.35-2.20. SRH and epigenetic ageing were synergistic risk factors of mortality in our study. These findings suggest that consideration of subjective and objective factors may improve general health assessment, which has implications for the ongoing development of molecular markers of ageing.

Ramadan fasting model modulates biomarkers of longevity and metabolism in male obese and non-obese rats

The health advantages of Ramadan fasting, a time-restricted eating from dawn to dusk, have garnered attention. Nevertheless, prior observational studies have found inconsistent findings because of challenges regulating variables such as sleep patterns, dietary habits, and physical activity. This study sought to investigate the impact of the Ramadan fasting model (RFM) on longevity and metabolic biomarkers in obese and non-obese rats. For 12 weeks, 48 male Wistar albino rats were separated into two groups and fed either a standard or a high-fat diet (HFD). During the final four weeks, rats in each group were separated into four subgroups to investigate the effect of RFM with/without training (on Treadmill) or glucose administration on the biomarkers of interest. The HFD groups subjected to RFM had significantly lower Insulin-like growth factor 1 (IGF-1) and mechanistic target of rapamycin (mTOR) serum, whereas AMPK, anti-inflammatory, and antioxidative stress serum levels were significantly higher. All groups reported decreased serum levels of Interleukin-6 (IL-6) and Tumor Necrosis Factor-alpha (TNF-α) compared to the HFD control group. Furthermore, the Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR) results indicated a significant elevation in the TP53 gene expression in groups subjected to RFM. The data indicate that RFM can improve longevity and metabolic biomarkers and reduce pro-inflammation and oxidative stress. Also, RFM improves anti-inflammatory and antioxidant markers in HFD-induced obese rats.

Glutathione peroxidase 3 is essential for countering senescence in adipose remodelling by maintaining mitochondrial homeostasis

Adipose tissue senescence is a precursor to organismal aging and understanding adipose remodelling contributes to discovering novel anti-aging targets. Glutathione peroxidase 3 (GPx3), a critical endogenous antioxidant enzyme, is diminished in the subcutaneous adipose tissue (sWAT) with white adipose expansion. Based on the active role of the antioxidant system in counteracting aging, we investigated the involvement of GPx3 in adipose senescence. We determined that knockdown of GPx3 in adipose tissue by adeno-associated viruses impaired mitochondrial function in mice, increased susceptibility to obesity, and exacerbated adipose tissue senescence. Impairment of GPx3 may cause mitochondrial dysfunction through inner mitochondrial membrane disruption. Adipose reshaping management (cold stimulation and intermittent diet) counteracted the aging of tissues, with an increase in GPx3 expression. Overall metabolic improvement induced by cold stimulation was partially attenuated when GPx3 was depleted. GPx3 may be involved in adipose browning by interacting with UCP1, and GPx3 may be a limiting factor for intracellular reactive oxygen species (ROS) accumulation during stem cell browning. Collectively, these findings emphasise the importance of restoring the imbalanced redox state in adipose tissue to counteract aging and that GPx3 may be a potential target for maintaining mitochondrial homeostasis and longevity.

Decoding visceral adipose tissue molecular signatures in obesity and insulin resistance: a multi-omics approach

OBJECTIVE

Obesity-associated insulin resistance (IR) is responsible for considerable morbidity and mortality globally. Despite vast genomic data, many areas, from pathogenesis to management, still have significant knowledge gaps. We aimed to characterize visceral adipose tissue (VAT) in obesity and IR through a multi-omics approach.

METHODS

We procured data on VAT samples from the Gene Expression Omnibus (GEO) for the following two groups: 1) populations with obesity (n = 34) versus those without (n = 26); and 2) populations with obesity and IR (n = 15) versus those with obesity but without IR (n = 15). Gene set enrichment, protein-protein interaction network construction, hub gene identification, and drug-gene interactions were performed, followed by regulatory network prediction involving transcription factors (TFs) and microRNAs (miRNAs).

RESULTS

Interleukin signaling pathways, cellular differentiation, and regulation of immune response revealed a significant cross talk between VAT and the immune system. Other findings include cancer pathways, neurotrophin signaling, and aging. A total of 10 hub genes, i.e., STAT1, KLF4, DUSP1, EGR1, FOS, JUN, IL2, IL6, MMP9, and FGF9, 24 TFs, and approved hub gene-targeting drugs were obtained. A total of 10 targeting miRNAs (e.g., hsa-miR-155-5p, hsa-miR-34a-5p) were associated with obesity and IR-related pathways.

CONCLUSIONS

Our multi-omics integration method revealed hub genes, TFs, and miRNAs that can be potential targets for investigation in VAT-related inflammatory processes and IR, therapeutic management, and risk stratifications.

Chronic trans fatty acid consumption shortens lifespan in male Drosophila melanogaster on a high-sugar and high-fat diet

Aging entails the progressive decline in the body's self-regulation and functionality over time. Notably, obesity and aging exhibit parallel phenotypes, with obesity further accelerating the aging process across multiple dimensions and diminishing lifespan. In this study, we explored the impact of trans fatty acid (TFA) consumption on the overall health and lifespan of male Drosophila melanogaster under an isocaloric high-sugar and high-fat diet. Our results indicate that TFA intake results in a shortened lifespan, elevated body weight, and increased triglyceride levels in flies fed a high-sugar and high-fat diet with equivalent caloric intake. Additionally, TFA exposure induces oxidative stress, locomotor deficits, and damage to the intestinal barrier in flies. Collectively, chronic TFA consumption expedites the aging process and reduces the lifespan of male Drosophila melanogaster. These results contribute supplementary evidence regarding the adverse health effects associated with TFAs.

Adiponectin Signaling Regulates Urinary Bladder Function by Blunting Smooth Muscle Purinergic Contractility

Lower urinary tract symptoms (LUTS) affect ∼ 50% of the population aged >40 years and are strongly associated with obesity and metabolic syndrome. Adipose tissue plays a key role in obesity/metabolic syndrome by releasing adipokines that regulate systemic energy/lipid metabolism, insulin resistance, and inflammation. Adiponectin (ADPN), the most abundant adipokine, modulates energy/metabolism homeostasis through its insulin-sensitizing and anti-inflammatory effects. Human plasma ADPN levels are inversely associated with obesity and diabetes. The role of adipokines such as ADPN in the LUTS associated with obesity/metabolic syndrome remains unknown. We have tested such a possible role in a global ADPN knockout mouse model ( Adpn -/- ). Adpn -/- mice exhibited increased voiding frequency, small voids, and reduced bladder smooth muscle (BSM) contractility with absence of purinergic contraction. Molecular examination indicated significantly altered metabolic and purinergic pathways. The ADPN receptor agonist AdipoRon was found to abolish acute BSM contraction. Intriguingly, both AMPK activators and inhibitors also abolished BSM purinergic contraction. These data indicate the important contribution of a novel ADPN signaling pathway to the regulation of BSM contractility. Dysregulation of this ADPN signaling pathway might be an important mechanism leading to LUTS associated with obesity/metabolic syndrome.

ARTICLE HIGHLIGHTS

Lower urinary tract symptom (LUTS) is strongly associated with obesity and metabolic syndrome, however, the underlying molecular mechanisms are missing. Dysregulation of adipokine signaling could be the link for this association.Whether adiponectin, the most abundant adipokine, plays a role in regulating bladder function and dysfunction.Mice null for adiponectin exhibited increased voiding frequency, small voids, and reduced bladder smooth muscle contractility, with corresponding metabolic and purinergic pathway changes.Dysregulation of adiponectin signaling might be an important mechanism leading to LUTS associated with obesity/metabolic syndrome.

Biological aging accelerates hepatic fibrosis: Insights from the NHANES 2017-2020 and genome-wide association study analysis

INTRODUCTION AND OBJECTIVES

This study aimed to investigate the association between biological aging and liver fibrosis in patients with metabolic dysfunction-associated steatotic liver disease (MASLD).

MATERIALS AND METHODS

We analyzed NHANES 2017-2020 data to calculate phenotypic age. Hepatic steatosis and fibrosis were identified using controlled attenuation parameters (CAP), fatty liver index (FLI) and transient elastography (TE). The odds ratios (ORs) and 95 % confidence intervals (CI) for significant MASLD fibrosis were calculated using multivariate logistic regression, and subgroup analyses were performed. We explored the potential causal relationship between telomere length and liver fibrosis using Mendelian randomization (MR). Additionally, we used the expression quantitative trait loci (eQTL) method and GSE197112 data to identify genes related to liver fibrosis and senescence. Finally, the APOLD1 expression was validated using GSE89632.

RESULTS

Phenotypic age was associated with liver fibrosis occurrence in MASLD (OR = 1.08, 95 % CI 1.05-1.12). Subgroup analyses by BMI and age revealed differences. For obese or young to middle-aged MASLD patients, phenotypic age is significantly associated with liver fibrosis. (OR = 1.14, 95 % CI 1.10-1.18; OR = 1.07, 95 % CI 1.01-1.14 and OR = 1.14, 95 % CI 1.07-1.22). MR revealed a negative association between telomere length and liver fibrosis (IVW method: OR = 0.63288, 95 % CI 0.42498-0.94249). The gene APOLD1 was identified as a potential target through the intersection of the GEO dataset and eQTL genes.

CONCLUSIONS

This study emphasized the link between biological aging and fibrosis in young to middle-aged obese MASLD patients. We introduced phenotypic age as a clinical indicator and identified APOLD1 as a potential therapeutic target.

Overweight and obesity significantly increase colorectal cancer risk: a meta-analysis of 66 studies revealing a 25-57% elevation in risk

The incidence of colorectal cancer (CRC) has been steadily rising, and obesity has been identified as a significant risk factor. Numerous studies suggest a strong correlation between excess body weight and increased risk of CRC, but comprehensive quantification through pooled analysis remains limited. This study aims to systematically review and meta-analyze the existing literature to evaluate the association between obesity and CRC risk, considering variations across sex and study designs. A systematic literature search was conducted in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science to identify randomized controlled trials and human clinical trials from 1992 to 2024. Statistical analysis was performed using the https://metaanalysisonline.com web application using a random effects model to estimate the pooled hazard rates (HR). Forest plots, funnel plots, and Z-score plots were utilized to visualize results. We identified 52 clinical trials and 14 case-control studies, encompassing a total of 83,251,050 and 236,877 subjects, respectively. The pooled analysis indicated that obesity significantly increased the prevalence of CRC (HR = 1.36, 95% CI = 1.24-1.48, p < 0.01). This effect was consistent across sexes, with HRs of 1.57 (95% CI = 1.38-1.78, p = 0.01) for males and 1.25 (95% CI = 1.14-1.38, p < 0.01) for females. Case-control studies specifically showed an effect, but with marginal significance only (HR = 1.27, 95% CI = 0.98-1.65, p = 0.07). The Z-score plot indicated the need for additional analysis in the case-control group. A significant heterogeneity was observed across studies in all four settings. This meta-analysis provides robust evidence that obesity is a significant risk factor for colorectal cancer, with an overall hazard rate indicating a 36% increased risk. The effect is pronounced across both sexes, with males showing a slightly higher risk compared to females. Although case-control studies showed a weaker association, the overall trend supports the link between obesity and CRC. These results underscore the importance of public health interventions aimed at reducing obesity to potentially lower the risk of colorectal cancer.

Phenotypes of Polish primary care patients using hierarchical clustering: Exploring the risk of mortality in the LIPIDOGEN2015 study cohort

BACKGROUND

Comorbidities in primary care do not occur in isolation but tend to cluster together causing various clinically complex phenotypes. This study aimed to distinguish phenotype clusters and identify the risks of all-cause mortality in primary care.

METHODS

The baseline cohort of the LIPIDOGEN2015 sub-study involved 1779 patients recruited by 438 primary care physicians. To identify different phenotype clusters, we used hierarchical clustering and investigated differences between clinical characteristics and mortality between clusters. We then performed causal analyses using causal mediation analysis to explore potential mediators between different clusters and all-cause mortality.

RESULTS

A total of 1756 patients were included (mean age 51.2, SD 13.0; 60.3% female), with a median follow-up of 5.7 years. Three clusters were identified: Cluster 1 (n = 543) was characterised by overweight/obesity (body mass index ≥ 25 kg/m2), older (age ≥ 65 years), more comorbidities; Cluster 2 (n = 459) was characterised by non-overweight/obesity, younger, fewer comorbidities; Cluster 3 (n = 754) was characterised by overweight/obesity, younger, fewer comorbidities. Adjusted Cox regression showed that compared with Cluster 2, Cluster 1 had a significantly higher risk of all-cause mortality (HR 3.87, 95% CI: 1.24-15.91), whereas this was insignificantly different for Cluster 3. Causal mediation analyses showed that decreased protein thiol groups mediated the hazard effect of all-cause mortality in Cluster 1 compared with Cluster 2, but not between Clusters 1 and 3.

CONCLUSION

Overweight/obesity older patients with more comorbidities had the highest risk of long-term all-cause mortality, and in the young group population overweight/obesity insignificantly increased the risk in the long-term follow-up, providing a basis for stratified phenotypic risk management.

Involvement of Single Nucleotide Variants in the Klotho Gene Among Obesity Individuals with and without Type 2 Diabetes Mellitus in the Saudi Population

Purpose

Aging is characterized by the gradual physiological changes and alterations that accumulate over time in the human body. The combination of obesity and ageing can lead to an increased risk of serious health issues or death. Single nucleotide variants (SNVs) in the Klotho gene were commonly studied, including that in type 2 diabetes mellitus (T2DM).

Aim

The aim of this study is to examine the possible effect of SNVs in Klotho on the obese population in Saudi Arabia using middle-aged participants with and without T2DM.

Methods

This study consists of 100 controls and 100 obesity patients, in which 50 had T2DM and the remaining 50 were obese without T2DM. Genotyping was performed with PCR, and Sanger sequencing analysis was used to validate the molecular association.

Results

In this study, rs1207568 (p = 0.001-0.003) and rs9527025 (p = 0.001-0.00004) SNVs were associated with obesity cases. However, none of the genotypes or allele frequencies showed a positive association with the rs564481 SNV (p = 0.344-0.881). The multiple linear regression model showed that waist and hip were associated (p = 0.01-0.02). ANOVA analysis showed age (p = 0.04), hip (p = 0.002), SBP, and TC (p = 0.02) were associated. Finally, SNV (rs1207568 and rs95270250) and obesity (p < 0.001) associations were confirmed through gene multifactor dimensionality reduction analysis with gene-gene interaction, dendrogram, and graphical depletion method.

Conclusion

This study concludes that rs1207568 and rs9527025 SNVs are associated with obesity in the Saudi population. Additional genetical statistics showed significant association between dependent and independent variables. SNVs in Klotho play a role in the Saudi population's susceptibility to obesity.

Hypothalamic SLC7A14 accounts for aging-reduced lipolysis in white adipose tissue of male mice

The central nervous system has been implicated in the age-induced reduction in adipose tissue lipolysis. However, the underlying mechanisms remain unclear. Here, we show the expression of SLC7A14 is reduced in proopiomelanocortin (POMC) neurons of aged mice. Overexpression of SLC7A14 in POMC neurons alleviates the aging-reduced lipolysis, whereas SLC7A14 deletion mimics the age-induced lipolysis impairment. Metabolomics analysis reveals that POMC SLC7A14 increased taurochenodeoxycholic acid (TCDCA) content, which mediates the SLC7A14 knockout- or age-induced WAT lipolysis impairment. Furthermore, SLC7A14-increased TCDCA content is dependent on intestinal apical sodium-dependent bile acid transporter (ASBT), which is regulated by intestinal sympathetic afferent nerves. Finally, SLC7A14 regulates the intestinal sympathetic afferent nerves by inhibiting mTORC1 signaling through inhibiting TSC1 phosphorylation. Collectively, our study suggests the function for central SLC7A14 and an upstream mechanism for the mTORC1 signaling pathway. Moreover, our data provides insights into the brain-gut-adipose tissue crosstalk in age-induced lipolysis impairment.

Characterization of age-associated inflammasome activation reveals tissue specific differences in transcriptional and post-translational inflammatory responses

Aging is associated with systemic chronic, low-grade inflammation, termed 'inflammaging'. This pattern of inflammation is multifactorial and is driven by numerous inflammatory pathways, including the inflammasome. However, most studies to date have examined changes in the transcriptomes that are associated with aging and inflammaging, despite the fact that inflammasome activation is driven by a series of post-translational activation steps, culminating in the cleavage and activation of caspase-1. Here, we utilized transgenic mice expressing a caspase-1 biosensor to examine age-associated inflammasome activation in various organs and tissues to define these post-translational manifestations of inflammaging. Consistent with other studies, we observe increased inflammation, including inflammasome activation, in aged mice and specific tissues. However, we note that the degree of inflammasome activation is not uniformly associated with transcriptional changes commonly used as a surrogate for inflammasome activation in tissues. Furthermore, we used a skull thinning technique to monitor central nervous system inflammasome activation in vivo in aged mice and found that neuroinflammation is significantly amplified in aged mice in response to endotoxin challenge. Together, these data reveal that inflammaging is associated with both transcriptional and post-translational inflammatory pathways that are not uniform between tissues and establish new methodologies for measuring age-associated inflammasome activation in vivo and ex vivo.

A nutrigeroscience approach: Dietary macronutrients and cellular senescence

Cellular senescence, a process in which a cell exits the cell cycle in response to stressors, is one of the hallmarks of aging. Senescence and the senescence-associated secretory phenotype (SASP)-a heterogeneous set of secreted factors that disrupt tissue homeostasis and promote the accumulation of senescent cells-reprogram metabolism and can lead to metabolic dysfunction. Dietary interventions have long been studied as methods to combat age-associated metabolic dysfunction, promote health, and increase lifespan. A growing body of literature suggests that senescence is responsive to diet, both to calories and specific dietary macronutrients, and that the metabolic benefits of dietary interventions may arise in part through reducing senescence. Here, we review what is currently known about dietary macronutrients' effect on senescence and the SASP, the nutrient-responsive molecular mechanisms that may mediate these effects, and the potential for these findings to inform the development of a nutrigeroscience approach to healthy aging.

Autophagy in aging-related diseases and cancer: Principles, regulatory mechanisms and therapeutic potential

Macroautophagy/autophagy is primarily accountable for the degradation of damaged organelles and toxic macromolecules in the cells. Regarding the essential function of autophagy for preserving cellular homeostasis, changes in, or dysfunction of, autophagy flux can lead to disease development. In the current paper, the complicated function of autophagy in aging-associated pathologies and cancer is evaluated, highlighting the underlying molecular mechanisms that can affect longevity and disease pathogenesis. As a natural biological process, a reduction in autophagy is observed with aging, resulting in an accumulation of cell damage and the development of different diseases, including neurological disorders, cardiovascular diseases, and cancer. The MTOR, AMPK, and ATG proteins demonstrate changes during aging, and they are promising therapeutic targets. Insulin/IGF1, TOR, PKA, AKT/PKB, caloric restriction and mitochondrial respiration are vital for lifespan regulation and can modulate or have an interaction with autophagy. The specific types of autophagy, such as mitophagy that degrades mitochondria, can regulate aging by affecting these organelles and eliminating those mitochondria with genomic mutations. Autophagy and its specific types contribute to the regulation of carcinogenesis and they are able to dually enhance or decrease cancer progression. Cancer hallmarks, including proliferation, metastasis, therapy resistance and immune reactions, are tightly regulated by autophagy, supporting the conclusion that autophagy is a promising target in cancer therapy.

A Case-Control Study of the Correlation Between Blood Parameters and Obesity

BACKGROUND

 Obesity has become a global health crisis in adults, and is linked to conditions like diabetes, cardiovascular diseases, and cancer. This study explored associations between body mass index (BMI) and laboratory parameters in healthy individuals to identify risk factors and guide targeted interventions in Turkey. It was found that screening and lifestyle changes can help prevent and manage obesity-related health issues.

METHODS

This retrospective case-control study analyzed 2153 adult participants using medical records between 2021 and 2024. The study included those with good overall health; those under 18 years of age or had organ failure, chronic metabolic disorders, obesity complications, or were on multiple obesity-related medications were excluded. Data collected included demographic details, waist-to-hip ratio (WHR), BMI, and laboratory findings. Statistical analyses, including Pearson and Spearman correlations, Mann-Whitney U test and t test, and receiver operating characteristic analysis, were performed using SPSS 24.0 (IBM Corp., Armonk, NY).

RESULTS

The study, comprising 1016 men and 1137 women, revealed that 31.8% of adults were obese. Gender disparities were evident, with a higher prevalence of obesity observed in women: 76.5%, 68.8%, and 45.3% for classes 1, 2, and 3, respectively, compared to corresponding rates of 23.5%, 31.2%, and 54.7% in men. BMI significantly correlated with WHR. Despite the disparity between BMI and WHR between men and women, positive correlations were found between BMI and age (r=0.4) and serum uric acid (SUA) levels (r=0.5). The Mann-Whitney U test also demonstrated a significant association between BMI and fasting plasma glucose level, low-density lipoprotein (LDL), triglycerides, alanine aminotransferase (ALT), uric acid, platelet count, and lymphocyte count (all p values<0.005). Despite the poor correlation with BMI, SUA levels emerged as a potential obesity predictor, with a 4.1 mg/dl cutoff value, exhibiting 50% sensitivity and 34% specificity (p<0.001; area under the curve, or AUC, 0.67; 95% CI 0.65-0.70). There was no significant link between BMI and aspartate aminotransferase, hemoglobin, mean platelet volume, neutrophil and lymphocyte count, vitamin D, thyroid-stimulating hormone, and free thyroxine 4 levels.

CONCLUSION

This study found significant associations between BMI and laboratory parameters, including serum uric acid, fasting glucose, LDL, triglycerides, and ALT. WHR was also closely linked to BMI, with notable gender differences in body composition. These significant findings underscore the complex nature of obesity and highlight the importance of gender-specific considerations and biomarkers in research and management strategies that are crucial for understanding and addressing this global health crisis.

New Insights into Adipose Tissue Metabolic Function and Dysfunction, 2nd Edition

The adipose organ is well recognized for its role in energy storage and mobilization, responding to nutrient availability, the body's needs, and thermogenesis, thereby regulating the organism's energy balance [...].

Adipocyte-targeted celastrol delivery via biguanide-modified micelles improves treatment of obesity in DIO mice

Obesity has emerged as a significant global health burden, exacerbated by serious side effects associated with existing anti-obesity medications. Celastrol (CLT) holds promise for weight loss but encounters challenges related to poor solubility and systemic toxicity. Here, we present chondroitin sulfate (CS)-derived micelles engineered for adipocyte-specific targeting, aiming to enhance the therapeutic potential of CLT while minimizing its systemic toxicity. To further enhance adipocyte affinity, we introduced a biguanide moiety into a micellar vehicle. CS is sequentially modified with hydrophilic metformin and hydrophobic 4-aminophenylboronic acid pinacol ester (PBE), resulting in the self-assembly of CLT-encapsulated micelles (MET-CS-PBE@CLT). This innovative design imparts amphiphilicity via the PBE moieties while ensuring the outward exposure of hydrophilic metformin moieties, facilitating active interactions with adipocytes. In vitro studies confirmed the enhanced uptake of MET-CS-PBE@CLT micelles by adipocytes, while in vivo studies demonstrated increased distribution within adipose tissues. In a diet-induced obese mouse model, MET-CS-PBE@CLT exhibited remarkable efficacy in weight loss without affecting food intake. This pioneering strategy offers a promising, low-risk, and highly effective solution to address the global obesity epidemic.

Association between weight change and serum anti-aging protein α-Klotho: a cross-sectional study in middle-aged and older adults

The relationship of weight change has extended to accelerated ageing, yet little is known about the association between weight change and anti-aging protein α-Klotho. This study included 10,972 subjects from the National Health and Nutrition Examination Survey 2007-2016. Participants were measured body weight and height at baseline and recalled weight at young adulthood and middle adulthood. α-Klotho concentrations were quantified. Generalized linear regression models were used to assess the association between weight change and α-Klotho. Across adulthood, maximal overweight, non-obese to obese, and stable obesity were consistently associated with lower serum Klotho levels. Compared with participants who remained at normal weight, from middle to late adulthood, participants experiencing maximal overweight, moving from the non-obese to obese, and maintaining obesity had 27.97 (95% CI: - 46.57 to - 9.36), 39.16 (95% CI: - 61.15 to - 17.18), and 34.55 (95% CI: - 55.73 to - 13.37) pg/ml lower α-Klotho, respectively; similarly, from young to late adulthood, those had 29.21 (95% CI: - 47.00 to - 11.42) , 34.14 (95% CI: - 52.88 to - 15.40), and 36.61 (95% CI: - 65.01 to - 8.21) lower, respectively. Interestingly, from middle to late adulthood, the absolute weight change values of 590 participants who changed from obese to non-obese were negatively associated with serum α-Klotho. Each 1 kg of weight loss during the process of changing from obese to non-obese brought about a relative increase in α-Klotho levels of 3.03 pg/ml. The findings suggest the potential role of weight management across adulthood for aging.

Neural ageing and synaptic plasticity: prioritizing brain health in healthy longevity

Ageing is characterized by a gradual decline in the efficiency of physiological functions and increased vulnerability to diseases. Ageing affects the entire body, including physical, mental, and social well-being, but its impact on the brain and cognition can have a particularly significant effect on an individual's overall quality of life. Therefore, enhancing lifespan and physical health in longevity studies will be incomplete if cognitive ageing is over looked. Promoting successful cognitive ageing encompasses the objectives of mitigating cognitive decline, as well as simultaneously enhancing brain function and cognitive reserve. Studies in both humans and animal models indicate that cognitive decline related to normal ageing and age-associated brain disorders are more likely linked to changes in synaptic connections that form the basis of learning and memory. This activity-dependent synaptic plasticity reorganises the structure and function of neurons not only to adapt to new environments, but also to remain robust and stable over time. Therefore, understanding the neural mechanisms that are responsible for age-related cognitive decline becomes increasingly important. In this review, we explore the multifaceted aspects of healthy brain ageing with emphasis on synaptic plasticity, its adaptive mechanisms and the various factors affecting the decline in cognitive functions during ageing. We will also explore the dynamic brain and neuroplasticity, and the role of lifestyle in shaping neuronal plasticity.

Nutritional Management and Physical Activity in the Treatment of Sarcopenic Obesity: A Review of the Literature

BACKGROUND

The prevalence of sarcopenic obesity among adults aged ≥65 years is increasing worldwide. It is a condition that describes the concomitant presence of sarcopenia and obesity, but it appears to be associated with greater increases in the risks for disability, morbidity, and mortality than the two conditions combined. The current review aims to summarize the available literature data on the effectiveness of lifestyle modification for the management of this high-risk geriatric syndrome.

METHODS

We conducted a comprehensive search across multiple databases, including PubMed, Scopus, Web of Science, and Cochrane Library, for publications published from January 1950 to June 2024.

RESULTS

The detection of early preventive and therapeutic approaches to combat sarcopenic obesity is essential for healthy aging. There is ample evidence that suggests that poor dietary habits and physical inactivity are the main reasons for the development of sarcopenic obesity and should thus be the main targets for intervention. In the absence of effective pharmacological interventions, the best effect on sarcopenic obesity is achieved by combination with proper dietary intervention and regular physical activity according to the individual's health condition.

CONCLUSIONS

Further research is needed to discover the most effective strategy for the prevention and treatment of sarcopenic obesity, as well as potential pharmacological options to improve muscle mass and function in older populations with physical restrictions.

Obesity-induced chronic low-grade inflammation in adipose tissue: A pathway to Alzheimer's disease

Alzheimer's disease (AD) is a leading cause of cognitive impairment worldwide. Overweight and obesity are strongly associated with comorbidities, such as hypertension, diabetes, and insulin resistance (IR), which contribute substantially to the development of AD and subsequent morbidity and mortality. Adipose tissue (AT) is a highly dynamic organ composed of a diverse array of cell types, which can be classified based on their anatomic localization or cellular composition. The expansion and remodeling of AT in the context of obesity involves immunometabolic and functional shifts steered by the intertwined actions of multiple immune cells and cytokine signaling within AT, which contribute to the development of metabolic disorders, IR, and systemic markers of chronic low-grade inflammation. Chronic low-grade inflammation, a prolonged, low-dose stimulation by specific immunogens that can progress from localized sites and affect multiple organs throughout the body, leads to neurodystrophy, increased apoptosis, and disruption of homeostasis, manifesting as brain atrophy and AD-related pathology. In this review, we sought to elucidate the mechanisms by which AT contributes to the onset and progression of AD in obesity through the mediation of chronic low-grade inflammation, particularly focusing on the roles of adipokines and AT-resident immune cells.

Autophagy and metabolic aging: Current understanding and future applications

"Metabolic aging" refers to the gradual decline in cellular metabolic function across various tissues due to defective hormonal signaling, impaired nutrient sensing, mitochondrial dysfunction, replicative stress, and cellular senescence. While this process usually corresponds with chronological aging, the recent increase in metabolic diseases and cancers occurring at younger ages in humans suggests the premature onset of cellular fatigue and metabolic aging. Autophagy, a cellular housekeeping process facilitated by lysosomes, plays a crucial role in maintaining tissue rejuvenation and health. However, various environmental toxins, hormones, lifestyle changes, and nutrient imbalances can disrupt autophagy in humans. In this review, we explore the connection between autophagy and cellular metabolism, its regulation by extrinsic factors and its modulation to prevent the early onset of metabolic aging.

Body mass index mediates the association between four dietary indices and phenotypic age acceleration in adults: a cross-sectional study

Background: Diet and body mass index (BMI) are widely recognized as being closely associated with aging. However, it remains unclear which dietary indices are associated with aging, and the extent to which BMI mediates the relationship between diet and aging. Therefore, this study investigates the mediating role of BMI in the association between various dietary indices and phenotypic age acceleration (PhenoAgeAccel). Methods: Data were sourced from the National Health and Nutrition Examination Survey (NHANES), using two 24 hour recall interviews to compute four dietary indices: the Dietary Inflammatory Index (DII), Healthy Eating Index-2020 (HEI-2020), Alternative Healthy Eating Index-2010 (AHEI-2010), and Composite Dietary Antioxidant Index (CDAI). Linear regression analyses and mediation analyses assessed the associations between dietary indices and PhenoAgeAccel and the mediating effects of BMI. Z-score transformations (zDII, zHEI-2020, zAHEI-2010, and zCDAI) were used to ensure comparability between different dietary indices. Results: After adjusting for covariates, the zHEI-2020, zAHEI-2010, and zCDAI were negatively associated with PhenoAgeAccel (P < 0.05), with β values being -0.36, -0.40, and -0.41, respectively. The zDII was positively associated with PhenoAgeAccel (P < 0.001) with a β value of 0.70. Mediation analyses suggested that BMI significantly mediated the relationships between these dietary indices and PhenoAgeAccel. The mediation proportions were 23.7% for zDII, 43.3% for zHEI-2020, 24.5% for zAHEI-2010, and 23.6% for zCDAI. Conclusions: This study indicates that all dietary indices and BMI were significantly associated with PhenoAgeAccel. In addition, BMI exhibited the highest mediation proportion in the relationship between HEI-2020 and PhenoAgeAccel.

Association of visceral adiposity index with phenotypic age acceleration: insight from NHANES 1999-2010

BACKGROUND

Obesity correlates with accelerated aging. This study aims to investigate the association between the visceral adiposity index (VAI) and accelerated aging.

METHODS

Biological aging was evaluated by phenotypic age acceleration (PhenoAgeAccel). Utilizing data from the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2010, we employed weighted multivariable logistic regression models, along with subgroup analysis, to examine the association between VAI and PhenoAgeAccel. Moreover, smooth curve fitting was utilized to identify potential nonlinear association, complemented by a two-piece linear regression model to investigate threshold effects.

RESULTS

Of the included 11,340 participants aged 20 years and older, the mean (95% CI) age was 46.569 (45.946, 47.191) years, and 49.189% were male. The mean (95% CI) VAI for all participants was 2.176 (2.114, 2.238), and the mean (95% CI) PhenoAgeAccel was -6.306 (-6.618, -5.994) years. In the fully adjusted model, each incremental unit increase of VAI was associated with a 0.312-year increase in PhenoAgeAccel (β = 0.312, 95% CI: 0.217, 0.408). This positive association was more statistically significant among individuals with cancer. Furthermore, a segmented association was observed between VAI and PhenoAgeAccel, with a turning point identified at 10.543. Below this threshold, VAI exhibited a positive correlation with PhenoAgeAccel (β = 0.617, 95% CI: 0.499, 0.735), while beyond it, the association became nonsignificant.

CONCLUSION

This study demonstrated a positive association between VAI and accelerated aging within a nationally representative population. The findings suggest that controlling adiposity may exert anti-aging effects and help prevent aging-related diseases.