Review of Interventions for the Frailty Syndrome and the Role of Metformin as a Potential Pharmacologic Agent for Frailty Prevention

Effects from medications on functional biomarkers of aging in three longitudinal studies of aging in Sweden

Antihypertensive, lipid-lowering, and blood glucose-lowering drugs have slowed down the aging process in animal models. In humans, studies are limited, have short follow-up times, and show mixed results. Therefore, this study aimed to estimate the effects of commonly used medications on functional aging, cognitive function, and frailty. We included information on individuals from three Swedish longitudinal population-based studies collected between 1986 and 2014. Our exposures were the 21 most used groups of medications among individuals aged 65 years and older in the Swedish population in 2022. Functional aging index (n = 1191), cognitive function (n = 1094), and frailty index (n = 1361) were the outcomes of interest. To estimate the medication effects, we used a self-controlled analysis, where each individual is his/her own control, thereby adjusting for all time-stable confounders. The analysis was additionally adjusted for time-varying confounders (chronological age, Charlson Comorbidity Index, smoking, body mass index, and the number of drugs). The participants were 65.5-82.8 years at the first in-person assessment. Adrenergics/inhalants (effect size = 0.089) and lipid-modifying agents/plain (effect size = 0.082) were associated with higher values of cognitive function (improvement), and selective calcium channel blockers with mainly vascular effects (effect size = -0.129) were associated with lower values of the functional aging index (improvement). No beneficial effects were found on the frailty index. Adrenergics/inhalants, lipid-modifying agents/plain, and selective calcium channel blockers with mainly vascular effects may benefit functional biomarkers of aging. More research is needed to investigate their clinical value in preventing adverse aging outcomes.

Biomarkers of frailty

Several biomarkers have been proposed to identify frailty, a multisystemic age-related syndrome. However, the complex pathophysiology and the absence of a consensus on a comprehensive and universal definition make it challenging to pinpoint a singular biomarker or set of biomarkers that conclusively characterize frailty. This review delves into the main laboratory biomarkers, placing special emphasis on those associated with various pathways closely tied to the frailty condition, such as inflammation, oxidative stress, mitochondrial dysfunction, metabolic and endocrine alterations and microRNA. Additionally, we provide a summary of different clinical biomarkers encompassing different tools that have been proposed to assess frailty. We further address various imaging biomarkers such as Dual Energy X-ray Absorptiometry, Bioelectrical Impedance analysis, Computed Tomography and Magnetic Resonance Imaging, Ultrasound and D3 Creatine dilution. Intervention to treat frailty, including non-pharmacological ones, especially those involving physical exercise and nutrition, and pharmacological interventions, that include those targeting specific mechanisms such as myostatin inhibitors, insulin sensitizer metformin and with special relevance for hormonal treatments are mentioned. We further address the levels of different biomarkers in monitoring the potential positive effects of some of these interventions. Despite the availability of numerous biomarkers, their performance and usefulness in the clinical arena are far from being satisfactory. Considering the multicausality of frailty, there is an increasing need to assess the role of sets of biomarkers and the combination between laboratory, clinical and image biomarkers, in terms of sensitivity, specificity and predictive values for the diagnosis and prognosis of the different outcomes of frailty to improve detection and monitoring of older people with frailty or at risk of developing it, being this a need in the everyday clinical practice.

The Impact of Behavioral Lifestyle Intervention on Inflammatory Cytokines in Older Adults Living With Type 2 Diabetes: A Feasibility Study

OBJECTIVE

This study investigates the effects of a behavioral lifestyle intervention on inflammatory cytokines and frailty in older adults (≥ 65 years) with type 2 diabetes (T2D).

METHOD

We conducted a single-arm, 6-month intervention supplemented with diet and activity self-monitoring technology. We assessed frailty using Fried criteria and quantified inflammatory cytokines (interleukin [IL]-2, IL-4, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating-factor [GM-CSF], interferon [IFN-γ], tumor necrosis factor [TNF-α]) using a multiplex assay. We used paired t-tests with significance at P < .05. We calculated the Spearman correlation and evaluated the relationship between frailty, BMI, and inflammatory cytokines.

RESULTS

Eighteen participants completed the study (mean ± SD: 71.5 ± 5.3 years; BMI: 34 ± 6 kg/m2). At baseline, we had 4 frail, 13 pre-frail, and 1 non-frail participant. At 6 months, we observed the therapeutic effects of the intervention on frailty score, BMI, IL-2, IFN-y, and GM-CSF.

DISCUSSION

The study highlights the importance of behavioral lifestyle intervention in improving inflammatory cytokines and frailty in older adults.

Drugs Targeting Mechanisms of Aging to Delay Age-Related Disease and Promote Healthspan: Proceedings of a National Institute on Aging Workshop

The geroscience hypothesis posits that by targeting key hallmarks of aging we may simultaneously prevent or delay several age-related diseases and thereby increase healthspan, or life span spent free of significant disease and disability. Studies are underway to examine several possible pharmacological interventions for this purpose. As part of a National Institute on Aging workshop on the development of function-promoting therapies, scientific content experts provided literature reviews and state-of-the-field assessments for the studies of senolytics, nicotinamide adenine dinucleotide (NAD+) boosters, and metformin. Cellular senescence increases with age, and preclinical studies demonstrate that the use of senolytic drugs improves healthspan in rodents. Human studies using senolytics are in progress. NAD+ and its phosphorylated form, NADP+, play vital roles in metabolism and cellular signaling. Increasing NAD+ by supplementation with precursors including nicotinamide riboside and nicotinamide mononucleotide appears to extend healthspan in model organisms, but human studies are limited and results are mixed. Metformin is a biguanide widely used for glucose lowering, which is believed to have pleiotropic effects targeting several hallmarks of aging. Preclinical studies suggest it improves life span and healthspan, and observational studies suggest benefits for the prevention of several age-related diseases. Clinical trials are underway to examine metformin for healthspan and frailty prevention. Preclinical and emerging clinical studies suggest there is potential to improve healthspan through the use of pharmacologic agents reviewed. However, much further research is needed to demonstrate benefits and general safety for wider use, the appropriate target populations, and longer-term outcomes.

Analysis of systolic and diastolic blood pressure variability in frail, pre-frail, and non-frail elderly patients: The relationship between frailty syndrome and blood pressure variability in the elderly

Frailty can change the prognosis and treatment approach of chronic diseases. We, therefore, conducted this study to explore the relationship between frailty syndrome and blood pressure variability in the elderly. The clinical data of 150 elderly patients with debilitating syndrome admitted to the neurology department of our hospital from May 2021 to May 2022 were selected, and they were grouped according to Fried debilitation scale and divided into 50 cases each in the debilitation group, pre-debilitation group, and no-debilitation group. The general data, co-morbidities, medications, and biochemical indexes were collected. The 24-hour ambulatory blood pressure monitoring was performed in each group, and the mean systolic blood pressure, diastolic blood pressure, nocturnal systolic load value, and diastolic load value were analyzed to determine the relationship between blood pressure variability and senile frailty. Serum albumin (ALB) and high-density lipoprotein were significantly lower in the debilitated and pre-debilitated groups than in the non-debilitated group (P < .05). Multivariate logistic regression analysis revealed that age (odds ratio [OR]: 3.910, 95% confidence intervals [CI]: 2.021-5.402) was a risk factor for frailty in the elderly, and serum ALB (OR: 0.656, 95% CI: 0.110-0.960) and HDL (OR: 0.581, 95% CI: 0.237-0.944) were protective factors for frailty in the elderly. Age, type of medication taken, co-morbidities, serum ALB, and HDL are influencing factors of debilitating syndrome. Serum ALB and HDL are protective factors against debilitating syndrome in the elderly. Age is an independent risk factor of debilitation in the elderly and increased fluctuation of blood pressure in the elderly can increase their risk of developing debilitating syndrome.

The Effect of Low-Dose Aspirin on Frailty Phenotype and Frailty Index in Community-Dwelling Older Adults in the ASPirin in Reducing Events in the Elderly Study

BACKGROUND

Frailty is associated with chronic inflammation, which may be modified by aspirin. The purpose of this study was to determine whether low-dose aspirin reduces incident frailty in healthy older adult participants of the ASPirin in Reducing Events in the Elderly (ASPREE) trial.

METHODS

In the United States and Australia, 19 114 community-dwelling individuals aged ≥70 and older (U.S. minorities ≥65 years) and free of overt cardiovascular disease, persistent physical disability, and dementia were enrolled in ASPREE, a double-blind, placebo-controlled trial of 100-mg daily aspirin versus placebo. Frailty, a prespecified study end point, was defined according to a modified Fried frailty definition (Fried frailty) and the frailty index based on the deficit accumulation model (frailty index). Competing risk Cox proportional hazard models were used to compare time to incident frailty by aspirin versus placebo. Sensitivity analysis was conducted to include frailty data with and without imputation of missing data.

RESULTS

Over a median 4.7 years, 2 252 participants developed incident Fried frailty, and 4 451 had incident frailty according to the frailty index. Compared with placebo, aspirin treatment did not alter the risk of incident frailty (Fried frailty hazard ratio [HR]: 1.04, 95% confidence interval [CI] 0.96-1.13; frailty index HR: 1.03, 95% CI 0.97-1.09). The proportion of individuals classified as frail, and the trajectory in continuous frailty scores over time, were not different between the aspirin and placebo treatment groups. The results were consistent across a series of subgroups.

CONCLUSIONS

Low-dose aspirin use in healthy older adults when initiated in older ages does not reduce risk of incident frailty or the trajectory of frailty.

The Function of Metformin in Aging-Related Musculoskeletal Disorders

Metformin is a widely accepted first-line hypoglycemic agent in current clinical practice, and it has been applied to the clinic for more than 60 years. Recently, researchers have identified that metformin not only has an efficient capacity to lower glucose but also exerts anti-aging effects by regulating intracellular signaling molecules. With the accelerating aging process and mankind’s desire for a long and healthy life, studies on aging have witnessed an unprecedented boom. Osteoporosis, sarcopenia, degenerative osteoarthropathy, and frailty are age-related diseases of the musculoskeletal system. The decline in motor function is a problem that many elderly people have to face, and in serious cases, they may even fail to self-care, and their quality of life will be seriously reduced. Therefore, exploring potential treatments to effectively prevent or delay the progression of aging-related diseases is essential to promote healthy aging. In this review, we first briefly describe the origin of metformin and the aging of the movement system, and next review the evidence associated with its ability to extend lifespan. Furthermore, we discuss the mechanisms related to the modulation of aging in the musculoskeletal system by metformin, mainly its contribution to bone homeostasis, muscle aging, and joint degeneration. Finally, we analyze the protective benefits of metformin in aging-related diseases of the musculoskeletal system.

A Behavioral Lifestyle Intervention to Improve Frailty in Overweight or Obese Older Adults with Type 2 Diabetes: A Feasibility Study

BACKGROUND

Older adults with Type 2 diabetes (T2D) are more likely to be frail, which increases the risk for disability and mortality.

OBJECTIVES

To determine the feasibility of a behavioral lifestyle intervention, enhanced with mobile health technology for self-monitoring of diet and activity, to improve frailty in overweight/obese older adults (≥65 years) diagnosed with T2D.

DESIGN, SETTING, AND PARTICIPANTS

Single arm, 6-month study of a behavioral lifestyle intervention in 20 overweight/obese (BMI>25) older adults (≥ 65 years) with self-reported T2D diagnosis who owned a smartphone. A Fitbit tracker was provided to all participants for self-monitoring of diet and physical activity. Our primary outcome of feasibility was measured by session attendance, adherence to Fitbit usage to self-monitor diet and physical activity, and study retention. Secondary outcomes included the preliminary efficacy of the intervention on frailty, physical function, quality of life, and T2D-related outcomes.

RESULTS

Eighteen participants completed the study. The mean age was 71.5 (SD ± 5.3) years, 56% were female, and half were Hispanic. At baseline, 13 (72%) were pre-frail, 4 (22%) were frail, and 1 (6%) were non-frail. At follow-up, frailty scores improved significantly from 1.61 ± 1.15 to 0.94 ± 0.94 (p=0.01) and bodyweight improved from 205.66 ± 45.52 lbs. to 198.33 ± 43.6 lbs. (p=<0.001).

CONCLUSION

This study provides evidence for the feasibility of a behavioral lifestyle intervention in overweight/obese older adults with T2D and preliminary results support its potential efficacy in improving frailty score.

Association between Frailty and 90-Day Outcomes amongst the Chinese Population: A Hospital-Based Multicentre Cohort Study

INTRODUCTION

Frailty has gained increasing attention as it is by far the most prevalent geriatric condition amongst older patients which heavily impacts chronic health status. However, the relationship between frailty and adverse health outcomes in China is far from clear. This study explored the relation between frailty and a panel of adverse health outcomes.

METHODS

We performed a multicentre cohort study of older inpatients at 6 large hospitals in China, with two-stage cluster sampling, from October 2018 to April 2019. Frailty was measured according to the FRAIL scale and categorized into robust, pre-frail, and frail. A multivariable logistic regression model and multilevel multivariable negative binomial regression model were used to analyse the relationship between frailty and adverse outcomes. Outcomes were length of hospitalization, as well as falls, readmission, and mortality at 30 and 90 days after enrolment. All regression models were adjusted for age, sex, BMI, surgery, and hospital ward.

RESULTS

We included 9,996 inpatients (median age 72 years and 57.8% male). The overall mortality at 30 and 90 days was 1.23 and 1.88%, respectively. At 30 days, frailty was an independent predictor of falls (odds ratio [OR] 3.19; 95% CI 1.59-6.38), readmission (OR 1.45; 95% CI 1.25-1.67), and mortality (OR 3.54; 95% confidence interval [CI] 2.10-5.96), adjusted for age, sex, BMI, surgery, and hospital ward clustering effect. At 90 days, frailty had a strong predictive effect on falls (OR 2.10; 95% CI 1.09-4.01), readmission (OR 1.38; 95% CI 1.21-1.57), and mortality (OR 6.50; 95% CI 4.00-7.97), adjusted for age, sex, BMI, surgery, and hospital ward clustering effect. There seemed to be a dose-response association between frailty categories and fall or mortality, except for readmission.

CONCLUSIONS

Frailty is closely related to falls, readmission, and mortality at 30 or 90 days. Early identification and intervention for frailty amongst older inpatients should be conducted to prevent adverse outcomes.

Implementing Precision Medicine in Human Frailty through Epigenetic Biomarkers

The main epigenetic features in aging are: reduced bulk levels of core histones, altered pattern of histone post-translational modifications, changes in the pattern of DNA methylation, replacement of canonical histones with histone variants, and altered expression of non-coding RNA. The identification of epigenetic mechanisms may contribute to the early detection of age-associated subclinical changes or deficits at the molecular and/or cellular level, to predict the development of frailty, or even more interestingly, to improve health trajectories in older adults. Frailty reflects a state of increased vulnerability to stressors as a result of decreased physiologic reserves, and even dysregulation of multiple physiologic systems leading to adverse health outcomes for individuals of the same chronological age. A key approach to overcome the challenges of frailty is the development of biomarkers to improve early diagnostic accuracy and to predict trajectories in older individuals. The identification of epigenetic biomarkers of frailty could provide important support for the clinical diagnosis of frailty, or more specifically, to the evaluation of its associated risks. Interventional studies aimed at delaying the onset of frailty and the functional alterations associated with it, would also undoubtedly benefit from the identification of frailty biomarkers. Specific to the article yet reasonably common within the subject discipline.

Preclinical models of frailty: Focus on interventions and their translational impact: A review

The concept of frailty refers to heterogeneity in the risk of adverse outcomes for people of the same age. It is traditionally thought of as the inability of the body to maintain homeostasis. It can help explain differences between chronological and biological age and can quantify healthspan in experimental studies. Although clinical studies have developed tools to quantify frailty over the past two decades, preclinical models of frailty have only recently been introduced. This review describes the notion of frailty and outlines two commonly used clinical approaches to quantify frailty: the frailty phenotype and the frailty index. Translation of these methodologies for use in animals is introduced and studies that use these models to evaluate interventions designed to attenuate or exacerbate frailty are discussed. These include studies involving manipulation of diet, implementation of exercise regimens and tests of pharmaceutical agents to exacerbate or attenuate frailty. Together, this body of work suggests that preclinical frailty assessment tools are a valuable new resource to quantify the impact of interventions on overall health. Future studies could deploy these models to evaluate new frailty therapies, test combinations of interventions and assess interventions to enhance the ability to resist stressors in the setting of ageing.

The Use of Metformin to Increase the Human Healthspan

Metformin is a safe, effective and useful drug for glucose management in patients with diabetes. However in recent years, more attention has been paid to the possibility of using metformin as an anti-aging drug. It was shown to significantly increase the lifespan in some model organisms and delay the onset of age-associated declines. The current review summarizes advances in clinical research on the potential role of metformin in the field of lifespan and healthspan extension. Growing amounts of evidence from clinical trials suggest that metformin can effectively reduce the risk of many age-related diseases and conditions, including cardiometabolic disorders, neurodegeneration, chronic inflammation and frailty. Metformin also holds promise as a drug that could be repurposed for chemoprevention or adjuvant therapy for certain types of cancer. Moreover, metformin induces autophagy by activation of AMPK and can thus be potentially used to promote heathspan by hormesis-like mechanisms. Although long-term intake of metformin is associated with low risk of adverse events, well-designed clinical trials are still required to uncover the potential use of this drug as a geroprotector.

Targeting Mitochondrial Network Architecture in Down Syndrome and Aging

Mitochondria are organelles that mainly control energy conversion in the cell. In addition, they also participate in many relevant activities, such as the regulation of apoptosis and calcium levels, and other metabolic tasks, all closely linked to cell viability. Functionality of mitochondria appears to depend upon their network architecture that may dynamically pass from an interconnected structure with long tubular units, to a fragmented one with short separate fragments. A decline in mitochondrial quality, which presents itself as an altered structural organization and a function of mitochondria, has been observed in Down syndrome (DS), as well as in aging and in age-related pathologies. This review provides a basic overview of mitochondrial dynamics, from fission/fusion mechanisms to mitochondrial homeostasis. Molecular mechanisms determining the disruption of the mitochondrial phenotype in DS and aging are discussed. The impaired activity of the transcriptional co-activator PGC-1α/PPARGC1A and the hyperactivation of the mammalian target of rapamycin (mTOR) kinase are emerging as molecular underlying causes of these mitochondrial alterations. It is, therefore, likely that either stimulating the PGC-1α activity or inhibiting mTOR signaling could reverse mitochondrial dysfunction. Evidence is summarized suggesting that drugs targeting either these pathways or other factors affecting the mitochondrial network may represent therapeutic approaches to improve and/or prevent the effects of altered mitochondrial function. Overall, from all these studies it emerges that the implementation of such strategies may exert protective effects in DS and age-related diseases.

Frailty, Quality of Life, Anxiety, and Other Factors Affecting Adherence to Physical Activity Recommendations by Hemodialysis Patients

Hemodialysis patients perform little physical activity. We formulated a hypothesis that some factors, i.e., frailty, medical and functional factors, psychological factors, quality of life, awareness of recommendations, and sociodemographic factors influence the decisions of taking up physical activity. This prospective study comprised 72 dialysis patients aged 57.8 ± 16.0 ( x ¯ ± SD; in the range of 19-87 years of age). The following research tools were used: an interview about awareness of the physical activity recommendations, the Canadian Study of Health and Aging Scale (CSHA-CFS), scales for the assessment of functional status, State-Trait Anxiety Inventory (STAI), Acceptance of Illness Scale (AIS), and the questionnaire of Kidney Disease Quality of Life (KDQOL-SF 1.3). The majority of patients diagnosed with frailty did not follow the physical activity recommendations (79.3%). Quality of life was better in active patients compared to inactive patients, especially in the domains of sleep and physical performance. The severity of trait anxiety was significantly higher in patients who did not follow the recommendations compared to patients who adhered to physical activity recommendations (46.0 ± 10.5 vs. 40.0 ± 8.2; p = 0.021 ). The likelihood of adherence decreased by 1% after each subsequent month of dialysis (odds ratio = 0.99; 95% confidence interval = 0.972-0.999; p = 0.047 ). Adherence was most limited by frailty. Adherence to recommendations on physical activity was affected by: motivation, lower levels of trait anxiety, and better quality of life. Age modified the effect of awareness and acceptance of the disease on adherence to physical activity recommendations.