White blood cell counts, insulin-like growth factor-1 levels, and frailty in community-dwelling older women

Longitudinal analysis on inflammatory markers and frailty progression: based on the English longitudinal study of aging

PURPOSE

Frailty is a common health state that is closely linked to adverse health outcomes in aging society. Although many inflammatory biomarkers have been cross-sectionally associated with frailty, knowledge on the longitudinal association is still limited. This study investigated the associations between inflammatory factors in clinical practice and frailty progression over time.

METHODS

To investigate the associations of three common inflammatory markers (hypersensitive C-reactive protein [hsCRP], white blood cell [WBC] and fibrinogen) with the progression of frailty.

METHODS

Data of 2316 participants (age 67.9 ± 6.1 years) were obtained from the English longitudinal study of aging (wave 4, 6 and 8) over an 8-year follow-up. The frailty index (FI) was calculated from 52 items. Mixed-effects models and Cox proportional hazards (Cox-PH) models were used to analyze the associations of hsCRP, WBC and fibrinogen with frailty progression. Values of inflammatory biomarkers were log-transformed. Age, sex and gross wealth were controlled.

RESULTS

Mixed-effects models showed that at a cross-sectional level, higher levels of hsCRP (β: 0.007, 95% CI 0.004-0.010), WBC (β: 0.021, 95% CI 0.010-0.032) and fibrinogen (β: 0.022, 95% CI 0.005-0.038) were associated with greater FI values while no significant time interaction was found. Cox-PH models showed that higher baseline levels of hsCRP (HR: 1.10, 95% CI 1.03-1.17) and WBC (HR: 1.23, 95% CI 1.10-1.37) were linked to a greater risk of developing frailty within 8 years.

CONCLUSIONS

We concluded that hsCRP, WBC and fibrinogen can reflect frailty status at a cross-sectional level while only hsCRP and WBC are associated with frailty progression over an 8-year period.

Frailty detection with routine blood tests using data from the english longitudinal study of ageing (ELSA)

PURPOSE

Frailty is a rising global health issue in ageing society. Easily accessible and sensitive tools are needed for frailty monitoring while routine blood factors can be potential candidates.

METHODS

Data from 1907 participants (aged 60 years or above) were collected from the 4th to 9th wave of the English longitudinal study of ageing. 14 blood factors obtained from blood tests were included in the analysis. A 52-item frailty index (FI) was calculated for frailty evaluation. Logistic regression and Cox proportional hazards analysis were used to explore the relationships between baseline blood factors and the incidence of frailty over time respectively. All analyses were controlled for age and sex.

RESULTS

The mean age of participants was 67.3 years and 47.2% of them were male. Our study identified that 8 blood factors (mean corpuscular haemoglobin, HDL, triglyceride, ferritin, hsCRP, dehydroepiandrosterone, haemoglobin, and WBC) involved in inflammatory, nutritional and metabolic processes were associated with frailty. The combined model with these 8 blood factors had an AUC of 0.758 at cross-sectional level. In the Cox proportional hazards analysis, higher triglyceride (HR: 1.30, 95%CI: 1.07 ~ 1.59), WBC (HR: 1.16, 95%CI: 1.05 ~ 1.28), and lower HDL (HR: 0.58, 95%CI: 0.38 ~ 0.90) at baseline were linked to greater risk of developing frailty within 10 years. Compared to adults without abnormal blood factors at baseline, the hazard ratios of participants with two or more abnormal blood factors were almost twofold higher in developing frailty over time.

CONCLUSIONS

Routine blood factors, particularly triglyceride, HDL and WBC, could be used for frailty screening in clinical practice and estimate the development of frailty over time.

To Be Frail or Not to Be Frail: This Is the Question-A Critical Narrative Review of Frailty

Many factors have contributed to rendering frailty an emerging, relevant, and very popular concept. First, many pandemics that have affected humanity in history, including COVID-19, most recently, have had more severe effects on frail people compared to non-frail ones. Second, the increase in human life expectancy observed in many developed countries, including Italy has led to a rise in the percentage of the older population that is more likely to be frail, which is why frailty is much a more common concern among geriatricians compared to other the various health-care professionals. Third, the stratification of people according to the occurrence and the degree of frailty allows healthcare decision makers to adequately plan for the allocation of available human professional and economic resources. Since frailty is considered to be fully preventable, there are relevant consequences in terms of potential benefits both in terms of the clinical outcome and healthcare costs. Frailty is becoming a popular, pervasive, and almost omnipresent concept in many different contexts, including clinical medicine, physical health, lifestyle behavior, mental health, health policy, and socio-economic planning sciences. The emergence of the new "science of frailty" has been recently acknowledged. However, there is still debate on the exact definition of frailty, the pathogenic mechanisms involved, the most appropriate method to assess frailty, and consequently, who should be considered frail. This narrative review aims to analyze frailty from many different aspects and points of view, with a special focus on the proposed pathogenic mechanisms, the various factors that have been considered in the assessment of frailty, and the emerging role of biomarkers in the early recognition of frailty, particularly on the role of mitochondria. According to the extensive literature on this topic, it is clear that frailty is a very complex syndrome, involving many different domains and affecting multiple physiological systems. Therefore, its management should be directed towards a comprehensive and multifaceted holistic approach and a personalized intervention strategy to slow down its progression or even to completely reverse the course of this condition.

Development and Validation of an Abridged Physical Frailty Phenotype for Clinical Use: A Cohort Study Among Kidney Transplant Candidates

BACKGROUND

Frailty is associated with poor outcomes in surgical patients including kidney transplant (KT) recipients. Transplant centers that measure frailty have better pre- and postoperative outcomes. However, clinical utility of existing tools is low due to time constraints. To address this major barrier to implementation in the preoperative evaluation of patients, we developed an abridged frailty phenotype.

METHODS

The abridged frailty phenotype was developed by simplifying the 5 physical frailty phenotype (PFP) components in a two-center prospective cohort of 3 220 KT candidates and tested for efficiency (time to completion) in 20 candidates evaluation (January 2009 to March 2020). We examined area under curve (AUC) and Cohen's kappa agreement to compare the abridged assessment with the PFP. We compared waitlist mortality risk (competing risks models) by frailty using the PFP and abridged assessment, respectively. Model discrimination was assessed using Harrell's C-statistic.

RESULTS

Of 3 220 candidates, the PFP and abridged assessment identified 23.8% and 27.4% candidates as frail, respectively. The abridged frailty phenotype had substantial agreement (kappa = 0.69, 95% CI: 0.66-0.71) and excellent discrimination (AUC = 0.861). Among 20 patients at evaluation, abridged assessment took 5-7 minutes to complete. The PFP and abridged assessment had similar associations with waitlist mortality (subdistribution hazard ratio [SHR] = 1.62, 95% CI: 1.26-2.08 vs SHR = 1.70, 95% CI: 1.33-2.16) and comparable mortality discrimination (p = .51).

CONCLUSIONS

The abridged assessment is an efficient and valid way to identify frailty. It predicts waitlist mortality without sacrificing discrimination. Surgical departments should consider utilizing the abridged assessment to evaluate frailty in patients when time is limited.

Genetic predisposition to white blood cells in relation to the risk of frailty

BACKGROUND

Observational studies have suggested an association between white blood cells (WBCs) and frailty, but considering the susceptibility to reverse causality and confounding, the causal direction and magnitude of this association remain ambiguous. Our aim was to investigate the causal effect of WBCs on frailty by means of a Mendelian randomization (MR) analysis.

METHODS

Based on the genome-wide association study (GWAS) summary statistics data provided by the European Bioinformatics Institute (EBI), we carried out a two-sample MR study. We applied the genetically predicted independent WBCs from GWAS as a measure of exposure data. The Rockwood Frailty Index (FI) was used as outcome measure, which was derived from a meta-analysis from GWAS in UK Biobank European ancestry participants and Swedish TwinGene participants. Our study applied inverse variance weighted (IVW), weighted median, Mendelian randomization-Egger (MR-Egger) and outlier test (MR-PRESSO) methods to explore relationships between various WBCs and frailty.

RESULTS

In our study, a possible causal relationship between eosinophil levels and frailty was demonstrated by two-sample MR analysis. Eosinophils were associated with FI (beta:0.0609; 95% CI 0.0382, 0.0836; P = 1.38E-07). Our results suggest that as the level of eosinophils increases, so does the risk of frailty. No meaningful causal relationship between neutrophils, lymphocytes, monocytes or basophils and FI was found in the MR results (P > 0.05).

CONCLUSIONS

According to this MR study, higher eosinophil counts are related to an increased risk of frailty. To validate these findings and investigate the mechanisms underlying these connections, future studies are warranted.

Neurosurgical perioperative management of frail elderly patients

With the rapid increase in global aging, the prevalence of frailty is increasing and frailty has emerged as an emerging public health burden. Frail elderly patients suffer from reduced homeostatic reserve capacity, which is associated with a disproportionate decline in physical status after exposure to stress and an increased risk of adverse events. Frailty is closely associated with changes in the volume of the white and gray matter of the brain. Sarcopenia has been suggested to be an important component of frailty, and reductions in muscle strength and muscle mass lead to reductions in physical function and independence, which are critical factors contributing to poor prognosis. Approximately 10-32% of patients undergoing neurological surgery are frail, and the risk of frailty increases with age, which is significantly associated with the occurrence of adverse postoperative events (major complications, total duration of hospitalization, and need for discharge to a nursing facility). The postoperative mortality rate in severely frail patients is 9-11 times higher than that in non-frail individuals. Therefore, due attention must be paid to neurosurgical frailty and muscle assessment in elderly patients. Specialized interventions in the perioperative period of neurosurgery in frail elderly patients may improve their postoperative prognosis.

Cholesterol alone or in combination is associated with frailty among community-dwelling older adults: A cross-sectional study

BACKGROUND

Biological markers contribute to the precise intervention across the continuum of frailty severity. Few studies have explored the advantages of biological markers collected as part of primary care data among community-dwelling older adult population and controversy remains regarding the classic biological markers for frailty.

METHODS

We recruited a total of 8791 adults with a mean age of 71.95 years who met the inclusion and exclusion criteria in Guancheng District and Dalang Town, Dongguan, China. Frailty was assessed by a Chinese frailty evaluation scale. Frailty status was classified with 33-item modified frailty index and latent class analysis was applied to explore the latent classes (subtypes) of frailty. We measured biological markers on blood samples collected. We identify association between specific biological markers or patterns and frailty by logistic regression and association rule mining (ARM) based on the Apriori algorithm.

RESULTS

Multivariable analysis of our data showed that an elevated white blood cell (WBC) count and high cholesterol (CHOL) level were associated with pre-frailty (adjusted odds ratio [aOR] = 1.231, 95 % confidence interval [CI] = 1.009-1.501; aOR = 0.703, 95 % CI = 0.623-0.793) and frailty (aOR = 1.500, 95 % CI = 1.130-1.993; aOR = 0.561, 95 % CI = 0.461-0.684) compared with the normal groups. Importantly, significantly high level of CHOL was associated with a lower risk of four frailty subtypes compared with relatively healthy participants with the most power of association in the multi-frail group (aOR = 0.182, 95 % CI = 0.086-0.386). Based on ARM technique to develop correlation analysis to identify important high-risk clusters among older adult transitions from non-frail to frailty, patterns for normal level of CHOL co-occurred with an elevated creatinine (CREA) level have a significant association with the risk of frailty (aOR = 7.787, 95 % CI = 1.978-30.648) after adjusting for targeted confounders.

CONCLUSIONS

Our study highlights the correlation between classic biological markers, especially CHOL and frailty status and subtypes among community-dwelling older adult, in the primary care setting. Further large-scale prospective studies are still needed to confirm the role of classic biological markers in frailty.

Psoas Muscle Morphology as a Sarcopenia Marker to Predict Outcomes of Geriatric Trauma Patients: A Systematic Review and Meta-analysis

Objective

To provide pooled evidence on the association between central sarcopenia and risk of mortality and/or complications among geriatric patients with moderate to severe trauma.

Methods

We conducted a systematic search in PubMed, EMBASE, and Scopus databases for relevant observational studies documenting the association of central sarcopenia with the risk of mortality and/or complications in geriatric patients with moderate to severe trauma. The studies reported computerized tomography (CT) based assessments of the psoas muscle cross-sectional area. We used a random effects model for the analysis and reported effect sizes as pooled odds ratios (ORs) or hazards ratios (HRs) along with 95% confidence intervals.

Results

We analyzed data from 13 studies and found an association between the presence of psoas muscle size reduction and the risk of in-hospital mortality (OR, 1.47; 95% CI, 1.13, 1.90). In addition, we found increased risk of mortality within 24 months of follow-up in patients with sarcopenia (HR, 2.40; 95% CI, 1.11-5.17). We found each unit increase in psoas muscle cross-sectional area to be significantly associated with reduced risk of mortality within 24 months of follow-up (HR, .92; 95% CI, .90-.95). Patients with sarcopenia also had an increased risk of complications (OR, 1.69; 95% CI, 1.08-2.63).

Conclusion

Central sarcopenia, assessed using psoas muscle morphology, among geriatric patients with moderate to severe trauma appears to be significantly associated with increased risks of mortality and complications.

Sleep duration and cognitive function among older adults with chronic kidney disease: results from the National Health and Nutrition Examination Survey (2011-2014)

BACKGROUND

Short and long sleep durations are associated with cognitive dysfunction. Given the increased prevalence of sleep abnormalities in the chronic kidney disease (CKD) population, we tested whether the association between sleep duration and cognitive function differed between older adults with and without CKD.

METHODS

This was a study of 3215 older adults (age ≥60 years) enrolled in the National Health and Nutrition Examination Survey (2011-14) evaluating sleep duration, cognitive function (immediate recall, delayed recall, verbal fluency, executive function and processing speed and global cognition) and kidney function. We quantified the association between sleep duration and cognitive function using linear regression and tested whether the associations differed among those with CKD and without using a Wald test for interaction.

RESULTS

Among 3215 participants, 13.3% reported 2-5 hours of sleep/day, 75.2% reported 6-8 hours, and 11.5% reported ≥9 hours. Persons with CKD were more likely to sleep ≥9 hours [odds ratio 1.73 (95% confidence interval 1.22-2.46)]. Among participants with CKD, those with a sleep duration ≥9 hours demonstrated worse global cognitive function (P for interaction = .01), immediate recall (P for interaction = .01) and verbal fluency (P for interaction = .004) than those with a sleep duration of 6-8 h; no differences were observed for participants with CKD who slept 2-5 hours. Among participants without CKD, sleep was not associated with any measures of cognitive function.

CONCLUSIONS

Longer sleep duration is associated with worse cognitive function only among persons with CKD, and global cognition, delayed recall and verbal fluency are particularly affected. Studies should identify interventions to improve sleep patterns and quality in this population.

Frailty biomarkers under the perspective of geroscience: A narrative review

Cellular and molecular aging biomarkers might contribute to identify at-risk individuals for frailty before overt clinical manifestations appear. Although studies on the associations of aging biomarkers and frailty exist, no investigation has gathered this information using a structured framework for identifying aging biomarkers; as a result, the evidence on frailty and aging biomarkers is diffuse and incomplete. Therefore, this narrative review aimed to gather information on the associations of the hallmarks of aging and frailty under the perspective of geroscience. The literature on human studies on this topic is sparse and mainly composed of cross-sectional investigations performed in small study samples. The main putative aging biomarkers associated to frailty were: mitochondrial DNA copy number (genomic instability and mitochondrial dysfunction), telomere length (telomere attrition), global DNA methylation (epigenetic alterations), Hsp70 and Hsp72 (loss of proteostasis), IGF-1 and SIRT1 (deregulated nutrient-sensing), GDF-15 (mitochondrial dysfunction, cellular senescence and altered intercellular communication), CD4 + and CD8 + cell percentages (cellular senescence), circulating osteogenic progenitor (COP) cells (stem cell exhaustion), and IL-6, CRP and TNF-alpha (altered intercellular communication). IGF-1, SIRT1, GDF-15, IL-6, CRP and TNF-alpha presented more evidence among these biomarkers, highlighting the importance of inflammation and nutrient sensing on frailty. Further longitudinal studies investigating biomarkers across the hallmarks of aging would provide valuable information on this topic.

C-reactive protein and white blood cell are associated with frailty progression: a longitudinal study

Background

Systemic inflammation has been linked to diseases and frailty. However, little is known about the effect of systemic inflammation on frailty progression with a longitudinal study design.

Objectives

This study aimed to investigate the associations of two inflammation indicators, C-reactive protein (CRP) and white blood cell (WBC), with frailty progression.

Methods

This study utilized data from the China Health and Retirement Longitudinal Study 2011–2018 (wave 1-wave 4). Frailty index (FI) was calculated using 40 items from wave 1 to wave 4 (range: 0 to 1). Two systemic inflammation biomarkers, CRP and WBC, were measured at baseline (wave 1) and logs transformed as continuous variables or grouped using quartiles. Linear mixed-effect models were used to analyze the associations of these two biomarkers with the progression of frailty with adjustment for potential confounding factors.

Results

The study enrolled 9111 middle-aged and older participants (52.7% females, mean age 58.8 ± 9.3 years). The median follow-up time was 7.0 years. In a fully adjusted model with further adjustment for baseline FI, higher CRP (β for the interaction with time = 0.239, 95% CI: 0.139 to 0.338) and WBC (β for the interaction with time = 0.425, 95% CI: 0.024 to 0.825) significantly accelerated the rate of increase in the FI during the follow-up period. The associations were more pronounced in younger people (< 60 years) than older people (≥60 years).

Conclusions

Higher CRP and WBC accelerated the progression of frailty, particularly in younger groups (< 60 years). The findings suggest the importance of systemic inflammation for the early identification of people at high risk of rapid progression of frailty.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12979-022-00280-1.

Frailty Syndrome-Fall Risk and Rehabilitation Management Aided by Virtual Reality (VR) Technology Solutions: A Narrative Review of the Current Literature

Frailty, a physiological syndrome (FS) affecting primarily the older adults, manifests itself through significantly depleted bodily reserves, and appreciably higher (up to over threefold) individual exposure to fall risk. Concomitant medical conditions such as balance impairment, reduced visual acuity, limited mobility, and significantly diminished daily functional performance further exacerbate the patients' condition. Their resultant susceptibility to frequent hospitalisations makes their prognosis even worse. This narrative review aimed to provide an overview of published studies focused on rehabilitation management approaches aided by virtual reality (VR) technology in frail older adults. The authors had it also augmented with their own, evidence-based body of experience in rehabilitation. Making use of technologically advanced exercise machinery, specially adapted for rehabilitating frail older adults, combined with a structured exercise regimen, further aided by the application of select virtual reality (VR) technology solutions, clearly proved effective. Consequently, the patients were helped to move back from the frail to the pre-frail stage, as well as had their motor and cognitive functions appreciably enhanced. The application of modern technology in rehabilitating older adults over 65, affected by FS, when specifically aided by the select VR technology solutions, was also proven to complement successfully the conventional rehabilitation management. The overall versatility of the VR technology solutions, e.g., adaptation for home use allowing remote supervision, also makes this novel approach to rehabilitation far more appealing to the patients. They find it both very attractive and far more mentally engaging. Its considerable potential lies mostly in being appreciably more effective in bringing in desirable therapeutic outcomes.

Iron Dysregulation and Frailty Syndrome

Patients with diagnosed frailty syndrome (FS) represent a special group of patients with chronic disease. In the classic definition, frailty syndrome includes such parameters as reduced muscle strength, subjective feeling of fatigue, unintentional weight loss, slow gait, and low physical activity. Frailty syndrome leads to an increased incidence of adverse events, such as falls, hospitalizations, and the need to place patients in care and health institutions associated with the loss of independence; frailty syndrome is also associated with an increased incidence of death. In European countries, the frequency of frailty syndrome in the geriatric population is estimated to be 17% with a range from 5.8% to 27%, and its incidence increases with age. A much higher percentage of frailty syndrome patients is also observed among hospitalized patients. The incidence of frailty syndrome is influenced by many socio-economic factors, but also medical factors. Materials and Methods: A total of 120 patients, >65 years of age, participated in the study. During the study, anthropometric measurements, surveys, laboratory determinations of basic biochemical parameters, and iron status were investigated; 5 mL of peripheral blood in EDTA was also collected for further laboratory tests of hepcidin and soluable transferrin receptor (sTfR) using ELISA. Then, the statistical analysis was performed based on survey and clinical data. Results: Among the patients >65 years of age, the incidence of frailty syndrome was 27.5%. It was found that its occurrence was associated with socio-economic factors, malnutrition, multiple morbidities, reduced muscle strength and gait speed, and polypharmacotherapy. The relationship between reduced iron concentration and the occurrence of frailty syndrome was confirmed. Conclusions: According to the analysis, it was found that a decrease in iron concentration was associated with frailty syndrome.

Evaluation of a Patient-reported Frailty Tool in Women With Systemic Lupus Erythematosus

OBJECTIVE

Frailty is associated with mortality in systemic lupus erythematosus (SLE), but how best to measure frailty is unclear. We aimed to compare 2 frailty metrics, the self-reported Fatigue, Resistance, Ambulation, Illnesses, and Loss of weight (FRAIL) scale (FS) and the Fried phenotype (FP), in SLE to evaluate differences between frail and nonfrail women and whether frailty is associated with self-reported disability.

METHODS

Adult women aged < 70 years with validated SLE and mild/moderate disease enrolled in this cross-sectional study between August 2018 and October 2019. Correlation and agreement between the FS and the FP were determined. Differences in sociodemographic and disease characteristics, patient-reported outcome measures (PROMs), and biomarkers between frail and nonfrail participants were evaluated, as well as the association of frailty with Valued Life Activities disability.

RESULTS

Of 67 participants, 27% and 18% were frail according to the FS and the FP, respectively. Correlation (r = 0.51; P < 0.0001) and agreement (κ = 0.46; P = 0.0004) between the FS and the FP were significant. Frail women had greater disease damage, high-sensitivity C-reactive protein, and interleukin 6, and worse PROMs according to both frailty definitions. Both frailty measures were associated with self-reported disability after adjustment for age, comorbidity, and disease activity and damage; this relationship was attenuated for the FP.

CONCLUSION

Frailty prevalence was high in this cohort of women with SLE using both frailty definitions, suggesting that frailty may be accelerated in women with SLE, particularly when based exclusively on self-report. Frailty remained associated with self-reported disability in adjusted analyses. The FS may be an informative point-of-care tool to identify frail women with SLE.

Supplementation with a Natural Source of Amino Acids, Sil-Q1 (Silk Peptide), Enhances Natural Killer Cell Activity: A Redesigned Clinical Trial with a Reduced Supplementation Dose and Minimized Seasonal Effects in a Larger Population

The aim of this study was to re-validate the changes in natural killer (NK) cell cytotoxicity and cytokines related to T cells after Sil-Q1 (SQ; silk peptide) supplementation in a larger pool of Korean adults with minimized daily dose of SQ and controlling seasonal influence compared to the previous study. A total of 130 subjects were randomly assigned (1:1) to consume either 7.5 g of SQ or placebo for 8 weeks. NK cell cytotoxicity and cytokines were measured at T0 (baseline) and T8 (follow-up). Comparing the NK cell cytotoxicity values at T0 and T8 within each group, the cytotoxicity at all effector cell (E) to target cell (T) ratios of 10:1, 5:1, 2.5:1, and 1.25:1 was significantly increased in the SQ group at T8. Additionally, significant differences in the changed value (Δ, subtract baseline values from follow-up values) comparison between the groups at E:T = 10:1, 5:1, and 2.5:1 were found. As a secondary endpoint, the interleukin (IL)-12 level in the SQ group was significantly increased for 8 weeks, and Δ IL-12 in the SQ group was greater than in the placebo group. In conclusion, the present study showed considerable practical implications of SQ supplementation. Thus, SQ is an effective and safe functional food supplement for enhancing immune function.

Blood-based biomarkers and long-term risk of frailty - experience from the Swedish AMORIS cohort

BACKGROUND

Frailty is associated with reduced quality of life, poor health outcomes, and death. Past studies have investigated how specific biomarkers are associated with frailty but understanding biomarkers in concert with each other and the associated risk of frailty is critical for clinical application.

METHODS

Using a sample aged ≥59 years at baseline from the Swedish AMORIS cohort (n=19341), with biomarkers measured at baseline (1985-1996), we conducted latent class analysis with 18 biomarkers and used Cox models to determine the association between class and frailty and all-cause mortality.

RESULTS

Four classes were identified. Compared to the largest class, the Reference class (81.7%), all other classes were associated with increased risk of both frailty and mortality. The Anemia class (5.8%), characterized by comparatively lower iron markers and higher inflammatory markers, had HR=1.54, 95% CI 1.38, 1.73 for frailty and HR=1.76, 95% CI 1.65, 1.87 for mortality. The Diabetes class (6.5%) was characterized by higher glucose and fructosamine, and had HR=1.59, 95% CI 1.43, 1.77 for frailty and HR=1.74, 95% CI 1.64, 1.85 for mortality. Finally, the Liver class (6.0%), characterized by higher liver enzyme levels, had HR=1.15, 95% CI 1.01, 1.30 for frailty and HR=1.40, 95% CI 1.31, 1.50 for mortality. Sex-stratified analyses did not show any substantial differences between men and women.

CONCLUSIONS

Distinct sets of commonly available biomarkers were associated with development of frailty and monitoring these biomarkers in patients may allow for earlier detection and possible prevention of frailty, with the potential for improved quality of life.

IL-6 Levels Influence 3-Month All-Cause Mortality in Frail Hospitalized Older Patients

The multidimensional prognostic index (MPI) is a sensitive and specific prognosis estimation tool that accurately predicts all-cause mortality in frail older patients. It has been validated to assess the risk of 1-month to 2-year mortality in frail older patients during hospitalization and after hospital discharge. However, whether the MPI is a valid prognostic tool for follow-up periods of different lengths remains to be validated. To this end, we followed up 80 hospitalized patients (female=37, male 43) at least 75 years of age (mean age=82.6±4.4, range=75-94 years) to assess the 3-month all-cause mortality (mean follow-up=61.0 ± 31.7 months [range 4-90 days]). Accordingly, patients were subdivided into low (MPI-1, score 0-0.33), moderate (MPI-2, score 0.34-0.66) and high (MPI-3, score 0.67-1) mortality risk classes. Moreover, baseline biochemical, inflammatory and metabolic parameters, as well as anamnestic and clinical characteristics, were obtained. Although the MPI-3 score was significantly associated with 3-month all-cause mortality in univariate analysis (HR=5.79, 95%CI=1.77-18.92, p=0.004), a multivariate model indicated that only low albumin (HR=0.33, 95%CI=0.16-0.68, p=0.003) and high IL6 (HR=1.01, 95%CI=1.00-1.02, p=0.010) levels were significantly associated with 3-month all-cause mortality. In conclusion, we suggest that measurement of IL6 as well as albumin, rather than the MPI score, may help in providing tailored therapeutic interventions to decrease short term mortality in older hospitalized individuals.

Circulating biomarkers characterizing physical frailty: CRP, hemoglobin, albumin, 25OHD and free testosterone as best biomarkers. Results of a meta-analysis

INTRODUCTION

During aging, individuals can be classified as being in one of 3 different states: robust, frail or dependent. Frailty is described as reversible, so early detection offers the potential of returning the subject to a robust status. There are multiple clinical frailty scales but no gold standard and frailty is not systematically assessed in clinicians' daily practice. Reliable biomarkers of frailty are lacking, however, while their identification and systematic use would make this simple scale a useful clinical tool.

OBJECTIVE

To conduct a review of the literature concerning the biomarkers associated with frailty and to compare in a meta-analysis the plasmatic values of each biomarker in the frail with the robust group.

RESULTS

503 articles were identified on PubMed, 467 on Scopus and 369 on Web Of Science. 67 articles were included, collecting a total of 32,934 robust subjects and 6864 frail subjects. C-reactive protein (CRP) (Standardized Mean Difference (SMD): 0.49 CI 95% [0.37-0.61]) was significantly higher in the frail group whereas hemoglobin (SMD: -0.67[-0.90; -0.44]), albumin (SMD: -0.62[-0.84; -0.41]), 25-hydroxyvitamin D (25OHD) (SMD: -0.43 [-0.64; -0.21]) and, in men, free testosterone (SMD: -0.77 [-1.05; -0.49]) were significantly lower in the frail group.

CONCLUSION

We found 5 biomarkers that were associated with frailty (CRP, hemoglobin, albumin, 25OHD and free testosterone in men) belonging to multiple physiological systems. Further cohort studies are needed to verify their ability to screen for frailty.

Derivation of a measure of physiological multisystem dysregulation: Results from WHAS and health ABC

INTRODUCTION

Multifactorial biological processes underpin dysregulation over several individual physiological systems. However, it is challenging to characterize and model this multisystemic dysregulation and its relationship with individual physiologic systems. We operationalized a theory-driven measure of multisystem dysregulation and empirically tested for measurement differences by key characteristics.

METHODS

We used the Women's Health and Aging Studies (WHAS) I and II (N = 649), and the Health ABC study (N = 1515). Twelve biomarkers representing multiple systems including stress response (e.g., inflammation), endocrine system, and energy regulation were identified. A series of confirmatory factor analyses (CFA) were conducted to evaluate the interplay between physiological systems and underlying multisystem dysregulation. We evaluated convergent criterion validity of a score for multisystem dysregulation against the physical frailty phenotype, and predictive criterion validity with incidence of walking difficulty and mortality.

RESULTS

A bifactor CFA, a model in which dysregulation of individual systems proceeds independently of generalized dysregulation, fit data well in WHAS (RMSEA: 0.019; CFI: 0.977; TLI: 0.961) and Health ABC (RMSEA: 0.047; CFI: 0.874; TLI: 0.787). The general dysregulation factor was associated with frailty (OR: 2.2, 95 % CI: 1.4, 3.5), and elevated risk of incident walking difficulty and mortality. Findings were replicated in Health ABC.

DISCUSSION

Biomarker data from two epidemiologic studies support the construct of multisystem physiological dysregulation. Results further suggest system-specific and system-wide processes have unique and non-overlapping contributions to dysregulation in biological markers.

Mastication and oral sensory function in frail edentulous elderly: a case-control study

OBJECTIVE

To evaluate the maximum bite force (MBF), masticatory performance and oral sensory function (OSF) of frail edentulous elderly. The correlation of MBF with maximum grip strength (MGS) was also assessed.

METHODS

Twenty edentulous elderly [10 with and 10 without the frailty phenotype (FP)] were selected to participate in this case-control study. The FP was diagnosed using the criteria of Fried et al., which consider weight loss, exhaustion, physical activity level, weakness and slowness to the evaluation. All volunteers received new complete dentures (CDs) to standardise the occlusal status, and after 2 months of use with no complaint, all variables were assessed. MBF was measured by pressure sensors positioned bilaterally on the first artificial molars. Masticatory performance was assessed using the sieving method and was expressed as the median particle size (X50 ) of Optocal after 40 masticatory cycles. OSF was evaluated using the oral stereognosis test, and MGS was measured using a dynamometer. Groups were compared using one-way analysis of variance. The Pearson coefficient of correlation between MBF and MGS was calculated.

RESULTS

Frail elderly people showed reduced MBF (P = 0.0431) and larger X50 values (P = 0.0053) than did non-frail elders, while OSF did not differ between the groups. MBF had a moderate positive correlation with MGS (r = 0.690, P = 0.003).

CONCLUSIONS

Frail elderly had reduced MBF and impaired mastication. On the other hand, OSF does not seem to be affected by frailty. MBF was moderately correlated with MGS.

Aging, sex, inflammation, frailty, and CMV and HIV infections

Aging is characterized by significant immune remodeling at both cellular and molecular levels, also known as immunosenescence. Older adults often manifest a chronic low-grade inflammatory phenotype. These age-related immune system changes have increasingly been recognized not only to lead to immune functional decline and increased vulnerability to infections, but also to play an important role in many chronic conditions such as frailty in older adults. In addition to sex as an important biological factor, chronic viral infections including that by human immunodeficiency virus (HIV) and cytomegalovirus (CMV) are all known to have major impact on the aging immune system. This article provides an overview of our current understanding of aging immunity, sex, inflammation, frailty, and HIV and CMV infections.

Determination of frail state and association of frailty with inflammatory markers among cardiac surgery patients in a Central European patient population

INTRODUCTION

With the aging of the population, the screening of frail patients, especially before high-risk surgery, come to the fore. The background of the frail state is not totally clear, most likely inflammatory processes are involved in the development.

METHODS

Our survey of patients over age of 65 who were on cardiac surgery were performed with Edmonton Frail Scale (EFS). Patients' demographic, perioperative data, incidence of complications and correlations of inflammatory laboratory parameters were studied with the severity of the frail state.

RESULTS

On the basis of EFS, 313 patients were divided into non-frail (NF,163,52%), pre-frail (PF,89,28.5%) and frail (F,61,19.5%) groups. Number of complications in the three groups were different (NF:0.67/patient, PF:0.76/patient, F:1.08/patient). We showed significant difference between NF and F in both intensive care and hospital stay, but there was no statistical difference between the groups in hospital deaths (NF:5/163, PF:3/89, F:5/61). We also found a significant difference between NF and F patients in preoperative fibrinogen-, CRP- and white blood cell count levels.

CONCLUSIONS

We first present the incidence of frailty in patients with heart surgery in a Central-European population. According to our results, inflammatory processes are likely to play a role in the development of the frail state.

Metabolic dysregulation in vitamin E and carnitine shuttle energy mechanisms associate with human frailty

Global ageing poses a substantial economic burden on health and social care costs. Enabling a greater proportion of older people to stay healthy for longer is key to the future sustainability of health, social and economic policy. Frailty and associated decrease in resilience plays a central role in poor health in later life. In this study, we present a population level assessment of the metabolic phenotype associated with frailty. Analysis of serum from 1191 older individuals (aged between 56 and 84 years old) and subsequent longitudinal validation (on 786 subjects) was carried out using liquid and gas chromatography-mass spectrometry metabolomics and stratified across a frailty index designed to quantitatively summarize vulnerability. Through multivariate regression and network modelling and mROC modeling we identified 12 significant metabolites (including three tocotrienols and six carnitines) that differentiate frail and non-frail phenotypes. Our study provides evidence that the dysregulation of carnitine shuttle and vitamin E pathways play a role in the risk of frailty.

Risk of age-related chronic disorders and decrease in resilience is associated with ageing. Here the authors analyse the human blood metabolome and identify metabolites associated with frailty.

Exploring the potential of salivary and blood immune biomarkers to elucidate physical frailty in institutionalized older women

Identification of older populations at increased risk of physical frailty using biochemical approaches could improve screening accuracy. The aim of this study was to study the relationship between immune markers and independent components of physical frailty in institutionalized older women. A sample of 358 institutionalized-dwelling women, aged 75 years and older, were assessed for biosocial factors and general health status, pro and anti-inflammatory cytokines, sex steroid hormones, salivary anti-microbial proteins, blood cells counts and the five Fried's physical frailty components that allowed for classification of the sample into frail, prefrailty and not-frail subgroups. Results showed that cytokines IL-6, IL-10, IL-1β, TNF-α, and the TNF-α/IL-10 ratio, mean corpuscular haemoglobin, salivary cortisol and α-amylase were all associated with frailty. Weakness and Exhaustion were the frailty components that were most strongly associated with these biomarkers. Salivary α-amylase was the biomarker that best explained frailty, as it was associated with all five components of physical frailty, and could be used as a potential screening tool. Future research needs to investigate the causal-effect association between salivary innate immune makers, susceptibility to infection and frailty.

If my muscle could talk: Myokines as a biomarker of frailty

Frailty is a potentially reversible state of increased vulnerability to negative health-related outcomes that occurs as a result of multisystem biological impairment and environmental aspects. Given the relevance of this condition in both clinics and research, biomarkers of frailty have been actively sought after. Although several candidate biomarkers of frailty have been identified, none of them has yet been incorporated in the assessment or monitoring of the condition. Over the last years, increasing research interest has been focused on myokines, a set of cytokines, small proteins and proteoglycan peptides that are synthetized, expressed and released by skeletal myocytes in response to muscular contractions. Myokines may act in autocrine, paracrine, and endocrine manner and regulate several processes associated with physical frailty, including muscle wasting, dynapenia, and slowness. This review discusses the rationale to support the use of myokines as biomarkers of frailty in older adults.

Soluble Factors Released From Activated T Lymphocytes Regulate C2C12 Myoblast Proliferation and Cellular Signaling, but Effects Are Blunted in the Elderly

The key objective of this work was to investigate the impact of young and old human lymphocyte secretomes on C2C12 myoblasts regeneration. Conditioned media were harvested from isolated young and older lymphocytes treated with (activated [AC]) or without (nonactivated [NA]), anti-CD3/CD28 activators for 4 days. AC conditioned media from older lymphocytes had decreased levels of amphiregulin (367 ± 208 pg/mL vs 904 ± 323 pg/mL; p = .018) and IGF-I (845 ± 88 ng/mL vs 1100 ± 48 ng/mL; p = .032) compared with younger AC lymphocytes. AC older versus younger lymphocytes had reduced expression of CD25 (24.6 ± 5.5%; p = .0003) and increased expression of FoxP3 (35 ± 15.7%; p = .032). Treatment of C2C12 myoblasts with young AC lymphocytes resulted in decreased expression of MyoD (0.46 ± 0.12; p =.004) and Myogenin (0.34 ± 0.05; p = .010) mRNA, increased activation of MEk1 (724 ± 140 mean fluorescent intensity [MFI]; p =.001) and ERK1/2 (3768 ± 314 MFI; p =.001), and a decreased activation of Akt (74.5 ± 4 MFI; p = .009) and mTOR (61.8 ± 7 MFI; p = .001) compared with old AC lymphocytes. By contrast, C2C12 myoblasts treated with older AC lymphocytes displayed increased expression of MyoD (0.7 ± 0.08; p =.004) and Myogenin (0.68 ± 0.05; p =.010) mRNA, decreased phosphorylation of MEk1 and ERK1/2 (528 ± 80 MFI; p = .008, and 1141 ± 668 MFI; p = .001, respectively), and increased Akt/mTOR activation (171 ± 35 MFI; p = .009, and 184 ± 33 MFI; p = .001, respectively). These data provide new evidence that differences between older and younger lymphocyte secretomes contribute to differential responses of C2C12 myoblasts in culture.

Inflammatory Pathways to Anemia in the Frail Elderly

Anemia is a common, yet often overlooked, geriatric syndrome characterized by reduced hemoglobin levels and associated with adverse health outcomes and early mortality. Evidence suggests that anemia is an independent risk factor for frailty in older adults. In this article, the authors review the evidence for the role of chronic inflammation in the pathogenesis of anemia in the frail elderly. Understanding the relationships between anemia, frailty, and chronic inflammation will pave the way for the development of novel interventional strategies for the treatment and prevention of anemia and, likely, also frailty in older adults.

Frailty, Inflammatory Markers, and Waitlist Mortality Among Patients With End-stage Renal Disease in a Prospective Cohort Study

BACKGROUND

Among community-dwelling older adults, frailty is associated with heightened markers of inflammation and subsequent mortality. Although frailty is common among end-stage renal disease (ESRD) patients, the role of frailty and markers of inflammation in this population remains unclear. We quantified these associations in patients on the kidney transplant waitlist and tested whether frailty and/or markers of inflammation improve waitlist mortality risk prediction.

METHODS

We studied 1975 ESRD patients on the kidney transplant waitlist (November 1, 2009, to February 28, 2017) in a multi-center cohort study of frailty. Serum inflammatory markers (interleukin-6 [IL-6], soluble tumor necrosis factor-α receptor-1 [sTNFR1], and C-reactive protein [CRP]) were analyzed in 605 of these participants; we calculated the inflammatory index score using IL-6 and sTNFR1. We compared the C-statistic of an established registry-based prediction model for waitlist mortality adding frailty and/or inflammatory markers (1 SD change in log IL-6, sTNFR1, CRP, or inflammatory index).

RESULTS

The registry-based model had moderate predictive ability (c-statistic = 0.655). Frailty was associated with increased mortality (2.19; 95% confidence interval [CI], 1.26-3.79) but did not improve risk prediction (c-statistic = 0.646; P = 0.65). Like frailty, IL-6 (2.13; 95% CI, 1.41-3.22), sTNFR1 (1.70; 95% CI, 1.12-2.59), CRP (1.68; 95% CI, 1.06-2.67), and the inflammatory index (2.09; 95% CI, 1.38-3.16) were associated with increased mortality risk; unlike frailty, adding IL-6 (c-statistic = 0.777; P = 0.02), CRP (c-statistic = 0.728; P = 0.02), or inflammatory index (c-statistic = 0.777; P = 0.02) substantially improved mortality risk prediction.

CONCLUSIONS

Frailty and markers of inflammation were associated with increased waitlist mortality risk, but only markers of inflammation significantly improved ESRD risk prediction. These findings help clarify the accelerated aging physiology of ESRD and highlight easy-to-measure markers of increased waitlist mortality risk.

Frailty and Access to Kidney Transplantation

BACKGROUND AND OBJECTIVES

Frailty, a syndrome distinct from comorbidity and disability, is clinically manifested as a decreased resistance to stressors and is present in up to 35% of patient with ESKD. It is associated with falls, hospitalizations, poor cognitive function, and mortality. Also, frailty is associated with poor outcomes after kidney transplant, including delirium and mortality. Frailty is likely also associated with decreased access to kidney transplantation, given its association with poor outcomes on dialysis and post-transplant. Yet, clinicians have difficulty identifying which patients are frail; therefore, we sought to quantify if frail kidney transplant candidates had similar access to kidney transplantation as nonfrail candidates.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied 7078 kidney transplant candidates (2009-2018) in a three-center prospective cohort study of frailty. Fried frailty (unintentional weight loss, grip strength, walking speed, exhaustion, and activity level) was measured at outpatient kidney transplant evaluation. We estimated time to listing and transplant rate by frailty status using Cox proportional hazards and Poisson regression, adjusting for demographic and health factors.

RESULTS

The mean age was 54 years (SD 13; range, 18-89), 40% were women, 34% were black, and 21% were frail. Frail participants were almost half as likely to be listed for kidney transplantation (hazard ratio, 0.62; 95% confidence interval, 0.56 to 0.69; P<0.001) compared with nonfrail participants, independent of age and other demographic factors. Furthermore, frail candidates were transplanted 32% less frequently than nonfrail candidates (incidence rate ratio, 0.68; 95% confidence interval, 0.58 to 0.81; P<0.001).

CONCLUSIONS

Frailty is associated with lower chance of listing and lower rate of transplant, and is a potentially modifiable risk factor.

Chronic Low-grade Inflammatory Phenotype (CLIP) and Senescent Immune Dysregulation

PURPOSE

The aim was to provide an overview of chronic low-grade inflammatory phenotype (CLIP) and evidence for its role in the pathogenesis of frailty and other chronic conditions as well as potential causative factors and interventions.

METHODS

We reviewed evidence from published clinical and laboratory studies and summarized the opinions of experts from published reviews.

FINDINGS

CLIP is a low-grade, systemic, unresolved, and smoldering chronic inflammatory state clearly indicated by a 2- to 4-fold increase in serum levels of inflammatory mediators, such as interleukin-6 and C-reactive protein. It involves many other cellular and molecular inflammatory mediators. CLIP typically occurs during aging, also known as "inflammaging," and is an integral part of the spectrum of immunosenescence. Causative factors likely include persistent viral infections, particularly chronic cytomegalovirus infection, cellular senescence, failure to eliminate degraded materials and waste products, dysregulated microbiota and gut permeability, obesity, and others. Substantial evidence supports CLIP as a powerful contributing factor to frailty and many other chronic conditions and adverse health outcomes. Many of the inflammatory mediators and their regulatory mechanisms in CLIP may serve as potential targets for therapeutic intervention. However, development of new interventional strategies for CLIP and its associated chronic conditions should take the complexity of the inflammatory network into consideration. Nonpharmacologic interventions, such as caloric restriction and exercise, may have significant impact on CLIP and its causative factors, leading to substantial health benefits. Metformin and resveratrol have anti-inflammatory property and may serve as a promising therapeutic agent for treatment of CLIP and frailty.

IMPLICATIONS

CLIP is a chronic inflammatory pathophysiologic process that plays an important role in the pathogenesis of frailty and many other chronic conditions. Improving our understanding of this phenotype may provide opportunities to identify potential targets of effective prevention and therapeutic strategies for frailty and other CLIP-associated conditions.

Frailty Screening: Inflammatory Markers Assessment and Identification of Adverse Health Factors in Hospitalized Older Adults

BACKGROUND AND PURPOSE

The detection of older individuals who are most vulnerable to adverse health effects (AHE) may be useful for practitioners in managing health care resources. The purpose of this study was to analyze the prevalence and identify AHE after hospital discharge (HD).

METHODS

This cohort study included 135 hospitalized older individuals. Fragility was assessed by changes in the plasma concentrations of C-reactive protein and / or leukocytes.

RESULTS

Fragile individuals had a higher risk of rehospitalization, consumption of drugs, functional impairment and mortality within 30 days post-HD, and higher risk of functional disability at 180 days post-HD.

CONCLUSION

More than one-third of hospitalized older individuals are fragile and require more attention in the first 30 days because of the associated AHE.

A framework for selection of blood-based biomarkers for geroscience-guided clinical trials: report from the TAME Biomarkers Workgroup

Recent advances indicate that biological aging is a potentially modifiable driver of late-life function and chronic disease and have led to the development of geroscience-guided therapeutic trials such as TAME (Targeting Aging with MEtformin). TAME is a proposed randomized clinical trial using metformin to affect molecular aging pathways to slow the incidence of age-related multi-morbidity and functional decline. In trials focusing on clinical end-points (e.g., disease diagnosis or death), biomarkers help show that the intervention is affecting the underlying aging biology before sufficient clinical events have accumulated to test the study hypothesis. Since there is no standard set of biomarkers of aging for clinical trials, an expert panel was convened and comprehensive literature reviews conducted to identify 258 initial candidate biomarkers of aging and age-related disease. Next selection criteria were derived and applied to refine this set emphasizing: (1) measurement reliability and feasibility; (2) relevance to aging; (3) robust and consistent ability to predict all-cause mortality, clinical and functional outcomes; and (4) responsiveness to intervention. Application of these selection criteria to the current literature resulted in a short list of blood-based biomarkers proposed for TAME: IL-6, TNFα-receptor I or II, CRP, GDF15, insulin, IGF1, cystatin C, NT-proBNP, and hemoglobin A1c. The present report provides a conceptual framework for the selection of blood-based biomarkers for use in geroscience-guided clinical trials. This work also revealed the scarcity of well-vetted biomarkers for human studies that reflect underlying biologic aging hallmarks, and the need to leverage proposed trials for future biomarker discovery and validation.

Frailty and Postkidney Transplant Health-Related Quality of Life

BACKGROUND

Health-related quality of life (HRQOL) reflects a patient's disease burden, treatment effectiveness, and health status and is summarized by physical, mental, and kidney disease-specific scales among end-stage renal disease patients. Although on average HRQOL improves postkidney transplant (KT), the degree of change depends on the ability of the patient to withstand the stressor of dialysis versus the ability to tolerate the intense physiologic changes of KT. Frail KT recipients may be extra vulnerable to either of these stressors, thus affecting change in HRQOL after KT.

METHODS

We ascertained frailty, as well as physical, mental, and kidney disease-specific HRQOL in a multicenter prospective cohort of 443 KT recipients (May 2014 to May 2017) using Kidney Disease Quality of Life Instrument Short Form. We quantified the short-term (3 months) rate of post-KT HRQOL change by frailty status using adjusted mixed-effects linear regression models.

RESULTS

Mean HRQOL scores at KT were 43.3 (SD, 9.6) for physical, 52.8 (SD, 8.9) for mental, and 72.6 (SD, 12.8) for kidney disease-specific HRQOL; frail recipients had worse physical (P < 0.001) and kidney disease-specific HRQOL (P = 0.001), but similar mental HRQOL (P = 0.43). Frail recipients experienced significantly greater rates of improvement in physical HRQOL (frail, 1.35 points/month; 95% confidence interval [CI], 0.65-2.05; nonfrail, 0.34 points/month; 95% CI, -0.17-0.85; P = 0.02) and kidney disease-specific HRQOL (frail, 3.75 points/month; 95% CI, 2.89-4.60; nonfrail, 2.41 points/month; 95% CI, 1.78-3.04; P = 0.01), but no difference in mental HRQOL (frail, 0.54 points/month; 95% CI, -0.17-1.25; nonfrail, 0.46 points/month; 95% CI, -0.06-0.98; P = 0.85) post-KT.

CONCLUSIONS

Despite decreased physiologic reserve, frail recipients experience improvement in post-KT physical and kidney disease-specific HRQOL better than nonfrail recipients.

Biological Processes and Biomarkers Related to Frailty in Older Adults: A State-of-the-Science Literature Review

The objectives of this literature review were to (1) synthesize biological processes linked to frailty and their corresponding biomarkers and (2) identify potential associations among these processes and biomarkers. In September 2016, PubMed, Cumulative Index to Nursing and Allied Health, Cochrane Library, and Embase were searched. Studies examining biological processes related to frailty in older adults (≥60 years) were included. Studies were excluded if they did not employ specific measures of frailty, did not report the association between biomarkers and frailty, or focused on nonelderly samples (average age < 60). Review articles, commentaries, editorials, and non-English articles were also excluded. Fifty-two articles were reviewed, reporting six biological processes related to frailty and multiple associated biomarkers. The processes (biomarkers) include brain changes (neurotrophic factor, gray matter volume), endocrine dysregulation (growth hormones [insulin-like growth factor-1 and binding proteins], hormones related to glucose and insulin, the vitamin D axis, thyroid function, reproductive axis, and hypothalamic–pituitary–adrenal axis), enhanced inflammation (C-reactive protein, interleukin-6), immune dysfunction (neutrophils, monocytes, neopterin, CD8+CD28−T cells, albumin), metabolic imbalance (micronutrients, metabolites, enzyme-activity indices, metabolic end products), and oxidative stress (antioxidants, telomere length, glutathione/oxidized glutathione ratio). Bidirectional interrelationships exist within and between these processes. Biomarkers were associated with frailty in varied strengths, and the causality remains unclear. In conclusion, frailty is related to multisystem physiological changes. Future research should examine the dynamic interactions among these processes to inform causality of frailty. Given the multifactorial nature of frailty, a composite index of multisystem biomarkers would likely be more informative than single biomarkers in early detection of frailty.

Frailty and the endocrine system

Frailty is a condition characterised by loss of biological reserves, failure of homoeostatic mechanisms, and vulnerability to adverse outcomes. The endocrine system is considered particularly important in frailty, because of its complex inter-relationships with the brain, immune system, and skeletal muscle. This Review summarises evidence indicating a key role for the hypothalamic-pituitary axis in the pathogenesis of frailty through aberrant regulation of glucocorticoid secretion, insulin-like growth factor signalling, and androgen production. Evidence also indicates a potential role for vitamin D and insulin resistance in the pathogenesis of frailty. The role of thyroid hormones in the pathogenesis of frailty remains uncertain. Key convergent pathological effects of frailty include loss of muscle mass and strength, with consequent impact on mobility and activities of daily living. Future translational research should focus on the understanding of endocrine mechanisms, to identify potential biomarkers of the condition, modifiable targets for treatment, and novel pharmacological drugs targeted at the endocrine components of frailty.

Frailty assessment in older adults with chronic obstructive respiratory diseases

The number of patients with chronic obstructive pulmonary disease (COPD) has been rising with continued exposure to environmental risk factors and aging of populations around the world. Frailty is a geriatric syndrome with a decline in physiological reserve and often coexists with chronic diseases such as COPD. Frailty is an independent risk factor for the development and progression of COPD, and COPD can lead to frailty; treating one might improve the other. Thus, there is an increasing interest in the assessment of frailty in patients with COPD. Furthermore, early identification and assessment of frailty in patients with COPD may affect the choice of intervention and improve its effectiveness. Based on the current literature, the intent of this review was to summarize and discuss frailty assessment tools used for COPD patients and the relevant clinical practices for predicting outcomes. We ascertain that using suitable frailty assessment tools could facilitate physicians to screen and stratify physically frail patients with COPD. Screening appropriately targeted population can achieve better intervention outcomes and pulmonary rehabilitation among frail COPD patients.

Frailty and chronic kidney disease: current evidence and continuing uncertainties

Frailty, the state of increased vulnerability to physical stressors as a result of progressive and sustained degeneration in multiple physiological systems, is common in those with chronic kidney disease (CKD). In fact, the prevalence of frailty in the older adult population is reported to be 11%, whereas the prevalence of frailty has been reported to be greater than 60% in dialysis-dependent CKD patients. Frailty is independently linked with adverse clinical outcomes in all stages of CKD and has been repeatedly shown to be associated with an increased risk of mortality and hospitalization. In recent years there have been efforts to create an operationalized definition of frailty to aid its diagnosis and to categorize its severity. Two principal concepts are described, namely the Fried Phenotype Model of Physical Frailty and the Cumulative Deficit Model of Frailty. There is no agreement on which frailty assessment approach is superior, therefore, for the time being, emphasis should be placed on any efforts to identify frailty. Recognizing frailty should prompt a holistic assessment of the patient to address risk factors that may exacerbate its progression and to ensure that the patient has appropriate psychological and social support. Adequate nutritional intake is essential and individualized exercise programmes should be offered. The acknowledgement of frailty should prompt discussions that explore the future care wishes of these vulnerable patients. With further study, nephrologists may be able to use frailty assessments to inform discussions with patients about the initiation of renal replacement therapy.

Frailty, Length of Stay, and Mortality in Kidney Transplant Recipients: A National Registry and Prospective Cohort Study

OBJECTIVE

To test whether frailty, a novel measure of physiologic reserve, is associated with longer kidney transplant (KT) length of stay (LOS), and modifies the association between LOS and mortality.

BACKGROUND

Better understanding of LOS is necessary for informed consent and discharge planning. Mortality resulting from longer LOS has important regulatory implications for hospital and transplant programs. Which recipients are at risk of prolonged LOS and its effect on mortality are unclear. Frailty is a novel preoperative predictor of poor KT outcomes including delayed graft function, early hospital readmission, immunosuppression intolerance, and mortality.

METHODS

We used registry-augmented hybrid methods, a novel approach to risk adjustment, to adjust for LOS risk factors from the Scientific Registry of Transplant Recipients (n = 74,859) and tested whether (1) frailty, measured immediately before KT in a novel cohort (n = 589), was associated with LOS (LOS: negative binomial regression; LOS ≥2 weeks: logistic regression) and (2) whether frailty modified the association between LOS and mortality (interaction term analysis).

RESULTS

Frailty was independently associated with longer LOS [relative risk = 1.15, 95% confidence interval (CI): 1.03-1.29; P = 0.01] and LOS ≥2 weeks (odds ratio = 1.57, 95% CI: 1.06-2.33; P = 0.03) after accounting for registry-based risk factors, including delayed graft function. Frailty also attenuated the association between LOS and mortality (nonfrail hazard rate = 1.55 95% CI: 1.30-1.86; P < 0.001; frail hazard rate = 0.97, 95% CI: 0.79-1.19, P = 0.80; P for interaction = 0.001).

CONCLUSIONS

Frail KT recipients are more likely to experience a longer LOS. Longer LOS among nonfrail recipients may be a marker of increased mortality risk. Frailty is a measure of physiologic reserve that may be an important clinical marker of longer surgical LOS.

Individual Frailty Components and Mortality in Kidney Transplant Recipients

BACKGROUND

Frailty increases early hospital readmission and mortality risk among kidney transplantation (KT) recipients. Although frailty represents a high-risk state for this population, the correlates of frailty, the patterns of the 5 frailty components, and the risk associated with these patterns are unclear.

METHODS

Six hundred sixty-three KT recipients were enrolled in a cohort study of frailty in transplantation (12/2008-8/2015). Frailty, activities of daily living (ADL)/instrumental ADL (IADL) disability, Centers for Epidemiologic Studies Depression Scale depression, education, and health-related quality of life (HRQOL) were measured. We used multinomial regression to identify frailty correlates. We identified which patterns of the 5 components were associated with mortality using adjusted Cox proportional hazards models.

RESULTS

Frailty prevalence was 19.5%. Older recipients (adjusted prevalence ratio [PR], 2.22; 95% confidence interval [CI], 1.21-4.07) were more likely to be frail. The only other factors that were independently associated with frailty were IADL disability (PR, 3.22; 95% CI, 1.72-6.06), depressive symptoms (PR, 11.31; 95% CI, 4.02-31.82), less than a high school education (PR, 3.10; 95% CI, 1.30-7.36), and low HRQOL (fair/poor: PR, 3.71; 95% CI, 1.48-9.31). The most common pattern was poor grip strength, low physical activity, and slowed walk speed (19.4%). Only 2 patterns of the 5 components emerged as having an association with post-KT mortality. KT recipients with exhaustion and slowed walking speed (hazards ratio = 2.43; 95% CI, 1.17-5.03) and poor grip strength, exhaustion, and slowed walking speed (hazard ratio, 2.61; 95% CI, 1.14-5.97) were at increased mortality risk.

CONCLUSIONS

Age was the only conventional factor associated with frailty among KT recipients; however, factors rarely measured as part of clinical practice, namely, HRQOL, IADL disability, and depressive symptoms, were significant correlates of frailty. Redefining the frailty phenotype may be needed to improve risk stratification for KT recipients.

Frailty Assessment in Hospitalized Older Adults Using the Electronic Health Record

INTRODUCTION

Frailty, a clinical syndrome of decreased physiologic reserve and dysregulation in multiple physiologic systems, is associated with increased risk for adverse outcomes.

PURPOSE

The aim of this retrospective, cross-sectional, correlational study was to characterize frailty in older adults admitted to a tertiary-care hospital using a biopsychosocial frailty assessment and to determine associations between frailty and time to in-hospital mortality and 30-day rehospitalization.

METHODS

The sample included 278 patients ≥55 years old admitted to medicine units. Frailty was determined using clinical data from the electronic health record (EHR) for symptoms, syndromes, and conditions and laboratory data for four serum biomarkers. A frailty risk score (FRS) was created from 16 risk factors, and relationships between the FRS and outcomes were examined.

RESULTS

The mean age of the sample was 70.2 years and mean FRS was 9.4 ( SD, 2.2). Increased FRS was significantly associated with increased risk of death (hazard ratio = 1.77-2.27 for 3 days ≤ length of stay (LOS) ≤7 days), but depended upon LOS ( p < .001). Frailty was marginally associated with rehospitalization for those who did not die in hospital (adjusted odds ratio = 1.18, p = .086, area under the curve [AUC] = 0.66, 95% confidence interval for AUC = [0.57, 0.76]).

DISCUSSION

Clinical data in the EHR can be used for frailty assessment. Informatics may facilitate data aggregation and decision support. Because frailty is potentially preventable and treatable, early detection is crucial to delivery of tailored interventions and optimal patient outcomes.

Frailty in Pulmonary and Critical Care Medicine

Conceptualized first in the field of geriatrics, frailty is a syndrome characterized by a generalized vulnerability to stressors resulting from an accumulation of physiologic deficits across multiple interrelated systems. This accumulation of deficits results in poorer functional status and disability. Frailty is a "state of risk" for subsequent disproportionate declines in health status following new exposure to a physiologic stressor. Two predominant models have emerged to operationalize the measurement of frailty. The phenotype model defines frailty as a distinct clinical syndrome that includes conceptual domains such as strength, activity, wasting, and mobility. The cumulative deficit model defines frailty by enumerating the number of age-related things wrong with a person. The biological pathways driving frailty include chronic systemic inflammation, sarcopenia, and neuroendocrine dysregulation, among others. In adults with chronic lung disease, frailty is independently associated with more frequent exacerbations of lung disease, all-cause hospitalization, declines in functional status, and all-cause mortality. In addition, frail adults who become critically ill are more likely develop chronic critical illness or severe disability and have higher in-hospital and long-term mortality rates. The evaluation of frailty appears to provide important prognostic information above and beyond routinely collected measures in adults with chronic lung disease and the critically ill. The study of frailty in these populations, however, requires multipronged efforts aimed at refining clinical assessments, understanding the mechanisms, and developing therapeutic interventions.