New horizons in frailty: ageing and the deficit-scaling problem

Association between frailty index based on laboratory tests and all-cause mortality in critically ill patients with heart failure

BACKGROUND

The frailty index based on laboratory tests (FI-lab) can identify individuals at increased risk for adverse health outcomes. The association between the FI-lab and all-cause mortality in patients with heart failure (HF) in the intensive care unit (ICU) remains unknown. This study aimed to determine the correlation between FI-lab and all-cause mortality to evaluate the impact of FI-lab on the prognosis of critically ill patients with HF.

METHODS

This retrospective observational study utilized data extracted from the Medical Information Mart for Intensive Care IV database. The FI-lab, which consists of 33 laboratory tests, was constructed. Patients were then grouped into quartiles (Q1-Q4) based on their FI-lab scores. Kaplan-Meier analysis was used to compare all-cause mortality among the four groups. A Cox proportional hazard analysis was conducted to examine the association between the FI-lab score and all-cause mortality. The incremental predictive value of adding FI-lab to classical disease severity scores was assessed using Harrell's C statistic, integrated discrimination improvement (IDI) and net reclassification improvement (NRI).

RESULTS

Among 3021 patients, 838 (27.74%) died within 28 days, and 1400 (46.34%) died within a 360 day follow-up period. Kaplan-Meier analysis indicated that patients with higher FI-lab scores had significantly higher risks of all-cause mortality (log-rank P < 0.001). Multivariable Cox regression suggested that FI-lab, evaluated as a continuous variable (for each 0.01 increase), was associated with increased 28 day mortality [hazard ratio (HR) 1.02, 95% confidence interval (CI) (1.01-1.03), P < 0.001] and 360 day mortality [HR 1.02, 95% CI (1.01-1.02), P < 0.001]. When assessed in quartiles, the 28 day mortality risk [HR 1.66, 95% CI (1.28-2.15), P < 0.001] and 360 day mortality risk [HR 1.48, 95% CI (1.23-1.8), P < 0.001] were significantly higher for FI-lab Q4 compared with FI-lab Q1. FI-lab significantly improved the predictive capability of classical disease severity scores for 28 and 360 day mortality.

CONCLUSIONS

In ICU patients diagnosed with HF, the FI-lab is a potent predictor of short-term and long-term mortality in critically ill patients with HF. The active use of FI-lab to identify high-risk groups among critically ill HF patients and initiate timely interventions may have significant value in improving the prognosis of critically ill patients with HF.

Deletion of quinolinate phosphoribosyltransferase gene accelerates frailty phenotypes and neuromuscular decline with aging in a sex-specific pattern

Decline in neuromuscular function with aging is known to be a major determinant of disability and all-cause mortality in late life. Despite the importance of the problem, the neurobiology of age-associated muscle weakness is poorly understood. In a previous report, we performed untargeted metabolomics on frail older adults and discovered prominent alteration in the kynurenine pathway, the major route of dietary tryptophan degradation that produces neurotoxic intermediate metabolites. We also showed that neurotoxic kynurenine pathway metabolites are correlated with increased frailty score. For the present study, we sought to further examine the neurobiology of these neurotoxic intermediates by utilizing a mouse model that has a deletion of the quinolinate phosphoribosyltransferase (QPRT) gene, a rate-limiting step of the kynurenine pathway. QPRT-/- mice have elevated neurotoxic quinolinic acid level in the nervous system throughout their lifespan. We found that QPRT-/- mice have accelerated declines in neuromuscular function in an age- and sex-specific manner compared to control strains. In addition, the QPRT-/- mice show premature signs of frailty and body composition changes that are typical for metabolic syndrome. Our findings suggest that the kynurenine pathway may play an important role in frailty and age-associated muscle weakness.

Costs and Survival of Patients having Experienced a Hospitalized Fall-Related Injury in France: A Population-Based Study

OBJECTIVES

To assess the annual costs 2 years before and 2 years after a hospitalized fall-related injury (HFRI) and the 2-year survival among the population 75+ years old.

DESIGN

We performed a population-based, retrospective cohort study using the French national health insurance claims database.

SETTING AND PARTICIPANTS

Patients 75+ years old who had experienced a fall followed by hospitalization, identified using an algorithm based on International Classification of Diseases codes. Data related to a non-HFRI population matched on the basis of age, sex, and geographical area were also extracted.

METHODS

Cost analyses were performed from a health insurance perspective and included direct costs. Survival analyses were conducted using Kaplan-Meier curves and Cox regression. Descriptive analyses of costs and regression modeling were carried out. Both regression models for costs and on survival were adjusted for age, sex, and comorbidities.

RESULTS

A total of 1495 patients with HFRI and 4484 non-HFRI patients were identified. Patients with HFRI were more comorbid than the non-HFRI patients over the entire periods, particularly in the year before and the year after the HFRI. Patients with HFRI have significantly worse survival probabilities, with an adjusted 2.14-times greater risk of death over 2-year follow-up and heterogeneous effects determined by sex. The annual incremental costs between patients with HFRI and non-HFRI individuals were €1294 and €2378, respectively, 2 and 1 year before the HFRI, and €11,796 and €1659, respectively, 1 and 2 years after the HFRI. The main cost components differ according to the periods and are mainly accounted for by paramedical acts, hospitalizations, and drug costs. When fully adjusted, the year before the HFRI and the year after the HFRI are associated with increase in costs.

CONCLUSIONS AND IMPLICATIONS

We have provided real-world estimates of the cost and the survival associated with patients with HFRI. Our results highlight the urgent need to manage patients with HFRI at an early stage to reduce the significant mortality as well as substantial additional cost management. Special attention must be paid to the fall-related increasing drugs and to optimizing management of comorbidities.

Relationship of Frailty with Kidney Function in Adults More Than 60-Years-Old: Effect of Using Different Formulas to Estimate Glomerular Filtration Rate

Objective

Determine the relationship of renal function with frailty using different formulas for estimated glomerular filtration rate (eGFR).

Methods

Individuals who were 60-years-old or more (n=507) were recruited from August 2020 to June 2021, and the FRAIL scale was used to classify them as non-frail or frail. The three equations used to compute the eGFR were based on serum creatinine (eGFRcr), cystatin C (eGFRcys), or SCr+CysC (eGFRcr-cys). Renal function was classified using eGFR and defined as normal (≥90 mL/min/1.73m²), mild damage (59-89 mL/min/1.73m²), or moderate damage (≤60 mL/min/1.73m²). The relationship of frailty with renal function was analyzed. A subset of participants (n=358) was used to analyze changes in eGFR from 1 January 2012 to 31 December 2021 according to frailty and using the different eGFR equations.

Results

There were significant differences between the eGFRcr-cys and eGFRcr values in the frail group (P<0.05), but not the non-frail group; however, the differences between the eGFRcr-cys and eGFRcys values were significant in the frail and non-frail groups (P<0.001). Based on each eGFR equation, the prevalence of frailty increased as eGFR decreased (P<0.001), but there was no significant relationship after adjusting for age or the age-adjusted Charlson co-morbidity index. There were temporal declines in eGFR in all three frailty groups (robust, pre-frail, and frail), especially in the frail group (2.226 mL/min/1.73m² per year; P<0.001).

Conclusion

For older individuals who are frail, the eGFRcr value may not provide accurate estimates of renal function. Frailty is associated with a rapid decline in kidney function.

The Clinical Frailty Scale for mortality prediction of old acutely admitted intensive care patients: a meta-analysis of individual patient-level data

BACKGROUND

This large-scale analysis pools individual data about the Clinical Frailty Scale (CFS) to predict outcome in the intensive care unit (ICU).

METHODS

A systematic search identified all clinical trials that used the CFS in the ICU (PubMed searched until 24th June 2020). All patients who were electively admitted were excluded. The primary outcome was ICU mortality. Regression models were estimated on the complete data set, and for missing data, multiple imputations were utilised. Cox models were adjusted for age, sex, and illness acuity score (SOFA, SAPS II or APACHE II).

RESULTS

12 studies from 30 countries with anonymised individualised patient data were included (n = 23,989 patients). In the univariate analysis for all patients, being frail (CFS ≥ 5) was associated with an increased risk of ICU mortality, but not after adjustment. In older patients (≥ 65 years) there was an independent association with ICU mortality both in the complete case analysis (HR 1.34 (95% CI 1.25-1.44), p < 0.0001) and in the multiple imputation analysis (HR 1.35 (95% CI 1.26-1.45), p < 0.0001, adjusted for SOFA). In older patients, being vulnerable (CFS 4) alone did not significantly differ from being frail. After adjustment, a CFS of 4-5, 6, and ≥ 7 was associated with a significantly worse outcome compared to CFS of 1-3.

CONCLUSIONS

Being frail is associated with a significantly increased risk for ICU mortality in older patients, while being vulnerable alone did not significantly differ. New Frailty categories might reflect its "continuum" better and predict ICU outcome more accurately.

TRIAL REGISTRATION

Open Science Framework (OSF: https://osf.io/8buwk/ ).

A novel easy-to-use index to predict institutionalization and death in older population - a 10-year population-based follow-up study

BACKGROUND

Various indexes have been developed to estimate the risk for mortality, institutionalization, and other adverse outcomes for older people. Most indexes are based on a large number of clinical or laboratory parameters. An index based on only a few parameters would be more practical to use in every-day clinical practice. Our aim was to create an index to predict the risk for mortality and institutionalization with as few parameters as possible without compromising their predictive ability.

METHODS

A prospective study with a 10-year follow-up period. Thirty-six clinical and fourteen laboratory parameters were combined to form an index. Cox regression model was used to analyze the association of the index with institutionalization and mortality. A backward statistical method was used to reduce the number of parameters to form an easy-to-use index for predicting institutionalization and mortality.

RESULTS

The mean age of the participants (n = 1172) was 73.1 (SD 6.6, range 64‒97) years. Altogether, 149 (14%) subjects were institutionalized, and 413 (35%) subjects deceased during the follow-up. Institutionalization and mortality rates increased as index scores increased both for the large 50-parameter combined index and for the reduced indexes. After a backward variable selection in the Cox regression model, three clinical parameters remained in the index to predict institutionalization and six clinical and three laboratory parameters in the index to predict mortality. The reduced indexes showed a slightly better predictive value for both institutionalization and mortality compared to the full index.

CONCLUSIONS

A large index with fifty parameters included many unimportant parameters that did not increase its predictive value, and therefore could be replaced with a reduced index with only a few carefully chosen parameters, that were individually associated with institutionalization or death.

Translational research into frailty from bench to bedside: Salivary biomarkers for inflammaging

Frailty is a complex physiological syndrome associated with adverse ageing and decreased physiological reserves. Frailty leads to cognitive and physical disability and is a significant cause of morbidity, mortality and economic costs. The underlying cause of frailty is multifaceted, including immunosenescence and inflammaging, changes in microbiota and metabolic dysfunction. Currently, salivary biomarkers are used as early predictors for some clinical diseases, contributing to the effective prevention and treatment of diseases, including frailty. Sample collection for salivary analysis is non-invasive and simple, which are paramount factors for testing in the vulnerable frail population. The aim of this review is to describe the current knowledge on the association between frailty and the inflammatory process and discuss methods to identify putative biomarkers in salivary fluids to predict this syndrome. This study describes the relationship between i.-inflammatory process and frailty; ii.-infectious, chronic, skeletal, metabolic and cognitive diseases with inflammation and frailty; iii.-inflammatory biomarkers and salivary fluids. There is a limited number of previous studies focusing on the analysis of inflammatory salivary biomarkers and frailty syndrome; hence, the study of salivary fluids as a source for biomarkers is an open area of research with the potential to address the increasing demands for frailty-associated biomarkers.

Measurements of damage and repair of binary health attributes in aging mice and humans reveal that robustness and resilience decrease with age, operate over broad timescales, and are affected differently by interventions

As an organism ages, its health-state is determined by a balance between the processes of damage and repair. Measuring these processes requires longitudinal data. We extract damage and repair transition rates from repeated observations of binary health attributes in mice and humans to explore robustness and resilience, which respectively represent resisting or recovering from damage. We assess differences in robustness and resilience using changes in damage rates and repair rates of binary health attributes. We find a conserved decline with age in robustness and resilience in mice and humans, implying that both contribute to worsening aging health - as assessed by the frailty index (FI). A decline in robustness, however, has a greater effect than a decline in resilience on the accelerated increase of the FI with age, and a greater association with reduced survival. We also find that deficits are damaged and repaired over a wide range of timescales ranging from the shortest measurement scales toward organismal lifetime timescales. We explore the effect of systemic interventions that have been shown to improve health, including the angiotensin-converting enzyme inhibitor enalapril and voluntary exercise for mice. We have also explored the correlations with household wealth for humans. We find that these interventions and factors affect both damage and repair rates, and hence robustness and resilience, in age and sex-dependent manners.

A frailty index based on routine laboratory data predicts increased risk of mortality in Chinese community-dwelling adults aged over 55 years: a five-year prospective study

Background

Frailty can be operationalized based on the accumulation of deficits using a frailty index (FI) and is associated with an increased risk of adverse health outcomes. Here, we aim to compare validity of a FI from laboratory data with that of the common clinical FI for prediction of mortality in adults aged 55 + years, also examine whether combined FI could improve identification of adults aged 55 + years at increased risk of death.

Methods

Data for this analysis were obtained from the Beijing Longitudinal Study of Aging that involved 1,257 community-dwelling Chinese people, aged 55 + years at baseline. The main outcome measure was 5-year mortality. An FI-self-report based on 30 self-reported health-related data was constructed. An FI-lab was developed using laboratory data, in addition to pulse, systolic and diastolic blood pressure, pulse pressure, body mass index (BMI) and waist. A combined FI comprised all items from each FI. Kaplan–Meier survival curve and Cox proportional hazards models were performed to evaluate the risk of each FI on death. The area under receiver operating characteristic(ROC) curves were used to compare the discriminative performance of each FI.

Results

Of 1257 participants, 155 died and 156 lost at the end of the 5-year follow-up. The mean FI-self-report score was 0.11 ± 0.10, the FI-lab score was 0.33 ± 0.14 and FI-combined score was 0.19 ± 0.09. Higher frailty level defined by each FI was associated with higher risk of death. After adjustment for age and sex, Cox proportional hazards models showed that the higher scores of frailty were associated with a higher risk of mortality for each FI, the hazard ratios for the FI-self-report and FI-lab and FI-combined were 1.04 (1.03 to 1.05) and 1.02 (1.01 to 1.03) and 1.05 (1.04 to 1.07), respectively. The areas under the ROC curve were 0.79 (0.77–0.82) for the FI-self-report, 0.77(0.75–0.80) for the FI-lab and 0.81(0.78–0.82) for FI-combined.

Conclusions

A FI from laboratory data can stratify older adults at increased risk of death alone and in combination with FI based on self-report data. Assessment in clinical settings of creating an FI using routine collected laboratory data needs to be further developed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03374-z.

Associations of social isolation, social participation, and loneliness with frailty in older adults in Singapore: a panel data analysis

BACKGROUND

There is a shortage of research evidence about how social isolation, social participation, and loneliness were longitudinally associated with frailty. This study was to 1) examine the associations of social isolation, social participation, and loneliness with level of frailty among community-dwelling older adults using panel data, and 2) explore the moderating effect of gender on the association of social isolation, social participation and loneliness with frailty.

METHODS

The study included 606 participants aged 60 years and above from the longitudinal Population Health Index Survey conducted in Singapore. At each timepoint, level of frailty was determined using the Clinical Frailty Scale. Social isolation was assessed by the Lubben Social Network Scale-6, and loneliness was assessed using the three-item UCLA Loneliness Scale. Fixed-effects ordinal logistic regressions were conducted with level of frailty as the dependent variable and social isolation and loneliness as the independent variables, adjusting for time-varying socio-demographic, lifestyle, and health-related factors.

RESULTS

Increase in social participation was associated with lower level of frailty (odds ratio: 0.96, 95% confidence interval: 0.93-0.99) and feeling lonely was associated with higher level of frailty (odds ratio: 2.90, 95% confidence interval: 1.44-5.84). Social isolation was not associated with frailty. Gender did not have moderating effect on these associations.

CONCLUSIONS

This study observed that social isolation and loneliness had differential longitudinal association with level of frailty among community-dwelling older adults and suggested that loneliness and frailty should be measured and addressed concurrently among community-dwelling older adults.

Frailty and the risk of kidney function decline in the elderly population: the Rugao Longevity and Ageing Study

BACKGROUND

The diverse risk factors for kidney impairments suggest that kidney function decline is more likely to occur in individuals with a broadly constituted health deficit. Here we conducted a longitudinal cohort study to evaluate the association of baseline frailty status with the risk of estimated glomerular filtration rate (eGFR) decline.

METHODS

Overall, 1269 participants aged 70-84 years from Rugao Longevity and Ageing cohort with 3-year follow-up were included. Frailty was measured using a modified Fried frailty assessment. GFR was estimated using the Chronic Kidney Disease Epidemiology Collaboration equation. Associations between baseline frailty status and rapid eGFR decline were examined by multinomial logistic analysis. A linear mixed-effect model was used to determine eGFR decline in mL/min/1.73 m2 over the study period comparing those with frail or prefrail at baseline versus those with robust status.

RESULTS

The mean (± standard deviation) age of participants was 75.1 ± 3.8 years. A total of 144 (11%) participants had rapid eGFR decline by at least 10% during the 3-year follow-up. Compared with robust status, baseline frail status was associated with a 2.48-fold [95% confidence interval (CI) 1.24-4.95] increased risk of rapid eGFR decline after multiple adjustments. In multivariate linear mixed model analysis, subjects with frail status but not prefrail status at baseline had a significant coefficient of -1.70 (95% CI -3.35 to -0.04) for the frail × visit term, which indicates an accelerated eGFR decline compared with robust subjects over the study period (P = 0.044).

CONCLUSIONS

Frailty may serve as an independent biomarker to predict the decline of kidney function.

Frailty and healthcare utilisation across care settings among community-dwelling older adults in Singapore

Background

Frailty is frequently found to be associated with increased healthcare utilisation in western countries, but little is known in Asian population. This study was conducted to investigate the association between frailty and healthcare utilisation in different care settings among community-dwelling older adults in Singapore.

Methods

Data from a population health survey among community-dwelling adults were linked with an administrative database to retrieve data of healthcare utilisation (including government primary care clinic visits, specialised outpatient clinic visits, emergency department visits, day surgery and hospitalisations) occurred during a six-month look-back period and six-month post-baseline respectively. Baseline frailty status was measured using the five-item FRAIL scale, which was categorised into three groups: robust (0), pre-frail (1–2), and frail (3–5). Negative binomial regression was applied to examine the association between frailty with respective healthcare utilisation (dependent variables), controlling for other confounding variables.

Results

In our sample of 701 older adults, 64.8% were of robust health, 27.7% were pre-frail, and 7.6% were frail. Compared to the robust group, frail individuals had a higher rate of specialised outpatient clinic visits (incidence rate ratio (IRR): 2.8, 95% confidence interval (CI): 1.2–6.5), emergency department visits (IRR: 3.1, 95%CI: 1.1–8.1), day surgery attendances (IRR: 6.4, 95%CI: 1.3–30.9), and hospitalisations (IRR: 6.7, 95%CI: 2.1–21.1) in the six-month period prior to the baseline and in subsequent 6 months (IRR: 3.3, 95%CI: 1.6–7.1; 6.4, 2.4–17.2; 5.8, 1.3–25.8; 13.1, 4.9–35.0; respectively), controlling for covariates.

Conclusions

Frailty was positively associated with the number of specialised outpatient clinic visits, emergency department visits, day surgeries and hospitalisations occurred during 6 months prior to and after the baseline. As frailty is a potentially reversible health state with early screening and intervention, providing preventive activities that delay the onset or progression of frailty should have potential effect on delaying secondary and tertiary care utilisation.

Frailty as a Prognostic Indicator in Intensive Care

BACKGROUND

The percentage of patients in intensive care who are 80 years old or older is continually increasing. Such patients already made up more than 20% of all patients in intensive care in Germany in the years 2007-2011. Meanwhile, effective treatments that support the organs of the body and keep severely ill patients alive are also being continually developed and refined. Frailty is a key prognostic parameter. The scientifically based assessment of frailty can be highly useful in intensive care medicine with regard to consented decision-making, individualized prognostication, treatment planning, and aftercare.

METHODS

Pertinent publications were retrieved by a selective search in the PubMed database. On the basis of the literature assessment, a variety of screening instruments were used to assess frailty and its significance for very old, critically ill patients in German intensive care units.

RESULTS

Only a small number of screening instruments are suitable for routine use in German intensive care units. The scores vary in diagnostic precision. The Clinical Frailty Scale (CFS) enables highly accurate prognostication; it considers the patient in relation to his or her social environment, and to the reference population. Categorization is achieved by means of pictograms that are supplemented with brief written descriptions. The CFS can be used prospectively and is easy to learn. Its interrater reliability is high (weighted Cohen's κ: 0.85 [0.84; 0.87]), and it has been validated for routine use in intensive care units in Germany.

CONCLUSION

None of the available scores enable perfect prognostication. In Germany, frailty in intensive-care patients is currently best assessed on a simple visual scale (CFS).

Frailty, a multisystem ageing syndrome

The management of frail older people is a key component of aged care. There has been a plethora of tools developed for the diagnosis and screening of frailty. Some of these tools are entering routine clinical practice at a time when the higher healthcare costs involved in caring for older people who are frail have become a potential target for cost-cutting. Yet there is still only limited evidence to support the widespread adoption of frailty tools, and foundational factors impact on their accuracy and validity. Despite the acceptance of frailty as a valid term in research and clinical practice, older people believe the term carries stigma. Such issues indicate that there may be a need to reconsider current approaches to frailty. Recent advances in the science of ageing biology can provide a new framework for reconfiguring how we screen, diagnose, treat and prevent frailty. Frailty can be considered to be a multisystem ageing syndrome of decreased physiological and functional reserve, where the biological changes of ageing are seen in most tissues and organs and are the pathogenic mechanism for frailty. Likewise age-related chronic disease and multimorbidity are syndromes where ageing changes occur in one or multiple systems, respectively. This model focusses diagnostic criteria for frailty onto the biomarkers of ageing and generates new targets for the prevention and treatment of frailty based on interventions that influence ageing biology.

Electrophysiological Measures of Aging Pharynx Function in C. elegans Reveal Enhanced Organ Functionality in Older, Long-lived Mutants

The function of the pharynx, an organ in the model system Caenorhabditis elegans, has been correlated with life span and motility (another measure of health) since 1980. In this study, in order to further understand the relationship between organ function and life span, we measured the age-related decline of the pharynx using an electrophysiological approach. We measured and analyzed electropharyngeograms (EPG) of wild type animals, short-lived hsf-1 mutants, and long-lived animals with genetically decreased insulin signaling or increased heat shock pathway signaling; we recorded a total of 2,478 EPGs from 1,374 individuals. As expected, the long-lived daf-2(e1370) and hsf-1OE(uthIs235) animals maintained pharynx function relatively closer to the youthful state during aging, whereas the hsf-1(sy441) and wild type animals' pharynx function deviated significantly further from the youthful state at advanced age. Measures of the amount of variation in organ function can act as biomarkers of youthful physiology as well. Intriguingly, the long-lived animals had greater variation in the duration of pharynx contraction at older ages.

Frailty assessment in older urological patients prior to surgery: a systematic review and narrative synthesis

Background:

Radical cystectomy (RC) and urinary diversion are the recommended treatment for patients with muscle invasive bladder cancer. This is complex surgery, associated with significant patient morbidity and mortality. Frailty has been shown to be an independent risk factor for adverse outcomes in several surgical populations. Preoperative assessment of frailty is advocated in current guidelines but is not yet standard clinical practice.

Aims:

This systematic review and narrative synthesis aims to examine whether patients undergoing RC are assessed for frailty, what tools are used, and whether an association is found between frailty and adverse outcomes in this population.

Results:

Nine studies, published within the last 4 years, describe the use of tools reporting to measure frailty in the RC population. All demonstrate increased risk of adverse postoperative outcomes with higher frailty levels. Only one study used a validated frailty tool. The majority of studies measure frailty using variations on a tool derived from a large database (ACS-NSQIP) effectively counting co-morbidities, rather than assessing the multidomain nature of the frailty syndrome.

Conclusion:

The recognition of frailty as an important consideration in the perioperative period is welcome. This systematic review and narrative synthesis demonstrates the need for collaboration in research and delivery of clinical care for older surgical patients. Such collaboration may provide clarity regarding terms such as frailty and multimorbidity, preventing the development of assessment tools inaccurately measuring these discreet syndromes interchangeably. More accurate assessment of patients in terms of frailty, multimorbidity and functional status may allow better modification and shared decision making leading to improved postoperative outcomes in older patients undergoing RC.

Prevalence and associated factors for frailty among elder patients in China: a multicentre cross-sectional study

Background

To date, most previous studies of frailty among hospitalized elderly Chinese patients have been conducted based on small samples, which cannot represent the elderly patient population. The aim of this study was to identify the prevalence of and risk factors for frailty among elderly patients in China.

Study design and setting

This cross-sectional study surveyed 9996 elderly patients from 6 tertiary-level hospitals in China. The prevalence of frailty among patients from selected wards was surveyed by trained investigators. A mixed-effects Poisson regression model was used to analyse the factors associated with frailty among elderly patients.

Results

The mean age of all subjects was 72.47 ± 5.77 years. The prevalence rate of frailty in this study was 18.02%. After adjustments were made for the confounding effect of the clustering of hospital wards, a mixed-effects Poisson regression model showed that the associated factors of frailty included the following: age (OR: 1.016, 95% CI: 1.012–1.020), BMI < 18.5 (OR: 1.248, 95% CI: 1.171–1.330), female gender (OR: 1.058, 95% CI: 1.004–1.115), ethnic minority (OR: 1.152, 95% CI: 1.073–1.236), admission to hospital by the emergency department (OR: 1.104, 95% CI: 1.030–1.184), transit from another hospital (OR: 1.159, 95% CI: 1.049–1.279), former alcohol use (OR: 1.094, 95% CI: 1.022–1.171), fall history in the past 12 months (OR: 1.257, 95% CI: 1.194–1.323), vision dysfunction (OR: 1.144, 95% CI: 1.080–1.211), cognition impairment (OR: 1.182, 95% CI: 1.130–1.237), sleeping dysfunction (OR: 1.215, 95% CI: 1.215–1.318), urinary dysfunction (OR: 1.175, 95% CI: 1.104–1.251), and defecation dysfunction (OR: 1.286, 95% CI: 1.217–1.358). The results also showed some of the following protective effects: BMI > 28 (OR: 0.897, 95% CI: 0.856–0.940); higher education level, including middle school (OR: 0.915, 95% CI: 0.857, 0.977) and diploma and above (OR: 0.891, 95% CI: 0.821, 0.966); and current alcohol use (OR: 0.869, 95% CI: 0.815, 0.927).

Conclusion

We identified a relatively high prevalence of frailty among elderly patients, and there are several associated factors among the population derived from this investigation of a large-scale, multicentre, nationally representative Chinese elderly inpatient population.

Trial registration

Chinese Clinical Trial Registry, ChiCTR1800017682, registered 09 August 2018.

Mobilization-based transplantation of young-donor hematopoietic stem cells extends lifespan in mice

Mammalian aging is associated with reduced tissue regeneration and loss of physiological integrity. With age, stem cells diminish in their ability to regenerate adult tissues, likely contributing to age-related morbidity. Thus, we replaced aged hematopoietic stem cells (HSCs) with young-donor HSCs using a novel mobilization-enabled hematopoietic stem cell transplantation (HSCT) technology as an alternative to the highly toxic conditioning regimens used in conventional HSCT. Using this approach, we are the first to report an increase in median lifespan (12%) and a decrease in overall mortality hazard (HR: 0.42, CI: 0.273-0.638) in aged mice following transplantation of young-donor HSCs. The increase in longevity was accompanied by reductions of frailty measures and increases in food intake and body weight of aged recipients. Young-donor HSCs not only preserved youthful function within the aged bone marrow stroma, but also at least partially ameliorated dysfunctional hematopoietic phenotypes of aged recipients. This compelling evidence that mammalian health and lifespan can be extended through stem cell therapy adds a new category to the very limited list of successful anti-aging/life-extending interventions. Our findings have implications for further development of stem cell therapies for increasing health and lifespan.

Tools for Assessing Frailty in Older People: General Concepts

The general notion of frailty is widely understood to be a state of increased vulnerability to stressors, following age-related declines in function and reserves across multiple physiological systems. Frailty is clinically characterised by slower and/or incomplete recovery from stressors such as infection, injury, surgery or psychosocial distress. There is however no consensus on a single operational definition. Numerous assessment tools and scores are promoted to detect or measure frailty but two have widest research background and acceptance, the Frailty Phenotype and the deficit based Frailty Index. We describe these and other approaches in the context of a description of the psychometric properties, types of scaling, uses and misuses of assessment tools. We advocate the choice of an appropriate measurement tool be based on the population characteristics and the purpose for which it is to be used and illustrate how an understanding of the properties of different tools helps to inform this choice.

A Murine Frailty Index Based on Clinical and Laboratory Measurements: Links Between Frailty and Pro-inflammatory Cytokines Differ in a Sex-Specific Manner

A frailty index (FI) based on clinical deficit accumulation (FI-Clinical) quantifies frailty in aging mice. We aimed to develop a laboratory test-based murine FI tool (FI-Lab) and to investigate the effects of age and sex on FI-Lab scores, FI-Clinical scores, and the combination (FI-Combined), as well as to explore links between frailty and inflammation. Studies used older (17 and 23 months) C57BL/6 mice of both sexes. We developed an FI-Lab (blood pressure, blood chemistry, echocardiography) based on deviation from reference values in younger adults (12 months), which showed similar characteristics to a human FI-Lab tool. Interestingly, while FI-Clinical scores were higher in females, the opposite was true for FI-Lab scores and there was no sex difference in FI-Combined scores. All three FI tools revealed a positive correlation between pro-inflammatory cytokine levels and frailty in aging mice that differed between the sexes. Elevated levels of the pro-inflammatory cytokines interleukin (IL)-6, IL-9, and interferon-γ were associated with higher FI scores in aging females, while levels of IL-12p40 rose as FI scores increased in older males. Thus, an FI tool based on common laboratory tests can quantify frailty in mice; the positive correlation between inflammation and frailty scores in naturally aging mice differs between the sexes.

Fluctuations in frailty among older adults

BACKGROUND

frailty fluctuations, that is, within-person up and down deviations from individual long-term frailty index trajectories represent a hitherto both conceptually and empirically untapped facet of frailty among older adults.

OBJECTIVE

to assess the size of frailty fluctuations in old age and their association with frailty levels, frailty growth as well as sex and socio-economic position.

METHODS

a total of 18,704 biannual observations from 4,514 community-dwelling older adults (65+) in 10 European countries over 12 years from the Survey of Health, Ageing and Retirement in Europe (SHARE) were analysed. A frailty index was constructed based on 50 items. Long-term frailty trajectories and fluctuations were modelled simultaneously using Bayesian mixed-effects location-scale regression models.

RESULTS

frailty index fluctuations were non-negligible among older adults, amounting to 0.04/0.05 FI or 2.0/2.5 health deficits on average. 30% of fluctuations were between 0.04 and 0.1 FI (2 and 5 health deficits) and 8% were larger than 0.1 FI (5 health deficits). Fluctuations increased with age and frailty levels, and were higher among women, those with low socio-economic position (education) and individuals who died during follow-up.

CONCLUSIONS

frailty index fluctuations refer to instabilities in an older person's health status and represent a hitherto untapped but relevant aspect of vulnerability in old age. Future analysis of frailty fluctuations should be based on a larger number of repeated observations with shorter time intervals.

Applicability of laboratory deficit-based frailty index in predominantly older patients with end-stage renal disease under chronic dialysis: A pilot test of its correlation with survival and self-reported instruments

AIM

Laboratory deficit-based frailty index (LFI) exhibited outcome-prediction ability in the elderly, but not in those with end-stage renal disease (ESRD). We hypothesized that LFI results might have outcome correlation and correlate closely with other instruments in ESRD patients.

METHODS

We prospectively enroled ESRD patients between 2014 and 2015 and administered self-report frailty instruments (Strawbridge questionnaire, Edmonton frail scale (EFS), Groningen frailty indicator (GFI), Tilburg frailty indicator, G8 questionnaire and FRAIL scale), and Cardiovascular Health Study (CHS) scale, with two types of LFI calculated. They were followed up until June 30, 2017. Correlations between the results of six instruments, CHS scale, and those of LFI were identified, followed by Kaplan-Meier survival analyses and logistic regression analyses to compare those with high and low LFI.

RESULTS

The frailty prevalence was 33.3% (CHS), 78.8% Strawbridge questionnaire, 45.5% (EFS), 57.6% (GFI), 27.3% (Tilburg frailty indicator), 84.8% (G8) and 18.2% (FRAIL) among ESRD participants. LFI-1 results were significantly correlated with those of LFI-2 (P < 0.01), EFS (P = 0.04) and GFI (P < 0.01), while LFI-2 results were not. Those with CHS or GFI-identified frailty had significantly lower 1,25-(OH)₂ -D levels than those without. After 32.3 ± 5.4 months, patients with high LFI-1 scores, but not LFI-2, had a significantly higher mortality than those with lower scores. GFI and EFS scores were also independently associated with LFI-1, while CHS scores exhibited borderline association only.

CONCLUSION

Among a group of predominantly older ESRD patients, LFI differentiates patients with good and poor outcomes, supporting its applicability in these patients.

Rodent models of frailty and their application in preclinical research

In clinical medicine, the concept of frailty is viewed as a state of high vulnerability to adverse health outcomes in people of the same age. Frailty is an important challenge because the loss of physiological reserve means that even minor stressors can lead to disability and death in those who are frail. Even so, the biology of frailty is not well understood. Rodent models of frailty are stimulating research into the biology of frailty. These pre-clinical models are based on "reverse-translation". Investigators have adapted either the "frailty phenotype" approach or the "frailty index" approach, originally developed in humans, for use in animals. This review briefly describes rodent models of frailty, discusses how these models have been used to explore mechanisms of frailty and how they have been employed to assess the impact of frailty on various experimental outcomes. The review also highlights studies that have used rodent models to investigate interventions to attenuate frailty, including drug treatment, dietary modifications and exercise. The ability to model frailty in animals is an exciting development that promises to accelerate the translation of laboratory discoveries into new clinical interventions, and situates frailty research in the larger context of geroscience.

Combining modifiable risk factors and risk of dementia: a systematic review and meta-analysis

OBJECTIVE

To systematically review the literature relating to the impact of multiple co-occurring modifiable risk factors for cognitive decline and dementia.

DESIGN

A systematic review and meta-analysis of the literature relating to the impact of co-occurring key risk factors for incident cognitive decline and dementia. All abstracts and full text were screened independently by two reviewers and each article assessed for bias using a standard checklist. A fixed effects meta-analysis was undertaken.

DATA SOURCES

Databases Medline, Embase and PsycINFO were searched from 1999 to 2017.

ELIGIBILITY CRITERIA

For inclusion articles were required to report longitudinal data from participants free of cognitive decline at baseline, with formal assessment of cognitive function or dementia during follow-up, and an aim to examine the impact of additive or clustered comorbid risk factor burden in with two or more core modifiable risk factors.

RESULTS

Seventy-nine full-text articles were examined. Twenty-two articles (18 studies) were included reporting data on >40 000 participants. Included studies consistently reported an increased risk associated with greater numbers of intraindividual risk factors or unhealthy behaviours and the opposite for healthy or protective behaviours. A meta-analysis of studies with dementia outcomes resulted in a pooled relative risk for dementia of 1.20 (95% CI 1.04 to 1.39) for one risk factor, 1.65 (95% CI 1.40 to 1.94) for two and 2.21 (95% CI 1.78 to 2.73) for three or more, relative to no risk factors. Limitations include dependence on published results and variations in study outcome, cognitive assessment, length of follow-up and definition of risk factor exposure.

CONCLUSIONS

The strength of the reported associations, the consistency across studies and the suggestion of a dose response supports a need to keep modifiable risk factor exposure to a minimum and to avoid exposure to additional modifiable risks. Further research is needed to establish whether particular combinations of risk factors confer greater risk than others.

PROSPERO REGISTRATION NUMBER

42016052914.

Nrf2 deficiency exacerbates frailty and sarcopenia by impairing skeletal muscle mitochondrial biogenesis and dynamics in an age-dependent manner

AIM

Mitochondrial dysfunction during aging is a key factor that contributes to sarcopenia. Nuclear factor erythroid 2-related factor 2 (Nrf2) has been increasingly recognized to regulate mitochondrial function. The present study aimed to investigate the role of Nrf2 in the development of frailty and sarcopenia during aging, and to demonstrate whether Nrf2 contributes to the maintenance of muscle mass and function by regulation of mitochondrial biogenesis and dynamics during the aging process.

METHODS

Young (5-6 months), middle-aged (11-13 months), old (20-24 months) Nrf2-/- (knockout, KO) mice and age-matched wild-type (WT) C57/BL6 mice were used in this study. Physical function of the mice in the 6 groups was assessed by grip strength test, four paw inverted hanging test, rotarod analysis, open field analysis, and treadmill endurance test. Muscle mass was measured by cross-sectional area (CSA) of tibialis anterior muscles and gastrocnemius muscle weight. The frailty status of the 25 old WT mice and 23 old KO mice were assessed based on the mouse frailty phenotype assessment. Expression levels of genes involved in mitochondrial biogenesis (nuclear respiratory factor 1 (Nrf1), peroxisome proliferative activated receptor, gamma, coactivator 1 alpha (PGC-1α), mitochondrial transcription factor A (TFAM)) and mitochondrial dynamics (optic atrophy protein 1 (Opa1), mitofusin 1 (Mfn1), mitofusin 2 (Mfn2), and dynamin-related protein 1 (Drp1)) were measured in the skeletal muscle. SDH staining was performed and mitochondrial DNA (mtDNA) copy number was measured. Transmission electron microscopy was used to measure the mitochondria number and morphology.

RESULTS

Physical function and muscle mass decreased during aging. The mRNA expression levels of Nrf2 decreased with increasing frailty phenotype scores in the old WT mice. There were minimal differences in the physical function and muscle mass between the WT and KO mice in the young groups, whereas Nrf2 deficiency caused a declined physical function and muscle mass in the middle-aged and old mice, and exacerbated frailty in the old mice. The decreases of the physical function and muscle mass were accompanied by the reduced expression levels of genes involved in mitochondrial biogenesis and dynamics, as well as a reduction of mitochondrial number, mitochondrial content, mtDNA copy number, and an impaired mitochondria morphology in the skeletal muscle.

CONCLUSION

Nrf2 deficiency exacerbated frailty and sarcopenia during aging, at least partially by impairing skeletal muscle mitochondrial biogenesis and dynamics in an age-dependent manner.

Frailty, nutrition-related parameters, and mortality across the adult age spectrum

BACKGROUND

Nutritional status and individual nutrients have been associated with frailty in older adults. The extent to which these associations hold in younger people, by type of malnutrition or grades of frailty, is unclear. Our objectives were to (1) evaluate the relationship between individual nutrition-related parameters and frailty, (2) investigate the association between individual nutrition-related parameters and mortality across frailty levels, and (3) examine whether combining nutrition-related parameters in an index predicts mortality risk across frailty levels.

METHODS

This observational study assembled 9030 participants aged ≥ 20 years from the 2003-2006 cohorts of the National Health and Nutrition Examination Survey who had complete frailty data. A 36-item frailty index (FI) was constructed excluding items related to nutritional status. We examined 62 nutrition-related parameters with established cut points: 34 nutrient intake items, 5 anthropometric measurements, and 23 relevant blood tests. The 41 nutrition-related parameters which were associated with frailty were combined into a nutrition index (NI). All-cause mortality data until 2011 were identified from death certificates.

RESULTS

All 5 anthropometric measurements, 21/23 blood tests, and 19/34 nutrient intake items were significantly related to frailty. Although most nutrition-related parameters were directly related to frailty, high alcohol consumption and high levels of serum alpha-carotene, beta-carotene, beta-cryptoxanthin, total cholesterol, and LDL-c were associated with lower frailty scores. Only low vitamin D was associated with increased mortality risk across all frailty levels. Seventeen nutrition-related parameters were associated with mortality in the 0.1-0.2 FI group, 11 in the 0.2-0.3 group, and 16 in the > 0.3 group. Overall, 393 (5.8%) of the participants had an NI score less than 0.1 (abnormality in ≤ 4 of the 41 parameters examined). Higher levels of NI were associated with higher mortality risk after adjusting for frailty and other covariates (HR per 0.1: 1.19 [95%CI 1.133-1.257]).

CONCLUSIONS

Most nutrition-related parameters were correlated to frailty, but only low vitamin D was associated with higher risk for mortality across levels of frailty. As has been observed with other age-related phenomena, even though many nutrition-related parameters were not significantly associated with mortality individually, when combined in an index, they strongly predicted mortality risk.

Effect of frailty on resource use and cost for Medicare patients

Aim: The effects of frailty and multiple chronic conditions (MCCs) on cost of care are rarely disentangled in archival data studies. We identify the marginal contribution of frailty to medical care cost estimates using Medicare data. Materials & methods: Use of the Faurot frailty score to identify differences in acute medical events and cost of care for patients, controlling for MCCs and medication use. Results: Estimated marginal cost of frailty was US$10,690 after controlling for demographics, comorbid conditions, polypharmacy and use of potentially inappropriate medications. Conclusion: Frailty contributes greatly to cost of care, but while often correlated, is not synonymous with MCCs. Thus, it is important to control separately for frailty in studies that compare medical care use and cost.

Investigating pathogen burden in relation to a cumulative deficits index in a representative sample of US adults

Pathogen burden is a construct developed to assess the cumulative effects of multiple, persistent pathogens on morbidity and mortality. Despite the likely biological wear and tear on multiple body systems caused by persistent infections, few studies have examined the impact of total pathogen burden on such outcomes and specifically on preclinical markers of dysfunction. Using data from two waves of the National Health and Nutrition Examination Survey, we compared three alternative methods for measuring pathogen burden, composed of mainly persistent viral infections, using a cumulative deficits index (CDI) as an outcome: single pathogen associations, a pathogen burden summary score and latent class analyses. We found significant heterogeneity in the distribution of the CDI by age, sex, race/ethnicity and education. There was an association between pathogen burden and the CDI by all three metrics. The latent class classification of pathogen burden showed particularly strong associations with the CDI; these associations remained after controlling for age, sex, body mass index, smoking, race/ethnicity and education. Our results suggest that pathogen burden may influence early clinical indicators of poor health as measured by the CDI. Our results are salient since we were able to detect these associations in a relatively young population. These findings suggest that reducing pathogen burden and the specific pathogens that drive the CDI may provide a target for preventing the early development of age-related physiological changes.

Relationship between frailty and Alzheimer's disease biomarkers: A scoping review

Introduction

Frailty and dementia appear to be closely linked, although mechanisms remain unclear. The objective was to conduct a scoping review of the association between frailty and Alzheimer's disease (AD) biomarkers in humans.

Methods

Three databases, PubMed, PsycINFO, and Embase, were searched for articles using the following search terms: “frail elderly”, “Alzheimer's disease”, “dementia biomarkers” and their synonyms. Inclusion was limited to original research in humans published before 2017, which included a frailty measure and AD biomarker (fluid markers, neuroimaging, and neuropathology).

Results

Five hundred twenty-two articles were identified and screened; 10 were included. Most were cross-sectional (n = 6), measured the frailty phenotype (n = 6), and included people with dementia (n = 7). Biomarkers examined were postmortem AD pathology (n = 3), brain atrophy (n = 5), and in vivo fluid markers (n = 2). Eight studies reported that increased frailty was associated with at least one biomarker abnormality.

Discussion

Evidence is limited and suffers from design limitations but suggests that frailty and AD biomarkers are closely linked. Longitudinal research examining multiple biomarkers and frailty is warranted.

•

Very few studies examined links between frailty and Alzheimer's disease biomarkers.

•

Generally, increased frailty was linked to increased Alzheimer's disease biomarker levels.

•

Studies investigating this topic were largely cross sectional and underpowered.

•

Future work should include longitudinal studies of frailty and multiple biomarkers.

Association between a frailty index based on common laboratory tests and QTc prolongation in older adults: the Rugao Longevity and Ageing Study

BACKGROUND

Risk factors for heart rate-corrected QT interval (QTc) proglongation should be explored to stratify high-risk individuals to aid the prevention of incident cardiovascular events and mortality. The diversity of risk factors for QTc prolongation suggests that use of the frailty index (FI), indicating general health deficits, may be an effective approach, especially in the elderly, to identify the risk of QTc prolongation.

METHODS

We used the data of 1,780 individuals aged 70-87 years from the Rugao Longevity and Ageing Study (RuLAS), a community-based longitudinal study. The FI was constructed using 20 routine laboratory tests, plus the body mass index and measures of systolic and diastolic blood pressures (FI-Lab).

RESULTS

The mean FI-Lab value was 0.24±0.09. The mean heart rate-corrected QT interval (QTc) was 407±38 ms. The prevalence of QTc prolongation was 5.2% in elderly community populations aged 70-87 years. A higher FI-Lab value was associated with a higher risk for QTc prolongation. Each 10% increase in the FI-Lab value increased the odds ratio (OR) by 33% (OR: 1.33; 95% CI: 1.07-1.64). Compared with the lowest quartile, the top quartile FI-Lab score was associated with a 2.50-fold QTc prolongation risk in elderly individuals (95% CI: 1.21-5.19).

CONCLUSION

An FI based on routine laboratory data can identify older adults at increased risk for QTc prolongation. The FI approach may therefore be useful for the risk stratification of QTc prolongation.

A frailty index from common clinical and laboratory tests predicts increased risk of death across the life course

A frailty index (FI) based entirely on common clinical and laboratory tests might offer scientific advantages in understanding ageing and pragmatic advantages in screening. Our main objective was to compare an FI based on common laboratory tests with an FI based on self-reported data; we additionally investigated if the combination of subclinical deficits with clinical ones increased the ability of the FI to predict mortality. In this secondary analysis of the 2003–2004 and 2005–2006 National Health and Nutrition Examination Survey data, 8888 individuals aged 20+ were evaluated. Three FIs were constructed: a 36-item FI using self-reported questionnaire data (FI-Self-report); a 32-item FI using data from laboratory test values plus pulse and blood pressure measures (FI-Lab); and a 68-item FI that combined all items from each index (FI-Combined). The mean FI-Lab score was 0.15 ± 0.09, the FI-Self-report was 0.11 ± 0.11 and FI-Combined was 0.13 ± 0.08. Each index showed some typical FI characteristics (skewed distribution with long right tail, non-linear increase with age). Even so, there were fewer people with low frailty levels and a slower increase with age for the FI-Lab compared to the FI-Self-report. Higher frailty level was associated with higher risk of death, although it was strongest at older ages. Both FI-Lab and FI-Self-report remained significant in a combined model predicting death. The FI-Lab was feasible and valid, demonstrating that even subclinical deficit accumulation increased mortality risk. This suggests that deficit accumulation, from the subcellular to the clinically visible is a useful construct that may advance our understanding of the ageing process.

A Cumulative Deficit Laboratory Test-based Frailty Index: Personal and Neighborhood Associations

OBJECTIVES

To explore the association between a newly developed cumulative laboratory-based frailty index (FI) and intrinsic (personal) and extrinsic (social, environmental) characteristics.

DESIGN

Cross-sectional longitudinal study.

SETTING

The third and fourth waves of the community-representative, five-county, 10-year Duke Established Populations for Epidemiologic Studies of the Elderly study, carried out in a health service-rich area.

PARTICIPANTS

Cognitively intact survivors of the third wave (N = 1,740), who provided blood samples for standard laboratory work.

MEASUREMENTS

Biomarkers (n = 28) were measured to develop a cumulative deficit laboratory test-based FI (Duke FI) derived from standard laboratory tests: SMAC-24 chemistry panel, high-density lipoprotein cholesterol panel, and complete blood count. Information was gathered on scales assessing intrinsic characteristics (personal locus of control, life satisfaction, self-esteem, depressive symptomatology) and extrinsic characteristics (support received from and provided to family and friends, stressful life events, neighborhood disadvantage).

RESULTS

The newly developed Duke FI had content, construct, concurrent, and predictive validity. In addition to sex, race, and income, the Duke FI was associated at the intrinsic level with locus of control, self-esteem, life satisfaction, and depressive symptomatology (each P < .01) and at the extrinsic level with provision (P < .01) and with receipt of instrumental help (P < .10), social stressors (P < .03), and neighborhood disadvantage (P < .01) in unadjusted analysis; race fully explained neighborhood disadvantage.

CONCLUSION

Intrinsic (personality) characteristics and personally close extrinsic characteristics (contacts with family and friends, personal stressors) are associated with laboratory test-based frailty, as is neighborhood disadvantage, although in this accessible, health service-rich environment, race fully explained association with neighborhood disadvantage, suggesting that interventions to reduce frailty in residents in such an environment should pay particular attention to characteristics that immediately affect the individual.

Dysnatremia in Relation to Frailty and Age in Community-dwelling Adults in the National Health and Nutrition Examination Survey

Background

Frailty represents an age-related state of increased risk of adverse health outcomes, reflecting some combination of increased damage and compromised repair processes. Our objectives were to establish whether frailty is associated with dysnatremia (a deviation of serum sodium from normal values), to determine whether frailty explains the previously established association between age and dysnatremia and to assay the impact of each on mortality.

Methods

The relationship between age, frailty, and dysnatremia was investigated across the adult life course in 8,911 respondents from the 2003-2004 and 2005-2006 cross-sectional National Health and Nutrition Examination Survey, on whom both laboratory and mortality data were available. A frailty index (FI) was calculated for each respondent and related to dysnatremia (serum sodium values outside a 136-144 mmol/L reference range).

Results

Dysnatremia was significantly related to both age and frailty; as the degree of frailty increased, so did the proportion with dysnatremia, for example, from 4.1% in those with FI less than 0.10, to 12.4% in those with FI 0.40 or more; p less than .001. Adjusted for frailty, the relationship between age and dysnatremia was no longer significant. In the age- and sex-adjusted Cox models, both frailty (hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 1.04-1.05 for every 0.01 increase in FI) and dysnatremia (HR: 1.85; 95% CI: 1.51-2.26) were significant predictors of mortality; when hyponatremia was separated from hypernatremia in the Cox models, hypernatremia wasn't significant, but only 41 participants were identified as hypernatremic.

Conclusion

Increasing frailty is associated with dysnatremia and confounds the association between age and dysnatremia.

Associations of Childhood and Adulthood Cognition with Bone Mineral Density in Later Adulthood: A Population-Based Longitudinal Study

This study explores the association between cognitive ability in childhood and midlife and bone health outcomes in early old age; and the relationships of these bone measures with contemporaneous and subsequent cognitive ability in the MRC National Survey of Health and Development (NSHD). This British birth cohort assessed areal and volumetric bone mineral density (aBMD and vBMD) at age 60-64, derived from peripheral quantitative computed tomography and dual-energy X-ray absorptiometry, and cognitive performance from childhood to age 69, among 866 women and 792 men. Cognitive performance at age 15 was assessed using tests of verbal and non-verbal ability, and mathematics; and memory and search speed tasks were administered at ages 53, 60-64, and 69. Covariates included body size, pubertal timing, smoking, leisure time physical activity, socioeconomic circumstances and menopause timing. Multiple linear regression analyses showed that higher childhood cognitive ability was associated with higher hip aBMD, in women, and greater cortical and trabecular vBMD, in men. For women, there were positive associations between hip aBMD and total vBMD, and contemporaneous cognitive ability with associations also extending to subsequent cognitive ability for total vBMD. For men, some associations with trabecular and total vBMD emerged at ages 60-64 and 69 but only after adjusting for education, occupational class and health behaviors. Our findings highlight that higher cognitive ability in childhood is associated with BMD in early old age and these associations might be explained by social and behavioral pathways. The results suggest that individuals with greater cognitive ability in early life are more likely to engage in healthy behaviors (e.g., leisure time physical activity) in adulthood, which in turn are associated with greater BMD later in life. Associations between bone health and cognitive performance should be considered within a life course framework; and the potential role of smoking and physical activity should be addressed when advising adults at high future risk of osteoporosis and fracture.

Absence of association between frailty index and survival in elderly Brazilians: the FIBRA Study

In Brazil, the frailty index has not been evaluated previously for its capacity to predict mortality in community-dwelling elderly. The objective of the current study was to evaluate the association between frailty index and mortality in the elderly. This was a prospective study consisting of data from the FIBRA Network-2008-2009 in Campinas, São Paulo State, with information on community-dwelling older adults from the urban area and through the Mortality Information System. Comparisons and statistical associations were performed with the following tests: Mann-Whitney, Kruskal-Wallis, chi-square, and Cox regression with 95% confidence intervals. A total of 689 older adults participated 72.1 ± 5.3 years), of whom 68.8% were women. The prevalence rate for frailty was 38.8%, compared to 51.6% for pre-frailty and 9.6% for fit elders; overall mean frailty index was higher in women. There was no association between frailty index and chronological age. Cox regression showed that the variables age HR: 1.10; 95%CI: 1.05-1.15) and gender HR: 0.57; 95%CI: 0.33-0.99) were significantly associated with mortality. No association was found between frailty index and mortality HR: 3.02; 95%CI: 0.24-37.64). Frailty index was not capable of predicting mortality in community-dwelling elderly Brazilians.

The impact of age and frailty on ventricular structure and function in C57BL/6J mice

KEY POINTS

Heart size increases with age (called hypertrophy), and its ability to contract declines. However, these reflect average changes that may not be present, or present to the same extent, in all older individuals. That aging happens at different rates is well accepted clinically. People who are aging rapidly are frail and frailty is measured with a 'frailty index'. We quantified frailty with a validated mouse frailty index tool and evaluated the impacts of age and frailty on cardiac hypertrophy and contractile dysfunction. Hypertrophy increased with age, while contractions, calcium currents and calcium transients declined; these changes were graded by frailty scores. Overall health status, quantified as frailty, may promote maladaptive changes associated with cardiac aging and facilitate the development of diseases such as heart failure. To understand age-related changes in heart structure and function, it is essential to know both chronological age and the health status of the animal.

ABSTRACT

On average, cardiac hypertrophy and contractile dysfunction increase with age. Still, individuals age at different rates and their health status varies from fit to frail. We investigated the influence of frailty on age-dependent ventricular remodelling. Frailty was quantified as deficit accumulation in adult (≈7 months) and aged (≈27 months) C57BL/6J mice by adapting a validated frailty index (FI) tool. Hypertrophy and contractile function were evaluated in Langendorff-perfused hearts; cellular correlates/mechanisms were investigated in ventricular myocytes. FI scores increased with age. Mean cardiac hypertrophy increased with age, but values in the adult and aged groups overlapped. When plotted as a function of frailty, hypertrophy was graded by FI score (r = 0.67-0.55, P < 0.0003). Myocyte area also correlated positively with FI (r = 0.34, P = 0.03). Left ventricular developed pressure (LVDP) plus rates of pressure development (+dP/dt) and decay (-dP/dt) declined with age and this was graded by frailty (r = -0.51, P = 0.0007; r = -0.48, P = 0.002; r = -0.56, P = 0.0002 for LVDP, +dP/dt and -dP/dt). Smaller, slower contractions graded by FI score were also seen in ventricular myocytes. Contractile dysfunction in cardiomyocytes isolated from frail mice was attributable to parallel changes in underlying Ca²⁺ transients. These changes were not due to reduced sarcoplasmic reticulum stores, but were graded by smaller Ca²⁺ currents (r = -0.40, P = 0.008), lower gain (r = -0.37, P = 0.02) and reduced expression of Cav1.2 protein (r = -0.68, P = 0.003). These results show that cardiac hypertrophy and contractile dysfunction in naturally aging mice are graded by overall health and suggest that frailty, in addition to chronological age, can help explain heterogeneity in cardiac aging.

Public health approach to preventing frailty in the community and its effect on healthy aging in Japan

Effective methods to prevent or delay the onset of frailty are urgently required in aging societies, such as Japan. As a public health approach, we carried out a 10-year community intervention for frailty prevention, and examined its impact on healthy aging among older adults. The target population was all residents aged 65 years or older in the town of Kusatsu, Gunma Prefecture, Japan. For community empowerment, we organized a community forum, and discussed how to address the frailty issue in the community. For primary prevention, we attempted to promote physical activity, nutrition and social participation by means of a health education program to motivate older residents. For secondary prevention, we added a comprehensive geriatric assessment to routine annual health check-ups, which helped older participants improve self-care ability of functional health. High-risk persons were screened and encouraged to participate in a frailty prevention class with a multicomponent program. The attendance rate at annual health check-ups has remained constant at 30-40% of the target population; however, over 80% of the population appeared at least once during the 10 year-period. For evaluation, we carried out biennial health monitoring surveys, and reviewed the records of the local Long-Term Care Insurance system. The functional health of older residents was significantly improved as a result of the interventions; the incidence rate of Long-Term Care Insurance system certification in the old-old population (age ≥75 years) was decreased by one second, and healthy life expectancy at age 70 years was extended by 1.2 years for women and 0.5 years for men. Such trends greatly contrasted with those in the reference area, and Japan as a whole. In summary, the present public health approach to frailty prevention appears to promote healthy aging among older adults.

A frailty index based on laboratory deficits in community-dwelling men predicted their risk of adverse health outcomes

BACKGROUND

abnormal laboratory test results accumulate with age and can be common in people with few clinically detectable health deficits. A frailty index (FI) based entirely on common physiological and laboratory tests (FI-Lab) might offer pragmatic and scientific advantages compared with a clinical FI (FI-Clin).

OBJECTIVES

to compare the FI-Lab with the FI-Clin and to assess their individual and combined relationships with mortality and other adverse health outcomes.

DESIGN AND SUBJECTS

secondary analysis of the eight-centre, longitudinal European Male Ageing Study (EMAS) of community-dwelling men aged 40-79 at baseline. Follow-up assessment occurred 4.4 ± 0.3 (mean ± SD) years later.

METHODS

we constructed a 23-item FI using common laboratory tests, blood pressure and pulse (FI-Lab), compared it with a previously validated 39-item FI using self-report and performance-based measures (FI-Clin) and finally combined both FIs to create a 62-item FI-Combined. Outcomes were all-cause mortality, institutionalisation, doctor visits, medication use, self-reported health, falls and fractures.

RESULTS

the mean FI-Lab score was 0.28 ± 0.11, the FI-Clin was 0.13 ± 0.11 and FI-Combined was 0.19 ± 0.09. Age-adjusted models demonstrated that each FI was associated with mortality [HR (CI) FI-Lab: 1.04 (1.03-1.06); FI-Clin: 1.05 (1.04-1.06); FI-Combined: 1.07 (1.06-1.09)], institutionalisation, doctor visits, medication use, self-reported health and falls. Combined in a model with FI-Clin, the FI-Lab remained independently associated with mortality, institutionalisation, doctor visits, medication use and self-reported health.

CONCLUSIONS

the FI-Lab detected an increased risk of adverse health outcomes alone and in combination with a clinical FI; further evaluation of the feasibility of the FI-Lab as a frailty screening tool within hospital care settings is needed.

The Microbiome and Musculoskeletal Conditions of Aging: A Review of Evidence for Impact and Potential Therapeutics

Recently, we have begun to realize that the billions of microorganisms living in symbiosis with us have an influence on disease. Evidence is mounting that the alimentary tract microbiome, in particular, influences both host metabolic potential and its innate and adaptive immune system. Inflammatory states characterize many bone and joint diseases of aging. This prompts the hypothesis that the gut microbiome could alter the inflammatory state of the individual and directly influence the development of these common and burdensome clinical problems. Because the microbiome is easily modifiable, this could have major therapeutic impact. This perspective discusses evidence to date on the role of the microbiome and the highly prevalent age-related disorders of osteoporosis, osteoarthritis, gout, rheumatoid arthritis, sarcopenia, and frailty. It also reviews data on the effects of probiotics and prebiotic interventions in animal and human models. Despite suggestive findings, research to date is not conclusive, and we identify priorities for research to substantiate and translate findings.

Signatures of early frailty in the gut microbiota

BACKGROUND

Frailty is arguably the biggest problem associated with population ageing, and associates with gut microbiome composition in elderly and care-dependent individuals. Here we characterize frailty associations with the gut microbiota in a younger community dwelling population, to identify targets for intervention to encourage healthy ageing.

METHOD

We analysed 16S rRNA gene sequence data derived from faecal samples obtained from 728 female twins. Frailty was quantified using a frailty index (FI). Mixed effects models were used to identify associations with diversity, operational taxonomic units (OTUs) and taxa. OTU associations were replicated in the Eldermet cohort. Phenotypes were correlated with modules of OTUs collapsed by co-occurrence.

RESULTS

Frailty negatively associated with alpha diversity of the gut microbiota. Models considering a number of covariates identified 637 OTUs associated with FI. Twenty-two OTU associations were significant independent of alpha diversity. Species more abundant with frailty included Eubacterium dolichum and Eggerthella lenta. A Faecalibacterium prausnitzii OTU was less abundant in frailer individuals, and retained significance in discordant twin analysis. Sixty OTU associations were replicated in the Eldermet cohort. OTU co-occurrence modules had mutually exclusive associations between frailty and alpha diversity.

CONCLUSIONS

There was a striking negative association between frailty and gut microbiota diversity, underpinned by specific taxonomic associations. Whether these relationships are causal or consequential is unknown. Nevertheless, they represent targets for diagnostic surveillance, or for intervention studies to improve vitality in ageing.

Frailty and the risk of cognitive impairment

Aging occurs as a series of small steps, first causing cellular damage and then affecting tissues and organs. This is also true in the brain. Frailty, a state of increased risk due to accelerated deficit accumulation, is robustly a risk factor for cognitive impairment. Community-based autopsy studies show that frail individuals have brains that show multiple deficits without necessarily demonstrating cognitive impairment. These facts cast a new light on the growing number of risk factors for cognitive impairment, suggesting that, on a population basis, most health deficits can be associated with late-life cognitive impairment. The systems mechanism by which things that are bad for the body are likely to be bad for the brain can be understood like this: the burden of health deficits anywhere indicates impaired ability to withstand or repair endogenous and environmental damage. This in turn makes additional damage more likely. If true, this suggests that a life course approach to preventing cognitive impairment is desirable. Furthermore, conducting studies in highly selected, younger, healthier individuals to provide ‘proof of concept’ information is now common. This strategy might exclude the very circumstances that are required for disease expression in the people in whom dementia chiefly occurs (that is, older adults who are often in poor health).

A long-recommended but seldom-used method of analysis for fall injuries found a unique pattern of risk factors in the youngest-old

Background

Few studies on fall risk factors use long-recommended methods for analysis of recurrent events. Previous falls are the biggest risk factor for future falls, but few fall studies focus on the youngest-old.

Aims

This study’s objective was to apply Cox regression for recurrent events to identify factors associated with injurious falls in the youngest-old.

Methods

Participants were community-dwelling residents of southern Sweden (n = 1,133), aged 59–67 at baseline (median 61.2), from the youngest cohorts of the larger Good Aging in Skåne (GÅS) study. Exposure variable data were collected from baseline study visits and medical records. Injurious falls, defined as emergency, inpatient, or specialist visits associated with ICD-10 fall codes during the follow-up period (2001–2011), were gathered from national and regional registries. Analysis was conducted using time to event Cox Regression for recurrent events.

Results

A majority (77.1 %) of injurious falls caused serious injuries such as fractures and open wounds. Exposure to nervous system medications [hazard ratio (HR) 1.40, 95 % confidence interval (CI) 1.03–1.89], central nervous system disease (HR 1.79, CI 1.18–2.70), and previous injurious fall(s) (HR 2.00, CI 1.50–2.68) were associated with increased hazard of injurious fall.

Conclusions

Regression for recurrent events is feasible with typical falls’ study data. The association of certain exposures with increased hazard of injurious falls begins earlier than previously studied. Different patterns of risk factors by age can provide insight into the progression of frailty. Tailored fall prevention screening and intervention may be of value in populations younger than those traditionally screened.