Is frailty a stable predictor of mortality across time? Evidence from the Cognitive Function and Ageing Studies

Associations between frailty, depression and risk of hospitalisation for infection: A large prospective cohort study

BACKGROUND

There is a considerable lack of epidemiological evidence on whether frailty, and frailty comorbid depression could increase the risk of infections in older adults. This study aimed to examine the prospective association between frailty, depression, and risk of infections.

METHODS

A total of 308,892 eligible participants were included. Linked hospital admission records (HES) were used to identify a primary or secondary diagnosis of depression, and infection. Frailty was assessed by Fried frailty phenotype indicators. Cox proportional hazard model was conducted to examine the associated risk between frailty, depression, comorbid frailty and depression and risk of incident infections. Results were stratified by age and gender.

RESULTS

During the follow-up, 74,749 (24.19 %) incident any infection cases were identified, the incidence density of any infection was 17.29/1000 person years. Frailty alone (HR = 1.38, 95 % CI: 1.33-1.43), depression alone (HR = 1.90, 95 % CI: 1.86-1.94), and comorbid frailty and depression (HR = 1.91, 95 % CI: 1.82-1.99) were associated with greater risks of any infections relative to participants with neither frailty nor depression. The associations between frailty alone, depression alone, comorbid frailty and depression, and any infections/most infection subtypes were significant for all age strata in both male and female.

LIMITATIONS

Frailty phenotype was assessed through the adapted Fried criteria, based on a mix of self-reported and objective measurements.

CONCLUSION

Frailty, depression, and comorbid frailty and depression were significantly associated with increased risk of incident infections.

Correlation of preoperative frailty with postoperative delirium and one-year mortality in Chinese geriatric patients undergoing noncardiac surgery: Study protocol for a prospective observational cohort study

BACKGROUND

To Frailty is associated with postoperative delirium (POD) but is rarely assessed in patients undergoing noncardiac surgery. In this study, the correlation between preoperative frailty and POD, one-year mortality will be investigated in noncardiac Chinese geriatric surgery patients.

METHODS

This study is a prospective, observational, cohort study conducted at a single center with Chinese geriatric patients. Patients who undergo noncardiac surgery and are older than 70 years will be included. A total of 536 noncardiac surgery patients will be recruited from the First Affiliated Hospital of Shandong First Medical University for this study. The Barthel Index (BI) rating will be used to assess the patient's ability to carry out everyday activities on the 1st preoperative day. The modified frailty index (mFI) will be used to assess frailty. Patients in the nonfrailty group will have an mFI < 0.21, and patients in the frailty group will have an mFI ≥ 0.21. The primary outcome is the incidence of POD. Three-Minute Diagnostic Interview for CAM-defined Delirium (3D-CAM) will be conducted twice daily during the 1st-7th postoperative days, or just before discharge. The secondary outcomes will include one-year mortality, in-hospital cardiopulmonary events, infections, acute renal injury, and cerebrovascular events.

DISCUSSION

This study will clarify the correlation of preoperative frailty with POD and one-year all-cause mortality in Chinese geriatric patients undergoing noncardiac surgery. Can preoperative frailty predict POD or one-year mortality? In the face of China's serious aging social problems, this result may have important clinical value for the surgical treatment of geriatric patients.

TRIAL REGISTRATION

This protocol has been registered with ClinicalTrials. Gov on 12 January 2022 (https://clinicaltrials.gov/ct2/show/NCT05189678).

Age- and sex-specific associations of frailty with mortality and healthcare utilization in community-dwelling adults from ontario, Canada

BACKGROUND

Understanding how health trajectories are related to the likelihood of adverse outcomes and healthcare utilization is key to planning effective strategies for improving health span and the delivery of care to older adults. Frailty measures are useful tools for risk stratification in community-based and primary care settings, although their effectiveness in adults younger than 60 is not well described.

METHODS

We performed a 10-year retrospective analysis of secondary data from the Ontario Health Study, which included 161,149 adults aged ≥ 18. Outcomes including all-cause mortality and hospital admissions were obtained through linkage to ICES administrative databases with a median follow-up of 7.1-years. Frailty was characterized using a 30-item frailty index.

RESULTS

Frailty increased linearly with age and was higher for women at all ages. A 0.1-increase in frailty was significantly associated with mortality (HR = 1.47), the total number of outpatient (IRR = 1.35) and inpatient (IRR = 1.60) admissions over time, and length of stay (IRR = 1.12). However, with exception to length of stay, these estimates differed depending on age and sex. The hazard of death associated with frailty was greater at younger ages, particularly in women. Associations with admissions also decreased with age, similarly between sexes for outpatient visits and more so in men for inpatient.

CONCLUSIONS

These findings suggest that frailty is an important health construct for both younger and older adults. Hence targeted interventions to reduce the impact of frailty before the age of 60 would likely have important economic and social implications in both the short- and long-term.

Frailty before and during austerity: A time series analysis of the English Longitudinal Study of Ageing 2002-2018

BACKGROUND

Frailty is characterised by a reduced resilience to adversity. In this analysis we examined changes in frailty in people aged 50+ before and during a period of austere public spending in England.

METHODS

Data from the English Longitudinal Study of Ageing 2002-2018 were analysed. Associations between austerity and frailty were examined using (1) Multilevel interrupted times series analysis (ITSA); and (2) Accelerated longitudinal modelling comparing frailty trajectories in people of the same age in 2002 and 2012.

RESULTS

The analysis included 16,410 people (mean age 67 years, 55% women), with mean frailty index score of 0.16. Mean scores in women (0.16) where higher than in men (mean 0.14), and higher in the poorest tertile (mean 0.20) than the richest (mean 0.12). In the ITSA, frailty index scores increased more quickly during austerity than before, with the additional increase in frailty 2012-2018 being similar in magnitude to the difference in mean frailty score between people aged 65-69 and 70-74 years. Steeper increases in frailty after 2012 were experienced across the wealth-spectrum and in both sexes but were greater in the very oldest (80+). In the accelerated longitudinal analysis, frailty was lower in 2012 than 2002, but increased more rapidly in the 2012 cohort compared to the 2002 cohort; markedly so in people aged 80+.

CONCLUSION

The period of austerity politics was associated with steeper increases in frailty with age compared to the pre-austerity period, consistent with previously observed increases in mortality.

Insights into the pathological basis of dementia from population-based neuropathology studies

The epidemiological neuropathology perspective of population and community-based studies allows unbiased assessment of the prevalence of various pathologies and their relationships to late-life dementia. In addition, this approach provides complementary insights to conventional case-control studies, which tend to be more representative of a younger clinical cohort. The Cognitive Function and Ageing Study (CFAS) is a longitudinal study of cognitive impairment and frailty in the general United Kingdom population. In this review, we provide an overview of the major findings from CFAS, alongside other studies, which have demonstrated a high prevalence of pathology in the ageing brain, particularly Alzheimer's disease neuropathological change and vascular pathology. Increasing burdens of these pathologies are the major correlates of dementia, especially neurofibrillary tangles, but there is substantial overlap in pathology between those with and without dementia, particularly at intermediate burdens of pathology and also at the oldest ages. Furthermore, additional pathologies such as limbic-predominant age-related TDP-43 encephalopathy, ageing-related tau astrogliopathy and primary age-related tauopathies contribute to late-life dementia. Findings from ageing population-representative studies have implications for the understanding of dementia pathology in the community. The high prevalence of pathology and variable relationship to dementia status has implications for disease definition and indicate a role for modulating factors on cognitive outcome. The complexity of late-life dementia, with mixed pathologies, indicates a need for a better understanding of these processes across the life-course to direct the best research for reducing risk in later life of avoidable clinical dementia syndromes.

Trends in Frailty Prevalence Among Older Adults in Korea: A Nationwide Study From 2008 to 2020

BACKGROUND

We aimed to evaluate the nationwide trend of the prevalence of frailty in older adults in Korea from 2008 to 2020 to inform future geriatric healthcare policies.

METHODS

The study used data of individuals aged 65 years and older from the Korea National Health and Nutrition Examination Survey, a nationwide repeated cross-sectional survey. Frailty was defined using frailty index, classified as non-frail (frailty index ≤ 0.15), pre-frail (0.15 < frailty index ≤ 0.25), or frail (frailty index > 0.25).

RESULTS

The study included 17,784 individuals, with the mean age of 72.4 and mean frailty index of 0.2. The prevalence of frailty in older adults in South Korea decreased significantly from 2008 (41.1%) to 2020 (23.1%). The decrease in the frailty index was observed in all age groups (all P < 0.05). As components of frailty index, we found that certain comorbidities, such as dyslipidemia, diabetes mellitus, and cardiovascular disease, have increased over time, while factors such as chewing difficulty, activity limitation, and smoking, have decreased.

CONCLUSION

The prevalence of frailty in older adults in South Korea has decreased significantly during the study period. Historical improvements in healthcare access and preventive measures may have contributed to this trend.

Differential utility of various frailty diagnostic tools in non-geriatric hospital departments of several countries: A longitudinal study

BACKGROUND

There is limited knowledge on the performance of different frailty scales in clinical settings. We sought to evaluate in non-geriatric hospital departments the feasibility, agreement and predictive ability for adverse events after 1 year follow-up of several frailty assessment tools.

METHODS

Longitudinal study with 667 older adults recruited from five hospitals in three different countries (Spain, Italy and United Kingdom). Participants were older than 75 years attending the emergency room, cardiology and surgery departments. Frailty scales used were Frailty Phenotype (FP), FRAIL scale, Tilburg and Groningen Frailty Indicators, and Clinical Frailty Scale (CFS). Analyses included the prevalence of frailty, degree of agreement between tools, feasibility and prognostic value for hospital readmission, worsening of disability and mortality, by tool and setting.

RESULTS

Emergency Room and cardiology were the settings with the highest frailty prevalence, varying by tool between 40.4% and 67.2%; elective surgery was the one with the lowest prevalence (between 13.2% and 38.2%). The tools showed a fair to moderate agreement. FP showed the lowest feasibility, especially in urgent surgery (35.6%). FRAIL, CFS and FP predicted mortality and readmissions in several settings, but disability worsening only in cardiology.

CONCLUSIONS

Frailty is a highly frequent condition in older people attending non-geriatric hospital departments. We recommend that based upon their current feasibility and predictive ability, the FRAIL scale, CFS and FP should be preferentially used in these settings. The low concordance among the tools and differences in prevalence reported and predictive ability suggest the existence of different subtypes of frailty.

Long-term fine particular exposure and incidence of frailty in older adults: findings from the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

The association between fine particular matter (PM2.5) and frailty is less studied, and the national burden of PM2.5-related frailty in China is unknown.

OBJECTIVE

To explore the association between PM2.5 exposure and incident frailty in older adults, and estimate the corresponding disease burden.

DESIGN

Chinese Longitudinal Healthy Longevity Survey from 1998 to 2014.

SETTING

Twenty-three provinces in China.

SUBJECTS

A total of 25,047 participants aged ≥65-year-old.

METHODS

Cox proportional hazards models were performed to evaluate the association between PM2.5 and frailty in older adults. A method adapted from the Global Burden of Disease Study was used to calculate the PM2.5-related frailty disease burden.

RESULTS

A total of 5,733 incidents of frailty were observed during 107,814.8 person-years follow-up. A 10 μg/m3 increment of PM2.5 was associated with a 5.0% increase in the risk of frailty (Hazard Ratio = 1.05, 95% confidence interval = [1.03-1.07]). Monotonic, but non-linear exposure-response, relationships of PM2.5 with risk of frailty were observed, and slopes were steeper at concentrations >50 μg/m³. Considering the interaction between population ageing and mitigation of PM2.5, the PM2.5-related frailty cases were almost unchanged in 2010, 2020 and 2030, with estimations of 664,097, 730,858 and 665,169, respectively.

CONCLUSIONS

This nation-wide prospective cohort study showed a positive association between long-term PM2.5 exposure and frailty incidence. The estimated disease burden indicated that implementing clean air actions may prevent frailty and substantially offset the burden of population ageing worldwide.

Biomass fuel usage for cooking and frailty among older adults in China: a population-based cohort study

Background

Although outdoor air pollution is reported to have a negative effect on frailty, evidence involving household air pollution is sparse.

Methods

A cohort study on older participants aged ≥65 years from the Chinese Longitudinal Healthy Longevity Survey was conducted between 2011/2012 and 2014. Household cooking fuel types were determined by self-reported questionaries, and were dichotomized into clean or biomass fuels. The frailty status was evaluated via a 46-item frailty index (FI) and the FRAIL scale, respectively. Frailty was identified if FI >0.21 or FRAIL score ≥3. Cox proportional hazards models were employed to examine the relationship between cooking fuels and incident frailty. And the effects of swapping cooking fuels on frailty risk were also explored.

Results

Among 4,643 participants (mean age at baseline 80.9 ± 9.6 years, 53.7% male) totaling 11,340 person-years, 923 (19.9%) incident frailty was identified using FI. Compared to clean fuels, cooking with biomass fuels was intricately linked to a 23% rise in frailty risk (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.06-1.43). A similar association was detected between biomass cooking fuels and frailty measured by the FRAIL scale (HR 1.24, 95% CI 1.04-1.50). Sensitive analyses supported the independent relationship between biomass fuels and frailty. Stratified analyses revealed that the frailty risk was higher among town residents (HR 1.44, 95% CI 1.13-1.84) and participants not exercising regularly (HR 1.35, 95% CI 1.11-1.64). In comparison with persistent biomass fuels usage, switching to clean fuels had a trend to reduce the frailty risk, and the opposite effect was observed when swapping from clean to biomass fuels.

Conclusion

Cooking with biomass fuels was associated with an increased frailty risk in older adults, especially amongst those living in town and those lacking regular exercise. More studies are needed to confirm our findings and to evaluate the potential benefits of reducing indoor biomass fuel usage.

Frailty: Pathophysiology, Theoretical and Operational Definition(s), Impact, Prevalence, Management and Prevention, in an Increasingly Economically Developed and Ageing World

The world's population is ageing, and most older adults experience a later life burdened with disease and disability. Frailty is a multidimensional and dynamic condition characterized by declines in reserve and function across multiple physiological systems, such that the ability to cope with every day or acute stressors becomes compromised. It is projected to become one of the most serious public health challenges economically developed societies will face in the coming century. This review provides a comprehensive overview of frailty, exploring its pathophysiology, theoretical and operational definition(s), impact, prevalence, management, and prevention, within the context of its emergence as a major public health challenge, in an increasingly economically developed and ageing world. Further, this review discusses the major limitations, deficiencies, and knowledge gaps presently within the field, and future research directions pertinent to the advancement of frailty research and the promotion of healthy longevity among the increasing global population of older adults.

Trajectories, Transitions, and Trends in Frailty among Older Adults: A Review

Frailty is an age-related clinical state associated with deterioration across multiple physiological systems and a leading cause of morbidity and mortality later in life. To understand how frailty develops and what causes its progression, longitudinal data with repeated frailty measurements are required. This review summarizes evidence from longitudinal studies on frailty trajectories, transitions, and trends. We identified several consistent findings: frailty increases with aging and is a dynamic condition, and more recent generations of older adults have higher frailty levels. These findings have both clinical and public health relevance, including the provision of healthcare and aged care services in the coming years. Further studies are required, particularly those conducted in low- and middle-income countries and those investigating factors associated with changes in frailty. The latter may help develop better-targeted interventions to reverse or slow the progression of frailty.

Relationship of body mass index with frailty and all-cause mortality among middle-aged and older adults

BACKGROUND

Parallel to growth of aging and obese populations, the prevalence of metabolic diseases is rising. How body mass index (BMI) relates to frailty and mortality across frailty levels is controversial. We examined the associations of high BMI with frailty and mortality and explored the effects of percent body fat on these associations.

METHODS

We included 29,937 participants aged ≥50 years from the 2001-2006 National Health and Nutrition Examination Survey (NHANES) cohorts (N=6062; 53.7% females) and from wave 1 (2004) of Survey of Health, Ageing and Retirement in Europe (SHARE) (N=23,875; 54% females). BMI levels were categorized as: normal: 18.5-24.9 kg/m², overweight: 25.0-29.9, obese grade 1: 30.0-34.9, and obese grade 2 or 3: >35.0. A frailty index (FI) was constructed excluding nutrition-related items: 36 items for NHANES and 57 items for SHARE. We categorized the FI using 0.1-point increments: FI ≤ 0.1 (non-frail), 0.1 < FI ≤ 0.2 (very mildly frail), 0.2 < FI ≤ 0.3 (mildly frail), and FI > 0.3 (moderately/severely frail). Percent body fat was measured using DXA for NHANES participants. All-cause mortality data were obtained until 2015 for NHANES and 2017 for SHARE to estimate 10-year mortality risk. All analyses were adjusted for age, sex, educational, marital, employment, and smoking statuses.

RESULTS

Mean age of participants was 63.3±10.2 years for NHANES and 65.0±10.0 years for SHARE. In both cohorts, BMI levels ≥25 kg/m² were associated with higher frailty, compared to normal BMI. In SHARE, having a BMI level greater than 35 kg/m² increased mortality risk in participants with FI≤0.1 (HR 1.31, 95%CI 1.02-1.69). Overweight participants with FI scores >0.3 were at lower risk for mortality compared to normal BMI [NHANES (0.79, 0.64-0.96); SHARE (0.71, 0.63-0.80)]. Higher percent body fat was associated with higher frailty. Percent body fat significantly mediated the relationship between BMI levels and frailty but did not mediate the relationship between BMI levels and mortality risk.

CONCLUSIONS

Being overweight or obese is associated with higher frailty levels. In this study, we found that being overweight is a protective factor of mortality in moderately/severely frail people and obesity grade 1 may be protective for mortality for people with at least a mild level of frailty. In contrast, obesity grades 2 and 3 may be associated with higher mortality risk in non-frail people. The relationship between BMI and frailty is partially explained by body fat.

Slowness as a Predictor of Functional Decline in Older Adults: Comparison of Moberg Picking-Up Test and Walking Speed

OBJECTIVES

Slowness, generally assessed by walking speed (WS), is an estimator of frailty and its outcomes. Because of potential difficulties in assessing WS, the Moberg picking-up test (MPUT) might be an alternative. This study investigated the capacity of slowness measurements (WS and MPUT) to predict nonfatal adverse consequences of frailty: primarily, decline in basic activities of daily living (BADL); and secondarily, decline in instrumental activities of daily living (IADL), fall, hospitalization, and incident disease.

DESIGN

Observational (prospective longitudinal study).

SETTING AND PARTICIPANTS

This study used data from the population-based Lausanne cohort 65+. At baseline, 1887 individuals (aged 72-77 years) completed both WS (time to walk 20 m at usual pace) and MPUT (time to pick up 12 objects) assessments.

METHODS

All outcomes, assessed at 1- and 4-year follow-ups, were entered in separate logistic regression models with adjustment for age, sex, and respective values at baseline. The prediction of all outcomes by either WS or MPUT was assessed using area under the receiver operating characteristic curve and compared by χ² tests.

RESULTS

There were positive associations between slowness either assessed by WS [relative risk (RR) = 2.48; P < .001] or MPUT (RR = 1.91; P < .001) and decline in BADL at 1-year follow-up. These associations remained significant at 4-year follow-up for both WS (RR = 2.28; P < .001) and MPUT (RR = 1.95; P < .001). There was no significant difference between predictive values of slow WS and MPUT for decline in BADL at 1-year (P = .328) and 4-year follow-ups (P = .413). The prediction was not significantly different for secondary outcomes, except for decline in IADL for which the prediction was slightly better for WS.

CONCLUSIONS AND IMPLICATIONS

MPUT may be an alternative measurement of slowness with predictive value of functional decline. No significant difference in predictive capabilities of MPUT and WS for specific adverse consequences of frailty is promising in favor of using MPUT for measuring slowness.

Risk factors for tuberculous or nontuberculous spondylitis after percutaneous vertebroplasty or kyphoplasty in patients with osteoporotic vertebral compression fracture: A case-control study

Objectives

The contributing factors for spondylitis after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) remain unclear. Here, we sought to investigate the factors affecting spondylitis occurrence after PVP/PKP. We also compared the clinical characteristics between patients with tuberculous spondylitis (TS) and nontuberculous spondylitis (NTS) following vertebral augmentation.

Methods

Literature searches (from January 1, 1982 to October 16, 2020) using MEDLINE, EMBASE, Google Scholar and Web of science databases were conducted to identify eligible studies according to predefined criteria. The local database was also retrospectively reviewed to include additional TS and NTS patients at our center.

Results

Thirty studies from the literature and 11 patients from our local institute were identified, yielding a total of 23 TS patients and 50 NTS patients for analysis. Compared with NTS group, patients in the TS group were more likely to have a history of trauma before PVP/PKP treatment. Univariate analyses of risk factors revealed pulmonary tuberculosis and diabetes were significant factors for TS after PVP/PKP. Analyzing NTS, we found obesity, a history of preoperative trauma, urinary tract infection, diabetes and multiple surgical segments (≥2) were significantly associated with its occurrence following PVP/PKP treatment. Multivariate logistic analyses showed a history of pulmonary tuberculosis and diabetes were independent risk factors for TS after PVP/PKP, while diabetes and the number of surgically treated segments independently influenced NTS development.

Conclusions

A history of pulmonary tuberculosis and diabetes were independent risk factors for TS. For NTS, diabetes and the number of surgically treated segments significantly influenced the occurrence of postoperative spinal infection. These data may be helpful for guiding risk stratification and preoperative prevention for patients, thereby reducing the incidence of vertebral osteomyelitis after PVP/PKP.

Effects of age, period, and cohort on the prevalence of frailty in Chinese older adults from 2002 to 2014

Background

Currently, longitudinal studies on frailty are in an early stage, particularly in low- and middle-income countries. Only one study was conducted in Hong Kong to examine age-period-cohort effects on the prevalence of frailty among Chinese older adults.

Objectives

This study aims to shed light on the prevalence trajectory of frailty among older adults in mainland China through the APC model and to analyze the effects of age, period, and cohort on the prevalence trajectory.

Methods

The sample for this study was older adults aged 65-109 years old from the 2002 to 2014 Chinese Longitudinal Healthy Longevity Survey (CLHLS). Frailty status was measured by Rockwood FI. An age-period-cohort model was used to describe the effects of age, period, and cohort on the prevalence trajectory of frailty.

Results

The prevalence of frailty among Chinese older adults changed significantly with age, period, and cohort. Furthermore, the effect of age was much stronger than the effect of period and cohort. The prevalence of frailty in the 101-103 and 104-106 age groups was 8.998 (95% CI 13.667-5.924) and 8.699 (95% CI 13.037-5.805) times higher than the in the 65-67 age group, respectively. The sensitivity analysis based on Fried's frailty phenotype showed similar results, confirming the robustness of our findings.

Conclusion

All of the age effect reflecting the individual aging process, period effect reflecting change in the social environment, and birth cohort effect reflecting different generations could influence the prevalence of frailty at the population level. In contrast, the age effect was the main effect.

Resilience is associated with frailty and older age in hospitalised patients

Background

Little is known about resilience in an internal medicine setting. We aimed to assess the relationship between resilience and frailty and other clinical and sociodemographic characteristics in a cohort of prospectively enrolled hospitalised patients.

Methods

In 2017–2019, we consecutively enrolled patients in our internal medicine wards. We selected all patients who filled in the 25-item Connor-Davidson resilience scale (CD-RISC). Mean resilience was evaluated according to baseline demographic (i.e., age, sex, marital and socioeconomic status) and clinical (i.e., Cumulative Illness Rating Scale [CIRS], Edmonton Frail Scale [EFS], Barthel index, Short Blessed test, length of stay [LOS]) data. A multivariable analysis for assessing factors affecting resilience was fitted.

Results

Overall, 143 patients (median age 69 years, interquartile range 52–79, 74 females) were included. Resilience was significantly lower in frail (p = 0.010), elderly (p = 0.021), dependent (p = 0.032), and more clinically (p = 0.028) and cognitively compromised patients (p = 0.028), and in those with a low educational status (p = 0.032). No relation between resilience and LOS was noticed (p = 0.597). Frail patients were significantly older (p < 0.001), had a greater disease burden as measured by CIRS comorbidity (p < 0.001) and severity indexes (p < 0.001), were more dependent (p < 0.001), more cognitively impaired (p < 0.001), and displayed a lower educational level (p = 0.011) compared to non-frail patients. At multivariable analysis, frailty (p = 0.022) and dependency (p = 0.031; according to the Barthel index) were associated with lower resilience in the age groups 18–64 and ≥ 65 years, respectively.

Conclusions

Low resilience was associated with frailty and dependency with an age-dependent fashion. Studies assessing the impact of this finding on important health outcomes are needed.

Trial registration

Clinical Complexity in Internal Medicine Wards. San MAtteo Complexity Study (SMAC); NCT03439410. Registered 01/11/2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03251-9.

Physiological Systems in Promoting Frailty

Frailty is a complex syndrome affecting a growing sector of the global population as medical developments have advanced human mortality rates across the world. Our current understanding of frailty is derived from studies conducted in the laboratory as well as the clinic, which have generated largely phenotypic information. Far fewer studies have uncovered biological underpinnings driving the onset and progression of frailty, but the stage is set to advance the field with preclinical and clinical assessment tools, multiomics approaches together with physiological and biochemical methodologies. In this article, we provide comprehensive coverage of topics regarding frailty assessment, preclinical models, interventions, and challenges as well as clinical frameworks and prevalence. We also identify central biological mechanisms that may be at play including mitochondrial dysfunction, epigenetic alterations, and oxidative stress that in turn, affect metabolism, stress responses, and endocrine and neuromuscular systems. We review the role of metabolic syndrome, insulin resistance and visceral obesity, focusing on glucose homeostasis, adenosine monophosphate-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and nicotinamide adenine dinucleotide (NAD⁺ ) as critical players influencing the age-related loss of health. We further focus on how immunometabolic dysfunction associates with oxidative stress in promoting sarcopenia, a key contributor to slowness, weakness, and fatigue. We explore the biological mechanisms involved in stem cell exhaustion that affect regeneration and may contribute to the frailty-associated decline in resilience and adaptation to stress. Together, an overview of the interplay of aging biology with genetic, lifestyle, and environmental factors that contribute to frailty, as well as potential therapeutic targets to lower risk and slow the progression of ongoing disease is covered. © 2022 American Physiological Society. Compr Physiol 12:1-46, 2022.

Association between Ultra-Processed Food Consumption and Frailty in American Elder People: Evidence from a Cross-Sectional Study

OBJECTIVES

Our study aims to explore the association between ultra-processed foods (UPFs) and frailty in participants with different body mass indexes (BMIs).

DESIGN

A cross-sectional study.

SETTING

Data were collected from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002.

PARTICIPANTS

We analyzed data from 2,329 participants.

MEASUREMENTS

Dietary data were obtained using 24-h dietary recall method. Frail status was assessed by modified Fried frailty phenotype. The association between the grams, energy, and energy proportion of UPFs and the risk of pre-frailty/frailty was estimated using logistic regression analysis, and odds ratio (OR) with 95% confidence intervals (CIs) were calculated. Participants were categorized into underweight-normal weight (BMI <25 kg/m2), overweight (25 kg/m2 ≤ BMI < 30 kg/m2), and obesity (BMI ≥ 30 kg/m2) groups. The multiplicative interaction between BMIs and UPFs on pre-frailty/frailty was assessed using the logistic regression analysis.

RESULTS

We analyzed data from 2,329 participants, and 2,267 (97.77%) of whom consumed UPFs. There were 1,063 participants in pre-frailty or frailty group and 1,266 participants in non-frailty group. In underweight-normal weight participants, every 100 kcal increase in energy of UPFs intake was associated with increased 0.08 times of pre-frailty or frailty risk (OR: 1.08, 95%CI: 1.00-1.16, P = 0.045), and every 10% increase in energy proportion of UPFs intake was correlated with a 0.02-fold increase in pre-frailty or frailty risk (OR: 1.02, 95%CI: 1.00-1.03, P = 0.018). Similar results were found in overweight participants, with OR of 1.06 (95%CI: 1.01-1.10) and 1.01 (95%CI: 1.00-1.02) for energy and energy proportion, respectively (both P < 0.05). This association was not found in obesity participants.

CONCLUSION

The energy and energy proportion of UPFs intake was positively associated with the frailty risk in underweight-normal weight and overweight people, indicating that population with BMI less than 30 kg/m2 should pay more attention to reasonable diet and balanced source of energy intake.

The correlation between nutrition and frailty and the receiver operating characteristic curve of different nutritional indexes for frailty

Background

Frailty is a kind of geriatric syndrome, which is very common in the elderly. Patients with malnutrition are at higher risk of frailty. This study explored the correlation between nutrition and frailty and compared the receiver operating characteristic curve of different nutritional indexes for frailty.

Methods

This cross-sectional study included 179 inpatients aged ≥65 years old. Frailty was measured using Fried Frailty Phenotype, handgrip strength was measured using JAMAR@Plus and the 4.57 m usual gait speed was measured using a stopwatch. Comprehensive nutritional assessment refers to the application of Mini Nutritional Assessment (MNA) to assess the nutritional status of patients.

Results

Compared with the non-frailty group, the upper arm circumference, calf circumference, hemoglobin, albumin, prealbumin, cholesterol and low density lipoprotein in the frailty group were lower (P < 0.05). Comprehensive nutritional assessment, whether as a categorical variable or a continuous variable, was significantly correlated with frailty (P < 0.05). Model1 showed that the risk of frailty in malnourished patients was 3.381 times higher than that in well nourished patients (P = 0.036). Model2 showed that the risk of frailty decreased by 13.8% for every 1 point increase in MNA score (P = 0.009). The area under the curves of albumin, prealbumin and hemoglobin was larger (AUC > 0.65), AUC was 0.718, 0.693 and 0.743, respectively.

Conclusions

Our results suggest that malnutrition is closely related to frailty. As for single nutritional indexes, albumin, prealbumin and hemoglobin were found to be associated with frailty. Further cohort studies are needed to verify their ability to screen for frailty.

Association between Dietary Patterns and Frailty Prevalence in Shanghai Suburban Elders: A Cross-Sectional Study

OBJECTIVE

To investigate the association between dietary patterns with frailty phenotypes in an elderly Chinese population.

METHODS

A cross-sectional study was performed in 780 Shanghai suburban elders aged 65-74 in 2019. Dietary data were collected using a food frequency questionnaire. Adherence to a priori dietary patterns, including the Chinese Healthy Eating Index (CHEI), Dietary Approaches to Stop Hypertension (DASH) diet and Mediterranean Diet (MD) were calculated. Three a posteriori dietary patterns were identified by factor analysis, namely, "protein-rich"; "vegetables"; and "sugar, oil, and condiments". Frailty was defined using the Fried frailty phenotype scale. Ordinal multiple logistic regression was applied to examine the associations between dietary patterns and frailty prevalence.

RESULTS

The prevalences of pre-frailty and frailty were 47.69% and 3.85%, respectively. Participants with a higher DASH score had a lower frailty prevalence in the sex- and age-adjusted models of the 780 subjects (OR = 0.97 (95% CI: 0.94-0.99), p < 0.05). The association slightly strengthened in the multivariate adjusted model of the 555 subjects after excluding the participants with chronic diseases may influence frailty (OR = 0.96 (95% CI: 0.92-1.00), p < 0.05). High "protein-rich" dietary pattern scores were negatively associated with frailty prevalence in the multivariate adjusted model of the 780 subjects (OR = 0.82 (95% CI: 0.69-0.98), p < 0.05). The association attenuated in the sex- and age-adjusted model of the 555 subjects (OR = 0.84 (95% CI: 0.69-1.00, p = 0.056).

CONCLUSION

A better diet quality as characterized by DASH and "protein-rich" was associated with a reduced prevalence of frailty in Shanghai suburban elders. The correlation of CHEI, MD or a posteriori dietary patterns with the development of frailty in Chinese older people remains to be explored.

Early-Life Socioeconomic Position and the Accumulation of Health-Related Deficits by Midlife in the 1958 British Birth Cohort Study

Reducing population levels of frailty is an important goal, and preventing its development in midadulthood could be pivotal. There is limited evidence on associations between childhood socioeconomic position (SEP) and frailty. Using data on the 1958 British birth cohort (followed from 1958 to 2016; n = 8,711), we aimed to 1) establish the utility of measuring frailty in midlife, by examining associations between a 34-item frailty index at age 50 years (FI_50y) and mortality at ages 50–58 years, and 2) examine associations between early-life SEP and FI_50y and investigate whether these associations were explained by adult SEP. Hazard ratios for mortality increased with increasing frailty; for example, the sex-adjusted hazard ratio for the highest quintile of FI_50y versus the lowest was 4.07 (95% confidence interval (CI): 2.64, 6.25). Lower early-life SEP was associated with higher FI_50y. Compared with participants born in the highest social class, the estimated total effect on FI_50y was 42.0% (95% CI: 35.5, 48.4) for participants born in the lowest class, with the proportion mediated by adult SEP being 0.45% (95% CI: 0.35, 0.55). Mediation by adult SEP was negligible for other early-life SEP classes. Findings suggest that early-life SEP is associated with frailty and that adult SEP only partially explains this association. Results highlight the importance of improving socioeconomic circumstances across the life course to reduce inequalities in midlife frailty.

The degree of frailty as a translational measure of health in aging

Frailty is a multiply determined, age-related state of increased risk for adverse health outcomes. We review how the degree of frailty conditions the development of late-life diseases and modifies their expression. The risks for frailty range from subcellular damage to social determinants. These risks are often synergistic-circumstances that favor damage also make repair less likely. We explore how age-related damage and decline in repair result in cellular and molecular deficits that scale up to tissue, organ and system levels, where they are jointly expressed as frailty. The degree of frailty can help to explain the distinction between carrying damage and expressing its usual clinical manifestations. Studying people-and animals-who live with frailty, including them in clinical trials and measuring the impact of the degree of frailty are ways to better understand the diseases of old age and to establish best practices for the care of older adults.

Trends in Frailty and Its Association With Mortality: Results From the Longitudinal Aging Study Amsterdam, 1995-2016

The aim of this study was to investigate trends in frailty and its relationship with mortality among older adults aged 64–84 years across a period of 21 years. We used data from 1995 to 2016 from the Longitudinal Aging Study Amsterdam. A total of 7,742 observations of 2,874 respondents in the same age range (64–84 years) across 6 measurement waves were included. Frailty was measured with a 32-item frailty index, with a cutpoint of ≥0.25 to indicate frailty. The outcome measure was 4-year mortality. Generalized estimating equation analyses showed that among older adults aged 64–84 years the 4-year mortality rate declined between 1995 and 2016, while the prevalence of frailty increased. Across all measurement waves, frailty was associated with 4-year mortality (odds ratio = 2.79, 95% confidence interval: 2.39, 3.26). There was no statistically significant interaction effect between frailty and time on 4-year mortality, indicating a stable association between frailty and mortality. In more recent generations of older adults, frailty prevalence rates were higher, while excess mortality rates of frailty remained the same. This is important information for health policy-makers and clinical practitioners, showing that continued efforts are needed to reduce frailty and its negative health consequences.

Dementia remains the major predictor of death among octogenarians. A study of two population cohorts of 85-year-olds examined 22 years apart

Dementia is the major predictor of death in old age. The aim of this paper was to determine whether 8-year mortality among 85-year olds with and without dementia, and if the contribution of dementia to mortality relative to other common diseases has changed. We used two population-based cohorts of 85-year-olds (N = 1065), born in 1901–02 and 1923–24, which were examined with identical methods in 1986–87 and 2008–2010 and followed for 8-year mortality according to data from the Swedish Tax Agency. Dementia was diagnosed according to DSM-III-R. Other diseases were diagnosed based on self-reports, close informant interviews, somatic examinations, and the Swedish National In-patient Register. Compared to cohort 1901–02, cohort 1923–24 had a lower 8-year mortality both among those with (HR 0.7; 95% CI 0.5–0.99) and without dementia (HR 0.7; 95% CI 0.5–0.9). Dementia was associated with increased mortality in both cohorts (cohort 1901–02, HR 2.6; 95% CI 2.0–3.2, cohort 1923–24, HR 2.8; 95% CI 2.3–3.5), and remained the major predictor of death, with a population attributable risk of 31.7% in 1986–87 and 27.7% in 2008–10. Dementia remained the most important predictor of death in both cohorts. The relative risk for mortality with dementia did not change between cohorts, despite a decreased mortality rate in the population.

Frailty degree and illness trajectories in older people towards the end-of-life: a prospective observational study

OBJECTIVES

To assess the degree of frailty in older people with different advanced diseases and its relationship with end-of-life illness trajectories and survival.

METHODS

Prospective, observational study, including all patients admitted to the Acute Geriatric Unit of the University Hospital of Vic (Spain) during 12 consecutive months (2014-2015), followed for up to 2 years. Participants were identified as end-of-life people (EOLp) using the NECPAL (NECesidades PALiativas, palliative care needs) tool and were classified according to their dominant illness trajectory. The Frail-VIG index (Valoración Integral Geriátrica, Comprehensive Geriatric Assessment) was used to quantify frailty degree, to calculate the relationship between frailty and mortality (Receiver Operating Characteristic (ROC) curves), and to assess the combined effect of frailty degree and illness trajectories on survival (Cox proportional hazards model). Survival curves were plotted using the Kaplan-Meier estimator with participants classified into four groups (ie, no frailty, mild frailty, moderate frailty and advanced frailty) and were compared using the log-rank test.

RESULTS

Of the 590 persons with a mean (SD) age of 86.4 (5.6) years recruited, 260 (44.1%) were identified as EOLp, distributed into cancer (n=31, 11.9%), organ failure (n=79, 30.4%), dementia (n=86, 33.1%) and multimorbidity (n=64, 24.6%) trajectories. All 260 EOLp had some degree of frailty, mostly advanced frailty (n=184, 70.8%), regardless of the illness trajectory, and 220 (84.6%) died within 2 years. The area under the ROC curve (95% CI) after 2 years of follow-up for EOLp was 0.87 (0.84 to 0.92) with different patterns of survival decline in the different end-of-life trajectories (p<0.0001). Cox regression analyses showed that each additional deficit of the Frail-VIG index increased the risk of death by 61.5%, 30.1%, 29.6% and 12.9% in people with dementia, organ failure, multimorbidity and cancer, respectively (p<0.01 for all the coefficients).

CONCLUSIONS

All older people towards the end-of-life in this study were frail, mostly with advanced frailty. The degree of frailty is related to survival across the different illness trajectories despite the differing survival patterns among trajectories. Frailty indexes may be useful to assess end-of-life older people, regardless of their trajectory.

The difference an end-of-life diagnosis makes: qualitative interviews with providers of community health care for frail older people

BACKGROUND

Increasing numbers of people die of the frailty and multimorbidity associated with old age, often without receiving an end-of-life diagnosis. Compared to those with a single life-limiting condition such as cancer, frail older people are less likely to access adequate community care. To address this inequality, guidance for professional providers of community health care encourages them to make end-of-life diagnoses more often in such people. These diagnoses centre on prognosis, making them difficult to establish given the inherent unpredictability of age-related decline. This difficulty makes it important to ask how care provision is affected by not having an end-of-life diagnosis.

AIM

To explore the role of an end-of-life diagnosis in shaping the provision of health care outside acute hospitals.

DESIGN AND SETTING

Qualitative interviews with 19 healthcare providers from community-based settings, including nursing homes and out-of-hours services.

METHOD

Semi-structured interviews (nine individual, three small group) were conducted. Data were analysed thematically and using constant comparison.

RESULTS

In the participants' accounts, it was unusual and problematic to consider frail older people as candidates for end-of-life diagnosis. Participants talked of this diagnosis as being useful to them as care providers, helping them prioritise caring for people diagnosed as 'end-of-life' and enabling them to offer additional services. This prioritisation and additional help was identified as excluding people who die without an end-of-life diagnosis.

CONCLUSION

End-of-life diagnosis is a first-class ticket to community care; people who die without such a diagnosis are potentially disadvantaged as regards care provision. Recognising this inequity should help policymakers and practitioners to mitigate it.

The Burden of Frailty Among U.S. Veterans and Its Association With Mortality, 2002-2012

BACKGROUND

Frailty is a key determinant of clinical outcomes. We sought to describe frailty among U.S. Veterans and its association with mortality.

METHODS

Nationwide retrospective cohort study of regular Veterans Affairs (VA) users, aged at least 65 years in 2002-2012, followed through 2014, using national VA administrative and Medicare and Medicaid data. A frailty index (FI) for VA (VA-FI) was calculated using the cumulative deficit method. Thirty-one age-related deficits in health from diagnostic and procedure codes were included and were updated biennially. Survival analysis assessed associations between VA-FI and mortality.

RESULTS

A VA-FI was calculated for 2,837,152 Veterans over 10 years. In 2002, 35.5% were non-frail (FI = 0-0.10), 32.6% were pre-frail (FI = 0.11-0.20), 18.9% were mildly frail (FI = 0.21-0.30), 8.7% were moderately frail (FI = 0.31-0.40), and 4.3% were severely frail (FI > 0.40). From 2002 to 2012, the prevalence of moderate frailty increased to 12.7%and severe frailty to 14.1%. Frailty was strongly associated with survival and was independent of age, sex, race, and smoking; the VA-FI better predicted mortality than age alone. Although prevalence of frailty rose over time, compared to non-frail Veterans, 2 years' hazard ratios (95% confidence intervals) for mortality declined from a peak in 2004 of 2.01 (1.97-2.04), 3.49 (3.44-3.55), 5.88 (5.79-5.97), and 10.39 (10.23-10.56) for pre-frail, mildly, moderately, and severely frail, respectively, to 1.51 (1.49-1.53), 2.36 (2.33-2.39), 3.68 (3.63-3.73), 6.62 (6.53-6.71) in 2012. At every frailty level, risk of mortality was lower for women versus men and higher for blacks versus whites.

CONCLUSIONS

Frailty affects at least 3 of every 10 U.S. Veterans aged 65 years and older, and is strongly associated with mortality. The VA-FI could be used to more accurately estimate life expectancy and individualize care for Veterans.

Frailty Confers High Mortality Risk across Different Populations: Evidence from an Overview of Systematic Reviews and Meta-Analyses

We performed an overview of systematic reviews and meta-analyses to summarize available data regarding the association between frailty and all-cause mortality. Medline, Embase, CINAHL, Web of Science, PsycINFO, and AMED (Allied and Complementary Medicine) databases were searched until February 2020 for meta-analyses examining the association between frailty and all-cause mortality. The AMSTAR2 checklist was used to evaluate methodological quality. Frailty exposure and the risk of all-cause mortality (hazard ratio [HR] or relative risk [RR]) were displayed in forest plots. We included 25 meta-analyses that pooled data from between 3 and 20 studies. The number of participants included in these meta-analyses ranged between <2000 and >500,000. Overall, 56%, 32%, and 12% of studies were rated as of moderate, low, and critically low quality, respectively. Frailty was associated with increased risk of all-cause mortality in 24/24 studies where the HR/RRs ranged from 1.35 [95% confidence interval (CI) 1.05-1.74] (patients with diabetes) to 7.95 [95% CI 4.88-12.96] (hospitalized patients). The median HR/RR across different meta-analyses was 1.98 (interquartile range 1.65-2.67). Pre-frailty was associated with a significantly increased risk of all-cause mortality in 7/7 studies with the HR/RR ranging from 1.09 to 3.65 (median 1.51, IQR 1.38-1.73). These data suggest that interventions to prevent frailty and pre-frailty are needed.

Management of frailty: opportunities, challenges, and future directions

Frailty is a complex age-related clinical condition characterised by a decline in physiological capacity across several organ systems, with a resultant increased susceptibility to stressors. Because of the heterogeneity of frailty in clinical presentation, it is important to have effective strategies for the delivery of care that range across the continuum of frailty severity. In clinical practice, we should do what works, starting with frailty screening, case identification, and management of frailty. This process is unarguably difficult given the absence of an adequate evidence base for individual and health-system interventions to manage frailty. We advocate change towards individually tailored interventions that preserve an individual's independence, physical function, and cognition. This change can be addressed by promoting the recognition of frailty, furthering advancements in evidence-based treatment options, and identifying cost-effective care delivery strategies.

Frailty: implications for clinical practice and public health

Frailty is an emerging global health burden, with major implications for clinical practice and public health. The prevalence of frailty is expected to rise alongside rapid growth in the ageing population. The course of frailty is characterised by a decline in functioning across multiple physiological systems, accompanied by an increased vulnerability to stressors. Having frailty places a person at increased risk of adverse outcomes, including falls, hospitalisation, and mortality. Studies have shown a clear pattern of increased health-care costs and use associated with frailty. All older adults are at risk of developing frailty, although risk levels are substantially higher among those with comorbidities, low socioeconomic position, poor diet, and sedentary lifestyles. Lifestyle and clinical risk factors are potentially modifiable by specific interventions and preventive actions. The concept of frailty is increasingly being used in primary, acute, and specialist care. However, despite efforts over the past three decades, agreement on a standard instrument to identify frailty has not yet been achieved. In this Series paper, we provide an overview of the global impact and burden of frailty, the usefulness of the frailty concept in clinical practice, potential targets for frailty prevention, and directions that need to be explored in the future.

Outcomes of hospital admissions among frail older people: a 2-year cohort study

Background

‘Frailty crises’ are a common cause of hospital admission among older people and there is significant focus on admission avoidance. However, identifying frailty before a crisis occurs is challenging, making it difficult to effectively target community services. Better longer-term outcome data are needed if services are to reflect the needs of the growing population of older people with frailty.

Aim

To determine long-term outcomes of older people discharged from hospital following short (<72 hours) and longer hospital admissions compared by frailty status.

Design and setting

Two populations aged ≥70 years discharged from hospital units: those following short ‘ambulatory’ admissions (<72 hours) and those following longer inpatient stays.

Method

Data for 2-year mortality and hospital use were compared using frailty measures derived from clinical and hospital data.

Results

Mortality after 2 years was increased for frail compared with non-frail individuals in both cohorts. Patients in the ambulatory cohort classified as frail had increased mortality (Rockwood hazard ratio 2.3 [95% confidence interval {CI} = 1.5 to 3.4]) and hospital use (Rockwood rate ratio 2.1 [95% CI = 1.7 to 2.6]) compared with those patients classified as non-frail.

Conclusion

Individuals with frailty who are discharged from hospital experience increased mortality and resource use, even after short ‘ambulatory’ admissions. This is an easily identifiable group that is at increased risk of poor outcomes. Health and social care systems might wish to examine their current care response for frail older people discharged from hospital. There may be value in a ‘secondary prevention’ approach to frailty crises targeting individuals who are discharged from hospital.

Changes of a frailty index based on common blood and urine tests during a hospital stay on geriatric wards predict 6-month and 1-year mortality in older people

Background

We aimed to evaluate the abilities of a 21-item frailty index based on laboratory blood and urine tests (FI-Lab21) assessed at different points in time, ie, at admission to hospital (FI-Lab21_admission) and before discharge from hospital (FI-Lab21_discharge), and the change of the FI-Lab21 during the hospital stay to predict 6-month and 1-year mortality in hospitalized geriatric patients.

Methods

Five hundred hospitalized geriatric patients aged ≥65 years were included in this analysis. Follow-up data were acquired after a period of 6 months and 1 year.

Results

The FI-Lab21_admission and FI-Lab21_discharge scores were 0.33±0.15 and 0.31±0.14, respectively (P<0.001). The FI-Lab21_admission and FI-Lab21_discharge both predicted 6-month and 1-year mortality (areas under the receiver operating characteristic curves: 0.72, 0.72, 0.77, and 0.75, respectively, all P<0.001). The predictive abilities for 6-month and 1-year mortality of the FI-Lab21_admission were inferior compared with those of the FI-Lab21_discharge (all P<0.05). Patients with a reduction in or stable FI-Lab21 score during the hospital stay revealed lower 6-month and 1-year mortality rates compared with the persons whose FI-Lab21 score increased during the hospital stay (all P<0.05). After adjustment for age, sex, and FI-Lab21_admission, each 1% decrease in the FI-Lab21 during the hospital stay was associated with a decrease in 6-month and 1-year mortality of 5.9% and 5.3% (both P<0.001), respectively.

Conclusion

The FI-Lab21 assessed at admission or discharge and the changes of the FI-Lab21 during the hospital stay emerged as interesting and feasible approaches to stratify mortality risk in hospitalized geriatric patients.

Current situation of frailty screening tools for older adults

Frailty is a geriatric syndrome associated with adverse outcomes such as falls, disability, and mortality. Frailty is common and contributes to rising health care costs. Early screening and timely tailored intervention may effectively prevent or delay the adverse outcomes in older adults. Studies on frailty and its specific measurement tools are increasing in number, but the debate on the screening instruments remains. Currently, self-reported screening tools can identify frailty and predict the risk of adverse outcomes in older adults. Because they are easy to use and quickly provide information, self-reported frailty screening tools have significant implication in primary care settings and clinics. We reviewed the frailty screening instruments in older adults and proposed a two-step pathway for frailty identification, and to manage declines in intrinsic capacity as well as boost resilience.

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.