In the Quest of a Standard Index of Intrinsic Capacity. A Critical Literature Review

Predictive Validity of Intrinsic Capacity Composite Scores for Risk of Frailty at 2 Years: A Comparison of 4 Scales

OBJECTIVE

Intrinsic capacity (IC) and frailty are complementary constructs that encapsulate functional capacities of older adults. Although earlier studies suggest the utility of composite IC scores in predicting risk of frailty, key gaps remain with the lack of direct comparative studies between different IC scales and lack of a composite score based on the World Health Organization Integrated Care for Older People (ICOPE) tool. We aimed to compare different IC scales, including an ICOPE-based scale, in their predictive ability for risk of frailty at 2 years in healthy community-dwelling older adults.

DESIGN

Cohort study.

SETTING AND PARTICIPANTS

A total of 230 participants (age: 67.2 ± 7.4 years) from the GeriLABS-2 cohort study.

METHODS

We derived composite scores by summing 4 IC domains (locomotion, cognition, vitality, and psychological). We compared composite scores of 4 scales: IC1-Chew 2021, range: 0-8; IC2-Liu 2021, range: 0-4; IC3-ICOPE, range: 0-4; IC4-modified ICOPE, range: 0-8. The primary outcome was risk of frailty using the modified Fried Frailty Phenotype. We performed logistic regression to examine the association of baseline composite IC with risk of frailty. We also examined the impact of individual domains and number of impaired domains on risk of frailty.

RESULTS

Among 193 (83.9%) older adults who completed 2-year follow-up, 20 (10.4%) met criteria for risk of frailty. When adjusted for covariates, 2-point per domain scales (IC1/IC4) predicted increased risk of frailty (OR, 4.31; 95% CI, 1.55-11.96; OR, 5.00; 95% CI, 1.75-14.26). When further adjusted for baseline frailty, only IC4 remained significant (OR, 4.28; 95% CI, 1.45-12.60). Among the domains, impaired locomotion and vitality were associated with risk of frailty. Greater number of impaired domains predicted increased risk of frailty (IC1/IC2: β = 0.18-0.19, P < .05).

CONCLUSIONS AND IMPLICATIONS

Baseline composite IC score using 2-point per domain scales better predicted risk of frailty at 2 years, predicated on impaired locomotion/vitality and greater number of impaired domains. For early identification of healthy older adults at risk of frailty, an ICOPE-based scale should be considered, as it is effective and accessible.

A simple scoring algorithm based on intrinsic capacity for functional ability in community-dwelling older adults in Taiwan

BACKGROUND

Intrinsic capacity (IC) is a comprehensive indicator of the overall well-being of older adults, and assessing of IC can help identify early stage of disability and tailor intervention to individual needs. However, there is a lack of effective and simple IC assessment tools. This study aimed to establish predictive scoring algorithms of IC to identify older adults at high risk of impaired functional ability.

METHODS

We conducted a cross-sectional study in Southern Taiwan, measuring IC using 7 subitems: cognition, locomotion, vitality, vision, hearing, psychological well-being, and medication usage were measured. Functional ability outcomes included frailty, basic activities of daily living, and instrumental activities of daily living (IADL). The capability of 7 domains of IC in predicting functional ability was assessed by multivariable logistic regression. The prediction of capability of scoring algorithms was indicated by receiver operating characteristic (AUC) curves and measures of sensitivity and specificity.

RESULTS

A total of 1,152 older adults were recruited and analyzed. Locomotion emerged as a significant predictor of IADL disability and worsening frailty. The IC-based weighted scoring algorism for predicting IADL demonstrated satisfactory capability (AUC: 0.80), as did the algorithm for predicting worsening frailty (AUC: 0.90). The optimal cutoff points for predicting IADL disability and frailty worse were estimated respectively at 13 and 16, with sensitivity/specificity values of 0.74/0.75 for the IADL prediction algorithm and 0.92/0.77 for the frailty prediction algorithm.

CONCLUSION

Our 7-domain IC screening tool proves to be sensitive and practical for early identification of functional disability and frailty among community-dwelling older adults in Taiwan.

Towards a core outcome set (COS) for intrinsic capacity (IC) intervention studies in adults in midlife and beyond: a scoping review to identify frequently used outcomes and measurement tools

This scoping review was conducted to identify the outcomes and measurement tools used in IC intervention studies, as first step towards the development of a core outcome set (COS) for IC trials. PRISMA-ScR and COS-STAD were followed. The review considered randomized controlled trials targeting IC published in Medline, Scopus, Embase, Cochrane Central Register of Controlled Trials, and clinicaltrials.gov, until June 2023. Of 699 references, 534 studies were screened once duplicates were removed, 15 were assessed for eligibility, and 7 (4 articles and 3 protocols) met eligibility criteria. Twenty-eight outcomes were identified (19 related to IC and its domains and 9 unrelated). The most reported primary outcome was the change in IC levels postintervention (5 over 7 studies) and the most reported outcomes (either as primary and/or secondary) were the changes in physical performance and in depressive symptoms (6 over 7 studies). Fifty-five tools used to construct the domains' z-scores and/or assess the effect of interventions were identified (47 related to IC and its domains and 8 unrelated). The most reported tool was an IC Z-score, calculated by 4 domains' z-scores: locomotor, vitality, cognitive, and psychological (5 over 7 studies). The tools differed among studies (10 locomotor related, 6 vitality related, 16 cognitive related, 8 psychological related, 6 sensorial related, 8 unrelated tools). The vast heterogeneity (28 outcomes and 55 tools within 7 studies) highlighted the need of a COS. These outcomes and tools will be presented to experts in a future step, to select the ones that should be taken into consideration in IC trials.

Association of intrinsic capacity with incidence and mortality of cardiovascular disease: Prospective study in UK Biobank

BACKGROUND

The World Health Organization proposed the concept of intrinsic capacity (IC; the composite of all the physical and mental capacities of the individual) as central for healthy ageing. However, little research has investigated the interaction and joint associations of IC with cardiovascular disease (CVD) incidence and CVD mortality in middle- and older-aged adults.

METHODS

Using data from 443 130 UK Biobank participants, we analysed seven biomarkers capturing the level of functioning of five domains of IC to calculate a total IC score (ranging from 0 [better IC] to +4 points [poor IC]). Associations between IC score and incidence of six long-term CVD conditions (hypertension, stroke/transient ischaemic attack stroke, peripheral vascular disease, atrial fibrillation/flutter, coronary artery disease and heart failure), and grouped mortality from these conditions were estimated using Cox proportional models, with a 1-year landmark analysis to triangulate the findings.

RESULTS

Over 10.6 years of follow-up, CVD morbidity grouped (n = 384 380 participants for the final analytic sample) was associated with IC scores (0 to +4): mean hazard ratio (HR) [95% confidence interval, CI] 1.11 [1.08-1.14], 1.20 [1.16-1.24], 1.29 [1.23-1.36] and 1.56 [1.45-1.59] in men (C-index = 0.68), and 1.17 [1.13-1.20], 1.30 [1.26-1.36], 1.52 [1.45-1.59] and 1.78 [1.67-1.89] in women (C-index = 0.70). In regard to mortality, our results indicated that the higher IC score (+4 points) was associated with a significant increase in subsequent CVD mortality (mean HR [95% CI]: 2.10 [1.81-2.43] in men [C-index = 0.75] and 2.29 [1.85-2.84] in women [C-index = 0.78]). Results of all sensitivity analyses by full sample, sex and age categories were largely consistent independent of major confounding factors (P < 0.001).

CONCLUSIONS

IC deficit score is a powerful predictor of functional trajectories and vulnerabilities of the individual in relation to CVD incidence and premature death. Monitoring an individual's IC score may provide an early-warning system to initiate preventive efforts.

Investigating three ways of measuring the intrinsic capacity domain of vitality: nutritional status, handgrip strength and ageing biomarkers

BACKGROUND

Vitality is conceptually considered as the underlying capacity influencing other intrinsic capacity (IC) domains and being related to nutrition, physiological reserve and biological ageing. However, there is no consensus on its operationalisation.

OBJECTIVE

To investigate the structure and magnitude of the association of vitality with other IC domains and functional difficulties using three operational definitions of vitality.

METHODS

We included 1,389 older adults from the Multidomain Alzheimer Preventive Trial with data on Mini Nutritional Assessment (MNA), handgrip strength and plasma biomarkers (comprising inflammatory and mitochondrial markers). Using path analysis, we examined the effects of vitality on difficulties in basic and instrumental activities of daily living (ADL and IADL) exerted directly and indirectly through the mediation of other IC domains: cognition, locomotion, psychological, vision and hearing. We further explored the longitudinal association of vitality with IC domains, ADL and IADL over 4 years using linear mixed-effect regression.

RESULTS

We observed significant indirect effects of vitality on IADL, mainly through cognitive, locomotor and psychological domains, regardless of the vitality measurement. Participants with higher vitality had fewer IADL difficulties at follow-up (MNA score: β [95% CI] = -0.020 [-0.037, -0.003]; handgrip strength: -0.011 [-0.023, 0.000]; plasma biomarker-based index: -0.015 [-0.028, -0.002]). Vitality assessed with the plasma biomarker-based index predicted improved locomotion over time.

CONCLUSION

Vitality was associated with disability primarily through the mediation of other IC domains. The three indicators examined are acceptable measurements of vitality; biomarkers might be more suitable for the early detection of locomotion decline.

Associations between Vitality/Nutrition and the Other Domains of Intrinsic Capacity Based on Data from the INSPIRE ICOPE-Care Program

BACKGROUND

The vitality domain of intrinsic capacity (IC) represents the synthesis of biological interactions and metabolism. As part of the Integrated Care for Older People (ICOPE) program developed by the World Health Organization (WHO), vitality focuses on the nutritional status of older adults. The objective of this work was to describe the vitality domain of IC in community-dwelling older people and to examine the associations of the vitality components (appetite loss and weight loss) with the other IC domains assessed within the framework of ICOPE.

METHODS

Cross-sectional data were obtained between January 2020 and February 2022 through the INSPIRE-ICOPE-Care program, a real-life ICOPE implementation initiative developed in the Occitania region of France. Participants were men and women aged 60 and older, looking for primary care services within the French healthcare system.

RESULTS

Appetite loss was reported by 14.0% (2013) of the participants, and weight loss by 12.4% (1788). A total of 863 participants (6.01%) declaring weight loss also suffered from appetite loss. In total, 2910 participants (20.27%) screened positive for the domain of vitality. Appetite loss was significantly associated with positive screenings for the domains of cognition (OR = 2.14 [1.84;2.48]), vision (OR = 1.51 [1.28;1.79]), hearing (OR = 1.18 [1.01;1.37]), psychology (OR = 3.95 [3.46;4.52]), and locomotion 'OR = 2.19 [1.91;2.51]). We found significant associations of weight loss with the IC domains of cognition (OR = 1.65 [1.42;1.93]), psychology (OR = 1.80 [1.56;2.07]), locomotion (OR = 1.64 [1.41;1.91]), vision (OR = 1.24 [1.04;1.47]), and hearing (OR = 1.32 [1.12;1.55]). People reporting simultaneous appetite and weight loss showed higher odds of screening positive for psychological (OR = 5.33 [4.53;6.27]) and locomotion impairments (OR = 3.38 [2.88;3.98]).

CONCLUSIONS

Appetite and weight loss are common among older people and are related to other potential IC impairments, especially psychological and locomotion. Further studies are needed to explore the longitudinal associations of vitality with the incidence of clinically meaningful declines in the other IC domains.

Measurements of Intrinsic Capacity in Older Adults: A Scoping Review and Quality Assessment

OBJECTIVES

This review summarizes the measurements of intrinsic capacity in 5 domains across different studies and evaluates the quality of research papers.

DESIGN

Scoping review of papers written in English and Chinese published in peer-reviewed journals.

SETTING AND PARTICIPANTS

The intrinsic capacity of older adults was assessed using the multidomain structure (Cognition, Locomotion, Psychological, Sensory and Vitality) proposed by the World Health Organization.

METHODS

We searched PubMed, MEDLINE, and Web of Science for papers in English, and CNKI, CBM for papers written in Chinese published until September 13, 2022. Both cross-sectional and cohort studies of multidomain measurements of intrinsic capacity were included. Three independent reviewers appraised the quality of studies, and Cohen's kappa was calculated to determine interrater reliability. Data were listed by author, year, setting, country, age range and number of participants, measurement and calculation of intrinsic capacity, and data acquisition method.

RESULTS

We included 53 studies. Twenty-one studies were of high quality, 31 studies were of moderate quality, and 1 study was of low quality. Measurements of intrinsic capacity and derivation of the summative index score were heterogeneous. Intrinsic capacity was usually assessed in 4 or 5 domains. Sensory was the most frequently overlooked domain or subdivided into vision and hearing in some studies. Indicators of vitality were the most heterogeneous. We also found consistency in heterogeneous measurements. The most common measurements of cognition, locomotion, and psychological capacity were the Mini-Mental State Examination, Short Physical Performance Battery, and Geriatric Depression Scale respectively. Self-reported questionnaires were commonly adopted in sensory domain. The Mini-Nutritional Assessment and grip strength were the most measured indicators of vitality.

CONCLUSIONS AND IMPLICATIONS

The focus on capacity and disease should be balanced to better promote healthy aging in older adults. Heterogeneity of intrinsic capacity measurements underscores the need for consensus about standardized measurements and calculation procedures.

Use of Intrinsic Capacity Domains as a Screening Tool in Public Health

The World Health Organization (WHO) created the concept of Integrated Care for Older People and one of its constructs is intrinsic capacity (IC). The study aimed to carry out a screening with the tools designated by the WHO to assess the IC domains and whether they can be used as indicators for decision-making on integrated care for older people based on risk categorization. The interaction between the risk category and the domain scores was verified. One hundred and sixty three (163) community-dwelling older people of both genders were evaluated. Domains assessed: cognitive, psychological, vitality, locomotion, and sensory. Scores indicating a low, moderate and high risk were assigned to each domain. For all domains, there were individuals in all risk groups. Effect of risk on the domains: cognitive [χ²(2) = 134.042; p < 0.001], psychological [χ²(2) = 92.865; p < 0.001], vitality [χ²(2) = 129.564; p < 0.001], locomotion [χ²(2) = 144.101; p < 0.001], and sensory [χ²(2) = 129.037; p < 0.001]. Scores of the CI domains were affected by the risk category. There were individuals in all risk groups, demonstrating the importance of screening as a public health strategy, making it possible to know which risk category each elderly person belongs to and thus develop strategies in the short-, medium- and long-term.

Development and validation of an intrinsic capacity composite score in the Longitudinal Aging Study Amsterdam: a formative approach

BACKGROUND

Intrinsic capacity (IC) defined by the WHO refers to the composite of five domains of capacities. So far, developing and validating a standardized overall score of the concept have been challenging partly because its conceptual framework has been unclear. We consider that a person's IC is determined by its domain-specific indicators suggesting a formative measurement model.

AIMS

To develop an IC score applying a formative approach and assess its validity.

METHODS

The study sample (n = 1908) consisted of 57-88-year-old participants from the Longitudinal Aging Study Amsterdam (LASA). We used logistic regression models to select the indicators to the IC score with 6-year functional decline as an outcome. An IC score (range 0-100) was constructed for each participant. We examined the known-groups' validity of the IC score by comparing groups based on age and number of chronic diseases. The criterion validity of the IC score was assessed with 6-year functional decline and 10-year mortality as outcomes.

RESULTS

The constructed IC score included seven indicators covering all five domains of the construct. The mean IC score was 66.7 (SD 10.3). The scores were higher among younger participants and those who had lower number of chronic diseases. After adjustment for sociodemographic indicators, chronic diseases, and BMI, a one-point higher IC score was associated with a 7% decreased risk for 6-year functional decline and a 2% decreased risk for 10-year mortality.

CONCLUSIONS

The developed IC score demonstrated discriminative ability according to age and health status and is associated with subsequent functional decline and mortality.

Moving towards the ICOPE Approach: Evaluation of Community-Based Intervention Activities on Improving Intrinsic Capacity

OBJECTIVES

Different types of community-based intervention activities may have differential effects in improving the intrinsic capacity (IC) of older people. This study aims to (i) identify subgroups of older people based on their IC impairments, (ii) examine the differential associations between different types of activity participations and change in IC across subgroups, and (iii) assess whether the activity participation patterns of older people align with the way that would benefit them the most.

METHODS

Participants were community-dwelling older people aged 60 years or above. They were screened for IC impairments at baseline, and their participation records of different types (cognitive, physical, nutritional, mental, and social) of intervention activities were collected for one year. An aggregated IC score was created based on four IC domains including cognitive (self-rated memory), locomotor (self-rated difficulties in walking), vitality (self-rated weight loss), and psychological (subjective well-being). Cluster analysis was used to group homogenous participants. Mixed-effects regression was used to examine the associations between activity counts (i.e., number of sessions participated) and change in IC. Activity participation patterns were also compared across subgroups.

RESULTS

Data were obtained from 7,357 participants (mean age = 74.72 years). Four clusters were identified, including those who were relatively robust (cluster 1, N = 4,380, 59.5%), those who had cognitive decline (cluster 2, N = 2,134, 29.0%), those who had impaired mobility and vitality (cluster 3, N = 319, 4.3%), and those with poor psychological well-being (cluster 4, N = 524, 7.1%). Overall, activity count was associated with IC improvement (β = 0.073, 95% CI [0.037, 0.108]). However, as regards the cluster-specific results, different types of activities were associated with IC improvement for different specific clusters. For instance, cognitive activity count was associated with IC improvement only for cluster 2 (β = 0.491, 95% CI [0.258, 0.732]). Notably, none of the activity types were associated with IC improvement for cluster 1. Regarding the activity participation patterns, there were no significant differences across the four clusters (Wilk's Λ = 0.997, F = 1.400, p = .138).

CONCLUSIONS AND IMPLICATIONS

IC improvement depended on the activity types and IC status of older people. In view of this, a people-centred and targeted approach should be adopted to maximize the overall benefits of intervention activities.

WHO working definition of vitality capacity for healthy longevity monitoring

Intrinsic capacity, a crucial concept in healthy ageing, is defined by WHO as "the composite of all the physical and mental capacities that an individual can draw on at any point in time". Vitality capacity is considered the underlying physiological determinant of intrinsic capacity. To advance the measurement and monitoring of vitality capacity, a working group of WHO staff members and twenty experts representing six WHO regions was convened to discuss and clarify the attributes of vitality capacity and to develop a clear working definition of the concept. Potential biomarkers to measure vitality capacity were identified, and the following consensual working definition was developed: vitality capacity is a physiological state (due to normal or accelerated biological ageing processes) resulting from the interaction between multiple physiological systems, reflected in (the level of) energy and metabolism, neuromuscular function, and immune and stress response functions of the body.

Establishment of Clinical Construct of Intrinsic Capacity in Older Adults and Its Prediction of Functional Decline

Background

The World Health Organization has conceptualised the health and healthcare of older adults around the concept of healthy ageing. Healthy ageing is defined as “the process of developing and maintaining the functional ability that enables well-being in older age”. This functional ability is the sum of two key factors: intrinsic capacity and interacting environment. This concept of intrinsic capacity encompasses a wide spectrum of health characteristics including the physiological and psychological changes associated with the ageing process. In general, IC declines from a high and stable state to an impaired status as people age. Monitoring individuals for changes in intrinsic capacity in the context of their environment will provide a holistic method of tracking the functioning of older adults at both a population and individual level, providing an opportunity to address any reversible factors of decline. However, this would require a clear and objective conceptualisation of the concept of intrinsic capacity.

Methodology

One hundred subjects were recruited via invitation by advertisement on the institute campus. Study participants underwent detailed physical examination and measurement of various physical and chemical biomarkers which were likely to represent intrinsic capacity as evidenced by the literature review. Outcomes measured were a decline in ADL, IADL, mortality and hospitalisation over a follow-up period of six months. Exploratory factor analysis (EFA) was done to obtain a clinical construct of the proposed entity of intrinsic capacity. Unpaired t-test and univariate logistic regression were used to check for the association between the composite score (IC) and its domains with the decline in ADL, IADL, mortality and hospitalisation.

Results

One composite score (composite IC score) and eight subfactors emerged. The composite score and subfactor domains showed good construct validity. Composite intrinsic capacity score and subdomains of strength and cognition were significantly different among subjects with and without ADL and IADL decline. Univariate logistic regression showed that composite intrinsic capacity score was a predictor of decline in ADL and IADL even after adjusting for age, sex, comorbidity status and education level of the subject with an adjusted odds ratio of 0.99 and 0.98, respectively. Subdomains of strength and cognition also predicted a decline in ADL and IADL independently.

Conclusion

The development of an objective construct of the concept of intrinsic capacity, using commonly measured clinical and biochemical parameters, is feasible and predictive of the subsequent functionality of an individual.

Exploring the conceptual framework and measurement model of intrinsic capacity defined by the World Health Organization: A scoping review

WHO has defined intrinsic capacity (IC) as the composite of all physical and mental capacities of an individual covering five subdomains: cognition, locomotion, sensory, vitality, and psychological. Despite this well accepted definition, the conceptual and measurement model of IC remains unclear, which hampers a standardized operationalization of the construct. We performed a scoping review to give a comprehensive overview of the extent to which the current literature of IC addresses and assumes the conceptual framework and measurement model of IC as reflective or formative. For inclusion, we considered all types of articles that were published in peer-reviewed journals except for protocol articles. A systematic search of 6 databases from different disciplines led to the inclusion of 31 papers. We found inconsistency and gaps in the descriptions of IC. Most of the papers did not define the measurement model. In the conceptual background and validation articles, we identified descriptions of both reflective and formative measurement models while in empirical studies applying IC measurements the underlying assumptions remained mainly unclear. Defining a measurement model is not merely a theoretical matter but influences the operationalization and validation processes of the construct. This study raised questions about the most fundamental features of the IC construct and discusses whether IC should be considered as an underlying latent trait of all capacities (reflective construct) or an aggregate summary measure of the subdomain capacities (formative construct).

A methodology to engineering continuous monitoring of intrinsic capacity for elderly people

Continuous monitoring of the well-being state of elderly people is about to become an urgent need in the early future due to population aging. Aiming a unified notion of well-being, we find the Intrinsic Capacity concept in accordance with the SMART BEAR project goals. In this study, we mainly focus on the enabling infrastructure, mapping our models to interoperable repositories and to streaming/computing components that can foster monitoring. Our method is also innovative for explicitly combining personalized and risk levels in generating the Intrinsic Capacity score. Leveraging on synthetic data, we represent the outcome trajectories of some sample patients for 1-year continuous monitoring and discuss approaches to characterize them based on the exhibited tendency and evaluate the results from the predictability point of view providing by the entropy of time series concept. At the end, we discuss the possible data quality issues in health care studies using synthetic data.

Defining and assessing intrinsic capacity in older people: A systematic review and a proposed scoring system

INTRODUCTION

The World Health Organization has introduced the term 'intrinsic capacity' (IC) as a marker of healthy ageing. However, controversy exists on the definition and assessment of IC. We aimed to review the definitions and methods used for the assessment of IC in older adults. In addition, we proposed a new IC scoring method.

METHODS

A systematic search was performed in PubMed, Web of Science, Cochrane Library, Scopus and SPORTDiscus (up to February 10th, 2022) for studies assesing IC in older adults (>60 years).

RESULTS

Thirty-three studies were included. There is overall consensus on the definition of IC as well as on its different dimensions, that is: locomotion, vitality, sensory, cognition and psychological. However, the methods for assessing each of these five dimensions differ substantially across studies and there is no consensus on the best method to compute an eventual global compound score to evaluate IC taking into account all its different dimensions.

CONCLUSIONS

The IC represents a highly relevant clinical concept that has been unfortunately underutilized. We propose a standardization for the assessment of each dimension of IC, with a global 0 (worst) to 10 (highest) score.

Adaptation and Validation of the Individual Lifestyle Profile Scale of Portuguese Older Adults Living at Home

(1) Background: Unadjusted lifestyles have been the main cause of risk for the loss of years of healthy life. However, currently valid and reliable instruments to assess the lifestyles of the elderly are quite long and difficult to interpret. For this reason, the objective of this study was to adapt and validate the 'Individual Lifestyle Profile' (ILP) scale in a sample of elderly people; (2) Methods: A methodological study was carried out and a sample of 300 older adults enrolled in a Health Unit located in the North of Portugal was used, who responded to the scale. We examined internal consistency, predictive validity, and discriminative ability; (3) Results: After the Exploratory Factorial analysis, a solution was found with four factors that explain a variance of 67.8%. The designation of the factors was changed from the original scale, with the exception of one dimension, and they were called Health Self-management, Social Participation and Group Interaction, Citizenship and Physical Activity. The total internal consistency (Cronbach's alpha) was 0.858, ranging from 0.666 to 0.860 in the mentioned factors; (4) Conclusions: The ILP scale proved to be easy to apply and presented a good reliability and validity index, based on internal consistency, AFE and AFC. The scale allows evaluating the lifestyle of older adults, and its use will be aimed at modifying behaviors associated with negative lifestyles of older adults and their individual needs.

Biological Features of the Outcome-Based Intrinsic Capacity Composite Scores From a Population-Based Cohort Study: Pas de Deux of Biological and Functional Aging

Introduction

This study aims to develop and validate an integrative intrinsic capacity (IC) scoring system, to investigate its associations with a wide spectrum of biomarkers and to explore the predictive value of the integrative IC score on 4-year mortality among community dwelling people aged 50 years and older.

Methods

We included 839 adults aged ≥50 years from the Social Environment and Biomarkers of Aging Study (SEBAS) and randomly divided them into derivation and validation cohorts to develop the IC scoring system. The multivariate logistic regression model was used to weight each subdomain (locomotion, sensory, vitality, psychological, and cognition) of IC according to its association with impairments in instrumental activities of daily living (IADL) and to construct the integrative IC score. Age-related biomarkers and genetic markers were compared between IC groups by ordinal logistic regression. A Cox proportional hazard model was used to examine the association between IC and mortality, and subgroup analysis was used to assess the robustness of the results among participants aged 60 years and older.

Results

A 12-score IC scoring system (AUROC = 0.83; Hosmer–Lemeshow goodness-of-fit test p = 0.17) was developed, and higher scores indicated better intrinsic capacity. High interleukin (IL)-6, high E-selectin, low serum albumin and low folate were significantly associated with low IC in the whole sample. However, high IL-6, low serum albumin, low folate, high allostatic load, and APOE ε4 genotype were significantly associated with low IC in those aged 60 years old and older. Compared to the high IC group, the low IC group was significantly associated with all-cause mortality (HR: 2.50, 95% CI: 1.22–5.11, p = 0.01 for all participants; HR 2.19, 95% CI 1.03–4.64, p = 0.04 for participants aged 60 years and older).

Conclusions

The conceptually proposed IC can be easily transformed into a scoring system considering different weights of individual subdomains, which not only predicts mortality but also suggests different pathophysiologies across the life course of aging (inflammation, nutrition, stress, and ApoE4 genotype). An intervention study is needed using the composite IC score to promote healthy aging and determine the underlying pathophysiology.

Functional health index of intrinsic capacity: multi-domain operationalisation and validation in the Singapore Longitudinal Ageing Study (SLAS2)

BACKGROUND

ad hoc approaches are used to create composite indexes of intrinsic capacity (IC) based on five domains recommended by the World Health Organization for healthy ageing. We examined how combinations of domain-specific measures determine measurement performances of composite IC indexes.

METHODS

in this population-based prospective cohort study, community-dwelling older persons (N = 2,906) aged 55 years and above were recruited. We used 12 domain-specific measures: cognition (Mini-Mental State Examination, MMSE), psychological (Geriatric Depression Scale, GDS), locomotion (Timed Up-and Go [TUG], GV, Knee Extension Strength, Performance Orientated Mobility Assessment), sensory (logarithm of the Minimum Angle of Resolution [LogMAR] vision and Whisper Test hearing) and vitality (forced expiratory volume in 1 second pulmonary function, Elderly Nutritional Indicators for Geriatric Malnutrition Assessment [ENIGMA], Nutritional Screening Initiative) to derive 144 composite 2- to 5-domain functional health indexes (FHI), and evaluated their abilities to predict 9-year mortality and their associations with health determinants.

RESULTS

with 5-domain FHI, TUG, logMAR and MMSE showed the largest factor loadings (0.65-0.75). All single-domain FHI were significantly associated with mortality risks. Area under the receiver operating characteristic curve (AUC) values of mortality prediction increased with the number of domains (from mean 0.615 for single-domain FHI to mean 0.705 for 5-domain FHI), but the difference between 3-domain versus 4-domain FHI (P = 0.082) or versus 5-domain FHI (P = 0.109) was not statistically significant. Highest AUCs (P < 0.001) of best performing FHI were single-domain TUG: 0.735; 2-domain TUG + ENIGMA: 0.743; 3-domain TUG + LogMAR + ENIGMA: 0.762; 4-domain TUG + MMSE + LogMAR + ENIGMA: 0.757; 5-domain TUG + MMSE + GDS + LogMAR + ENIGMA: 0.751. FHI showed excellent construct validity based on correlations with known health determinants.

CONCLUSIONS

among Singaporean older adults, cognition, sensory and locomotion are predominant IC domains. A multi-domain IC index performs better with more domain measures, but a minimalist 3-domain index performs just as robustly as a 4- or 5-domain index.

Integrated Multi-Omics for Novel Aging Biomarkers and Antiaging Targets

Aging is closely related to the occurrence of human diseases; however, its exact biological mechanism is unclear. Advancements in high-throughput technology provide new opportunities for omics research to understand the pathological process of various complex human diseases. However, single-omics technologies only provide limited insights into the biological mechanisms of diseases. DNA, RNA, protein, metabolites, and microorganisms usually play complementary roles and perform certain biological functions together. In this review, we summarize multi-omics methods based on the most relevant biomarkers in single-omics to better understand molecular functions and disease causes. The integration of multi-omics technologies can systematically reveal the interactions among aging molecules from a multidimensional perspective. Our review provides new insights regarding the discovery of aging biomarkers, mechanism of aging, and identification of novel antiaging targets. Overall, data from genomics, transcriptomics, proteomics, metabolomics, integromics, microbiomics, and systems biology contribute to the identification of new candidate biomarkers for aging and novel targets for antiaging interventions.

Intrinsic Capacity vs. Multimorbidity: A Function-Centered Construct Predicts Disability Better Than a Disease-Based Approach in a Community-Dwelling Older Population Cohort

Objective: This study aimed to assess the status of intrinsic capacity (IC)—a novel function-centered construct proposed by the WHO and examine whether impairment in IC predicts subsequent 1-year activities of daily living (ADL) disability better than a disease-based approach, i. e., multimorbidity status.

Methods: This study included data of community-dwelling older adults from the Beijing Longitudinal Study on Aging II aged 65 years or older who were followed up at 1 year. Multivariate logistic regressions were performed to estimate the odds of ADL disability at baseline and 1-year follow-up.

Results: A total of 7,298 older participants aged 65 years or older were included in the current study. About 4,742 older adults were followed up at 1 year. At baseline, subjects with a higher impairment in IC domains showed higher odds of ADL disability [adj. odds ratio (OR) = 9.51 for impairment in ≥3 domains, area under the curve (AUC) = 0.751] compared to much lower odds of ADL disability in subjects with a higher number (≥3) of chronic diseases (adj. OR 3.92, AUC = 0.712). At 1-year follow-up, the overall incidence of ADL disability increased with the impairment in IC domains higher than the increase in multimorbidity status. A higher impairment in IC domains showed higher odds of incidence ADL disability for impairment in 2 or ≥3 IC domains (adj. OR 2.32 for impairment in ≥3 domains, adj. OR 1.43 for impairment in two domains, AUC = 0.685). Only subjects who had ≥3 chronic diseases had higher odds of 1-year incident ADL disability (adj. OR 1.73, AUC = 0.681) that was statistically significant.

Conclusion: Our results imply that a function-centered construct could have higher predictability of disability compared to the multimorbidity status in community older people. Our results need to be confirmed by studies with longer follow-up.

Screening for intrinsic capacity impairments as markers of increased risk of frailty and disability in the context of integrated care for older people: Secondary analysis of MAPT

AIM

This longitudinal secondary analysis of the Multidomain Alzheimer Preventive Trial (MAPT) aimed to test whether the Integrated Care for Older People (ICOPE) Step 1 screening tool is able to identify people at risk of developing frailty and disability in basic (ADL) and instrumental (IADL) activities of daily living among community-dwelling older adults.

PARTICIPANTS AND SETTING

Seven hundred and fifty-nine (n = 759) non-demented participants of the MAPT aged 70-89 years were assessed in memory clinics in France between 2008 and 2013.

METHODS

We measured six intrinsic capacity (IC) impairments, adapted from the ICOPE screening tool. We used Cox models to estimate the adjusted hazard ratios of incident frailty and IADL/ADL disability. Incident frailty was defined by Fried's phenotype, and incident disability was measured according to Lawton and Katz for IADLs and ADLs.

RESULTS

Limited mobility (HR= 2.97, 95%CI= 1.85-4.76), depressive symptoms (HR= 2.07, 95%CI= 1.03-4.19), and visual impairment (HR= 1.70, 95%CI 1.01-2.86) were associated with a higher incidence of frailty over 5 years. Each additional IC condition demonstrated a positive association with a higher risk of incident frailty, IADL, ADL disability, with risk increased by 47%, 27%, and 23% over 5 years, respectively.

CONCLUSION

Screening for IC impairments identifies older adults at higher risk of incident frailty and incident IADL/ADL disability. It is relevant to screen for these impairments together because the risk of frailty and disability increases with each additional one. ClinicalTrials.gov identifier: NCT00672685.

Promising biomarkers of human aging: In search of a multi-omics panel to understand the aging process from a multidimensional perspective

The aging process has been linked to the occurrence of chronic diseases and functional impairments, including cancer, sarcopenia, frailty, metabolic, cardiovascular, and neurodegenerative diseases. Nonetheless, aging is highly variable and heterogeneous and represents a challenge for its characterization. In this sense, intrinsic capacity (IC) stands as a novel perspective by the World Health Organization, which integrates the individual wellbeing, environment, and risk factors to understand aging. However, there is a lack of quantitative and qualitative attributes to define it objectively. Therefore, in this review we attempt to summarize the most relevant and promising biomarkers described in clinical studies at date over different molecular levels, including epigenomics, transcriptomics, proteomics, metabolomics, and the microbiome. To aid gerontologists, geriatricians, and biomedical researchers to understand the aging process through the IC. Aging biomarkers reflect the physiological state of individuals and the underlying mechanisms related to homeostatic changes throughout an individual lifespan; they demonstrated that aging could be measured independently of time (that may explain its heterogeneity) and to be helpful to predict age-related syndromes and mortality. In summary, we highlight the areas of opportunity and gaps of knowledge that must be addressed to fully integrate biomedical findings into clinically useful tools and interventions.