Intrinsic Capacity to Predict Future Adverse Health Outcomes in Older Adults: A Scoping Review

Dietary patterns and intrinsic capacity in older adults: a 6-year prospective cohort study

OBJECTIVES

Only a few studies have investigated dietary patterns and intrinsic capacity (IC). This study examined the prospective associations between dietary patterns, IC, and IC sub-domains over 6 years in community-dwelling Korean older adults.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

Data were obtained from participants aged 70-84 years in the Korean Frailty and Aging Cohort Study (2016-2022). The study population included 665 enrollees at baseline who completed IC and dietary data.

METHODS

Dietary data were obtained from baseline surveys of the nutritional sub-cohort using two nonconsecutive 24-hour dietary recalls, and dietary patterns were derived using cluster analysis. IC was constructed by measuring cognitive, locomotor, vitality, sensory, and psychological domains. A generalized estimating equation was used to analyze the longitudinal associations between dietary patterns, IC, and IC sub-domain scores.

RESULTS

In total, 665 enrollees were included in the analysis. After adjusting for confounders, in older men, the dietary pattern of cluster 1 (variety of healthy foods and alcohols) compared to that of cluster 2 (rice and kimchi) was positively associated with changes in the IC score (ß = 0.41, 95% confidence interval [CI] = 0.04-0.78). In older women, the dietary pattern of cluster 1 (variety of healthy foods) was positively associated with changes in the IC score (ß = 0.30, 95% CI = 0.02-0.58), IC score group (ß = 0.11, 95% CI = 0.02-0.20), and psychological domain (ß = 0.25, 95% CI = 0.11-0.38) compared to that of cluster 3 (rice, vegetables, and kimchi).

CONCLUSIONS

Dietary patterns (variety of healthy foods) were positively associated with changes in IC scores and their sub-domains in older adults.

The Global Research Trends on Intrinsic Capacity of Older Adults: A Bibliometric and Visual Analysis of Papers Published During 2015-2023

Objective

The concept of intrinsic capacity (IC) revolves around healthy aging and active aging. Since the Introduction of the concept by the World Health Organization in 2015, a series of studies have been conducted by scholars from multiple fields. However, no bibliometric analysis has systematically investigated this issue. We aim to identify the current landscape and frontier trends of scientific achievements on IC in older adults through bibliometric approaches.

Methods

Quantitative analysis of publications relating to IC in older adults from 2015 to 2023 was interpreted and graphed through the Web of Science Core Collection database on December 5, 2023. A variety of quantitative variables was analyzed, including publication and citation counts, H-index, and journal citation reports. Co-authorship, citation, co-citation, and co-occurrence analyses were performed for countries/regions, institutions, authors, and keywords using the VOSviewer and CiteSpace.

Results

A total of 952 original and review articles in English were identified. The European countries possessed an absolute advantage in this field. The most contributive institution was the University of São Paulo. The most productive author is Cesari Matteo from France, followed by Qaisar Rizwan from the United Arab Emirates. However, a relatively low level of research cooperation existed between institutions and authors. Important topics mainly include the connotations, theoretical framework models, evaluation, screening tools, and application scenarios of IC. Among the promising hotspots, "biological aging", "ICOPE", "Covid-19", "prevention", "inflammation", "caf22", "prevalence", and "randomized controlled trial" displayed relatively latest average appearing year.

Conclusion

Global trends indicate a growing scientific output on IC in older adults, and developed countries are leading the way. There is still room for improvement in research team collaboration. The focus gradually shifts from theoretical research to empirical research. It is recommended to pay attention to the latest hot spots, such as "biological aging", "ICOPE implementation", "post-COVID-19 syndrome", and "biomarkers".

Adverse health effects of declined intrinsic capacity in middle-aged and older adults: a systematic review and meta-analysis

BACKGROUND

Intrinsic capacity refers to a broad range of health traits, including the physiological and psychological changes brought on by aging. Previous research has shown that intrinsic capacity, as an independent emerging construct, is a highly effective predictor of several health outcomes.

OBJECTIVE

We aimed to summarise the predictive effect of intrinsic capacity at baseline on health outcomes among middle-aged and older adults.

DESIGN

A systematic review and meta-analysis.

PARTICIPANTS

Middle-aged and older adults.

METHODS

We systematically searched up to 3 April 2024 in 10 electronic databases. Studies investigating the predictive effect of baseline composite intrinsic capacity and health outcomes were included. Publications that had reported hazard ratios (HRs) or odd ratios (ORs) and 95% confidence intervals (CIs) as effect size were considered.

RESULTS

A total of 23 publications were included. The sample size ranged from 100 to 17 031. The results of the meta-analysis showed statistically significant prediction of adverse health outcomes such as disability (OR = 1.84, 95% CI: 1.68-2.03, I2 = 41%, Pheterogeneity=.10), falls (OR = 1.38, 95% CI: 1.19-1.60, I2 = 45%, Pheterogeneity=.11), hospitalisation (OR = 2.25, 95% CI: 1.17-4.3, I2 = 68%, Pheterogeneity=.08), mortality (OR = 1.72, 95% CI: 1.54-1.91, I2 = 32%, Pheterogeneity=.12) and frailty (OR = 1.57, 95% CI: 1.45-1.70, I2 = 2%, Pheterogeneity=.31) by the baseline composite intrinsic capacity.

CONCLUSIONS

Declined intrinsic capacity has potential predictive value for adverse health outcomes, further high-quality study is needed to validate these findings and strengthen their cumulative impact. Attention to health outcomes should also focus on both breadth and category precision.

Obesity paradox of cardiovascular mortality in older adults in the United States: A cohort study using 1997-2018 National Health Interview Survey data linked with the National Death Index

BACKGROUND

Large-scale, population-based investigations primarily investigating the association between body mass index (BMI) and cardiovascular disease (CVD) mortality among older and younger adults in the United States (U.S.) are lacking.

OBJECTIVE

To evaluate the relationship between BMI and CVD mortality in older (≥65 years) and younger (<65 years) adults and to identify the nadir for CVD mortality.

DESIGN

This cohort study used serial cross-sectional data from the 1997 to 2018 National Health Interview Survey (NHIS) linked with the National Death Index. NHIS is an annual nationally representative household interview survey of the civilian noninstitutionalized U.S.

POPULATION

SETTING

Residential units of the civilian noninstitutionalized population in the U.S.

PARTICIPANTS

The target population for the NHIS is the civilian noninstitutionalized U.S. population at the time of the interview. We included all adults who had BMI data collected at 18 years and older and with mortality data being available. To minimize the risk of reverse causality, we excluded adults whose survival time was ≤2 years of follow-up after their initial BMI was recorded and those with prevalent cancer and/or CVD at baseline.

METHODS

We used the BMI record obtained in the year of the NHIS survey. Total CVD mortality used the NHIS data linked to the latest National Death Index data from the survey inception to December 31, 2019. We performed multivariable Cox proportional hazards regression models to estimate adjusted hazard ratios (aHRs) and 95 % confidence intervals (CIs).

RESULTS

The study included 425,394 adults; the mean (SD) age was 44 (16.7) years. During a median follow-up period of 11 years, 12,089 CVD-related deaths occurred. In older adults, having overweight was associated with a lower risk of CVD mortality (aHR 0.92 [95 % CI, 0.87-0.97]); having class I obesity (1.04 [0.97-1.12]) and class II obesity (1.12 [1.00-1.26]) was not significantly associated with an increased CVD mortality; and having class III obesity was associated with an increased risk of CVD mortality (1.63 [1.35-1.98]), in comparison with adults who had a normal BMI. Yet, in younger adults, having overweight, class I, II, and III obesity was associated with a progressively higher risk of CVD mortality. The nadir for CVD mortality is 28.2 kg/m2 in older adults and 23.6 kg/m2 in younger adults.

CONCLUSION

This U.S. population-based cohort study highlights the significance of considering age as a crucial factor when providing recommendations and delivering self-care educational initiatives for weight loss to reduce CVD mortality.

Association of intrinsic capacity with functional decline and mortality in older adults: a systematic review and meta-analysis of longitudinal studies

BACKGROUND

Together with environmental factors, intrinsic capacity (the composite of all the physical and mental capacities of an individual) has been proposed as a marker of healthy ageing. However, whether intrinsic capacity predicts major clinical outcomes is unclear. We aimed to explore the association of intrinsic capacity with functional decline and mortality in older adults.

METHODS

In this systematic review and meta-analysis, we conducted a systematic search in MEDLINE (via PubMed), Scopus, and Web of Science from database inception to Feb 14, 2024, of observational longitudinal studies conducted in older adults (age ≥60 years) assessing the association of intrinsic capacity with impairment in basic activities of daily living (BADL) or instrumental activities of daily living (IADL) or risk of mortality. Estimates were extracted by two reviewers (JLS-S and W-HL) and were pooled using three-level meta-analytic models. The quality of each study was independently assessed by two authors (JLS-S and PLV) using the Newcastle-Ottawa Scale for longitudinal studies. Heterogeneity was evaluated using the I2 indicator at two levels: within-study (level 2) and between-study (level 3) variation. For associations between intrinsic capacity and IADL and BADL, we transformed data (standardised β coefficients and odds ratios [ORs]) into Pearson product moment correlation coefficients (r) using Pearson and Digby formulas to allow comparability across studies. For associations between intrinsic capacity and risk of mortality, hazard ratios (HRs) with 95% CIs were extracted from survival analyses. This study is registered with PROSPERO, CRD42023460482.

FINDINGS

We included 37 studies (206 693 participants; average age range 65·3-85·9 years) in the systematic review, of which 31 were included in the meta-analysis on the association between intrinsic capacity and outcomes; three studies (2935 participants) were included in the meta-analysis on the association between intrinsic capacity trajectories and longitudinal changes in BADL or IADL. Intrinsic capacity was inversely associated with longitudinal impairments in BADL (Pearson's r -0·12 [95% CI -0·19 to -0·04]) and IADL (-0·24 [-0·35 to -0·13]), as well as with mortality risk (hazard ratio 0·57 [95% CI 0·51 to 0·63]). An association was also found between intrinsic capacity trajectories and impairment in IADL (but not in BADL), with maintained or improved intrinsic capacity over time associated with a lower impairment in IADL (odds ratio 0·37 [95% CI 0·19 to 0·71]). There was no evidence of publication bias (Egger's test p>0·05) and there was low between-study heterogeneity (I2=18·4%), though within-study (I2=63·2%) heterogeneity was substantial.

INTERPRETATION

Intrinsic capacity is inversely associated with functional decline and mortality risk in older adults. These findings could support the use of intrinsic capacity as a marker of healthy ageing, although further research is needed to refine the structure and operationalisation of this construct across settings and populations.

FUNDING

None.

TRANSLATIONS

For the Spanish and French translations of the abstract see Supplementary Materials section.

Transitions in intrinsic capacity among community-dwelling older people and their associated factors: a multistate modelling analysis

OBJECTIVES

Trajectory of intrinsic capacity (IC) can be non-linear and discontinuous, which traditional linear models may not be able to handle. This study thus aimed to model the trajectory of IC as transitions between different IC states and examine their associated factors.

METHODS

Longitudinal data from a sample of community-dwelling older people aged 60 years or above (n = 1,588) was analysed. A set of 14 self-reported items representing different domains of IC were administered annually to measure IC at four time points. Based on the number of impaired IC domains (i.e., cognitive, locomotor, vitality, sensory, and psychological), participants at each time point were classified into one of three IC states, namely state 1 (0 impaired domain), state 2 (1-2 impaired domains), and state 3 (3-5 impaired domains). Multistate modelling was used to identify factors associated with the transitions from one state to another.

RESULTS

The mean age of participants was 75.0 years, and 77.4% of them were female. At baseline, 12.4% were in state 1, 51.8% were in state 2, and 35.8% were in state 3. 62.8% of participants experienced at least one transition between states, among which 12% experienced a transition every year. The transitions occurred mostly between adjacent IC states and could take place back and forth. Age, sex, marital status, perceived financial adequacy, number of chronic diseases, and self-rated health were the factors associated with the transitions.

CONCLUSION

Findings may serve as a valuable reference for guiding future policies to optimize IC and promote healthy ageing using a person-centred approach.

Development and validation of an intrinsic capacity score in the UK Biobank study

BACKGROUND

In 2015, the World Health Organization introduced the concept of intrinsic capacity (IC) to define the individual-level characteristics that enable an older person to be and do the things they value. This study developed an intrinsic capacity score for UK Biobank study participants and validated its use as a tool for health outcome prediction, understanding healthy aging trajectories, and genetic research.

METHODS

Our analysis included data from 45,208 UK biobank participants who had a complete record of the ten variables included in the analysis. Factor adequacy was tested using Kaiser-Meyer-Olkin, Barthelt's, and the determinant of matrix tests, and the number of factors was determined by the parallel analysis method. Exploratory and confirmatory factor analyses were employed to determine the structure and dimensionality of indicators. Finally, the intrinsic capacity score was generated, and its construct and predictive validities as well as reliability were assessed.

RESULTS

The factor analysis identified a multidimensional construct comprising one general factor (intrinsic capacity) and five specific factors (locomotor, vitality, cognitive, psychological, and sensory). The bifactor structure showed a better fit (comparative fit index = 0.995, Tucker Lewis index = 0.976, root mean square error of approximation = 0.025, root mean square residual = 0.009) than the conventional five-factor structure. The intrinsic capacity score generated using the bifactor confirmatory factor analysis has good construct validity, as demonstrated by an inverse association with age (lower intrinsic capacity in older age; (β) =-0.035 (95%CI: -0.036, -0.034)), frailty (lower intrinsic capacity score in prefrail participants, β = -0.104 (95%CI: (-0.114, -0.094)) and frail participants, β = -0.227 (95%CI: -0.267, -0.186) than robust participants), and comorbidity (a lower intrinsic capacity score associated with increased Charlson's comorbidity index, β =-0.019 (95%CI: -0.022, -0.015)). The intrinsic capacity score also predicted comorbidity (a one-unit increase in baseline intrinsic capacity score led to a lower Charlson's comorbidity index, β = 0.147 (95%CI: -0.173, -0.121)) and mortality (a one-unit increase in baseline intrinsic capacity score led to 25 % lower risk of death, odds ratio = 0.75(95%CI: 0.663, 0.848)).

CONCLUSION

The bifactor structure showed a better fit in all goodness of fit tests. The intrinsic capacity construct has strong structural, construct, and predictive validities and is a promising tool for monitoring aging trajectories.

The assessment and detection rate of intrinsic capacity deficits among older adults: a systematic review and meta-analysis

BACKGROUND

Assessing and monitoring intrinsic capacity (IC) is an effective strategy to promote healthy ageing by intervening early in high-risk populations. This review systematically analyzed the global detection rates of IC deficits and explored variations across diverse populations and data collection methods.

METHODS

This study was preregistered with PROSPERO, CRD42023477315. In this systematic review and meta-analysis, we systematically searched ten databases from January 2015 to October 2023, for peer-reviewed, observational studies or baseline survey of trials that assessed IC deficits among older adults aged 50 and above globally following the condition, context and population approach. The main outcome was intrinsic capacity deficits which could be assessed by any tools. Meta-analyses were performed by a random-effect model to pool the detection rates across studies and subgroup analyses were conducted by populations and data collection methods.

RESULTS

Fifty-six studies conducted in 13 countries were included in the review and 44 studies with detection rates of IC were included in the meta-analysis. The pooled detection rate of IC deficits was 72.0% (65.2%-78.8%) and deficits were most detected in sensory (49.3%), followed by locomotion (40.0%), cognition (33.1%), psychology (21.9%), and vitality (20.1%). Variations in detection rates of IC deficits were observed across studies, with higher rates observed in low- and middle-income countries (74.0%) and hyper-aged societies (85.0%). Study population and measurement tools also explained the high heterogeneity across studies.

CONCLUSION

IC deficits are common among older adults, while heterogeneity exists across populations and by measurement. Early monitoring with standardized tools and early intervention on specific subdomains of IC deficits are greatly needed for effective strategies to promote healthy ageing.

Technological Perception with Rural and Urban Differentiation and Its Influence on the Quality of Life of Older People with Age-Related Macular Degeneration

The past decade has seen a global increase in population age, especially in developed countries, where aging involves visual diseases such as age-related macular degeneration (AMD), which severely affect quality of life (QoL) and mental health, as well as increase isolation and care costs. This study investigated how persons with AMD perceive the impact of technology use on their QoL, focusing on potential disparities between urban and rural contexts in Spain. Using a cross-sectional observational design, data from the 2020 National Statistics Institute's Disability, Personal Autonomy, and Dependency Situations Survey were analyzed, focusing on QoL aspects based on the WHO items of the WHOQOL-100 scale. The results revealed a generally positive perception of technology among participants, with urban residents perceiving technology's positive impact more favorably. Sex discrepancies in technology perception were also observed, as women exhibited a more positive outlook on technology's influence on QoL. The analysis of QoL aspects, such as 'Visibility', 'Learning', 'Mobility', and 'Domestic life', highlighted distinct challenges faced by rural and urban populations, underscoring the importance of context-specific approaches in technology interventions. However, these perceptions were intertwined with comorbidities, which can exacerbate AMD-related issues. Furthermore, this study explored the role of technology in enhancing QoL among older adults with AMD, examining how it influences daily activities and independence, particularly in the context of AMD management. This study concluded that developing more-inclusive policies tailored to the specific needs of persons with AMD, with special attention to environmental and sex differences, is imperative to enhance the positive impact of technology on their QoL.

Wrist-to-Tibia/Shoe Inertial Measurement Results Translation Using Neural Networks

Most of the established gait evaluation methods use inertial sensors mounted in the lower limb area (tibias, ankles, shoes). Such sensor placement gives good results in laboratory conditions but is hard to apply in everyday scenarios due to the sensors' fragility and the user's comfort. The paper presents an algorithm that enables translation of the inertial signal measurements (acceleration and angular velocity) registered with a wrist-worn sensor to signals, which would be obtained if the sensor was worn on a tibia or a shoe. Four different neural network architectures are considered for that purpose: Dense and CNN autoencoders, a CNN-LSTM hybrid, and a U-Net-based model. The performed experiments have shown that the CNN autoencoder and U-Net can be successfully applied for inertial signal translation purposes. Estimating gait parameters based on the translated signals yielded similar results to those obtained based on shoe-sensor signals.

Composition of healthy diets for older persons

PURPOSE OF REVIEW

This study aims to review recent evidence (2022-2023) on the role of diet in promoting healthy aging in older adults.

RECENT FINDINGS

Current evidence of diet and healthy aging is limited to epidemiological studies. A healthy diet is beneficial for individual domains of intrinsic capacity, that is, cognition, locomotion, vitality, psychological, and/or sensory functions, with sex-specific differences reported. Only a few studies used the multidimensional concept of intrinsic capacity as an outcome. This review supports that a healthy diet for older adults consists of plenty of plant-based foods, adequate protein-rich foods, and healthy fats. Next to quantity, improving the quality and variety within food groups play a role in optimizing health. Data on the associations between adherence to national food-based dietary guidelines and intrinsic capacity are scarce.

SUMMARY

A healthy diet, centered on plant-based foods, adequate protein-rich foods and healthy fats, potentially promotes healthy aging. Future studies may evaluate the association between adherence to healthy dietary patterns (particularly national food-based dietary guidelines) and the multidimensional concept of intrinsic capacity, with consideration of sex-specific differences. Clinical trials are warranted to inform the causal effects of diet and outcomes related to intrinsic capacity.

Resilience-happiness nexus in community-dwelling middle-aged and older adults: Results from Gan-Dau Healthy Longevity Plan

The core of healthy aging is intrinsic capacity (IC) that consists of major elements, i.e., cognition, locomotion, vitality, sensory capacity, and psychological aspect. This cross-sectional study analyzes data of the Gan-Dau Healthy Longevity Plan, targeting community-dwelling adults aged 50 years or older. The participants completed the assessment, in addition to WHO IC, including the Mini-Mental Status Examination (MMSE) for cognitive performance, 6 m walking speed (m/s),timed up-and-go test (s) and hand grip strength (Kg) for locomotor assessment, Cardiovascular health study (CHS) for frailty assessment, Mini Nutrition assessment short form (MNA-SF) for nutrition. Psychological aspect including the Pittsburgh Sleep Quality Index (PSQI) for sleep quality, the Geriatric Depression Scale-5 (GDS-5) for depressive symptoms, the Brief Resilience Scale (BRS) for resilience, and the Chinese Happiness Inventory (CHI) for happiness levels. The study enrolled 810 participants (mean age of 68.45 ± 8.05 years, 32% male) and revealed that 94.7% of participants exhibited impairments in IC, with visual capacity and cognition being the most common deficit items of IC. Resilience levels varied, with 37.4% of men and 33.5% of women exhibiting moderate to low resilience. Only 23.4% of male participants and 21.1% female participants reported a high level of happiness. Resilience was found to partially mediate the relationship between intrinsic capacity and happiness, with approximately 6.6% of the variance in happiness being mediated by resilience. In conclusion, the study provides valuable insights into the connections between psychological aspect, IC, and healthy aging.