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Alzheimer's disease is strongly linked to metabolic abnormalities. We aimed to distinguish amyloid-positive people who progressed to cognitive decline from those who remained cognitively intact. We performed untargeted metabolomics of blood samples from amyloid-positive individuals, before any sign of cognitive decline, to distinguish individuals who progressed to cognitive decline from those who remained cognitively intact. A plasma-derived metabolite signature was developed from Supercritical Fluid chromatography coupled with high-resolution mass spectrometry (SFC-HRMS) and nuclear magnetic resonance (NMR) metabolomics. The 2 metabolomics data sets were analyzed by Data Integration Analysis for Biomarker discovery using Latent approaches for Omics studies (DIABLO), to identify a minimum set of metabolites that could describe cognitive decline status. NMR or SFC-HRMS data alone cannot predict cognitive decline. However, among the 320 metabolites identified, a statistical method that integrated the 2 data sets enabled the identification of a minimal signature of 9 metabolites (3-hydroxybutyrate, citrate, succinate, acetone, methionine, glucose, serine, sphingomyelin d18:1/C26:0 and triglyceride C48:3) with a statistically significant ability to predict cognitive decline more than 3 years before decline. This metabolic fingerprint obtained during this exploratory study may help to predict amyloid-positive individuals who will develop cognitive decline. Due to the high prevalence of brain amyloid-positivity in older adults, identifying adults who will have cognitive decline will enable the development of personalized and early interventions. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: In previous studies, plasma neurofilament light chain (NfL) and progranulin (PGRN) levels are associated with cognitive and physical impairment in older individuals. However, evidence of their relationships with frailty is lacking. This study aims to explore the associations of plasma NfL and PGRN levels with frailty in community‐dwelling older adults. Methods: We included 507 older adults (mean [standard deviation] age, 76.7 [4.5] years) with plasma NfL and PGRN measurements from the Multidomain Alzheimer Preventive Trial (MAPT). The timepoint of biomarker measurements, either 12 or 24 months after study enrollment, was defined as the baseline for each participant. Frailty phenotype (robust, pre‐frail, and frail) was assessed at 12, 24, 36, 48, and 60 months by Fried's frailty criteria. The cross‐sectional associations between plasma neurodegenerative biomarkers and frailty severity were examined using logistic regressions. We further used Cox proportional hazard models to evaluate the associations between plasma biomarkers and incident frailty among robust or pre‐frail participants at baseline (n = 403). Results: At baseline, participants with high plasma NfL levels (>93.11 pg/ml [the upper quartile]) had a higher likelihood of pre‐frailty or frailty compared to their normal NfL counterparts (odds ratio = 1.68; 95% confidence interval = 1.10–2.57); however, this association did not remain significant after controlling for covariates. Neither NfL nor PGRN levels showed prospective associations with incident frailty over 4 years. Conclusions: This study failed to find associations of circulating NfL and PGRN levels with frailty among community‐dwelling older adults in adjusted analyses. Whether plasma neurodegenerative markers serve as potential biomarkers of frailty requires further investigation. [ABSTRACT FROM AUTHOR]

Background: This study aims to investigate the predictive value of biological and neuroimaging markers to determine incident frailty among older people for a period of 5 years.Methods: We included 1394 adults aged 70 years and older from the Multidomain Alzheimer Preventive Trial, who were not frail at baseline (according to Fried's criteria) and who had at least 1 post-baseline measurement of frailty. Participants who progressed to frailty during the 5-year follow-up were categorized as "incident frailty" and those who remained non-frail were categorized as "without frailty." The differences of baseline biochemical factors (25-hydroxyvitamin D, homocysteine, omega-3 index, C-reactive protein), other biological markers (Apolipoprotein E genotypes, amyloid-β deposits), and neuroimaging data (gray matter volume, hippocampal volume, white matter hyperintensities) were compared between groups. Cox proportional hazard model was used to evaluate the associations between biomarkers and incident frailty.Results: A total of 195 participants (14.0%) became frail over 5 years. Although 25-hydroxyvitamin D deficiency, homocysteine levels, low-grade inflammation (persistently increased C-reactive protein 3-10 mg/L), gray matter, and hippocampal volume were significantly associated with incident frailty in unadjusted models, these associations disappeared after adjustment for age, sex, and other confounders. Omega-3 index was the sole marker that presented a trend of association with incident frailty (hazard ratio: 0.92; 95% confidence interval: 0.83-1.01; p = .082).Conclusions: This study failed to identify biomarkers able to predict frailty incidence in community-dwelling older adults for a period of 5 years. Further longitudinal research with multiple measurements of biomarkers and frailty is needed to evaluate the long-term relationships between changes in biomarkers levels and frailty evolution. [ABSTRACT FROM AUTHOR]

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 I 2 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 (I 2 =18·4%), though within-study (I 2 =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., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

The existence of intrinsic capacity (IC) subtypes and their distinct impacts on age-related outcomes remain unexplored. This study sought to investigate IC impairment trajectories across domains and their associations with the risk of age-related outcomes, including falls, functional limitations, reduced quality of life (QoL) and mortality at 4- and 8-year follow-ups. The study sample comprised 1,782 older adults residing in the community from the Taiwan Longitudinal Study on Ageing (TLSA). Utilizing group-based multitrajectory modeling, distinct subtypes of IC decline trajectories across various domains were identified. Cox proportional hazard models and multivariable logistic regression analyses were employed to assess the associations between the identified subtypes and age-related outcomes. We identified four subtypes of IC decline: robust with mild decline (n=902), hearing loss with cognitive decline (n=197), physio-cognitive decline (PCD) with depression (n=373), and severe IC decline (n=310). Over the 4-year study period, compared to the robust with mild decline group, hearing loss with cognitive decline group exhibited a significantly higher risk of diminished QoL (OR=2.53 [1.66-3.86], p<0.01), whereas those in the PCD with depression group experienced an elevated risk of falls (OR=1.62 [1.18-2.23], p<0.01), as well as functional limitation (OR=2.61 [1.81-3.75], p<.01). Individuals in the severe IC decline group faced a substantially increased risk of all outcomes of interest. Distinct subtypes of IC decline across different domains have varying impacts on age-related outcomes, highlighting the need for a personalized approach to promote healthy ageing at the population level, while further investigation into specific pathophysiological mechanisms is warranted as well.