Brain-derived neurotrophic factor (BDNF) is a key indicator in the brain-muscle axis. This study aimed to investigate the association of plasma BDNF and intrinsic capacity (IC) in older people, and to examine the mediating role of inflammation and oxidative stress. This cross-sectional study included 658 community-dwelling older adults (70.38 ± 6.06 years, 59.42% female). Intrinsic capacity including five domains was evaluated according to the World Health Organization recommendation. Plasma BDNF, high sensitivity C-reactive protein (hs-CRP), Interleukin-6 (IL-6), Tumor necrosis factor-alpha (TNF-a), Interleukin-1 beta (IL-1β), Malondialdehyde (MDA), Superoxide dismutase (SOD), Glutathione peroxidase (GSH-Px), and Glutathione reductase (GR)were measured by enzyme-linked immunosorbent assay methods. Restricted cubic spline and multivariate logistic regression were conducted to explore the association of BDNF with IC impairment. Mediation analyses were used to explore the potential mechanisms. Demographic characteristics, health behaviors, and comorbidities were included as covariates. 247(37.54%) participants had IC impairment. Older individuals with impaired IC had lower levels of BDNF, IL-1β, SOD, and GR, while showed higher levels of hs-CRP and MDA compared to the normal group. There was an L-shaped negative correlation between BDNF levels and the odds of IC impairment (P-nonlinear <0.001). After adjusting for all confounders, the odds for IC impairment in the medium and high BDNF tertiles were significantly lower than in the low BDNF tertile, with ORs of 0.43(95% CI: 0.26-0.89, P = 0.004) and 0.38(95% CI: 0.20-0.71, P = 0.007), respectively. Plasma SOD and GR mediated 4.13% (95% CI: 1.15, 7.16) and 7.82% (95% CI: 3.24, 12.48) of the total effect of BDNF on IC. High levels of circulatory BDNF may be related to lower odds of IC impairment. Oxidative stress status partially explains the mechanisms underlying the association.

Background and Objectives: Early detection of mild cognitive impairment (MCI) is vital for managing cognitive decline in older adults. Hand movements are closely linked to cognitive function, prompting this study to develop a virtual reality (VR)-based wearable system to capture detailed hand movements. The main goal was to assess the system’s potential in predicting cognitive health and aiding MCI diagnosis. Research Design and Methods: The study involved 607 participants aged 60–84 (mean age 67.41 ± 4.71 years). Each completed four VR tasks while wearing the system, which recorded fine hand movement data. Cognitive function was assessed using the Beijing version of the Montreal Cognitive Assessment (MoCA-BJ). Statistical analyses were conducted to correlate hand movement metrics with cognitive performance. Results: Participants with cognitive impairments performed worse on VR-based fine motor tasks. Metrics from tests like the Pegboard, Block Placement—Flipping, and Tapping Tests were predictive of cognitive abilities. Indicators related to finer movements and non-dominant (left) hand use showed superior predictive power, achieving an AUC of 0.687 for predicting MCI, comparable to machine learning models such as Random Forest (0.762) and SVM (0.644). Discussion and Implications: Hand movement data can provide valuable insights into cognitive function in older adults, highlighting the importance of fine motor skills in early MCI detection. This VR-based system could serve as a useful clinical tool for assessing cognitive health and supporting MCI diagnosis, enabling timely intervention strategies for cognitive decline.

Background: Intrinsic capacity (IC), as a potential proxy for healthy aging, guidance on framing the concept is limited. Furthermore, research on the relationship between IC and catastrophic health expenditure (CHE) is scarce. The current study aims to construct a validated IC framework using structural equation modeling (SEM) and examine such an association among older adults in China. Methods: Using a 4-year prospective observational study, we enrolled 5 427 participants from Wave 1 and Wave 3 in the China Health and Retirement Longitudinal Study for analysis. The SEM was used to construct IC score, and assessed its association with medical and financial burdens by using negative binomial regression and logistic mixed-effects models, where financial burden was defined as CHE according to the World Bank definitions. Results: The SEM results showed a clear 5-subfactor structure for IC. After adjustment for potential confounders, the populations with poor and moderate IC had 1.927 times (95% confidence intervals [95% CIs]: 1.559–2.382) and 1.548 times (95% CI: 1.281–1.872) higher risk for inpatient visits in comparison with the group showing high IC, respectively, and also experiencing 2.163 times (95% CI: 1.674–2.795) and 1.687 times (95% CI: 1.347–2.112) risk for CHE, respectively. Conclusions: Our analysis with both cross-sectional and longitudinal representative national data provided an extensive picture of the adverse effects of IC loss, demonstrating that a favorable IC is important to reduce medical and financial burden. IC is applicable to more widely as a usual clinical assessment tool to reduce effectively health burden.