Dose-Responsive Impacts of Social Frailty on Intrinsic Capacity and Healthy Aging among Community-Dwelling Middle-aged and Older Adults: Stronger Roles of Social Determinants over Biomarkers.

OBJECTIVE: The intricate relationship between social determinants, e.g., social frailty, biomarkers and healthy aging remains largely unexplored, despite the potential for social frailty to impact both intrinsic capacity (IC) and functional ability in the aging process. DESIGN: Retrospective longitudinal cohort study. SETTING AND PARTICIPANTS: Participants aged 50+ years from the Social Environment and Biomarkers of Aging Study (SEBAS) in Taiwan, stratified into three age groups: 50-64, 65-74 and 75+. MEASUREMENTS: Social frailty was defined based on a score derived from four domains: exclusion from general resources, social resources, social activity, and fulfillment of basic social needs. The scores were categorized as score=0 (no social frailty), 1 (social pre-frailty), and 2+ (social frailty). Multivariable logistic regression and Cox proportional hazard models were employed to examine the dose-responsive relationship between social frailty, low IC, functional and psychological health, and mortality. RESULTS: Of 1015 study participants, 24.9% and 7.9% were classified as social pre-frailty and social frailty, respectively. No significant differences were observed in most biomarkers between those with social frailty and those without. A dose-responsive relationship was found between social frailty and increased risk of low IC (social pre-frailty: aOR 2.20 [95% CI 1.59-3.04]; social frailty: 5.73 [3.39-9.69]). Similar results were found for functional and psychological health. However, no significant association between social frailty and all-cause mortality was found at the 4-year follow-up (social pre-frailty: aHR 1.52 [95% CI 0.94-2.43]; social frailty: 1.59 [0.81-3.09]). CONCLUSIONS: The significant association between social frailty and low IC, functional limitations, cognitive declines, and depressive symptoms underscores the pressing need for research on intervention strategies to enhance healthy aging in the lifespan course.

Roles of Baseline Intrinsic Capacity and its Subdomains on the Overall Efficacy of Multidomain Intervention in Promoting Healthy Aging among Community-Dwelling Older Adults: Analysis from a Nationwide Cluster-Randomized Controlled Trial.

BACKGROUND: Impaired intrinsic capacity (IC), which affects approximately 90% of older adults, is associated with a significantly heightened risk of frailty and cognitive decline. Existing evidence suggests that multidomain interventions have the potential to enhance cognitive performance and yield positive effects on physical frailty. OBJECTIVE: To examine roles of baseline IC and its subdomains on the efficacy of multidomain interventions in promoting healthy aging in older adults. DESIGN: a cluster-randomized controlled trial. SETTING AND PARTICIPANTS: 1,054 community-dwelling older adults from 40 community-based clusters across Taiwan. INTERVENTION: A 12-month pragmatic multidomain intervention of exercise, cognitive training, nutritional counseling and chronic condition management. MEASUREMENTS: Baseline IC was measured by 5 subdomains, including cognition (Montreal Cognitive Assessment, MoCA), sensory (visual and hearing impairment), vitality (handgrip strength or Mini-Nutritional Assessment-short form), psychological well-being (Geriatric Depression Scale-5), and locomotion (6m gait speed). Outcomes of interest were cognitive performance (MoCA scores) and physical frailty (CHS frailty score) over a follow-up period of 6 and 12 months. RESULTS: Of all participants (mean age:75.1±6.4 years, 68.6% female), about 90% participants had IC impairment at baseline (2.0±1.2 subdomains). After covariate adjustment using a generalized linear mixed model (GLMM), the multidomain intervention significantly prevented cognitive declines and physical frailty, particularly in those with IC impairment ≥ 3 subdomains (MoCA: coefficient: 1.909, 95% CI: 0.736 ~ 3.083; CHS frailty scores: coefficient = -0.405, 95% CI: -0.715 ~ -0.095). To assess the associations between baseline poor capacity in each IC subdomain and MoCA/CHS frailty scores over follow-up, a 3-way interaction terms (time*intervention*each poorer IC subdomains) were added to GLMM models. Significant improvements in MoCA scores were shown for participants with poorer baseline cognition (coefficient= 1.138, 95% CI: 0.080 ~ 2.195) and vitality domains (coefficient= 1.651, 95% CI: 0.541 ~ 2.760). The poor vitality domain also had a significant modulating effect on the reduction of CHS frailty score after the 6- and 12-month intervention period (6 months: coefficient= -0.311, 95% CI: -0.554 ~ -0.068; 12 months: coefficient= -0.257, 95% CI: -0.513 ~ -0.001). CONCLUSION AND IMPLICATIONS: A multidomain intervention in community-dwelling older adults improves cognitive decline and physical frailty, with its effectiveness influenced by baseline IC, highlighting the importance of personalized strategies for healthy aging.