Multimorbidity was significantly associated with intrinsic capacity decline (total effect β=0.211; 95% CI 0.123-0.300; P<0.001), with frailty mediating 27.5% of this relationship.
Cross-Sectional (n=468)
Does frailty mediate the association between multimorbidity and intrinsic capacity decline in older adults?
Frailty partially mediates the relationship between multimorbidity and intrinsic capacity decline in older adults, highlighting the need for integrated management of both conditions.
Effect estimate: β 0.211 (95% CI 0.123-0.300)
p-value: p=<0.001
BACKGROUND: Intrinsic capacity (IC) proposed by the World Health Organization (WHO) is the core indicator of healthy aging, directly affecting functional ability and quality of life in older adults. Both multimorbidity and frailty are linked to poor health outcomes. Although pairwise associations between these factors have been examined, their comprehensive interrelationship remains unexplored. This study aims to explore the mediating role of frailty in the association between multimorbidity and IC decline. METHODS: This population-based cross-sectional study included 468 individuals from community settings and nursing homes in Lianyungang city, Jiangsu Province (the WHO ICOPE Pilot in China). Age, gender, education, marital status, and nursing home residence were assessed at baseline. Multimorbidity was assessed based on clinical experience, the Charlson Comorbidity Index (CCI) and the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). Frailty was evaluated using the FRAIL scale. IC was measured using the WHO ICOPE screening tool (including assessments of cognitive function, motor function, nutritional status, sensory ability, and depressive symptoms). Binary logistic regression was employed to calculate the associations between multimorbidity, frailty, and IC decline. Mediation analysis was conducted to explore the mediating role of frailty in the multimorbidity-IC decline relationship. RESULTS: After adjusting for all covariates (age, gender, marital status, education level and residence in community or nursing home), multimorbidity was found to be positively correlated with IC decline. Subjects with ≥ 3 multimorbidity exhibited a 1.6-fold higher risk of IC impairment than those without multimorbidity. Subgroup analyses revealed that the multimorbidity and IC decline relationship was robust. The direct effect of multimorbidity on IC decline was significant (β = 0.154, 95% CI: 0.064, 0.243, p < 0.001). Frailty significantly mediated the relationship between multimorbidity and IC decline (β = 0.058, 95% CI: 0.029, 0.092, p < 0.001; mediation proportion: 27.5%). The total effect of multimorbidity on IC decline was also significant (β = 0.211, 95% CI: 0.123, 0.300, p < 0.001). CONCLUSIONS: This study first found frailty as partially mediating the multimorbidity-IC decline relationship, explaining 27.5% of the effect. The results underscore the necessity of integrated multimorbidity and frailty management to prevent and delay IC decline in older adults.
Xiao et al. (2025) conducted a cross-sectional in Intrinsic capacity decline (n=468). Multimorbidity vs. No multimorbidity was evaluated on Intrinsic capacity (IC) decline (β 0.211, 95% CI 0.123-0.300, p=<0.001). Multimorbidity was significantly associated with intrinsic capacity decline (total effect β=0.211; 95% CI 0.123-0.300; P<0.001), with frailty mediating 27.5% of this relationship.