Differential interplay between multimorbidity patterns and frailty and their mutual mediation effect on mortality in old age

• Published in: The Journal of nutrition, health & aging health & aging, 2024-08, Vol.28 (8), p.100305, Article 100305
• Main Authors: She, Rui, Vetrano, Davide Liborio, Leung, Maria Kwan Wa, Jiang, Hui, Qiu, Chengxuan
• Format: Article
• Language: English
• Subjects: Bidirectional association; Death; Frailty; Multimorbidity; Population-based study
• ISSN: 1279-7707; 1760-4788; 1760-4788
• DOI: 10.1016/j.jnha.2024.100305

•This study revealed a significant bidirectional association between multimorbidity, measured as the number of chronic diseases, and frailty among a nationally representative sample of 16,563 older adults in China.•Different multimorbidity patterns exhibited varying associations with frailty, with the cognitive-sensory disease pattern showing a stronger reciprocal association with frailty.•Multimorbidity and frailty were associated with an increased risk of mortality directly and indirectly via each other’s mediation effect, with frailty acting as a more prominent pathway in the association between multimorbidity and mortality. Multimorbidity and frailty often concurrently occur among older adults. To assess the reciprocal association between multimorbidity (condition count and patterns) and frailty and examine the mutual mediation effect of multimorbidity and frailty in their associations with mortality among Chinese older adults. This nationwide population-based longitudinal study included 16,563 participants aged ≥65 years in the Chinese Longitudinal Healthy Longevity Survey who were surveyed in 2008 and followed up in 2011, 2014, and 2018. Frailty phenotype was assessed by the modified Fried criteria and vital status was ascertained from family members. Cross-lagged panel model (CLPM) was used to test bidirectional associations between multimorbidity and frailty. The direct and indirect effects of multimorbidity and frailty on mortality were evaluated using the combined CLPM with survival analysis. Three multimorbidity patterns were identified: cardiometabolic diseases, cognitive-sensory disorder, and arthritis-digestive-respiratory diseases. The number of chronic conditions and cognitive-sensory disease pattern showed bidirectional associations with frailty across waves (range for β: 0.046−0.109; all P