Differential associations of novel metaflammation indices with incident stroke across traditional Chinese medicine constitutions: a retrospective community-based cohort study of older adults.

Objective: To examine associations between novel metaflammation indices (LHR, MHR, NHR, PHR) and first stroke risk in community-dwelling older adults, and assess their differences across Traditional Chinese medicine (TCM) constitution types. Methods: A retrospective cohort study included 2,999 stroke-free adults (≥65 years) followed for 4 years. Data were collected through standardized questionnaires, physical examinations, and blood tests. Multivariable Cox proportional hazards models were used to evaluate the associations between these indices and incident stroke. Stratified analyses were conducted according to TCM constitution types. Results: During the follow-up period, 36 incident stroke cases were recorded. After multivariable adjustment, LHR (HR = 1.68, 95% CI: 1.09-2.61) and PHR (HR = 1.01, 95% CI: 1.00-1.01) were significantly positively associated with stroke risk in the overall population. Individuals with high-risk biased constitutions had a significantly elevated stroke risk (HR = 3.42, 95% CI: 1.32-8.80). Stratified analysis suggested that the associations of LHR and PHR with stroke were statistically significant in the balanced constitution and low-risk biased constitution subgroups, but not in the high-risk biased constitution subgroup. However, no significant interaction was observed. Conclusion: LHR and PHR may be associated with incident stroke in community-dwelling older adults, and their associations may vary across TCM constitution types. Therefore, integrating traditional risk factors, metaflammation indices, and TCM constitution identification might contribute to developing a more refined and personalized stroke risk assessment strategy. However, no significant interaction was observed, indicating that these variations should be interpreted cautiously and require further validation.