Body roundness index shows significant association with metabolic syndrome but constrained predictive ability for other CKM outcomes.

BackgroundThe accumulation of visceral fat is a pivotal factor in the development and progression of Cardiovascular-Kidney-Metabolic (CKM) Syndrome. The early identification of high-risk individuals is crucial for delaying disease progression. The body roundness index (BRI) is a novel measures for assessing visceral fat, but its association with CKM-related outcomes lacks comprehensive evidence.MethodsA comprehensive literature search was conducted to identify observational studies that examined the association between BRI and CKM-related outcomes. The search was performed in PubMed, Web of Science, and Embase, and updated to July 7, 2025. Effect sizes were pooled using a random-effects model, with heterogeneity and publication bias evaluated. Additionally, a diagnostic meta-analysis was performed to assess the discriminatory ability of BRI for specific metabolic risk factors.ResultsA total of 93 studies (involving 13 countries) were included. BRI was significantly associated with the risk of multiple CKM-related outcomes, but its strength varied by outcome and gender subgroup. For metabolic syndrome, BRI exhibited consistent risk associations in the overall population and gender subgroups, with good discriminatory ability in the diagnostic meta-analysis. However, its predictive ability for chronic kidney disease, cardiovascular disease, and mortality was relatively constrained.ConclusionWithin the CKM framework, a significant association between BRI and the risk of multiple CKM-related outcomes has been identified, with favorable risk assessment and discriminatory performance of BRI observed, especially for metabolic abnormalities. As a complementary tool to conventional anthropometric indices, BRI can provide incremental information to optimize the identification and risk stratification of CKM-related risks. Further definition of the long-term predictive value and clinical utility of BRI across diverse global populations is warranted through high-quality prospective cohort studies.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/, identifier CRD420251110973.