Risk of Malignancies According to Trajectory Patterns of Metabolic Syndrome: Data From Korean National Health Insurance Service Data

Background: Because the components of metabolic syndrome (MetS) are modifiable, its status can change over time.We aimed to determine the impact of long-term MetS status, assessed using trajectory patterns, on the incidence of malignancies in a nationwide Korean cohort.Methods: We analyzed 465,180 adults aged over 20 years who had undergone at least three national health screening examinations.Group-based trajectory modeling identified six longitudinal patterns of MetS.Incidence rates of overall malignancies were compared across groups, and Cox proportional hazards models were used to estimate malignancy risk associated with each trajectory.Results: Six distinct MetS trajectories were identified: stable low-risk (51.9%), gradual risk increase (9.5%), fluctuating to final decline (15.5%), partial risk reduction (4.4%), accelerated risk progression (9.6%), and persistent high-risk (9.2%).During follow-up, 10,366 malignancies (2.23%) occurred, including 9,850 solid cancers and 516 hematologic malignancies.Compared with the stable low-risk group, incidence rate ratios (IRRs) for malignancies were significantly higher in the fluctuating to final decline (IRR, 1.34; 95% confidence interval [CI], 1.27-1.41),gradual risk increase (IRR, 1.16; 95% CI, 1.08-1.24),accelerated risk progression (IRR, 1.47; 95% CI, 1.38-1.56),partial risk reduction (IRR, 1.46; 95% CI, 1.34-1.60),and persistent high-risk (IRR, 1.84; 95% CI, 1.73-1.95)groups.In multivariable analyses, accelerated risk progression (HR, 1.13; 95% CI, 1.05-1.22)and persistent high-risk (HR, 1.20; 95% CI, 1.11-1.30)remained significantly associated with increased malignancy risk.Conclusion: Long-term low-risk MetS trajectory was associated with the lowest malignancy incidence.Sustained metabolic stability may contribute to reduced cancer risk.