Background: Metabolic syndrome (MetS) is a key predictor of non-communicable diseases (NCDs) and mortality, causing public health challenge worldwide. This study aimed to estimate the incidence rates and to assess the risk factors of MetS among adults in a prospective cohort study.

Methods: This population-based cohort study was conducted on 10,009 adult individuals in southwest Iran. After applying the exclusion criteria to the baseline cohort, 1,781 at-risk individuals were eligible and included for follow-up. Incidence rates (IRs) of metabolic syndrome were calculated by dividing the number of new events during the follow-up period by the person-years at risk. The effects of various explanatory variables on these incidence rates were assessed using Poisson regression models.

Results: The overall incidence rate of metabolic syndrome (MetS) was 102.23 per 1,000 person-years, higher in females than males, and incidence was significantly associated with older age, female sex, marital status (married / divorced), higher BMI, history of cardiovascular disease, as well as abnormal FBS and elevated triglyceride levels (all p < 0.05). Conclusion: Targeted public health strategies and lifestyle interventions are crucial for reducing the incidence of metabolic syndrome, particularly among high-risk groups such as women, older adults, and individuals with a history of cardiovascular disease.