ObjectiveHigh-normal albuminuria has recently been associated with an elevated risk of cardiovascular disease. However, it is uncertain whether high-normal albuminuria is associated with metabolic syndrome (MetS). The objective of this prospective cohort study was to investigate whether a temporal relationship exists between a high-normal urine albumin-to-creatinine ratio (UACR) and the development of MetS. Study designA total of 4338 healthy Korean men who had their UACRs and MetS components assessed in 2005 were enrolled in the study. A MetS-free cohort of 1364 individuals, who did not have any conditions that would have excluded them from the study, was followed up until 2010. Main outcome measureMetS was defined according to the joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention. ResultsCox proportional hazards models were used to estimate the hazard ratio (HR) associated with normal UACR values stratified into following tertiles: <3.12μg/mg, ≥3.12, <4.87μg/mg, and ≥4.87μg/mg. The UACR was categorised into the following tertiles. During 4470.6 person-years of follow-up, 247 incident cases of MetS developed between 2006 and 2010. The third UACR tertile was associated with the development of MetS after adjusting for multiple baseline covariates (HR 1.57; 95% confidence interval: 1.14–2.18). ConclusionsOn the basis of our 5-year follow-up study, a high-normal UACR predicts the development of MetS in Korean men.