Chronic kidney disease coexists with metabolic syndrome and this relationship may be apparent before overt manifestations of cardiovascular disease. To investigate early stages of the natural history of associations between renal function and metabolic syndrome, we phenotyped 1572 young (mean age=18.4 years), apparently healthy men for metabolic risk factors and estimated their creatinine clearance based on the Cockcroft-Gault equation. High metabolic risk (clustering of at least three metabolic risk factors) was revealed in 8.7% (137) of the subjects and was associated with a 6.9-fold increase in the odds of glomerular hyperfiltration (95% confidence interval (CI): 3.9-11.5) when compared to reference (from none to two metabolic risk factors). Overweight, elevated blood pressure, and low high-density lipoprotein (HDL) cholesterol increased the multivariate-adjusted odds ratio of glomerular hyperfiltration to 6.6 (95% CI: 3.8-11.6), 1.8 (95% CI: 1.0-3.0), and 2.5 (95% CI: 1.5-4.3), respectively. Systolic and diastolic blood pressures clustered together with leptin in the factor analysis and this blood pressure-adiposity component correlated with estimated creatinine clearance (r=0.329, P<0.0001) and explained on its own 10.2% of the variance in the estimated renal function. Our data reveal the silent epidemics of metabolic risk among young, apparently healthy men. Furthermore, the results indicate that high metabolic risk is associated with glomerular hyperfiltration before overt manifestations of cardiovascular disease.