The Minneapolis Childhood Cohort Studies (MPLS) began in 1977 with school screenings for high blood pressure in 10,423 children aged 6 to 8 years. A total of 1207 were stratified by race and sex for long-term evaluation. A second cohort was started in 1985 with screening of 19,452, aged 11–14 years, with 283 entered into a clinical trial to compare the relation of sodium vs. potassium to BP. The third cohort began in 1995 with school screening of 12,000 youth aged 10–14 years. A randomly selected sample of these students and their siblings was recruited for repeated measures of CV risk factors and insulin clamp studies. The major findings of these studies relate to the influence of insulin resistance, measured accurately with the gold-standard euglycemic insulin clamp, on BP and other CV risk factors. This cohort has also contributed data relating measures of adiposity and IR to cardiac and vascular target organ injury. Finally, as part of the International CV Cohort Consortium, these data contributed to the finding that CV risk factors measured in youth significantly predict CV events over 40 years later.