Primary Objectives: To measure the prevalence of undiagnosed Diabetes Mellitus (DM) and the annual incidence of new cases of DM among veterans between the ages of 45 and 64 and to compare the health-related quality of life (HRQoL) of veterans with undiagnosed DM to those without DM but who are at comparable risk for DM, both at baseline and over three years of follow-up.