Background: Diabetes prevalence is increasing in the population, both in the young and the elderly. We assessed the impact of increasing prevalence of diabetes on admissions for acute myocardial infarctions(MI) from 1990 through 1997. Methods and results: We retrospectively identified all patients discharged with the primary diagnosis of MI from any Veteran’ s Affairs Medical Center(VAMC) in the country between October 1990 and September 1997. Patients were classified as having diabetes from the ICD-9-CM codes and stratified by age. Demographic data were extracted from the patient treatment files. Prevalence of diabetes among MI patients for the years 1990 through 1997 was compared to that in the general population obtained from the Center for Disease Control. We identified 67,889 patients with MI of whom 17,756(26% ) had diabetes. In the age group ≤ 44 years, the prevalence of diabetes remained at approximately 11.5% from 1991 to 1998. In the age group 45-64 years, the increase was from 23% to 28% -a 23% increase(p< 0.001), while in the older age group over 65 years, it increased from 25% to 33.5% -a 34% increase(p< 0.001). In the general population, prevalence of diabetes increased by 50% , 63% and 44% in the three age groups. Conclusions: Despite substantial increase in prevalence of diabetes among the younger population, it does not appear to be predisposing them to increased risk for MI. The prevalence of diabetes among older patients with MI paralleled the increase seen in the general population with the steepest increase seen in the group ≥ 65 years. These data are important in focusing our resources for preventive measures. We assessed the impact of increasing prevalence of diabetes on admissions for acute myocardial infarctions (MI) from 1990 through 1997. Methods and results: We retrospectively identify all patients discharged with the primary diagnosis of MI from any Veteran’s Affairs Medical Center (VAMC) in the country between October 1990 and September 1997. Patients were classified as having diabetes from the ICD-9-CM codes and stratified by age. Demographic data were Prevalence of diabetes among MI patients for the years 1990 through 1997 was compared to that in the general population obtained from the Center for Disease Control. We identified 67,889 patients with MI of whom 17,756 (26%) had diabetes In the age group ≤ 44 years, the prevalence of diabetes remained at about 11.5% from 1991 to 1998. In the age group 45-64 years, the increase was from 23% to 28% -a 23% increase (p <0.001), while in the older age group over 65 years, it increased from 25% to 33.5% -a 34% increase (p <0.001). In the general population , prevalence of diabetes increased by 50%, 63% and 44% in the three age groups. Conclusions: Despite substantial increase in prevalence of diabetes among the younger population, it does not appear to be predisposing them to increased risk for MI. The prevalence of diabetes among older patients with MI paralleled the increase seen in the general population with the steepest increase seen in the group ≥ 65 years. These data are important in focusing our resources for preventive measures.