RT Journal Article SR Electronic T1 Changes in Age at Diagnosis of Type 2 Diabetes Mellitus in the United States, 1988 to 2000 JF The Annals of Family Medicine JO Ann Fam Med FD American Academy of Family Physicians SP 60 OP 63 DO 10.1370/afm.214 VO 3 IS 1 A1 Richelle J. Koopman A1 Arch G. Mainous III A1 Vanessa A. Diaz A1 Mark E. Geesey YR 2005 UL http://www.annfammed.org/content/3/1/60.abstract AB PURPOSE The prevalence of diabetes in the United States is increasing. There is also concern that diabetes may be occurring at a greater frequency in youth and in young adults. We describe US population trends in self-reported age at diagnosis of type 2 diabetes mellitus. METHODS We undertook a secondary analysis of data from the National Health and Nutrition Examination Survey (NHANES) 1999–2000 and NHANES III (1988–1994). Both surveys are stratified, multistage probability samples targeting the civilian, noninstitutionalized US population, which allow calculation of population estimates. We included adults aged 20 years and older. We compared self-reported age at diagnosis of type 2 diabetes between the 2 survey periods. RESULTS The mean age at diagnosis decreased from 52.0 to 46.0 years (P <.05). Racial and ethnic differences in age at diagnosis found in 1988 to 1994 are no longer found in 1999 to 2000. CONCLUSIONS The age at diagnosis of type 2 diabetes mellitus has decreased with time. This finding likely represents a combination of changing diagnostic criteria, improved physician recognition of diabetes, and increased public awareness. Younger age at diagnosis may also reflect a true population trend of earlier onset of type 2 diabetes.