Prevalence of adult-onset IDDM in the U.S. population.

Abstract

To investigate the prevalence of adult-onset insulin-dependent diabetes mellitus (IDDM) in a nationally representative sample of adults 30-74 years of age. Although it is a widely held belief that onset of IDDM in adults is rare, there are few objective data to support this. Adult-onset IDDM may represent a disease that is biologically distinct from youth-onset IDDM, and it would be important to distinguish these two entities. The Second National Health and Nutrition Examination Survey (NHANES II) contained a national probability sample of 12,102 subjects 30-74 years of age in the U.S. population. All subjects with diabetes diagnosed by a physician before the survey were identified. Cases of IDDM defined by age at diagnosis > or = 30 years, continuous or nearly continuous insulin treatment since diagnosis of diabetes, and relative body weight < or = 125 were classified as adult-onset IDDM. Subjects with adult-onset IDDM represented 0.30% of the U.S. population 30-74 years of age and 7.4% of all diabetic patients diagnosed at 30-74 years of age. These data indicate that onset of IDDM in adults is uncommon. Given the limitations of the survey instrument, subclinical or slowly progressive IDDM (as distinguished from non-insulin-dependent diabetes mellitus with progressive loss of beta-cell function) would not have been detected, and these would constitute additional cases of adult-onset IDDM. However, the data suggest that a very large population base would be required to identify sufficient numbers of adult-onset IDDM cases for study of the etiology and pathogenesis of this disease.