Onset of type 2 diabetes before age 20 in a population of American Indians is associated with a substantially increased risk of end-stage kidney disease and death between 25 and 55 years of age, according to a study in the July 26 issue of JAMA.

The current increase in obesity prevalence in children and adolescents in many parts of the world has led to an increasing prevalence of type 2 diabetes mellitus in these age groups, according to background information in the article. The long-term outcome of persons with youth-onset type 2 diabetes mellitus is not clear.

Meda E. Pavkov, M.D., Ph.D., of the National Institutes of Health, and colleagues examined the impact of age at onset of type 2 diabetes mellitus on the incidence of end-stage renal disease (ESRD) and on natural causes of death in young and middle-aged American Indians. Type 2 diabetes has been increasingly diagnosed in children and adolescents and kidney disease is a major complication of diabetes mellitus in this population.

Participants in the study, conducted between 1965 and 2002, were divided into 2 groups: (1) youth-onset type 2 diabetes mellitus (onset at less than 20 years of age ) and; (2) older-onset type 2 diabetes mellitus (onset between 20 - 55 years of age).

Among the 1,856 diabetic participants, 96 had youth-onset type 2 diabetes mellitus. The researchers found that the sex-adjusted incidence rate of ESRD in youth-onset diabetes mellitus was 25 cases per 1,000 person-years; this rate was 8.4 times as high as in older-onset diabetes mellitus for ages 25 to 34 years, 5.0 times as high for ages 35 to 44 years, and 4.0 times as high for ages 45 to 54 years.

The age-sex - adjusted death rate in participants with youth-onset diabetes mellitus was 15.4 deaths per 1,000 person-years, which was 3.0 times as high as in nondiabetic participants and 2.1 times as high as in individuals with older-onset diabetes mellitus. The death rate in individuals with older-onset diabetes mellitus was 1.4 times as high as in the nondiabetic participants.

“The longer duration of diabetes mellitus by middle age in individuals diagnosed younger than age 20 years largely accounts for these outcomes,” the authors write.

“Because youth-onset diabetes mellitus leads to substantially increased complication rates and mortality in middle age, efforts should focus on preventing or delaying the onset of diabetes, delaying the onset of diabetic nephropathy, or both,” the researchers conclude.

(JAMA. 2006;296:421-426. Available pre-embargo to the media at http://www.jamamedia.org)