Three-year prevalence and incidence of diabetes among American Indian youth in Montana and Wyoming, 1999 to 2001

Objectives To estimate the prevalence and incidence of type 2 diabetes among American Indian youth. Study design Medical records were reviewed annually for all patients with diabetes who were <20 years of age at 6 Indian Health Service facilities in Montana and Wyoming. All cases :5 5 years of age or weight per age less than or equal to10th percentile at diagnosis or with islet cell antibodies were considered as probable type 1. Among the remaining cases, probable type 2 diabetes was defined when a child had one or more of the following characterisitics: weight per age greater than or equal to95th. percentile or acanthosis nigricans at diagnosis, elevated,C-peptide or insulin, family history of type 2 diabetes; treatment with oral agents with or without insulin or no hypoglycemic therapy after 1 year of follow-up. Results From 1999 to 2001, 53% of prevalent cases and 70% of incident. cases were categorized as probable type 2 diabetes. The average annual prevalence of probable type 1 and type 2 diabetes was 0.7 and 1.3 per 1000. The average annual incidence rates for probable type 1, and type 2 diabetes were 5.8, 23.3 per 100,000. Conclusions The incidence of probable type 2 diabetes was approximately 4 times higher than type I diabetes among American Indian youth in Montana and Wyoming.