Frequency of abnormal carbohydrate metabolism and diabetes in a population-based screening of adolescents.

Objective: To document the frequency of glucose intolerance in adolescents in a population-based study of primarily African-American/Non-Hispanic whites in an urban-suburban school district.

Study Design: Measurement of fasting and 2-hour post-glucose load plasma glucose concentrations.

Results: Carbohydrate intolerance (either impaired fasting glucose, impaired glucose tolerance, or both) was identified in 8.0%, near-diabetes (1 fasting glucose > or = 126 mg/dL [7.0 mmol/L] and/or 2-hour glucose > or = 200 mg/dL [11.1 mmol/L]) in 0.3%, and diabetes in 0.36% (type 1A = 0.24%; type 2 = 0.08%; undiagnosed type 2 = 0.04%). A model for abnormal carbohydrate metabolism was constructed with regression analysis in the Carbohydrate Intolerance (CI)/near-diabetes group and with logistic regression in the entire study population. Risk factors for the development of CI/near-diabetes included having a 1 unit increase in body mass index (BMI) z-score and either being non-Hispanic white or in the pubertal group. Increased fasting glucose correlated with having puberty and decreased BMI z-score, whereas 2-hour glucose correlated with increased BMI z-score. By using National Health and Nutrition Survey (NHANES) III (1988-1994) definitions, impaired fasting glucose was present in 2.0% in this study versus 1.7% (NHANES III).

Conclusion: The prevalence of CI/near-diabetes was 8.3%. Undiagnosed diabetes mellitus was rare. One third of adolescents with diabetes mellitus could be classified as having type 2 diabetes mellitus. The adult model of the progression of insulin resistance to type 2 diabetes mellitus in adolescents may be valid. Despite the increase in the overweight population since NHANES III, abnormalities in glucose metabolism have not changed significantly.