Comparison of the Effect of Plasma Glucose Concentrations on Microvascular Disease Between Pima Indian Youths and Adults

Abstract

OBJECTIVE—To examine whether the current adult guidelines for diagnosis of diabetes are applicable to youth (age <20 years). RESEARCH DESIGN AND METHODS—We analyzed fasting plasma glucose (FPG) and 2-h plasma glucose (PG) in two groups of Pima Indians, youths aged 5–19 years and adults aged 20–34 years, in relation to the incidence of microvascular disease when subjects were reexamined at ages 25–39 (youths) and 40–54 (adults). Microvascular disease was defined as retinopathy or a urine protein-to-creatinine ratio ≥0.5 g. RESULTS—An increase in the incidence of microvascular disease occurred at nearly the same level of glycemia in both groups. For youths, this increase occurred at FPG ∼7.3 mmol/l and 2-h PG ∼10.0 mmol/l; for adults, this increase occurred at FPG ∼7.5 mmol/l and 2-h PG ∼10.3 mmol/l. Sensitivity of the adult diagnostic guidelines of FPG ≥7.0 mmol/l and 2-h PG ≥11.1 mmol/l for the detection of microvascular disease was much lower (with higher specificity) in youths than in adults. Receiver operating characteristics (ROC) curve areas were lower for FPG and 2-h PG for youths, suggesting that microvascular disease was less strongly predicted by baseline glucose. CONCLUSION—The current adult guidelines for diagnosis of diabetes are applicable to youth, as they identify a population at high risk of microvascular complications.