Prevalence, Diagnosis, and Treatment of Impaired Fasting Glucose and Impaired Glucose Tolerance in Nondiabetic U.S. Adults

OBJECTIVE: To estimate the rates of prevalence, diagnosis, and treatment of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). RESEARCH DESIGN AND METHODS: A representative sample of the U.S. population (the National Health and Nutrition Examination Survey [NHANES]) from 2005–2006 including 1,547 nondiabetic adults (>18 years of age) without a history of myocardial infarction was assessed to determine the proportion of adults who met the criteria for IFG/IGT, and the proportion of IFG/IGT subjects who: 1) reported receiving a diagnosis from their physicians; 2) were prescribed lifestyle modification or an antihyperglycemic agent; and 3) were currently on therapy. We used multivariable regression analysis to identify predictors of diagnosis and treatment. RESULTS: Of the 1,547 subjects, 34.6% (CI 30.3–38.9%) had pre-diabetes; 19.4% had IFG only; 5.4% had IGT only, and 9.8% had both IFG and IGT. Only 4.8% of those with pre-diabetes reported having received a formal diagnosis from their physicians. No subjects with pre-diabetes received oral antihyperglycemics, and the rates of recommendation for exercise or diet were 31.7% and 33.5%, respectively. Among the 47.7% pre-diabetic subjects who exercised, 49.4% reported exercising for at least 30 min daily. CONCLUSIONS: Three years after a major clinical trial demonstrated that interventions could greatly reduce progression from IFG/IGT to type 2 diabetes, the majority of the U.S. population with IFG/IGT was undiagnosed and untreated with interventions. Whether this is due to physicians being unaware of the evidence, unconvinced by the evidence, or clinical inertia is unclear.