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.