Combining fasting plasma glucose and glycosylated hemoglobin improved the accuracy for detecting patients with diabetes.

D e s c r i p t i o n o f t e s t s a n d d i a g n o s t i c s t a n d a r d FPG and 2-hour post–glucose-load (i.e., after ingestion of 75 g of oral glucose) plasma glucose were measured using enzymatic methods with a hexokinase reference. HbA1c was analyzed using high-performance liquid chromatography. The 1998 WHO diagnostic criteria were used as the “gold standard” to classify the participants into 3 categories: normal (FPG < 7.0 mmol/L and a 2-h glucose < 7.8 mmol/L), IGT (FPG < 7.0 mmol/L and a 2-h glucose 7.8 to 11.0 mmol/L), or diabetic (FPG ≥ 7.0 mmol/L or a 2-hour glucose ≥ 11.1 mmol/L). The American Diabetes Association criteria were also applied, and participants were classified into the 3 categories: normal (FPG < 6.1 mmol/L), impaired fasting glucose (FPG 6.1 to 6.9 mmol/L), or diabetic (FPG ≥ 7.0 mmol/L).