答案:Diabetes mellitus is diagnosed in one of four ways:1.classic symptoms plus2.a plasma glucose (PG) >= 11.1 mmol/L (200 mg/dL), 3.fasting (for at least 8 h) PG >=7.0 mmol/L (126 mg/dL), 4.2 h post load PG >=11.1 mmol/L (200 mg/dL) during an oral glucosetolerance test (OGTT), or hemoglobin A1c >=6.5%.