Table 1.

Overview of diagnostic criteria used in the included studies

Criteria used	Definitions
WHO	Fasting plasma glucose ≥7.0 mmol/L (126 mg/dL) or 2–h plasma glucose ≥11.1 mmol/L (200 mg/dL).
ADA	Fasting plasma glucose ≥126 mg/dL (7.0 mmol/L) or 2-hour plasma glucose ≥200 mg/dL (11.1 mmol/L) during OGTT (75 g) or A1C≥6.5% (48 mmol/mol) or Random plasma glucose ≥200 mg/dL (11.1 mmol/L)
NCEP cut-offs	Fasting plasma glucose ≥5.6 mmol/L
IDF	FPG≥100 mg/dl (5.6 mmol/L)

A1C, glycated haemoglobin; ADA, American diabetes association; IDF, International Diabetes Federation; FPG, fasting plasma glucose; NCEP, National Cholesterol Education Programme; OGTT, oral glucose tolerance test.