Table 1.

Diagnostic criteria for total subjects

Subjects	Test	Category	Diagnostic criteria	Venous plasma glucose (mmol/L)
History of diabetes	Steamed bread test	Diagnosed diabetes a	A positive response to the question, “Has a doctor ever told you that you have diabetes?”
No history of diabetes	OGTT [10]	Undiagnosed diabetes	Fasting	≥7.0
			2-h	≥11.1
		Isolated IGT	Fasting	<6.1
			2-h	≥7.8 and <11.1
		Isolated IFG	Fasting	≥6.1 and <7.0
			2-h	<7.8
		Combined IFG and IGT	Fasting	≥6.1 and <7.0
			2-h	≥7.8 and <11.1
		Normal	Fasting	<6.1
			2-h	<7.8

IGT, impaired glucose tolerance.

IFG, impaired fasting glucose.

^a The diagnosed diabetes was identified by a positive response to the following question, “Has a doctor ever told you that you have diabetes?” [3].