Table 1.

The general characteristics among 4071 Chinese women twins aged 20~60 years by normal glucose tolerance (NGT) and pre-diabetes.

Variables	NGT (n=3280)	Pre-diabetes a (n=791)	P
	Mean ± S.D.
Age, year	31.7 ± 7.5	33.7 ± 8.6	<0.0001
Height, m	1.5 ± 0.1	1.5 ± 0.1	0.0920
Weight, kg	52.5 ± 6.9	53.4 ± 7.5	0.0014
BMI, kg/m2	22.2 ± 2.5	22.7 ± 2.8	<0.0001
Whole body fat, kg	13.9 ± 4.7	14.6 ± 5.2	0.0002
%whole body fat b	25.9 ± 6.0	26.8 ± 6.3	0.0002
Truncal fat, kg	7.0 ± 2.7	7.6 ± 3.0	<0.0001
%Truncal fat c	49.8 ± 4.4	50.9 ± 4.3	<0.0001
Lower body fat, kg	4.5 ± 1.4	4.6 ± 1.4	0.0981
%Lower body fat d	33.3 ± 5.0	32.3 ± 4.9	<0.0001
Waist circumference (WC), cm	72.2 ± 7.3	74.3 ± 8.1	<0.0001
Fasting insulin, mU/L	6.7 ± 6.2	7.6 ± 9.1	0.0097
Fasting glucose, mmol/L	4.4 ± 0.6	5.7 ± 0.8	<0.0001
HOMA-1e	1.3 ± 1.2	1.9 ± 2.5	<0.0001
2H-OGTT insulin, mU/L	24.2 ± 23.3	28.1 ± 26.9	0.0001
2H-OGTT glucose, mmol/L	5.2 ± 1.1	7.0 ± 1.9	<0.0001
	N (%)
Education
Illiterate	1256(38.3)	343(43.4)	0.0050
Primary School	1067(32.5)	265(33.5)
Middle School	745(22.7)	140(17.7)
Higher Middle School	212(6.5)	43(5.4)
Farmer	2505(76.4)	639(80.8)	0.0080
Previous Alcohol Use	36(1.1)	12(1.5)	0.3270
Current Alcohol Use	79(2.4)	23(2.9)	0.4200

^aNGT, normal glucose tolerance; pre-diabetes: fasting glucose: 5.6~7.0 mmol/L and/or 2H-OGTT glucose: 7.8~11.1 mmol/L;

^b% whole body fat (%BF) = 100 × (whole body fat) ÷ Weight;

^c%Truncal fat (%TF)= 100 × (Truncal fat) ÷ Whole body fat;

^d%Lower body fat (%LF)=100 × (whole body fat-truncal fat-upper extremities fat-head fat ) ÷ whole body fat;

^eHOMA-1 = fast insulin × fast glucose ÷ 22.5, where the unit of fasting glucose and fasting insulin is mmol/L and mU/L, respectively;

P value was generated by t-test for continuous variables and Chi square test for categorical variables.