Are body mass index and waist circumference significant predictors of diabetes and prediabetes risk: Results from a population based cohort study

Table 1 Characteristics of study population at baseline

	Normal (n = 599)1	Pre-diabetes (n = 307)1	Diabetes (n = 45)1	P value
Whole population
Age (yr)	42.06 ± 6.17	42.72 ± 6.20	43.20 ± 6.19	0.197
Energy intake (kcal/d)	1844.32 ± 553.85	1793.43 ± 571.48	1908.95 ± 598.94	0.646
Weight (kg)	72.09 ± 12.10	73.51 ± 12.49	78.22 ± 11.96	0.943
Height (cm)	160.21 ± 8.31	160.09 ± 8.62	159.81 ± 8.58	0.197
Body mass index (kg/m2)	28.09 ± 4.17	28.66 ± 4.18	30.63 ± 4.15	< 0.0001
Waist circumference (cm)	87.00 ± 9.58	88.72 ± 9.75	92.86 ± 9.08	< 0.0001
Hip circumference (cm)	106.21 ± 8.54	107.35 ± 8.77	110.35 ± 9.27	0.003
Waist to hip ratio	0.82 ± 0.07	0.83 ± 0.07	0.84 ± 0.05	0.078
Fasting blood sugar	87.04 ± 7.99	89.30 ± 7.03	91.0 ± 6.14	< 0.0001
Blood sugar after 30 min (mg/dL)	127.41 ± 25.19	136.43 ± 26.48	141.49 ± 25.48	< 0.0001
Blood sugar after 60 min (mg/dL)	123.02 ± 32.06	136.19 ± 31.17	151.81 ± 36.61	< 0.0001
Blood sugar after 120 min (mg/dL)	98.11 ± 21.15	104.81 ± 21.08	110.94 ± 18.80	< 0.0001
HbA1c (%)	4.94 ± 0.78	5.08 ± 0.75	5.17 ± 0.78	0.014
Triglyceride (mg/dL)	150.15 ± 77.29	156.50 ± 83.83	200.82 ± 130.48	< 0.0001
Total cholesterol (mg/dL)	190.30 ± 38.16	192.47 ± 35.97	205.51 ± 50.56	0.034
LDL-C (mg/dL)	116.34 ± 33.45	117.04 ± 32.26	123.52 ± 52.88	0.436
HDL-C (mg/dL)	45.04 ± 11.75	44.78 ± 10.31	45.12 ± 11.55	0.944
Systolic blood pressure (mmHg)	110.23 ± 10.49	110.73 ± 10.66	110.76 ± 10.64	< 0.0001
Diastolic blood pressure (mmHg)	70.37 ± 10.11	70.64 ± 10.20	70.65 ± 10.26	0.002
Abdominal obese (WC > 90 cm) (%)	32.9	41.8	57.4	< 0.0001
Men
Age (yr)	43.04 ± 6.73	42.48 ± 6.20	43.85 ± 7.16	0.71
Energy intake (kcal/d)	2384.54 ± 558.37	2176.44 ± 648.34	2536.88 ± 651.42	0.343
Weight (kg)	77.98 ± 12.95	79.43 ± 13.44	81.38 ± 6.13	0.53
Height (cm)	170.78 ± 6.47	170.56 ± 6.30	169.55 ± 5.22	0.802
Body mass index (kg/m2)	26.66 ± 3.53	27.22 ± 3.82	28.32 ± 1.82	0.201
Waist circumference (cm)	92.63 ± 9.43	93.14 ± 9.86	97.65 ± 7.64	0.19
Hip circumference (cm)	102.76 ± 6.68	103.91 ± 7.76	108.15 ± 7.19	0.025
Waist to hip ratio	0.90 ± 0.06	0.89 ± 0.05	0.90 ± 0.03	0.754
Fasting blood sugar	87.55 ± 8.25	90.34 ± 6.91	92.54 ± 4.11	0.005
Blood sugar after 30 min (mg/dL)	133.20 ± 28.96	140.95 ± 28.86	144.42 ± 31.05	0.091
Blood sugar after 60 min (mg/dL)	128.50 ± 35.76	136.26 ± 35.35	147.69 ± 44.80	0.081
Blood sugar after 120 min (mg/dL)	91.18 ± 24.14	92.40 ± 21.22	110.08 ± 20.20	0.019
HbA1c (%)	4.94 ± 0.66	5.09 ± 0.89	5.15 ± 1.01	0.293
Triglyceride (mg/dL)	178.85 ± 97.60	177.54 ± 92.37	219.23 ± 101.25	0.328
Total cholesterol (mg/dL)	189.49 ± 383.49	189.45 ± 31.95	204.31 ± 51.08	0.312
LDL-C (mg/dL)	114.74 ± 30.58	113.56 ± 31.07	118.60 ± 43.79	0.87
HDL-C (mg/dL)	40.92 ± 12.01	41.49 ± 9.21	45.92 ± 12.16	0.301
Systolic blood pressure (mmHg)	110.46 ± 10.51	110.87 ± 10.75	120.69 ± 10.48	0.011
Diastolic blood pressure (mmHg)	70.48 ± 10.13	70.83 ± 10.30	80.08 ± 10.08	0.04
Abdominal obese (WC > 90 cm) (%)	59.1	63.5	92.3	0.058
Women
Age (yr)	41.70 ± 5.92	42.81 ± 6.21	42.94 ± 5.86	0.059
Energy intake (kcal/d)	1738.47 ± 488.91	1674.05 ± 491.68	1715.73 ± 447.60	0.643
Weight (kg)	70.05 ± 11.11	71.17 ± 11.30	77.06 ± 13.36	0.002
Height (cm)	156.52 ± 5.12	156.96 ± 5.25	156.27 ± 6.59	0.43
Body mass index (kg/m2)	28.58 ± 4.26	29.23 ± 4.19	31.47 ± 4.45	< 0.0001
Waist circumference (cm)	85.10 ± 8.88	87.00 ± 9.16	91.03 ± 9.02	< 0.0001
Hip circumference (cm)	107.37 ± 8.79	108.68 ± 8.79	111.21 ± 9.94	0.02
Waist to hip ratio	0.79 ± 0.05	0.80 ± 0.05	0.82 ± 0.03	0.018
Fasting blood sugar	86.87 ± 7.91	88.89 ± 7.05	90.41 ± 6.71	0.001
Blood sugar after 30 min (mg/dL)	125.21 ± 23.32	134.55 ± 25.26	140.42 ± 23.59	< 0.0001
Blood sugar after 60 min (mg/dL)	120.96 ± 30.41	136.16 ± 29.46	153.38 ± 33.60	< 0.0001
Blood sugar after 120 min (mg/dL)	100.58 ± 19.45	109.63 ± 18.99	111.26 ± 18.55	< 0.0001
HbA1c (%)	4.94 ± 0.82	5.08 ± 0.68	5.18 ± 0.69	0.05
Triglyceride (mg/dL)	140.11 ± 66.06	148.32 ± 79.00	193.34 ± 141.41	< 0.0001
Total cholesterol (mg/dL)	190.74 ± 39.60	193.63 ± 37.41	206.00 ± 51.16	0.092
LDL-C (mg/dL)	117.04 ± 34.27	118.31 ± 32.67	125.64 ± 56.94	0.44
HDL-C (mg/dL)	46.48 ± 11.34	45.99 ± 10.45	44.77 ± 11.48	0.658
Systolic blood pressure (mmHg)	110.15 ± 10.48	110.67 ± 10.63	110.40 ± 10.58	< 0.0001
Diastolic blood pressure (mmHg)	70.33 ± 10.10	70.56 ± 10.15	70.48 ± 10.31	0.044
Abdominal obese (WC > 90 cm) (%)	24.1	33.3	44.1	0.004

¹Values are mean ± SD. LDL-C: Low-density lipoprotein cholesterol; HDL-C: High-density lipoprotein cholesterol; HbA1c: Glycosylated haemoglobin.

Table 2 Crude and multivariable-adjusted relative risk and 95%CI for relative risk obtained from logistic regression

	Total		Men		Women
	Pre-diabetes	Diabetes	Pre-diabetes	Diabetes	Pre-diabetes	Diabetes
BMI
Crude	1.03 (1.00, 1.07)	1.14 (1.07, 1.21)	1.04 (0.97, 1.13)	1.14 (0.97, 1.34)	1.04 (1.00, 108)	1.15 (1.07, 1.23)
Model 1	1.04 (1.00, 1.07)	1.14 (1.06, 1.22)	1.14 (0.97, 1.35)	1.04 (0.97, 1.12)	1.03 (0.99, 1.07)	1.14 (1.06, 1.23)
Model 2	1.06 (0.98, 1.15)	1.24 (1.06, 1.46)	1.06 (0.80, 1.40)	1.30 (0.75, 2.26)	1.07 (0.98, 1.17)	1.25 (1.02, 1.53)
Model 3	1.05 (0.96, 1.14)	1.36 (1.05, 1.77)	1.00 (0.75, 1.35)	1.44 (0.42, 4.88)	1.07 (0.97, 1.17)	1.44 (1.05, 1.98)
Model 4	1.04 (0.96, 1.14)	1.38 (1.05, 1.82)	1.00 (0.75, 1.35)	Inestimable	1.07 (0.97, 1.18)	1.51 (1.06, 2.14)
WC
Crude	1.02 (1.00, 1.03)	1.06 (1.03, 1.09)	1.01 (0.98, 1.03)	1.06 (1.00, 1.13)	1.02 (1.01, 1.04)	1.07 (1.03, 1.11)
Model 1	1.02 (1.00, 1.03)	1.07 (1.03, 1.10)	1.01 (0.98, 1.03)	1.06 (1.00, 1.13)	1.02 (1.00, 1.04)	1.07 (1.03, 1.11)
Model 2	1.04 (1.00, 1.08)	1.16 (1.06, 1.27)	1.00 (0.90, 1.12)	1.08 (0.87, 1.33)	1.05 (1.01, 1.09)	1.20 (1.07, 1.35)
Model 3	1.03 (0.99, 1.07)	1.20 (1.04, 1.38)	0.97 (0.85, 1.09)	1.58 (0.37, 6.76)	1.04 (1.00, 1.09)	1.21 (1.03, 1.42)
Model 4	1.03 (0.99, 1.07)	1.20 (1.04, 1.38)	0.97 (0.86, 1.09)	Inestimable	1.04 (1.00, 1.09)	1.22 (1.03, 1.45)

Model 1: Adjusted for age, and sex only in the whole population; Model 2: Further adjustment was made for physical activity and energy intake; Model 3: Further adjustment was made for blood sugar and HbA1c; Model 4: Further control was made for lipid profile and blood pressure; BMI: Body mass index; WC: Waist circumference.

Table 3 Area under the curve (95%CI for area under the curve) for body mass index and waist circumference on predicting the pre-diabetes or diabetes

	Total		Men		Women
	Pre-diabetes	Diabetes	Pre-diabetes	Diabetes	Pre-diabetes	Diabetes
Body mass index	0.541 (0.502, 0.581)	0.673 (0.596, 0.749)	0.538 (0.460, 0.617)	0.664 (0.551, 0.778)	0.544 (0.498, 0.590)	0.691 (0.598, 0.784)
Waist circumference	0.552 (0.513, 0.592)	0.674 (0.602, 0.746)	0.508 (0.432, 0.585)	0.613 (0.505, 0.721)	0.564 (0.518, 0.611)	0.691 (0.604, 0.778)

Table 4 Optimal cutoff points for general obesity and abdominal adiposity to predict incidence of pre-diabetes and diabetes

	Whole population		Men		Women
	BMI	WC	BMI	WC	BMI	WC
Diabetes
Cutoff point 1	28.5	86.25	26.2	89.7	28.6	84.3
Sensitivity	0.733	0.787	0.917	1	0.818	0.818
Specificity	0.579	0.495	0.477	0.356	0.53	0.5
Cutoff point 2	29	86.75	27	90	29	85
Sensitivity	0.6	0.766	0.75	0.917	0.667	0.758
Specificity	0.614	0.514	0.53	0.423	0.566	0.532
Pre-diabetes
Cutoff point 1	28.3	86	29.6	89.7	28.3	88.2
Sensitivity	0.528	0.787	0.294	0.706	0.583	0.45
Specificity	0.559	0.495	0.819	0.356	0.516	0.686
Cutoff point 2	29	87	30	90	29	89
Sensitivity	0.427	0.723	0.235	0.635	0.468	0.376
Specificity	0.614	0.453	0.826	0.409	0.564	0.718

BMI: Body mass index; WC: Waist circumference.