Cut-off value of glycated hemoglobin A1c for detecting diabetic retinopathy in the Chinese population

Table 1 Basic characteristics and physical parameters data of participants in the training set and validation set

	Training set (n = 591)	Validation set (n = 296)	P value
Chinese Korean population, n (%)	400 (67.68)	189 (63.85)	0.2832
Female, n (%)	387 (65.48)	186 (62.84)	0.4759
Age (yr)	55.82 ± 11.41	54.81 ± 11.24	0.1913
BMI (kg/m2)	25.38 ± 3.84	25.66 ± 4.03	0.5643
Waist circumference (cm)	80.17 ± 9.77	80.88 ± 9.84	0.4620
Systolic blood pressure (mmHg)	136.67 ± 21.83	137.62 ± 20.48	0.4574
Diastolic blood pressure (mmHg)	80.56 ± 12.59	80.57 ± 12.26	0.4661
Beats per minute	80.58 ± 11.85	80.54 ± 13.04	0.9233
FBG (mmol/L)	6.20 ± 1.62	6.14 ± 1.65	0.1461
2 h-PG (mmol/L)	7.59 ± 3.02	7.58 ± 3.62	0.7261
HbA1c (%)	5.83 ± 1.06	5.81 ± 1.07	0.7282
White blood cell count (109/L)	5.73 ± 1.47	5.89 ± 1.69	0.2423
Red blood cell count (1012/L)	4.71 ± 0.45	4.74 ± 0.48	0.7093
Blood platelet count (109/L)	225.47 ± 57.29	227.50 ± 57.49	0.6463
Hemoglobin (g/L)	144.99 ± 16.27	145.81 ± 15.45	0.7393
Total cholesterol (mmol/L)	5.28 ± 1.05	5.29 ± 1.17	0.9639
Triglyceride (mmol/L)	1.76 ± 1.41	1.79 ± 1.44	0.8220
Low-density lipoprotein (mmol/L)	3.02 ± 0.83	3.04 ± 0.88	0.8941
High-density lipoprotein (mmol/L)	1.49 ± 0.37	1.49 ± 0.32	0.8240
Creatinine (μmol/L)	57.88 ± 15.08	57.87 ± 15.02	0.8231
Urea nitrogen (mmol/L)	5.03 ± 1.42	4.96 ± 1.33	0.6231
Uric acid (μmol/L)	280.60 ± 82.06	284.96 ± 81.33	0.6276

BMI: Body mass index; FBG: Fasting blood glucose; 2 h-PG: 2-h plasma glucose; HbA1c: Glycated hemoglobin A1c.

Table 2 Factors associated with glycated hemoglobin A1c

	Coefficient	SE	P value
Age (yr)	0.350	0.0017	0.0042
BMI (kg/m2)	0.283	0.0643	< 0.0001
FBG (mmol/L)	0.547	0.0121	< 0.0001

BMI: Body mass index; FBG: Fasting blood glucose.