Molecular Vision: Li, Mol Vis 2008; 14:1698-1704. Table 1

Table 1. Clinical and metabolic characteristics of patients with type 2 diabetes

Characteristic	DM (n=127)	All DR (n=216)	NPDR (n=144)	PDR (n=72)
Age (years)	68.8±11.2	66.8±10.4	69.1±9.4	62.7±11.0^4,5
Gender (% male)	60.6	60.6	59.4	62.5
Age at onset of DM (years)	53.8±11.9	53.0±10.8	55.4±10.4	48.4±10.0^6,7
Duration of diabetes (years)	14.7±4.8	13.9±8.3	13.7±8.0	14.4±8.8
Age at onset of DR (years)	None	62.1±10.2	65.6±9.4	56.8±9.9
Gap between DR and DM onset ages (years)	None	8.4±8.8	9.1±7.6	7.3±11.1
Duration of DR (years)	None	4.9±3.8	4.6±3.6	5.6±4.1
HbA1c (%)	6.90±0.91	7.35±1.39¹	7.53±1.56³	6.98±0.94
Fasting plasma glucose (mM)	8.24±1.98	8.26±2.83	8.09±2.86	8.81±2.89
Insulin use (% of patients)	2.4	11.5²	8.3	18.1⁸
Family history of DM (% of patients)	17.7	25.3	22.5	29.2
Hypertension (% of patients)	68.8	67.1	66	69.4
Hyperlipidemia (% of patients)	26.8	24.8	24.5	26.4
Renal failure (% of patients)	0.8	4.1	3.5	5.6
Current smoking (% of patients)	9.2	11.1	11.1	11.1
Diabetic macular edema (% of patients)	None	31.9	26.4	43.1⁹

The table showed the comparisons of the clinical and metabolic characteristics among diabetes mellitus controls (DM) and diabetic retinopathy (DR) and DR subtypes. All p values were computed by χ2 or student t-tests. DR group showed a significantly higher level of HbA1c and higher percentage of patients receiving insulin treatment than controls (1: p=0.046; 2: p<0.00001). By Tukey’s test for Post Hoc multiple comparisons (the Bonferroni corrected significance level was 0.025=0.05÷2), the significant difference of HbA1c level was only found between nonproliferative diabetic retinopathy (NPDR) and controls (2: p=0.001) and the significant higher percentage of the patients receiving insulin treatment was only due to proliferative diabetic retinopathy (PDR) group (8: p=0.00009). The PDR group was slightly younger than NPDR (4: p=0.001) and controls (5: p=0.00005) and with earlier onset of diabetes than other two groups (6: p=0.0008; 7: p=0.000003). The presence of diabetic macular edema was evident in PDR compared to NPDR (9: p=0.001).