Table 2. Baseline characteristics of participants in the Beijing Desheng Diabetic Eye Study.
| Characteristics | All | NDR | Any DR | P |
| Number | 1438 | 929 | 509 | |
| Age (a) | 65.04±8.25 | 65.24±8.25 | 64.68±8.26 | 0.22 |
| Male, n (%) | 575 (40.0) | 346 (37.2) | 229 (45.0) | 0.004 |
| Nationality, n (%) | 0.07 | |||
| Han | 1332 (92.6) | 852 (91.7) | 480 (94.3) | |
| Minority | 106 (7.4) | 77 (8.3) | 29 (5.7) | |
| Monthly income (CNY), n (%) | 0.01 | |||
| <2000 | 462 (32.1) | 272 (29.3) | 190 (37.3) | |
| 2000-2999 | 655 (45.5) | 431 (46.4) | 224 (44.0) | |
| 3000-3999 | 185 (12.9) | 130 (14.0) | 55 (10.8) | |
| ≥4000 | 130 (9.0) | 91 (9.8) | 39 (7.7) | |
| Education, n (%) | 0.004 | |||
| Lower than primary school | 166 (11.5) | 100 (10.8) | 66 (13.0) | |
| Middle/high school | 860 (59.8) | 536 (57.7) | 324 (63.7) | |
| College and above | 412 (28.7) | 293 (31.5) | 119 (23.4) | |
| Marital, n (%) | 0.39 | |||
| Single | 10 (0.7) | 7 (0.8) | 3 (0.6) | |
| Married | 1280 (89.0) | 817 (87.9) | 463 (91.0) | |
| Divorced | 10 (0.7) | 7 (0.8) | 3 (0.6) | |
| Widow/widower | 138 (9.6) | 98 (10.5) | 40 (7.9) | |
| Age of diabetic onset (a) | 55.62±10.70 | 57.67±8.96 | 51.90±12.48 | <0.001 |
| Duration of diabetes (y) | 9.42±8.60 | 7.58±6.31 | 12.78±10.89 | <0.001 |
| Use of insulin, n (%) | 347 (24.1) | 136 (14.6) | 211 (41.5) | <0.001 |
| Smoking status, n (%) | 0.007 | |||
| Current smoking | 202 (14.0) | 114 (12.3) | 88 (17.3) | |
| Ex-smoking | 270 (18.8) | 167 (18.0) | 103 (20.2) | |
| Never smoking | 960 (66.8) | 646 (69.5) | 314 (61.7) | |
| BMI (kg/m2) | 25.63±3.62 | 25.56±3.59 | 25.76±3.67 | 0.30 |
| WHR | 0.92±0.07 | 0.92±0.07 | 0.92±0.06 | 0.18 |
| SBP (mm Hg) | 135.08±16.68 | 133.56±16.21 | 137.85±17.19 | <0.001 |
| DBP (mm Hg) | 78.14±9.86 | 77.78±9.66 | 78.80±10.19 | 0.06 |
| FPG (mmol/L) | 7.78±2.56 | 7.33±2.14 | 8.62±3.01 | <0.001 |
| HbA1c, n (%) | <0.001 | |||
| <7.0% | 877 (61.0) | 638 (68.7) | 239 (47.0) | |
| ≥7.0% | 465 (32.3) | 235 (25.3) | 230 (45.2) | |
| High albuminuria, n (%) | 233 (15.5) | 114 (12.3) | 109 (21.4) | <0.001 |
| CRP (mg/dL) | 0.12 (0.05,0.24) | 0.12 (0.05,0.24) | 0.11 (0.05,0.23) | 0.36 |
| Creatinine (mg/dL) | 66.00 (57.00,78.00) | 65.00 (56.00,76.00) | 68.00 (58.00,81.00) | 0.005 |
| Uric acid (µmol/L) | 285.00 (238.00,342.00) | 286.40 (239.00,341.15) | 280.00 (234.00,344.00) | 0.38 |
| TG (mmol/L) | 1.39 (0.94,2.02) | 1.41 (0.97,2.04) | 1.34 (0.90,1.98) | 0.12 |
| TC (mmol/L) | 4.95 (4.26,5.65) | 4.93 (4.29,5.60) | 5.01 (4.21,5.77) | 0.16 |
| HDL-C (mmol/L) | 1.19 (1.03,1.40) | 1.20 (1.03,1.39) | 1.18 (1.02,1.42) | 0.69 |
| LDL-C (mmol/L) | 2.99 (2.43,3.60) | 2.97 (2.45,3.93) | 3.03 (2.40,3.66) | 0.49 |
The data were expressed as numbers (%) for categorical variables, mean±SD for normally distributed variables, and the median (interquartile range) for skewed distributed variables. NDR: No diabetic retinopathy; any DR: Any diabetic retinopathy; CNY: China Yuan; BMI: Body mass index; WHR: Waist and hip ratio; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; FPG: Fasting plasma glucose; HbA1c: Glycosylated hemoglobin A1c; CRP: C-reactive protein; TG: Triglycerides; TC: Total cholesterol; HDL-C: High-density lipoprotein cholesterol; LDL-C: Low-density lipoprotein cholesterol. Differences in baseline characteristics of patients in the NDR and any DR groups were compared using independent sample t-tests or Mann-Whitney U test for continuous variables as appropriate, and Chi-square test or Fisher's exact test for categorical variables as appropriate. P<0.05 was considered statistically significant.