The incidence of DR in patients with different smoking statuses
| Items | Non-smoking, n (%) | Light and moderate smoking, n (%) | Heavy smoking, n (%) | χ2 | P value | |
| BMI (kg/m2) | ≥28 | 27 (12.4) | 11 (12.1) | 20 (28.2) | 11.163 | 0.004 |
| <28 | 66 (22.0) | 31 (25.6) | 37 (25.2) | 0.901 | 0.637 | |
| Age (years) | <50 | 37 (21.8) | 15 (13.8) | 10 (33.3) | 6.300 | 0.043 |
| ≥50,<60 | 23 (14.6) | 17 (35.4) | 32 (29.4) | 13.080 | 0.001 | |
| ≥60 | 33 (17.5) | 10 (18.2) | 15 (19.0) | 0.090 | 0.956 | |
BMI, body mass index; DR, diabetic retinopathy.