Table 5.
Risk of NPDR in different metformin dose and aDCSI score groups (metformin+DPP4i vs. metformin alone).
| Total | <3 months | 3 months to 1.5 years | >1.5 years | |||||
|---|---|---|---|---|---|---|---|---|
| HR (95% CI) | Adjusted HR∗ (95% CI) | HR (95% CI) | Adjusted HR∗ (95% CI) | HR (95% CI) | Adjusted HR∗ (95% CI) | HR (95% CI) | Adjusted HR∗ (95% CI) | |
| Metformin dose | ||||||||
| ≤360 DDDs | 0.50 (0.33–0.76) | 0.49 (0.32–0.75) | 0.37 (0.21–0.67) | 0.38 (0.21–0.68) | 0.48 (0.19–1.23) | 0.46 (0.17–1.19) | 1.37 (0.59–3.17) | 1.34 (0.57–3.15) |
| 361–720 DDDs | 0.40 (0.25–0.64) | 0.36 (0.22–0.59) | 0.38 (0.20–0.74) | 0.36 (0.19–0.69) | 0.28 (0.09–0.94) | 0.28 (0.08–0.96) | 0.58 (0.24–1.42) | 0.45 (0.18–1.15) |
| >720 DDDs | 0.61 (0.41–0.9) | 0.59 (0.39–0.88) | 0.51 (0.31–0.85) | 0.50 (0.3–0.83) | 0.65 (0.28–1.49) | 0.62 (0.26–1.44) | 1.19 (0.39–3.65) | 1.36 (0.41–4.49) |
| aDCSI score | ||||||||
| 0 | 0.46 (0.34–0.62) | 0.45 (0.33–0.61) | 0.36 (0.24–0.54) | 0.36 (0.24–0.55) | 0.50 (0.25–0.97) | 0.49 (0.24–0.97) | 1.05 (0.51–2.17) | 0.96 (0.46–2.02) |
| 1 | 0.31 (0.16–0.58) | 0.32 (0.17–0.60) | 0.23 (0.09–0.58) | 0.23 (0.09–0.58) | 0.15 (0.02–1.09) | 0.16 (0.02–1.18) | 0.71 (0.26–1.96) | 0.53 (0.18–1.58) |
| ≥2 | 0.47 (0.24–0.91) | 0.45 (0.23–0.89) | 0.41 (0.18–0.95) | 0.38 (0.16–0.89) | 0.88 (0.18–4.36) | 0.96 (0.17–5.35) | 0.56 (0.12–2.54) | 0.44 (0.09–2.13) |
∗Adjusted for gender, age, comorbidities, medications, aDCSI scores, and other antidiabetic drugs use. NPDR: nonproliferative diabetic retinopathy; DDD: defined daily dose; aDCSI scores: adapted Diabetes Complications Severity Index scores; HR: hazard ratio.