Table 1.
Hazard ratios for development of retinopathy and microalbuminuria outcomes according to TIR
| Retinopathy outcome |
Microalbuminuria outcome |
|||||||
|---|---|---|---|---|---|---|---|---|
| TIR | N | N (%) with outcome | Unadjusted HR (95% CI)* | Adjusted HR (95% CI)† | N | N (%) with outcome | Unadjusted HR (95% CI)* | Adjusted HR (95% CI)† |
| Overall | ||||||||
| ≥50% | 466 | 36 (8) | 1.00 | 1.00 | 412 | 10 (2) | 1.00 | 1.00 |
| 40 to <50% | 319 | 32 (10) | 1.54 (0.94–2.55) | 1.61 (0.97–2.65) | 291 | 20 (7) | 2.44 (1.05–5.67) | 2.40 (1.03–5.58) |
| 30 to <40% | 271 | 59 (22) | 3.38 (2.22–5.15) | 3.37 (2.20–5.15) | 242 | 29 (12) | 4.74 (2.16–10.40) | 4.39 (2.01–9.58) |
| <30% | 384 | 144 (38) | 6.23 (4.25–9.13) | 6.93 (4.69–10.24) | 338 | 57 (17) | 6.68 (3.35–13.29) | 6.98 (3.49–13.96) |
| Primary cohort | ||||||||
| ≥50% | 228 | 8 (4) | 1.00 | 1.00 | 222 | 3 (1) | 1.00 | 1.00 |
| 40 to <50% | 159 | 10 (6) | 2.43 (0.91–6.53) | 2.43 (0.90–6.54) | 153 | 4 (3) | 1.25 (0.19–8.41) | 1.24 (0.18–8.36) |
| 30 to <40% | 131 | 25 (19) | 7.08 (3.09–16.23) | 6.51 (2.82–15.02) | 123 | 6 (5) | 3.68 (1.00–13.47) | 3.61 (0.98–13.21) |
| <30% | 208 | 64 (31) | 11.29 (5.13–24.85) | 11.16 (5.05–24.64) | 200 | 23 (12) | 7.35 (2.22–24.26) | 7.24 (2.19–23.94) |
| Secondary cohort | ||||||||
| ≥50% | 238 | 28 (12) | 1.00 | 1.00 | 190 | 7 (4) | 1.00 | 1.00 |
| 40 to <50% | 160 | 22 (14) | 1.30 (0.73–2.31) | 1.38 (0.77–2.45) | 138 | 16 (12) | 2.91 (1.05–8.02) | 2.92 (1.05–8.08) |
| 30 to <40% | 140 | 34 (24) | 2.39 (1.43–3.97) | 2.50 (1.50–4.17) | 119 | 23 (19) | 5.11 (1.91–13.65) | 4.76 (1.79–12.68) |
| <30% | 176 | 80 (45) | 4.95 (3.16–7.77) | 5.72 (3.60–9.09) | 138 | 34 (25) | 6.93 (2.90–16.59) | 6.78 (2.83–16.25) |
Strata based on TIR averaged over the entire DCCT study period. HR, hazard ratio.
*From discrete Cox proportional hazards regression models. P value, computed using TIR as a time-dependent continuous variable, is <0.001 for each cohort. †From discrete Cox proportional hazards regression models stratified by the ETDRS level of retinopathy at baseline and adjusted for the pre-DCCT glycemic exposure represented by the preexisting duration of diabetes separately for the primary and secondary cohorts. P value, computed using TIR as a time-dependent continuous variable, is <0.001 for each cohort. An additional model which included age and sex as covariates produced similar results.