Table 1.
HRs for 15-year incidence of type 2 diabetes according to HbA1c
| HbA1c category |
||||
|---|---|---|---|---|
| <5.00% | 5.00–5.49% | 5.50–5.99% | 6.00–6.49% | |
| n | 112 | 345 | 315 | 70 |
| Cases of incident diabetes | 3 | 9 | 31 | 20 |
| Cases per 1,000 person-years | 1.9 | 1.9 | 7.8 | 25.8 |
| HRs (95% CIs) in models with baseline variables* |
||||
| Model 0 | Model 1 | Model 2 | Model 3 | |
| HbA1c category | ||||
| <5.00% | 1.00 (0.27–3.68) | 1.11 (0.30–4.14) | 1.18 (0.31–4.41) | 1.27 (0.34–4.79) |
| 5.00–5.49% (reference) | 1.00 | 1.00 | 1.00 | 1.00 |
| 5.50–5.99% | 4.30 (2.05–9.03) | 3.79 (1.79–8.06) | 3.24 (1.50–6.98) | 3.21 (1.49–6.92) |
| 6.00–6.49% | 15.67 (7.13–34.47) | 12.50 (5.51–28.34) | 9.74 (4.21–22.56) | 9.26 (4.01–21.40) |
| P value for trend | <0.001 | <0.001 | <0.001 | <0.001 |
| HbA1c (per 1% increase) | 11.00 (5.66–21.39) | 8.54 (4.21–17.31) | 6.08 (2.96–12.47) | 6.05 (2.90–12.60) |
| HRs (95% CIs) in models with updated variables† |
||||
| Model 0 | Model 1 | Model 2 | Model 3 | |
| HbA1c category | ||||
| <5.00% | 2.31 (0.39–13.92) | 2.55 (0.42–15.39) | 2.55 (0.42–15.58) | 2.43 (0.40–14.97) |
| 5.00–5.49% (reference) | 1.00 | 1.00 | 1.00 | 1.00 |
| 5.50–5.99 | 12.58 (3.83–41.30) | 11.62 (3.52–38.36) | 10.97 (3.30–36.47) | 11.43 (3.43–38.07) |
| 6.00–6.49% | 61.05 (18.23–204.4) | 52.82 (15.57–179.3) | 45.52 (13.1–158.0) | 46.72 (13.4–163.3) |
| P value for trend | <0.001 | <0.001 | <0.001 | <0.001 |
| HbA1c (per 1% increase) | 41.37 (18.79–91.07) | 36.82 (16.30–83.21) | 31.10 (13.31–72.7) | 32.24 (13.60–76.41) |
Model 0 was unadjusted. Model 1 included age and sex. Model 2 included the variables in model 1 plus LDL and HDL cholesterol levels, log-transformed triglyceride levels, BMI, waist-to-hip ratio, hypertension, family history of diabetes, education, alcohol use, physical activity score, and smoking status. Model 3 included all variables in model 2 plus white blood cell count, hemoglobin, ferritin, and creatinine.
*Cox models in which HbA1c and other variables at baseline were used to predict diabetes in the 15-year follow-up.
†Cox models in which updated HbA1c and other variables were used to predict diabetes in subsequent 5-year follow-up periods (see text for details).