Table 2.
Incidence and risk (OR) of diabetes over 3 years by baseline HbA1c categories in the EPIC-Norfolk cohort (N = 5,735)
| Variable | Total | HbA1c level |
P for trend | |||
|---|---|---|---|---|---|---|
| <5.0% | 5.0–5.4% | 5.5–5.9% | 6.0–6.4% | |||
| Clinically diagnosed diabetes | ||||||
| N (% of total participants) | 5,735 | 1,849 (32) | 2,119 (37) | 1,397 (24) | 370 (6) | — |
| Incident cases (% of total cases) | 37 | 7 (19) | 6 (16) | 15 (41) | 9 (24) | — |
| Three-year cumulative incidence, % | 0.6 (0.4–0.9) | 0.4 (0.2–0.8) | 0.3 (0.1–0.6) | 1.1 (0.6–1.8) | 2.4 (1.3–4.6) | — |
| Unadjusted OR | 1.0 | 0.7 (0.3–2.2) | 2.9 (1.2–7.0) | 6.6 (2.4–17.7) | <0.001 | |
| Age-adjusted OR | 1.0 | 0.8 (0.3–2.4) | 3.3 (1.3–8.4) | 8.0 (2.8–22.7) | <0.001 | |
| Age- and sex-adjusted OR | 1.0 | 0.8 (0.3–2.4) | 3.3 (1.3–8.3) | 7.9 (2.8–22.4) | <0.001 | |
| Multivariable-adjusted OR* | 1.0 | 0.8 (0.3–2.3) | 3.0 (1.2–7.8) | 6.8 (2.3–20.1) | <0.001 | |
| Clinically diagnosed and/or HbA1c-defined diabetes | ||||||
| N (% of total participants) | 5,735 | 1,849 (32) | 2,119 (37) | 1,397 (24) | 370 (6) | — |
| Incident cases (% of total cases) | 72 | 9 (13) | 16 (22) | 21 (29) | 26 (36) | — |
| Three-year cumulative incidence, % | 1.3 (1.0–1.5) | 0.5 (0.3–0.9) | 0.8 (0.5–1.2) | 1.5 (1.0–2.3) | 7.0 (4.8–10.1) | — |
| Unadjusted OR | 1.0 | 1.6 (0.7–3.5) | 3.1 (1.4–6.8) | 15.5 (7.2–33.3) | <0.001 | |
| Age-adjusted OR | 1.0 | 1.6 (0.7–3.8) | 3.5 (1.6–7.8) | 18.0 (8.1–40.0) | <0.001 | |
| Age- and sex-adjusted OR | 1.0 | 1.6 (0.7–3.7) | 3.4 (1.5–7.7) | 17.7 (8.0–39.5) | <0.001 | |
| Multivariable-adjusted OR* | 1.0 | 1.6 (0.7–3.6) | 3.3 (1.5–7.4) | 15.6 (6.9–35.7) | <0.001 | |
*Adjusted for age, sex, social class, self-reported family history of diabetes, smoking, use of corticosteroids and antihypertensive drugs, BMI, waist circumference, systolic blood pressure, cholesterol, HDL cholesterol, and triglyceride.