TABLE 4.
Demographic adjusted hazard ratio and Harrell’s C-statistic (95% confidence intervals) for incident outcomes by different clinical categories of prediabetes and undiagnosed diabetes
| Incident diabetes | Chronic kidney disease | Atherosclerotic cardiovascular disease | Peripheral arterial disease | All-cause mortality HR | ||
|---|---|---|---|---|---|---|
| HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | (95% CI) | ||
| Visit 2 (1990–92) | ||||||
| ADA fasting glucose definition | < 5.6 mmol/L | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 5.6–6.9 mmol/L | 2.91 (2.69, 3.15)* | 1.17 (1.08, 1.27)* | 1.24 (1.12, 1.38)* | 1.34 (1.03, 1.74)* | 1.12 (1.04, 1.21)* | |
| ≥ 7.0 mmol/L‡ | 19.7 (17.6, 22.2)* | 1.75 (1.49, 2.05)* | 2.10 (1.74, 2.53)* | 3.40 (2.30, 5.01)* | 1.55 (1.35, 1.79)* | |
| C-statistic (95% CI) | 0.713 (0.704, 0.723) | 0.636 (0.625, 0.647) | 0.662 (0.649, 0.676) | 0.701 (0.670, 0.733) | 0.683 (0.674, 0.692) | |
| WHO fasting glucose definition | < 6.1 mmol/L | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 6.1–6.9 mmol/L | 3.81 (3.48, 4.16)* | 1.28 (1.14, 1.43)* | 1.22 (1.05, 1.41)* | 1.35 (0.95, 1.92) | 1.25 (1.13, 1.38)* | |
| ≥ 7.0 mmol/L‡ | 14.5 (13.0, 16.2)* | 1.69 (1.45, 1.97)* | 1.95 (1.63, 2.34)* | 3.09 (2.14, 4.47)* | 1.52 (1.32, 1.75)* | |
| C-statistic (95% CI) | 0.693 (0.683, 0.703) | 0.636 (0.625, 0.647) | 0.660 (0.646, 0.673) | 0.700 (0.668, 0.732) | 0.683 (0.674, 0.693) | |
| ADA HbA1c definition | < 39 mmol/mol | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 39–46 mmol/mol | 3.42 (3.15, 3.72)* | 1.42 (1.29, 1.57)* | 1.70 (1.51, 1.92)* | 1.84 (1.37, 2.47)* | 1.49 (1.37, 1.62)* | |
| ≥ 48 mmol/mol‡ | 20.8 (18.4, 23.4)* | 2.04 (1.73, 2.40)* | 2.40 (1.98, 2.90)* | 5.38 (3.75, 7.73)* | 1.81 (1.57, 2.10)* | |
| C-statistic (95% CI) | 0.693 (0.683, 0.703) | 0.640 (0.629, 0.651) | 0.672 (0.659, 0.685) | 0.722 (0.690, 0.754) | 0.688 (0.679, 0.697) | |
| IEC HbA1c definition | < 42 mmol/mol | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 42–46 mmol/mol | 4.14 (3.74, 4.58)* | 1.50 (1.32, 1.70)* | 1.91 (1.65, 2.21)* | 1.95 (1.34, 2.82)* | 1.56 (1.40, 1.73)* | |
| ≥ 48 mmol/mol‡ | 17.9 (15.9, 20.2)* | 1.96 (1.67, 2.30)* | 2.27 (1.88, 2.74)* | 4.99 (3.49, 7.11)* | 1.73 (1.50, 1.99)* | |
| C-statistic (95% CI) | 0.669 (0.659, 0.680) | 0.639 (0.628, 0.650) | 0.668 (0.655, 0.682) | 0.718 (0.686, 0.750) | 0.687 (0.678, 0.696) | |
| Visit 4 (1996–98) | ||||||
| ADA fasting glucose definition | < 5.6 mmol/L | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 5.6–6.9 mmol/L | 3.43 (3.10, 3.80)* | 1.08 (0.96, 1.21) | 1.25 (1.07, 1.45)* | 1.09 (0.73, 1.63) | 1.15 (1.03, 1.28)* | |
| ≥ 7.0 mmol/L‡ | 25.3 (21.9, 29.2)* | 1.45 (1.16, 1.82)* | 1.79 (1.36, 2.37)* | 1.99 (1.02, 3.88)* | 1.68 (1.37, 2.05)* | |
| C-statistic (95% CI) | 0.726 (0.714, 0.738) | 0.624 (0.609, 0.639) | 0.660 (0.641, 0.680) | 0.707 (0.660, 0.754) | 0.686 (0.673, 0.699) | |
| WHO fasting glucose definition | < 6.1 mmol/L | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 6.1–6.9 mmol/L | 4.48 (3.97, 5.05)* | 1.23 (1.04, 1.47)* | 1.10 (0.87, 1.40) | 0.63 (0.29, 1.35) | 1.29 (1.10, 1.51)* | |
| ≥ 7.0 mmol/L‡ | 18.5 (16.2, 21.2)* | 1.45 (1.16, 1.81)* | 1.67 (1.27, 2.20)* | 1.85 (0.96, 3.56) | 1.65 (1.35, 2.01)* | |
| C-statistic (95% CI) | 0.694 (0.681, 0.708) | 0.625 (0.610, 0.640) | 0.658 (0.638, 0.677) | 0.710 (0.662, 0.757) | 0.687 (0.673, 0.700) | |
| ADA/WHO 2-hour glucose definition | < 7.8 mmol/L | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) | 1 (Ref) |
| 7.8–11.0 mmol/L | 2.56 (2.30, 2.86)* | 1.16 (1.03, 1.31)* | 1.08 (0.92, 1.27) | 0.83 (0.54, 1.29) | 1.17 (1.05, 1.31)* | |
| ≥ 11.0 mmol/L‡ | 10.6 (9.41, 11.9)* | 1.39 (1.18, 1.63)* | 1.44 (1.17, 1.78)* | 0.93 (0.50, 1.72) | 1.33 (1.15, 1.55)* | |
| C-statistic (95% CI) | 0.728 (0.716, 0.741) | 0.626 (0.611, 0.641) | 0.659 (0.639, 0.678) | 0.705 (0.658, 0.752) | 0.685 (0.672, 0.698) | |
Adjusted for age, sex (male, female), race-center (white, Minneapolis, MN; black, Jackson, MS; white, Washington County, MD; black, Forsyth County, NC; white, Forsyth County, NC)
Undiagnosed diabetes
p < 0.05
Abbreviations: ADA, American Diabetes Association; CI, confidence interval; IEC, International Expert Committee; HbA1c, hemoglobin A1c; HR, hazard ratio; WHO, World Health Organization
Outcome Definitions: Incident diabetes: self-report of a physician diagnosis of diabetes or use of glucose-lowering medication during a study visit or annual telephone call; Chronic kidney disease: subsequent estimated glomerular filtration rate (eGFR) measurement < 60 mL/min/1.73 m2 measured at a study visit and an eGFR decline from baseline visit of at least 25% at the follow-up visit, or chronic kidney disease related hospitalization or death, or an end stage renal disease event identified by the United States Renal Data System registry; Atherosclerotic cardiovascular disease: any coronary heart disease hospitalization and death and ischemic stroke hospitalization and death (adjudicated events); Peripheral arterial disease: events identified from hospitalization records (International Classification of Disease, Ninth Revision (ICD-9) discharge codes) for peripheral arterial disease (440.2, 440.3, 440.4) or leg revascularization (38.18, 39.25, 39.29, 39.50); All-cause mortality: ascertained from hospital and National Death Index records