Table 1. Baseline characteristics of the study population.
| Cross-sectional validation | Longitudinal validation | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Characteristics | Normal (n = 25,859) | Undiagnosed DM (n = 816) | Known DM (n = 1,543) | P value (group comparison)* | P value (normal vs. undiagnosed DM)† | P value (normal vs. known DM)† | P value (undiagnosed DM vs. known DM)† | Normal at f/u (n = 2,893) | Incident DM (n = 136) | P value |
| Age (years) | 48.5 ± 11.1 | 55.6 ± 9.5 | 58.1 ± 9.8 | <0.001 | <0.001 | <0.001 | <0.001 | 47.1 ± 9.8 | 52.0 ± 8.2 | <0.001 |
| Male | 13,890 (53.7) | 592 (72.5) | 1,172 (76) | <0.001 | <0.001 | <0.001 | 0.070 | 1659 (57.3) | 95 (69.9) | 0.004 |
| Height (cm) | 165.7 ± 8.2 | 166.9 ± 8.3 | 166.4 ± 7.8 | <0.001 | <0.001 | 0.002 | 0.462 | 165.7 ± 8.0 | 166.8 ± 8.0 | 0.108 |
| Weight (kg) | 63.9 ± 11.9 | 71.5 ± 11.8 | 68.4 ± 11.1 | <0.001 | <0.001 | <0.001 | <0.001 | 64.2 ± 11.1 | 70.6 ± 11.3 | <0.001 |
| BMI (kg/m2) | 23.1 ± 3.1 | 25.6 ± 3.2 | 24.6 ± 3.0 | <0.001 | <0.001 | <0.001 | <0.001 | 23.3 ± 2.8 | 25.3 ± 2.9 | <0.001 |
| Waist circumference (cm) | 83.4 ± 10.3 | 90.6 ± 8.1 | 88.6 ± 8.2 | <0.001 | <0.001 | <0.001 | <0.001 | 84.0 ± 7.7 | 89.3 ± 7.0 | <0.001 |
| Hypertension | 5,705 (22.1) | 407 (49.9) | 841 (54.5) | <0.001 | <0.001 | <0.001 | 0.032 | 743 (25.7) | 56 (41.2) | <0.001 |
| Family history of diabetes | 5,015 (19.4) | 258 (31.6) | 649 (42.1) | <0.001 | <0.001 | <0.001 | <0.001 | 610 (21.1) | 44 (32.4) | 0.002 |
| Current Smoking | 4,330 (16.7) | 172 (21.1) | 323 (20.9) | <0.001 | 0.001 | <0.001 | 0.934 | 528 (18.3) | 32 (23.5) | 0.121 |
| Regular exercise | 19,991 (77.3) | 569 (69.7) | 1,254 (81.3) | <0.001 | <0.001 | <0.001 | <0.001 | 1767 (61.1) | 88 (64.7) | 0.396 |
| Alcohol intake (glasses/day) | 1.3 ± 1.8 | 1.9 ± 2.1 | 1.6 ± 1.9 | <0.001 | <0.001 | <0.001 | 0.018 | 1.1 ± 1.9 | 1.4 ± 2.0 | 0.079 |
| Fasting plasma glucose (mg/dL) | 93.5 ± 9.8 | 131.3 ± 25.9 | 132.4 ± 35.3 | <0.001 | <0.001 | <0.001 | 0.141 | 96.1 ± 9.8 | 106.8 ± 10.7 | <0.001 |
| HbA1c (%) | 5.6 ± 0.3 | 6.8 ± 0.9 | 6.9 ± 1.1 | <0.001 | <0.001 | <0.001 | <0.001 | 5.5 ± 0.3 | 5.9 ± 0.3 | <0.001 |
| Total cholesterol (mg/dL) | 194.1 ± 33.1 | 201 ± 40.4 | 175.9 ± 36.2 | <0.001 | <0.001 | <0.001 | <0.001 | 197.1 ± 32.8 | 206.0 ± 32.6 | 0.002 |
| Triglyceride (mg/dL) | 107.6 ± 73.8 | 157 ± 96.9 | 130.4 ± 90.6 | <0.001 | <0.001 | <0.001 | <0.001 | 108.6 ± 69.4 | 144.5 ± 80.7 | <0.001 |
| HDL cholesterol (mg/dL) | 53 ± 11.6 | 48.2 ± 9.9 | 48.3 ± 10.5 | <0.001 | <0.001 | <0.001 | 0.986 | 54.7 ± 13.2 | 50.1 ± 13.3 | <0.001 |
Abbreviations: DM, diabetes mellitus; BMI, body mass index; HbA1c, hemoglobin A1c.
Data are the mean ± SD or n (%).
*P values for the group difference were calculated by one-way ANOVA test for continuous variables and chi-square test for categorical variables.
†P values for the comparison of each pair of groups were calculated by the post hoc test of ANOVA with Tukey’s method for continuous variables and chi-square tests for categorical variables.