Table 2.
Baseline characteristics of the study population.
| Oxidative Balance Score | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total | Men | Women | ||||||||||
| Variables | T1 (n = 1923) |
T2 (n = 1757) |
T3 (n = 2115) |
p * | T1 (n = 798) |
T2 (n = 779) |
T3 (n = 1087) |
p * | T1 (n = 1125) |
T2 (n = 978) |
T3 (n = 1028) |
p * |
| Men, n (%) | 798 (41.5%) | 779 (44.3%) | 1087 (51.4%) | <0.001 | N/A | N/A | N/A | N/A | N/A | N/A | ||
| Age, years | 52.4 ± 8.4 | 51.8 ± 8.5 | 50.3 ± 8.2 | <0.001 | 50.5 ± 7.7 | 51.5 ± 8.4 | 50.8 ± 8.2 | 0.593 | 53.8 ± 8.6 | 52.1 ± 8.7 | 49.9 ± 8.1 | <0.001 |
| MBP, mmHg | 98.0 ± 13.2 | 96.7 ± 12.7 | 94.0 ± 12.6 | <0.001 | 98.4 ± 12.2 | 98.1 ± 11.9 | 96.2 ± 12.3 | <0.001 | 97.6 ± 13.8 | 95.6 ± 13.3 | 91.7 ± 12.6 | <0.001 |
| Glucose, mg/dL | 87.3 ± 18.8 | 86.6 ± 18.9 | 85.7 ± 20.6 | 0.008 | 90.1 ± 20.8 | 89.0 ± 18.6 | 88.4 ± 23.2 | 0.089 | 85.3 ± 17.0 | 84.6 ± 19.0 | 82.8 ± 16.8 | 0.001 |
| Insulin, µU/mL | 8.2 ± 5.5 | 7.7 ± 4.7 | 7.2 ± 4.0 | <0.001 | 7.4 ± 4.5 | 7.2 ± 4.0 | 6.8 ± 3.6 | <0.001 | 8.7 ± 6.1 | 8.1 ± 5.1 | 7.6 ± 4.3 | <0.001 |
| Total cholesterol, mg/dL | 194.7 ± 34.5 | 191.0 ± 35.7 | 187.8 ± 33.5 | <0.001 | 195.4 ± 34.9 | 193.4 ± 36.2 | 190.3 ± 34.3 | 0.002 | 194.1 ± 34.2 | 189.1 ± 35.2 | 185.0 ± 32.5 | <0.001 |
| Triglyceride, mg/dL | 176.6 ± 108.5 | 160.3 ± 102.7 | 147.8 ± 94.8 | <0.001 | 196.3 ± 121.9 | 180.2 ± 123.0 | 161.3 ± 101.9 | <0.001 | 162.6 ± 95.4 | 144.3 ± 79.6 | 133.5 ± 84.4 | <0.001 |
| HDL cholesterol, mg/dL | 43.3 ± 9.3 | 44.7 ± 10.2 | 45.1 ± 9.9 | <0.001 | 42.3 ± 9.2 | 43.3 ± 9.7 | 43.9 ± 10.0 | 0.001 | 44.0 ± 9.2 | 45.8 ± 10.4 | 46.4 ± 9.7 | <0.001 |
| CRP, mg/dL | 0.2 ± 0.4 | 0.3 ± 0.8 | 0.2 ± 0.4 | 0.016 | 0.2 ± 0.3 | 0.3 ± 0.8 | 0.2 ± 0.3 | 0.157 | 0.2 ± 0.5 | 0.2 ± 0.8 | 0.2 ± 0.4 | 0.041 |
| eGFR, mL/min/1.73 m2 | 91.8 ± 13.2 | 92.8 ± 13.2 | 94.2 ± 12.8 | <0.001 | 91.2 ± 13.4 | 91.5 ± 13.4 | 91.8 ± 13.0 | 0.321 | 92.2 ± 13.0 | 93.9 ± 12.9 | 96.6 ± 12.2 | <0.001 |
| Education level, n (%) | <0.001 | 0.928 | <0.001 | |||||||||
| Elementary/middle school | 1165 (60.9%) | 951 (54.5%) | 1018 (48.3%) | 312 (39.1%) | 303 (39.1%) | 437 (40.4%) | 853 (76.5%) | 648 (66.7%) | 581 (56.7%) | |||
| High school | 529 (27.7%) | 559 (32.0%) | 747 (35.5%) | 307 (38.5%) | 303 (39.1%) | 402 (37.1%) | 222 (19.9%) | 256 (26.4%) | 345 (33.7%) | |||
| College/university | 219 (11.4%) | 236 (13.5%) | 342 (16.2%) | 179 (22.4%) | 169 (21.8%) | 244 (22.5%) | 40 (3.6%) | 67 (6.9%) | 98 (9.6%) | |||
| Household income, n (%) | <0.001 | 0.159 | <0.001 | |||||||||
| <100 million Korean Won | 706 (37.2%) | 603 (34.7%) | 588 (28.1%) | 187 (23.6%) | 204 (26.3%) | 265 (24.5%) | 519 (46.9%) | 399 (41.5%) | 323 (31.9%) | |||
| 100–200 million Korean Won | 545 (28.7%) | 499 (28.7%) | 633 (30.2%) | 242 (30.6%) | 212 (27.4%) | 352 (32.5%) | 303 (27.4%) | 287 (29.8%) | 281 (27.8%) | |||
| >200 million Korean Won | 647 (34.1%) | 635 (36.6%) | 872 (41.7%) | 363 (45.8%) | 359 (46.3%) | 465 (43.0%) | 284 (25.7%) | 276 (28.7%) | 407 (40.3%) | |||
| Total energy intake, kcal/day | 1820.0 ± 528.8 | 2134.7 ± 755.2 | 2519.8 ± 868.2 | <0.001 | 1926.4 ± 507.4 | 2209.1 ± 762.0 | 2556.4 ± 769.6 | <0.001 | 1744.5 ± 531.0 | 2075.4 ± 744.8 | 2481.2 ± 960.4 | <0.001 |
| † Protein/total energy intake, % | 12.7 ± 2.0 | 13.3 ± 2.3 | 14.2 ± 2.4 | <0.001 | 13.0 ± 2.0 | 13.5 ± 2.3 | 14.1 ± 2.3 | <0.001 | 12.4 ± 2.0 | 13.2 ± 2.2 | 14.3 ± 2.5 | <0.001 |
* p value for the comparison of the baseline characteristics among sex-specific tertile groups of oxidative balance score at the baseline survey. † Protein/total energy intake was calculated as 100 × 4 (kcal/g) × protein intake (g/day)/total energy intake (kcal/day). Statistical significance was set at p < 0.05. Abbreviations: MBP, mean blood pressure; HDL, high-density lipoprotein; CRP, C-reactive protein; eGFR, estimated glomerular filtration rate.