Table 2. General characteristics of the participants according to the PI quintiles (KNHANES 2008–2016, n = 31,319).
| Quintile of PI | P value | ||||||
|---|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | Q5 | |||
| No. of participants | 6,263 | 6,264 | 6,264 | 6,264 | 6,264 | ||
| PI, median | 3.23 | 7.40 | 12.04 | 18.23 | 30.82 | ||
| Sex, men | 3,143 (50.18) | 2,924 (46.68) | 2,582 (41.22) | 2,195 (35.04) | 1,717 (27.41) | < 0.001 | |
| Age (yrs) | < 0.001 | ||||||
| 19–29 | 1,654 (26.41) | 1,111 (17.74) | 917 (14.64) | 695 (11.10) | 517 (8.25) | ||
| 30–39 | 1,794 (28.64) | 1,803 (28.78) | 1,522 (24.30) | 1,260 (20.11) | 991 (15.82) | ||
| 40–49 | 1,223 (19.53) | 1,520 (24.27) | 1,505 (24.03) | 1,547 (24.70) | 1,387 (22.14) | ||
| 50–59 | 688 (10.99) | 889 (14.19) | 1,136 (18.14) | 1,350 (21.55) | 1,720 (27.46) | ||
| ≥ 60 | 904 (14.43) | 941 (15.02) | 1,184 (18.90) | 1,412 (22.54) | 1,649 (26.33) | ||
| Household income2) | < 0.001 | ||||||
| Low | 1,872 (30.26) | 1,569 (25.33) | 1,447 (23.32) | 1,290 (20.79) | 1,200 (19.32) | ||
| Mid-low | 1,610 (26.02) | 1,586 (25.61) | 1,544 (24.88) | 1,540 (24.82) | 1,452 (23.38) | ||
| Mid-high | 1,468 (23.73) | 1,571 (25.36) | 1,591 (25.64) | 1,641 (26.45) | 1,653 (26.61) | ||
| High | 1,237 (19.99) | 1,468 (23.70) | 1,623 (26.16) | 1,733 (27.93) | 1,906 (30.69) | ||
| Education level2) | < 0.001 | ||||||
| Less than high school graduation | 1,336 (22.29) | 1,397 (23.19) | 1,565 (26.07) | 1,684 (28.10) | 1,804 (30.16) | ||
| High school graduation or higher | 4,658 (77.71) | 4,628 (76.81) | 4,439 (73.93) | 4,309 (71.90) | 4,178 (69.84) | ||
| Smoking status2) | < 0.001 | ||||||
| Non-smoker | 3,062 (50.32) | 3,392 (55.59) | 3,755 (61.70) | 4,151 (68.17) | 4,612 (75.68) | ||
| Smoker | 3,023 (49.68) | 2,710 (44.41) | 2,331 (38.30) | 1,938 (31.83) | 1,482 (24.32) | ||
| Alcohol consumption (yes)2) | 5,026 (82.79) | 4,991 (81.91) | 4,712 (77.56) | 4,458 (73.33) | 4,146 (68.12) | < 0.001 | |
| Obesity status2) | 0.008 | ||||||
| Underweight/normal | 3,192 (51.04) | 3,046 (48.69) | 3,141 (50.19) | 3,095 (49.45) | 3,010 (48.08) | ||
| Overweight/obese | 3,062 (48.96) | 3,210 (51.31) | 3,117 (49.81) | 3,164 (50.55) | 3,250 (51.92) | ||
| Physical activity1,2) | < 0.001 | ||||||
| Low | 2,112 (35.21) | 2,018 (33.48) | 2,049 (34.08) | 1,982 (33.06) | 1,841 (30.76) | ||
| Middle | 1,899 (31.66) | 2,002 (33.21) | 1,987 (33.05) | 2,022 (33.72) | 2,141 (35.77) | ||
| High | 1,988 (33.14) | 2,008 (33.31) | 1,977 (32.88) | 1,992 (33.22) | 2,003 (33.47) | ||
Values are presented as number of patients (%).
PI, phytochemical index; KNHANES, Korea National Health and Nutrition Examination Survey; Q, quintile.
1)Physical activity level was calculated as metabolic equivalents of task (MET-hours per week) and grouped into tertiles.
2)These categories had missing data, and the total n values are not identical.