TABLE 1.
Characteristics of the participants according to the quartiles of dietary inflammatory index.
| Variable | Total | Q1 (anti-inflammatory) | Q2 | Q3 | Q4 (pro- inflammatory) | P-value* | |
| Total (%) | 9,824 (100) | 2,456 (25.0) | 2,456 (25.0) | 2,456 (25.0) | 2,456 (25.0) | ||
| Mean (min, max) | –0.84 (–5.00, 4.64) | –2.82 (–5.00, –2.02) | –1.51 (–2.08, –1.02) | –0.45 (–1.02, 0.25) | 1.40 (0.25, 4.64) | ||
| Gender | Male | 4,610 (46.93) | 1,518 (32.93) | 1,389 (30.13) | 1,049 (22.75) | 654 (14.19) | <.001 |
| Female | 5,214 (53.07) | 938 (17.99) | 1,067 (20.46) | 1,407 (26.99) | 1,802 (34.56) | ||
| Age group | 35–45 | 4,298 (43.75) | 1,172 (27.27) | 1,198 (27.87) | 1,074 (24.99) | 854 (19.87) | <.001 |
| 46–55 | 3,284 (33.43) | 850 (25.88) | 779 (23.72) | 479 (21.36) | 821 (25.00) | ||
| 56–65 | 2,242 (22.82) | 434 (25.00) | 479 (21.36) | 548 (24.44) | 781 (34.83) | ||
| Education level | Illiterate | 2,435 (24.79) | 389 (15.98) | 452 (18.56) | 602 (24.72) | 992 (40.74) | <.001 |
| 1–5 years | 3,762 (38.29) | 844 (22.43) | 937 (24.91) | 989 (26.29) | 992 (26.37) | ||
| 6–9 years | 1,629 (16.58) | 502 (30.82) | 468 (28.73) | 4,069 (24.92) | 253 (15.53) | ||
| 10.12 years | 1,224 (12.46) | 425 (34.72) | 363 (29.66) | 293 (23.94) | 143 (11.68) | ||
| >13ψεαρσ | 774 (7.88) | 296 (38.24) | 236 (30.49) | 166 (21.45) | 76 (9.82) | ||
| Place of residence | City | 5,806 (59.10) | 1,912 (32.93) | 1,610 (27.73) | 1,344 (23.15) | 940 (16.19) | <.001 |
| Village | 4,018 (40.90) | 544 (13.54) | 846 (21.06) | 1,112 (27.68) | 15,169 (37.73) | ||
| Physical Activity (MET-hours per day) | 24–36.5 | 2,724 (24.74) | 694 (25.48) | 699 (25.66) | 6,849 (25.11) | 647 (23.75) | <.001 |
| 36.6–44.9 | 5,073 (51.66) | 1,188 (23.42) | 1,209 (23.83) | 1,285 (25.33) | 1,391 (27.42) | ||
| ≥45 | 2,023 (20.60) | 573 (28.32) | 547 (27.04) | 485 (23.97) | 418 (20.66) | ||
| Smoking status | No | 7,866 (80.27) | 1,897 (24.12) | 1,910 (24.25) | 2,002 (25.45) | 2,057 (26.15) | <.001 |
| Current | 1,130 (11.53) | 311 (27.52) | 324 (28.67) | 273 (24.16) | 222 (19.65) | ||
| Former | 804 (8.20) | 239 (29.73) | 216 (26.87) | 177 (22.01) | 172 (21.39) | ||
| BMI (kg/m2) | <18.9 | 164 (1.68) | 21 (12.80) | 34 (20.73) | 52 (31.71) | 57 (34.76) | <.001 |
| 19–24.9 | 2,683 (27.52) | 594 (22.14) | 638 (23.78) | 676 (25.20) | 775 (28.89) | ||
| 25–29.9 | 4,241 (43.51) | 1,078 (25.42) | 1,115 (26.29) | 1,052 (24.81) | 996 (23.49) | ||
| 30–34.9 | 2,087 (21.41) | 574 (27.50) | 519 (24.87) | 509 (24.39) | 485 (23.24) | ||
| ≥35 | 573 (5.88) | 167 (29.14) | 135 (23.56) | 143 (24.96) | 128 (22.34) | ||
| HEI | 1st quintile (poorest) | 2,071 (21.09) | 143 (6.90) | 342 (16.51) | 585 (28.25) | 1,001 (48.330 | <.001 |
| 2nd quintile | 1,890 (19.24) | 287 (15.19) | 481 (25.45) | 537 (28.41) | 585 (30.95) | ||
| 3rd quintile | 2,115 (21.54) | 497 (23.5) | 579 (27.38) | 582 (27.52) | 457 (21.61) | ||
| 4th quintile | 1,845 (18.79) | 634 (34.36) | 5,499 (29.76) | 414 (22.44) | 248 (13.44) | ||
| 5th quintile (highest) | 1,900 (19.35) | 895 (47.11) | 505 (26.58) | 337 (17.74) | 163 (8.58) | ||
| Kidney stone | No | 8,025 (81.74) | 1,958 (24.40) | 2,030 (25.30) | 2,001 (24.93) | 2,036 (25.37) | 0.01 |
| Yes | 1,791 (18.24) | 498 (27.69) | 424 (23.67) | 418 (23.34) | 418 (23.34) | ||
| Type 2 diabetes | No | 8,964 (91.79) | 2,239 (24.98) | 2,243 (25.02) | 2,236 (25.06) | 2,246 (25.06) | 0.98 |
| Yes | 802 (8.21) | 200 (24.94) | 198 (24.69) | 205 (25.56) | 199 (24.81) | ||
| Hypertension | No | 8,251 (84.18) | 2,111 (25.58) | 2,126 (25.77) | 2,043 (24.76) | 1971 (23.89) | <.001 |
| Yes | 1,551 (15.82) | 341 (21.99) | 328 (21.15) | 405 (26.11) | 477 (30.75) | ||
| eGFR | Mean ± SD | 76.1 ± 14.1 | 80.0 ± 13.4 | 78.3 ± 14.3 | 75.5 ± 13.7 | 70.7 ± 13.4 | <.001 |
| Creatinine (mg/dL) | Mean ± SD | 0.99 ± 0.18 | 0.98 ± 0.17 | 0.99 ± 0.19 | 0.98 ± 0.17 | 0.99 ± 0.17 | 0.9 |
| Urea | Mean ± SD | 13.56 ± 4.2 | 13.91 ± 4.1 | 13.7 ± 4.1 | 13.3 ± 3.9 | 13.2 ± 2.3 | 0.4 |
*p-value < 0.05 were considered statistically significant.