Table 1.
Participants’ characteristics across quartiles of dietary inflammatory index (DII) among 1534 controls. Italy, 1992–2004.
| Characteristics | DII quartiles | ||||
|---|---|---|---|---|---|
| < −1.88 | −1.88,−0.66 | −0.65,0.78 | >0.78 | p valueb | |
| N (%) | N (%) | N (%) | N (%) | ||
| Sex | <0.0001 | ||||
| Male | 284 (74.1) | 256 (66.7) | 236 (61.5) | 212 (55.4) | |
| Female | 99 (25.9) | 128 (33.3) | 148 (38.5) | 171 (44.6) | |
| Age (years) | 0.004 | ||||
| <50 | 79 (20.6) | 65 (16.9) | 53 (13.8) |
49 (12.8) | |
| 50–59 | 108 (28.2) | 111 (28.9) | 108 (28.1) | 80 (20.9) | |
| 60–69 | 125 (32.6) | 130 (33.8) | 138 (35.9) | 162 (42.3) | |
| ≥70 | 71 (18.5) | 78 (20.3) | 85 (22.1) | 92 (24.0) | |
| Education (years) | 0.35 | ||||
| <7 | 207 (54.1) | 198 (51.6) | 216 (56.3) | 228 (59.5) | |
| 7–11 | 120 (31.3) | 118 (30.7) | 115 (30.0) | 104 (27.2) | |
| ≥12 | 56 (14.6) | 68 (17.7) | 53 (13.8) | 51 (13.3) | |
| Body mass index(kg/m2) a | 0.01 | ||||
| <25 | 120 (31.3) | 125 (32.6) | 158 (41.4) | 158 (41.6) | |
| 25 to <30 | 203 (53.0) | 201 (52.3) | 178 (46.6) | 168 (44.2) | |
| ≥30 | 60 (15.7) | 58 (15.1) | 46 (12.0) | 54 (14.2) | |
| Tobacco smoking | 0.13 | ||||
| Never smokers | 150 (39.2) | 156 (40.6) | 161 (41.9) |
173 (45.2) | |
| Ex-smokersc | 130 (33.9) | 105 (27.3) | 97 (25.3) | 96 (25.1) | |
| Current smokers | |||||
| <20 cigarettes/day |
60 (15.7) | 79 (20.6) | 70 (18.2) | 68 (17.8) | |
| ≥20 cigarettes/day |
43 (11.2) | 44 (11.5) | 56 (14.6) | 46 (12.0) | |
| Family history of kidney cancerd |
0.01 | ||||
| No | 383 | 383 (99.7) | 378 (98.4) | 382 (99.7) | |
| Yes | 0 (0.0) | 1 (0.3) | 6 (1.6) | 1 (0.3) | |
a
The sum does not add up to the total because of some missing values
b
p value from Chi-square test
c
Ex-smokers were subjects who had stopped smoking for at least 4 years
d
In first-degree relatives