Logistic regression estimates of colon outcomes according to quartiles of total dietary, soluble and insoluble fibres and measures of non-steroidal anti-inflammatory drug use (n fibre =2194; n NSAID =2548)
| Polyps | High-risk adenomatous polyps | |||||||
| Controls | Cases | Crude OR (95% CI) | Adjusted* OR (95% CI) | Controls | Cases | Crude OR (95% CI) | Adjusted* OR (95% CI) | |
| Total dietary fibre† | ||||||||
| Q1 (low) | 320 | 228 | 1.0 (ref.) | 1.0 (ref.) | 506 | 42 | 1.0 (ref.) | 1.0 (ref.) |
| Q2 | 330 | 215 | 0.91 (0.72 to 1.16) | 0.88 (0.68 to 1.14) | 509 | 36 | 0.85 (0.54 to 1.35) | 0.82 (0.50 to 1.34) |
| Q3 | 334 | 215 | 0.90 (0.71 to 1.15) | 0.86 (0.65 to 1.13) | 510 | 39 | 0.92 (0.59 to 1.45) | 0.93 (0.53 to 1.51) |
| Q4 (high) | 347 | 205 | 0.83 (0.65 to 1.06) | 0.77 (0.56 to 1.07) | 529 | 23 | 0.52 (0.31 to 0.88) | 0.46 (0.23 to 0.93) |
| Ptrend=0.14 | Ptrend=0.14 | Ptrend=0.03 | Ptrend=0.08 | |||||
| Soluble fibre‡ | ||||||||
| Q1 (low) | 314 | 233 | 1.0 (ref.) | 1.0 (ref.) | 506 | 41 | 1.0 (ref.) | 1.0 (ref.) |
| Q2 | 341 | 210 | 0.83 (0.65 to 1.06) | 0.76 (0.59 to 0.99) | 517 | 34 | 0.81 (0.51 to 1.30) | 0.75 (0.45 to 1.25) |
| Q3 | 321 | 224 | 0.94 (0.74 to 1.20) | 0.83 (0.63 to 1.09) | 503 | 42 | 1.03 (0.66 to 1.61) | 0.96 (0.57 to 1.63) |
| Q4 (high) | 355 | 196 | 0.74 (0.58 to 0.95) | 0.62 (0.44 to 0.88) | 528 | 23 | 0.54 (0.32 to 0.91) | 0.48 (0.23 to 0.98) |
| Ptrend=0.05 | Ptrend=0.02 | Ptrend=0.07 | Ptrend=0.16 | |||||
| Insoluble fibre§ | ||||||||
| Q1 (low) | 320 | 227 | 1.0 (ref.) | 1.0 (ref.) | 503 | 44 | 1.0 (ref.) | 1.0 (ref.) |
| Q2 | 333 | 212 | 0.90 (0.70 to 1.14) | 0.89 (0.68 to 1.15) | 510 | 35 | 0.78 (0.49 to 1.24) | 0.80 (0.49 to 1.31) |
| Q3 | 327 | 221 | 0.95 (0.75 to 1.21) | 0.94 (0.71 to 1.23) | 511 | 37 | 0.83 (0.53 to 1.30) | 0.84 (0.50 to 1.41) |
| Q4 (high) | 351 | 203 | 0.82 (0.64 to 1.04) | 0.77 (0.56 to 1.07) | 530 | 24 | 0.52 (0.31 to 0.86) | 0.48 (0.25 to 0.93) |
| Ptrend=0.16 | Ptrend=0.19 | Ptrend=0.02 | Ptrend=0.06 | |||||
| Ever used NSAIDs | ||||||||
| No | 513 | 433 | 1.0 (ref.) | 1.0 (ref.) | 850 | 96 | 1.0 (ref.) | 1.0 (ref.) |
| Yes | 937 | 665 | 0.84 (0.72 to 0.99) | 0.98 (0.83 to 1.16) | 1509 | 93 | 0.55 (0.41 to 0.73) | 0.65 (0.47 to 0.89) |
| NSAID daily dose-years¶ | ||||||||
| None | 513 | 433 | 1.0 (ref.) | 1.0 (ref.) | 850 | 96 | 1.0 (ref.) | 1.0 (ref.) |
| T1 | 246 | 221 | 0.76 (0.61 to 0.94) | 0.87 (0.69 to 1.09) | 536 | 31 | 0.51 (0.34 to 0.78) | 0.60 (0.39 to 0.92) |
| T2 | 279 | 224 | 0.95 (0.77 to 1.18) | 1.12 (0.89 to 1.41) | 469 | 34 | 0.64 (0.43 to 0.96) | 0.76 (0.50 to 1.17) |
| T3 (high) | 312 | 220 | 0.84 (0.67 to 1.04) | 0.99 (0.79 to 1.25) | 504 | 28 | 0.49 (0.32 to 0.76) | 0.63 (0.40 to 1.00) |
| Ptrend=0.21 | Ptrend=0.58 | Ptrend<0.01 | Ptrend=0.03 | |||||
| NSAID use frequency | ||||||||
| No regular use | 513 | 433 | 1.0 (ref.) | 1.0 (ref.) | 850 | 96 | 1.0 (ref.) | 1.0 (ref.) |
| Monthly | 245 | 161 | 0.79 (0.64 to 0.99) | 1.00 (0.79 to 1.26) | 383 | 23 | 0.47 (0.30 to 0.74) | 0.60 (0.37 to 0.95) |
| Weekly | 162 | 130 | 0.89 (0.70 to 1.15) | 1.06 (0.81 to 1.38) | 273 | 19 | 0.56 (0.35 to 0.92) | 0.72 (0.43 to 1.20) |
| Daily | 272 | 193 | 0.84 (0.67 to 1.05) | 0.91 (0.71 to 1.15) | 442 | 23 | 0.46 (0.29 to 0.74) | 0.53 (0.32 to 0.86) |
| Ptrend=0.18 | Ptrend=0.70 | Ptrend<0.01 | Ptrend=0.01 | |||||
*Multivariate models adjusted for age, sex, BMI, smoking status (never, former and current), reason for colonoscopy (average risk, FOBT/FIT+ and family history) and family history of polyps (yes, no). Dietary fibre intake analyses additionally adjusted for total daily caloric intake.
†Quartile cut-offs for total dietary fibre intake were: ≤14.3, 14.31–19.14, 19.15–25.51 and ≥25.52 g/day.
‡Quartile cut-offs for dietary soluble fibre intake were: ≤4.83, 4.84–6.42, 6.43–8.44 and ≥8.45 g/day.
§Quartile cut-offs for dietary insoluble fibre intake were: ≤9.36, 9.37–12.72, 12.73–16.96 and ≥16.98 g/day.
¶Tertile cut-offs for NSAID use were: 4.5×10−5–00.164, 0.165–0.894 and ≥0.904 daily dose-years.
NSAID, non-steroidal anti-inflammatory drug; Ref., reference group.