Table 4.
Association Between Dietary Total and Heme Iron Intake and Risk of Crohn’s and Ulcerative Colitis According to Genetic Susceptibility*
| Control (n=693) | Crohn’s disease (n=161) | Ulcerative colitis (n= 185) | ||
|---|---|---|---|---|
| Entire Cohort (NHS + NHSII) | ||||
| Dietary Iron Intake | ||||
| RS1801274 (FcγRIIA) | GG (n = 205) | 1.00 | 0.98 (0.70–1.38) | 0.91 (0.66–1.26) |
| GA (n = 391) | 1.00 | 1.01 (0.83–1.22) | 1.04 (0.89–1.21) | |
| AA (n = 227) | 1.00 | 1.06 (0.83–1.33) | 1.00 (0.80–1.25) | |
| Pinteraction§ | 0.68 | 0.65 | ||
| Dietary Heme Iron Intake | ||||
| RS1801274 (FcγRIIA) | GG (n = 205) | 1.00 | 0.55 (0.17–1.80) | 0.11 (0.03–0.37) |
| GA (n = 391) | 1.00 | 0.61 (0.28–1.29) | 1.27 (0.65–2.50) | |
| AA (n = 227) | 1.00 | 1.22 (0.45–3.34) | 2.76 (1.02–2.78) | |
| Pinteraction§ | 0.40 | 7.00E-05 |
*
Odds ratios are calculated for every 1 g increase in dietary total or heme iron intake.
§
Models are adjusted for age (years), ancestry (Scandinavian, southern European/Mediterranean, others), smoking (never, past, current), body mass index at baseline (< 20,20–24.9, 25–29.9, ≥ 30 kg/m2, cumulative average of physical activity (MET-hr/wk), cohorts (NHS, NHSII), cumulative average of fiber intake (g/day), and total caloric intake.