TABLE 2.
Total meat, red meat, and total processed meat intakes and the risk of glioma in the Health Professionals Follow-Up Study (HPFS; 1986–2004), Nurses’ Health Study I (NHS I; 1980–2004), and NHS II (1991–2005)
| Quintile of intake |
||||||
| 1 | 2 | 3 | 4 | 5 | P for trend1 | |
| Total meat2 | ||||||
| Cases | 82 | 66 | 55 | 68 | 64 | |
| Person-years | 810,691 | 826,958 | 835,781 | 835,382 | 792,300 | |
| RR (95% CI)3 | 1.0 | 0.71 (0.51, 0.99) | 0.66 (0.43, 1.01) | 0.88 (0.63, 1.24) | 0.81 (0.55, 1.19) | 0.65 |
| Red meat2 | ||||||
| Cases | 76 | 68 | 66 | 62 | 63 | |
| Person-years | 806,694 | 833,135 | 834,460 | 831,669 | 794,937 | |
| RR (95% CI)3 | 1.0 | 1.12 (0.81, 1.54) | 0.96 (0.68, 1.36) | 0.93 (0.64, 1.34) | 1.09 (0.62, 1.93) | 0.57 |
| Total processed meat2 | ||||||
| Cases | 46 | 69 | 85 | 70 | 65 | |
| Person-years | 545,587 | 831,353 | 929,827 | 903,604 | 890,740 | |
| RR (95% CI)3 | 1.0 | 1.11 (0.75, 1.63) | 1.14 (0.77, 1.69) | 1.17 (0.79, 1.73) | 0.92 (0.48, 1.77) | 0.99 |
Based on the median value of each intake category and modeling these as continuous variables in a Cox proportional hazards model.
Total meat consists of all meats except fish; red meat consists of total meat less chicken and turkey; total processed meat consists of processed meat items (eg, salami and sausage), bacon, and hot dogs. Cutoffs for quintiles were different for each cohort and are based on cumulative updated averages (g/d) over the follow-up periods: total meat (HPFS: 75, 102, 130, and 166; NHS I: 80, 119, 133, and 161; NHS II: 83, 110, 135, and 171), red meat (HPFS: 29, 51, 77, and 111; NHS I: 29, 43, 60, and 79; NHS II: 34, 52, 70, and 102), and total processed meats (HPFS: 1.8, 4.4, 7.6, and 13.9; NHS I: 1.3, 3.9, 7.1, and 12.4; NHS II: 2.1, 4.7, 7.8, and 13.2).
Rate ratios (RRs) and 95% CIs from Cox proportional hazards models were adjusted for age and caloric intake (quintiles). Results were obtained from pooling the β coefficient and SE estimates by using the DerSimonian and Laird random-effects model; no significant evidence of heterogeneity by cohort was observed (α = 0.05).