Table 3.

Multivariate HR and 95% CI according to quintile of nitrite and nitrate intake and glioma risk

Nitrite or nitrate intakeQuintile of intakeP for trendP for sex interaction
Q1Q2Q3Q4Q5
Nitrite
    Median intake*0.450.570.650.740.90
    No. of cases101129106118131
    Multivariate HR1.001.251.031.161.320.0890.32
    95% CI(Reference)0.96–1.630.79–1.360.89–1.521.01–1.71
Plant sources
    Median intake*0.250.340.420.510.68
    No. of cases87142117112127
    Multivariate HR1.001.621.361.351.590.0280.030
    95% CI(Reference)1.24–2.121.03–1.801.01–1.791.20–2.10
    Plant sources (males)
        No. of cases59113847786
        Multivariate HR1.002.021.611.632.040.0026
        95% CI(Reference)1.47–2.771.15–2.251.16–2.301.46–2.87
    Plant sources (females)
        No. of cases2829333541
        Multivariate HR1.000.840.840.790.840.57
        95% CI(Reference)0.50–1.410.51–1.400.48–1.300.51–1.36
Animal sources
    Median intake*0.100.150.200.250.36
    No. of cases123112119107124
    Multivariate HR1.000.870.910.800.900.450.11
    95% CI(Reference)0.68–1.130.71–1.170.62–1.040.70–1.16
Nitrate
    Median intake*19.3529.9240.9557.4094.85
    No. of cases98114135126112
    Multivariate HR1.001.161.411.371.280.140.99
    95% CI(Reference)0.89–1.521.09–1.841.05–1.790.97–1.70
Plant sources
    Median intake*16.5627.0338.0154.4992.06
    No. of cases101109136125114
    Multivariate HR1.001.081.381.311.260.120.98
    95% CI(Reference)0.82–1.411.06–1.791.01–1.710.96–1.67
Animal sources
    Median intake*1.512.172.693.284.34
    No. of cases119125121105115
    Multivariate HR1.001.020.990.881.030.860.32
    95% CI(Reference)0.80–1.310.77–1.280.68–1.150.79–1.33
Nitrite plus nitrate
Processed meat sources
    Median intake*0.110.290.490.771.43
    No. of cases100121135109120
    Multivariate HR1.001.151.240.971.040.560.79
    95% CI(Reference)0.88–1.500.95–1.610.74–1.280.79–1.36
  • *mg/1,000 kcal/d.

  • Adjusted for sex, age (continuous), race (non-Hispanic white, non-Hispanic black, other, and missing), energy intake (continuous), education (<high school, high school graduate, post–high school other than college, some college, college graduate, postgraduate, and missing), height (eight prespecified categories and missing), and history of cancer at baseline (yes, no, and missing).