Table 4.

Cumulative updated intake of caffeine, and the risk of glioma among men in the HPFS (1986-2004) and women in the NHS I (1980-2004) and NHS II (1991-2005)

Quantity of intakeTrend test P
Men
Caffeine (quintile)12345
    Median (mg/d)1473166307538
    Cases/person-years39/150,16128/155,22021/155,11327/158,24718/157,086
    MV RR (95% CI)*1.00 (Reference)0.66 (0.40-1.07)0.52 (0.31-0.90)0.67 (0.41-1.11)0.46 (0.26-0.81)0.03
Women
Caffeine (quintile)12345
    Median (mg/d)40145251378606
    Cases/person-years44/637,95146/671,57639/676,96130/675,91943/666,682
    Pooled MV RR (95% CI)*,1.00 (Reference)0.96 (0.64-1.46)0.80 (0.52-1.23)0.75 (0.30-1.87)0.91 (0.60-1.40)0.43

NOTE: Glioma risk was assessed with relation to the cumulative average of dietary intakes, which was calculated from all dietary questionnaires (see Materials and Methods).

  • *Multivariate RR and 95% CI adjusted for age and total caloric intake.

  • Results were obtained from pooling the β-coefficient and SEM estimates for the women by using the DerSimonian and Laird random-effects model. No significant evidence of heterogeneity by cohort was observed (α = 0.05).