TABLE 4.
Cumulative updateda intake of caffeine, and the risk of glioma among men in the Health Professionals Follow-up Study (HPFS, 1986–2004) and women in the Nurses’ Health Study (NHS I, 1980–2004) and NHS II (1991–2005)
| Quantity of Intake | Trend test p-value | |||||
|---|---|---|---|---|---|---|
| Men | ||||||
| Caffeine (quintile) | 1 | 2 | 3 | 4 | 5 | |
| Median (mg/day) | 14 | 73 | 166 | 307 | 538 | |
| Cases/Person-years | 39/150,161 | 28/155,220 | 21/155,113 | 27/158,247 | 18/157,086 | |
| MV RR (95% CI)b | 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) | 1 | 2 | 3 | 4 | 5 | |
| Median (mg/day) | 40 | 145 | 251 | 378 | 606 | |
| Cases/Person-years | 44/637,951 | 46/671,576 | 39/676,961 | 30/675,919 | 43/666,682 | |
| Pooled MV RR (95% CI)b, c | 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 |
a
Glioma risk was assessed with relation to the cumulative average of dietary intakes which was calculated from all dietary questionnaires (see Methods).
b
Multivariate (MV) RR and 95% confidence interval (CI) adjusted for age and total caloric intake.
c
Results were obtained from pooling the beta-coefficient and standard error estimates for the women by using the DerSimonian and Laird random-effects model. No significant evidence of heterogeneity by cohort was observed (alpha=0.05).