Table 2.
RRs (95% CIs) for bladder cancer in relation to quintiles of nitrate exposure in age- and sex-adjusted and multivariable analyses: the Netherlands Cohort Study, 1986–1995.
| Nitrate exposure [range (median), mg/day] | Cases | Subcohort (PY) | RR (95% CI)a | RR (95% CI)b | RR (95% CI)c |
|---|---|---|---|---|---|
| Food | |||||
| 2.0–69.0 (57.4) | 168 | 8,512 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 69.0–88.0 (78.6) | 186 | 8,652 | 1.14 (0.89–1.45) | 1.16 (0.90–1.50) | 1.15 (0.89–1.50) |
| 88.0–107.5 (97.8) | 181 | 8,706 | 1.00 (0.78–1.27) | 1.04 (0.80–1.34) | 1.05 (0.81–1.37) |
| 107.5–135.3 (119.5) | 180 | 8,707 | 1.02 (0.80–1.30) | 1.06 (0.82–1.37) | 1.05 (0.81–1.37) |
| 135.3–451.1 (158.9) | 174 | 8,564 | 1.01 (0.79–1.29) | 1.06 (0.81–1.37) | 1.04 (0.80–1.36) |
| p-Trend | 0.72 | 0.96 | 0.96 | ||
| Increment in 10 mg/day | 1.00 (0.98–1.01) | 1.00 (0.98–1.02) | 1.00 (0.98–1.02) | ||
| Drinking water | |||||
| 0–0.9 (0.5) | 167 | 8,421 | 1.00 (Reference) | 1.00 (Reference) | 1.00 (Reference) |
| 0.9–2.4 (1.4) | 147 | 8,386 | 0.86 (0.66–1.10) | 0.84 (0.64–1.11) | 0.84 (0.64–1.11) |
| 2.4–4.4 (3.4) | 185 | 8,476 | 1.10 (0.86–1.40) | 1.11 (0.86–1.44) | 1.11 (0.86–1.44) |
| 4.4–7.7 (5.6) | 179 | 8,530 | 1.05 (0.82–1.34) | 1.08 (0.84–1.40) | 1.08 (0.84–1.40) |
| 7.7–92.7 (10.6) | 193 | 8,515 | 1.11 (0.87–1.41) | 1.06 (0.82–1.37) | 1.06 (0.82–1.38) |
| p-Trend | 0.14 | 0.23 | 0.24 | ||
| Increment in 10 mg/day | 1.10 (0.98–1.23) | 1.09 (0.96–1.24) | 1.09 (0.96–1.24) | ||
| Total nitrate | |||||
| 2.4–72.7 (60.5) | 159 | 8,297 | 1.00 (Reference) | 1.00 (Reference) | |
| 72.7–92.9 (83.2) | 179 | 8,496 | 1.20 (0.93–1.53) | 1.26 (0.97–1.64) | |
| 92.9–112.7 (102.4) | 189 | 8,606 | 1.11 (0.87–1.42) | 1.18 (0.91–1.53) | |
| 112.7–140.8 (125.0) | 174 | 8,530 | 1.08 (0.84–1.39) | 1.17 (0.89–1.52) | |
| 140.8–525.4 (165.4) | 170 | 8,399 | 1.03 (0.80–1.32) | 1.09 (0.84–1.42) | |
| p-Trend | 0.86 | 0.77 | |||
| Increment in 10 mg/day | 1.00 (0.98–1.02) | 1.00 (0.99–1.02) | |||
PY, person-years.
a
Adjusted for age (years) and sex.
b
Adjusted for age (years), sex, current smoking (yes/no), smoking amount (cigarettes/day), and smoking duration (years).
c
Adjusted for age (years), sex, current smoking (yes/no), smoking amount (cigarettes/day), smoking duration (years), and nitrate exposure from food (for drinking water analyses only) or nitrate exposure from drinking water (for food analyses only).