Zeegers Maurice P, Selen Roel F M, Kleinjans Jos C S, Goldbohm R Alexandra, van den Brandt Piet A
Department of Public Health and Epidemiology, University of Birmingham, Birmingham, United Kingdom.
Environ Health Perspect. 2006 Oct;114(10):1527-31. doi: 10.1289/ehp.9098.
N-nitroso compounds, endogenously formed from nitrate-derived nitrite, are suspected to be important bladder carcinogens. However, the association between nitrate exposure from food or drinking water and bladder cancer has not been substantially investigated in epidemiologic studies.
We evaluated the associations between nitrate exposure and bladder cancer in the Netherlands Cohort Study, conducted among 120,852 men and women, 55-69 years of age at entry. Information on nitrate from diet was collected via a food frequency questionnaire in 1986 and a database on nitrate content of foods. Individual nitrate exposures from beverages prepared with tap water were calculated by linking the postal code of individual residence at baseline to water company data. After 9.3 years of follow-up and after excluding subjects with incomplete or inconsistent dietary data, 889 cases and 4,441 subcohort members were available for multivariate analyses. We calculated incidence rate ratios (RR) and corresponding 95% confidence intervals (CIs) using Cox regression analyses. We also evaluated possible effect modification of dietary intake of vitamins C and E (low/high) and cigarette smoking (never/ever).
The multivariate RRs for nitrate exposure from food, drinking water, and estimated total nitrate exposure were 1.06 (95% CI, 0.81-1.31), 1.06 (95% CI, 0.82-1.37), and 1.09 (95% CI, 0.84-1.42), respectively, comparing the highest to the lowest quintiles of intake. Dietary intake of vitamins C and E (low/high) and cigarette smoking (never/ever) had no significant impact on these results.
Although the association between nitrate exposure and bladder cancer risk is biologically plausible, our results in this study do not support an association between nitrate exposure and bladder cancer risk.
由硝酸盐衍生的亚硝酸盐内源性形成的N-亚硝基化合物被怀疑是重要的膀胱癌致癌物。然而，食物或饮用水中硝酸盐暴露与膀胱癌之间的关联在流行病学研究中尚未得到充分调查。
我们在荷兰队列研究中评估了硝酸盐暴露与膀胱癌之间的关联，该研究纳入了120,852名年龄在55至69岁之间的男性和女性。1986年通过食物频率问卷以及食物硝酸盐含量数据库收集了饮食中硝酸盐的信息。通过将个体在基线时的居住邮政编码与自来水公司数据相联系，计算了用自来水制备的饮料中的个体硝酸盐暴露量。经过9.3年的随访，并排除了饮食数据不完整或不一致的受试者后，889例病例和4441名队列成员可用于多变量分析。我们使用Cox回归分析计算发病率比值（RR）和相应的95%置信区间（CI）。我们还评估了维生素C和E的饮食摄入量（低/高）以及吸烟（从不/曾经）可能产生的效应修饰作用。
食物、饮用水中硝酸盐暴露以及估计的总硝酸盐暴露的多变量RR分别为1.06（95%CI，0.81 - 1.31）、1.06（95%CI，0.82 - 1.37）和1.09（95%CI，0.84 - 1.42），比较的是摄入量最高与最低五分位数。维生素C和E的饮食摄入量（低/高）以及吸烟（从不/曾经）对这些结果没有显著影响。
尽管硝酸盐暴露与膀胱癌风险之间的关联在生物学上看似合理，但我们在本研究中的结果并不支持硝酸盐暴露与膀胱癌风险之间存在关联。
