Plasma folate, vitamin B6,vitamin B12, homocysteine, and risk of breast cancer
Plasma folate, vitamin B6,vitamin B12, homocysteine, and risk of breast cancer
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DOI：
10.1093/jnci/95.5.373
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发表时间：
2003-03-05
期刊：
影响因子：
--
通讯作者：
Hankinson, SE
中科院分区：
文献类型：
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作者：
Zhang, SM;Willett, WC;Hankinson, SE
背景资料。在几项流行病学调查中，叶酸摄入似乎可以降低与适度饮酒相关的乳腺癌风险。然而，将血浆叶酸水平与乳腺癌风险联系起来的数据很少。在一项前瞻性的嵌套病例对照研究中，我们调查了血浆叶酸和其他维生素与乳腺癌的关系。方法：采自1989~1990年间参加护士健康研究的32 826名妇女的血样，这些妇女在1996年间接受了乳腺癌的跟踪调查。我们确定了712例乳腺癌患者，并选择了712名单独匹配的对照受试者。饮食信息是通过1980年、1984年、1986年和1990年提供的食物频率问卷获得的。用Logistic回归估计乳腺癌的相对危险度(在调整潜在危险因素后)，并用广义线性模型计算血浆叶酸、维生素B-6、维生素B-12和同型半胱氨酸估计值与叶酸、维生素B-6和维生素B-12摄入量之间的皮尔逊相关系数。所有的统计检验都是双面的。结果：比较血浆叶酸最高五分之一和最低五分位数的多变量RR为0.73(95%可信区间[CI]=0.50~1.07；P趋势=0.06)。在每天饮酒至少15克(即大约1杯/天)的女性(多变量RR=0.11，95%CI=0.02至0.59，最高与最低五分之一)与每天饮酒少于15克(多变量RR=0.72，95%CI=0.49至1.05)的女性中，血浆叶酸与乳腺癌风险之间的负相关在统计学上具有非常显著的意义。血浆维生素B-6水平最高五分位数与最低五分位数比较的多变量RR为0.70(95%CI=0.48~1.02；P-趋势=0.09)。在绝经前妇女中，血浆维生素B-12水平与乳腺癌风险呈负相关(多变量RR=0.36，最高与最低五分位数的95%CI=0.15~0.86)，但在绝经后妇女中不存在。血浆同型半胱氨酸与乳腺癌风险无关。结论：较高的血浆叶酸水平和可能的维生素B-6水平可能会降低患乳腺癌的风险。对于患乳腺癌风险较高的女性来说，达到足够的叶酸循环水平可能特别重要，因为女性饮酒量较高。
Background. In several epidemiologic investigations, folate intake has appeared to reduce the elevated risk of breast cancer associated with moderate alcohol consumption. However, data relating plasma folate levels to breast cancer risk are sparse. We investigated the association between plasma folate and other vitamins with breast cancer in a prospective, nested case-control study. Methods: Blood samples were obtained during 1989 and 1990 from 32 826 women in the Nurses' Health Study who were followed through 1996 for the development of breast cancer. We identified 712 breast cancer case patients and selected 712 individually matched control subjects. Dietary information was obtained using food frequency questionnaires given in 1980, 1984, 1986, and 1990. Logistic regression was used to estimate the relative risks (RRs) of breast cancer (after adjustment for potential risk factors), and a generalized linear model was used to calculate the Pearson correlation coefficients between plasma estimates of folate, vitamin B-6, vitamin B-12, and homocysteine, and intakes of folate, vitamin B-6, and vitamin B-12. All statistical tests were two-sided. Results: The multivariable RR comparing women in the highest quintile of plasma folate with those in the lowest was 0.73 (95% confidence interval [CI] = 0.50 to 1.07; P-trend =.06). The inverse association between plasma folate and breast cancer risk was highly statistically significant among women consuming at least 15 g/day (i.e., approximately 1 drink/day) of alcohol (multivariable RR = 0.11, 95% CI = 0.02 to 0.59 for highest versus lowest quintile) in contrast with that of women consuming less than 15 g/day (multivariable RR = 0.72, 95% CI = 0.49 to 1.05). The multivariable RR comparing women in the highest quintile of plasma vitamin B-6 levels with those in lowest quintile was 0.70 (95% CI = 0.48 to 1.02; P-trend =.09). Plasma vitamin B-12 levels were inversely associated with breast cancer risk among premenopausal women (multivariable RR = 0.36, 95% CI = 0.15 to 0.86 for highest versus lowest quintile) but not among postmenopausal women. Plasma homocysteine was not associated with breast cancer risk. Conclusions: Higher plasma levels of folate and possibly vitamin B-6 may reduce the risk of developing breast cancer. Achieving adequate circulating levels of folate may be particularly important for women at higher risk of developing breast cancer because of higher alcohol consumption.