Taylor Caroline M, Atkinson Charlotte, Penfold Chris, Bhattacharya Sohinee, Campbell Doris, Davey Smith George, Leary Sam, Ness Andy
NIHR Biomedical Research Unit in Nutrition, Diet and Lifestyle, University of Bristol, Bristol, UK.
Dugald Baird Centre for Research on Women's Health, University of Aberdeen, Aberdeen Maternity Hospital, Aberdeen, UK.
J Epidemiol Community Health. 2015 Aug;69(8):789-94. doi: 10.1136/jech-2014-205324. Epub 2015 Apr 8.
Supplemental periconceptional folic acid is recommended to reduce the risk of fetal neural tube defects. A previous report indicated an elevated risk of breast cancer and all cancer deaths in later life among women randomised by alternate allocation to high-dose (5 mg/day) folic acid in pregnancy compared with placebo; however, findings were based on small numbers of cases. Our aim was to extend the previous analysis by including data from an additional 10 years of follow-up.
Records of participants in a large (n=2928) trial of folate supplementation (5 or 0.2 mg folic acid, or placebo) in pregnancy in the 1960s were linked to central registries in Scotland. Unadjusted and adjusted HRs were calculated for all-cause, cardiovascular, all cancer and breast cancer mortality, and all cancer and breast cancer morbidity. Analyses were done using (1) data from the time of the previous linkage (2002) to March 2013; and (2) data from 1980 to March 2013.
There was no evidence to suggest an excess risk of morbidity or mortality in either supplementation group compared with placebo for 2002-2013 and no associations were seen for the full time period (1980-2013).
Findings from this extended follow-up do not support our previous observation of an elevated risk of mortality from breast cancer or all cancers in later life among women who had taken 5 mg folic acid/day during pregnancy. Furthermore, there were no associations with risk of mortality from all-causes, all cancers or cardiovascular disease.
建议孕期补充叶酸以降低胎儿神经管缺陷的风险。先前的一份报告指出，与安慰剂相比，孕期随机分配接受高剂量（5毫克/天）叶酸的女性在晚年患乳腺癌及所有癌症死亡的风险有所升高；然而，这些发现基于少量病例。我们的目的是通过纳入另外10年的随访数据来扩展先前的分析。
20世纪60年代一项关于孕期补充叶酸（5毫克或0.2毫克叶酸，或安慰剂）的大型试验（n = 2928）参与者的记录与苏格兰的中央登记处相关联。计算了全因、心血管、所有癌症和乳腺癌死亡率以及所有癌症和乳腺癌发病率的未调整和调整后的风险比。分析使用了（1）从先前关联时间（2002年）到2013年3月的数据；以及（2）1980年到2013年3月的数据。
对于2002 - 2013年，没有证据表明任何一个补充组与安慰剂相比存在发病或死亡风险过高的情况，并且在整个时间段（1980 - 2013年）未发现关联。
此次延长随访的结果不支持我们先前的观察，即孕期每天服用5毫克叶酸的女性在晚年患乳腺癌或所有癌症死亡风险升高。此外，与全因、所有癌症或心血管疾病的死亡风险没有关联。
