Zhang Yu-Fei, Zhou Li, Zhang Hong-Wei, Hou An-Ji, Gao Hong-Fang, Zhou Yu-Hao
Department of Oncology, Shanghai Seventh People's Hospital, Shanghai, China.
Department of Rehabilitation Institute, Shanghai Seventh People's Hospital, Shanghai, China.
PLoS One. 2014 Apr 8;9(4):e93465. doi: 10.1371/journal.pone.0093465. eCollection 2014.
Studies have reported inconsistent results regarding the existence of an association between folate intake and the risk of lung cancer. The purpose of this study was to summarize the evidence from prospective cohort studies regarding this relationship by using a dose-response meta-analytic approach.
In September 2013, we performed electronic searches in PubMed, Embase, and the Cochrane Library to identify studies examining the effect of folate intake on the incidence of lung cancer. Only prospective cohort studies that reported the effect estimates about the incidence of lung cancer with 95% confidence intervals (CIs) for more than 2 categories of folate intake were included. Overall, we examined 9 cohort studies reporting the data of 566,921 individuals. High folate intake had little effect on the risk of lung cancer (risk ratio [RR], 0.92; 95% CI, 0.84-1.01; P = 0.076). Dose-response meta-analysis also suggested that a 100 µg/day increase in folate intake had no significant effect on the risk of lung cancer (RR, 0.99; 95% CI, 0.97-1.01; P = 0.318). Subgroup analysis suggested that the potential protective effect of low folate intake (100-299 µg/day) was more evident in women than men, while the opposite was true of high folate intake (>400 µg/day). Finally, subgroup analyses of a 100 µg/day increment in folate intake indicated that its potential protective effect was more evident in men than in women.
CONCLUSION/SIGNIFICANCE: Our study revealed that folate intake had little or no effect on the risk of lung cancer. Subgroup analyses indicated that an increased folate intake was associated with a reduced risk of lung cancer in men. Furthermore, low folate intake may be a protective factor for women, and high folate intake for men.
关于叶酸摄入量与肺癌风险之间是否存在关联，研究报告的结果并不一致。本研究的目的是通过剂量反应荟萃分析方法，总结前瞻性队列研究中关于这种关系的证据。
2013年9月，我们在PubMed、Embase和Cochrane图书馆进行了电子检索，以识别研究叶酸摄入量对肺癌发病率影响的研究。仅纳入报告了超过2类叶酸摄入量的肺癌发病率效应估计值及95%置信区间（CI）的前瞻性队列研究。总体而言，我们审查了9项队列研究，报告了566,921人的数据。高叶酸摄入量对肺癌风险影响不大（风险比[RR]，0.92；95%CI，0.84 - 1.01；P = 0.076）。剂量反应荟萃分析还表明，叶酸摄入量每天增加100μg对肺癌风险无显著影响（RR，0.99；95%CI，0.97 - 1.01；P = 0.318）。亚组分析表明，低叶酸摄入量（100 - 299μg/天）的潜在保护作用在女性中比男性更明显，而高叶酸摄入量（>400μg/天）则相反。最后，叶酸摄入量每天增加100μg的亚组分析表明，其潜在保护作用在男性中比女性更明显。
结论/意义：我们的研究表明，叶酸摄入量对肺癌风险几乎没有影响。亚组分析表明，叶酸摄入量增加与男性肺癌风险降低有关。此外，低叶酸摄入量可能是女性的保护因素，而高叶酸摄入量对男性而言。
