背景:尽管孕前1,1,1-三氯-2,2,双(对氯苯基)乙烷(DDT)暴露和维生素B缺乏均显示出对人类生殖结果的负面影响,对它们的联合作用知之甚少。
目的:我们试图研究B族维生素充足是否可以防止DDT对临床妊娠(CP)和亚临床早期妊娠丢失(EPL)的不利影响。
方法:我们测量了孕前血浆B族维生素(维生素B-6,维生素B-12和叶酸)和血清总DDT的浓度[p,p\'和o,在291名来自安徽的无效妊娠妇女中,DDT和1,1-二氯-2,2-双(对氯苯基)乙烯的p'异构体,中国,他们在1996-1998年学习。从停止避孕到CP(胎龄≥42d)或12个月(以先发生者为准),对妇女进行前瞻性随访。EPL是通过每天使用尿液人绒毛膜促性腺激素来鉴定的。根据B族维生素状态(不足与不足)和DDT浓度(高与低)对妇女进行分类。
结果:在291名研究女性中,共发生385个概念(其中31%以EPL结尾)和265个CP。与具有足够B族维生素和低DDT的女性相比,B族维生素缺乏症和高DDT浓度女性的CP发生率降低(P<0.05)。最值得注意的是,在维生素B-12充足的女性中,DDT与CP的发病率无关;相反,在缺乏维生素B-12的女性中,高DDT与CP发生率较低相关(HR:0.44;95%CI:0.23,0.84);交互作用检验显著(P<0.05).EPL的几率降低了45%(95%CI:21%,62%)对于DDT浓度高的女性中叶酸的四分位数间距增加,交互作用检验具有显著性(P=0.006)。
结论:我们的研究结果提供了证据,表明维生素B-12和叶酸盐的充足性可能有助于防止滴滴涕暴露对生殖的不利影响。需要更多的研究来证实我们的发现。
BACKGROUND: Although preconception 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane (DDT) exposure and B-vitamin deficiencies have each been shown to negatively affect human reproductive outcomes, little is known about their joint effect.
OBJECTIVE: We sought to examine whether B-vitamin sufficiency protects against adverse effects of DDT on clinical pregnancy (CP) and subclinical early pregnancy loss (EPL).
METHODS: We measured preconception concentrations of plasma B vitamins (vitamin B-6, vitamin B-12, and folate) and serum total DDT [sum of p,p\' and o,p\' isomers of DDT and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] in 291 nulligravid women from Anhui,
China, who were studied in 1996-1998. The women were followed prospectively from the time they stopped contraception until CP (gestational age ≥42 d) or 12 mo (whichever occurred first). EPL was identified by using daily urinary human chorionic gonadotropin. The women were categorized according to B-vitamin status (deficiency compared with sufficiency) and DDT concentration (high compared with low).
RESULTS: Of 291 study women, a total of 385 conceptions (31% of which ended in EPL) and 265 CPs occurred. Compared with women with adequate B-vitamins and low DDT, incidence rates of CP were reduced in women with B-vitamin deficiency and a high DDT concentration (P < 0.05 for all). Most notably, in women with sufficient vitamin B-12, DDT was not associated with the incidence of CP; in contrast, in women with vitamin B-12 deficiency, high DDT was associated with a lower incidence of CP (HR: 0.44; 95% CI: 0.23, 0.84); and the test for interaction was significant (P < 0.05). The odds of EPL decreased by 45% (95% CI: 21%, 62%) for each interquartile distance increase in folate in women with high DDT concentrations, and the test for interaction was significant (P = 0.006).
CONCLUSIONS: Our results provide suggestive evidence that vitamin B-12 and folate sufficiency may help protect against adverse reproductive effects of DDT exposure. Additional studies are needed to confirm our findings.