纽约(路透社健康版)12月19日——卡罗琳斯卡大学的研究者在11月号的《生育与不育》上撰文指出，细胞色素P450酶多态性携带者妊娠早期流产的风险要大一些。
细胞色素P450 1B1 (CYP1B1)参与雄性激素和雌性激素以及茶碱、咖啡因还有其它外源化合物与前致癌剂的代谢。CYP1B1在子宫、卵巢和乳房中表达。
斯德哥尔摩的Anna-Helena Karypidis博士和同事们进行了一项人群调查，包括507名妊娠早期流产的妇女和908名妊娠早期正常的对照者。所有的妇女都是CYP1B1基因多态型。母亲的年龄、吸烟状况、咖啡和酒精的摄入、胎儿的染色体组型和恶心以及呕吐都被纳入评估。
Karypidis博士的团队发现CYP1B1变体携带者中流产的概率比是1.46。在妊娠头三个月，CYP1B1多态性同型结合携带者中，咖啡饮用者比不饮用者流产的风险略高。咖啡因增加的风险似乎在吸烟者中无效。
Karypidis博士告诉路透社健康版，咖啡消费与流产之间的关系“可能增加了对自然流产病因学的理解”。
“然而，在介入研究完成之前，基于CYP1B1基因筛选的饮食限制建议是不成熟的，”她警告说。“如果未来的介入试验证实在那些携有危险基因型的人群中限制咖啡因能够降低自然流产的比率，那么那时候进行基因筛选和饮食控制可能是恰当的。”
“CYP1B1酶在子宫中表达，代谢性激素和外源性物质，包括咖啡因，”她解释说。“咖啡因是世界上应用最广泛的外源性化合物之一，并且早年被认为与大量咖啡饮用者中增加的妊娠早期自然流产风险有关。”
研究者补充说，这种变体“确实普遍，因而它在能导致妊娠早期流产的机制中发挥的作用可能有重大临床意义。”
英文原文：
Cytochrome P450 Variant Associated With First Trimester Miscarriage
NEW YORK (Reuters Health) Dec 19 - Carriers of a polymorphism of the cytochrome P450 enzyme are at higher risk of miscarriage in the first trimester of pregnancy, Karolinska University investigators report in the November issue of Fertility and Sterility.
The variant of cytochrome P450 1B1 (CYP1B1) is involved in the metabolism of androgens and estrogen, as well as theophylline, caffeine and other xenobiotics and some procarcinogens. CYP1B1 is expressed in the uterus, ovaries and breast.
Dr. Anna-Helena Karypidis, and colleagues in Stockholm, conducted a population-based study of 507 women with first trimester miscarriages and 908 controls with normal first trimester pregnancies. All of the women were genotyped for the CYP1B1 polymorphism. Maternal age, smoking status, coffee and alcohol intake, fetal karyotype and nausea and vomiting were also assessed.
Dr. Karypidis's team found an odds ratio of 1.46 for miscarriage among carriers of the CYP1B1 variant. Coffee drinkers who were homozygous carriers of the CYP1B1 polymorphism had a slightly higher risk than carriers who did not drink coffee during the first trimester. The increased risk with caffeine appeared to be nullified among smokers.
The link between coffee consumption and miscarriage "might add to the understanding of the etiology of spontaneous abortions," Dr. Karypidis told Reuters Health.
"However, before intervention studies are done, recommendations of diet restrictions based on genetic screening of CYP1B1 are premature," she cautioned. "If future intervention trials prove that caffeine restriction in those carrying the risk genotype will reduce their rate of spontaneous abortions, screening and diet guidance might be appropriate" at that time.
"The enzyme CYP1B1 is present in the uterus and metabolizes both sex hormones and xenobiotics, including caffeine," she explained. "Caffeine is one of the most widely used xenobiotic compounds in the world and has earlier been linked to an increased risk of first trimester spontaneous abortion among heavy coffee drinkers."
The investigators add that the variant "is rather common, and therefore its role in the mechanisms that lead to first trimester miscarriage may be clinically significant."
