Levine Lindsay D, Kim Keewan, Purdue-Smithe Alexandra, Sundaram Rajeshwari, Schisterman Enrique F, Connell Matthew, Devilbiss Elizabeth A, Alkhalaf Zeina, Radoc Jeannie G, Buck Louis Germaine M, Mumford Sunni L
Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, Maryland.
Biostatistics and Bioinformatics Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, Maryland.
J Endocr Soc. 2019 Dec 5;4(2):bvz003. doi: 10.1210/jendso/bvz003. eCollection 2020 Feb 1.
Phytoestrogens may influence fecundability, although biological mechanisms remain elusive. Since it is hypothesized that phytoestrogens may act through influencing hormone levels, we investigated associations between phytoestrogens and menstrual cycle length, a proxy for the hormonal milieu, in healthy women attempting pregnancy.
A population-based prospective cohort of 326 women ages 18 to 40 with self-reported cycles of 21 to 42 days were followed until pregnancy or for 12 months of attempting pregnancy.
Urinary genistein, daidzein, O-desmethylangolensin, equol, enterodiol, and enterolactone were measured upon enrollment. Cycle length was determined from fertility monitors and daily journals. Linear mixed models assessed associations with continuous cycle length and were weighted by the inverse number of observed cycles. Logistic regression models assessed menstrual regularity (standard deviation > 75th vs ≤ 75th percentile). Models were adjusted for age, body mass index, race, creatinine, exercise, supplements, lipids, lead, cadmium, cotinine, parity, alcohol, and other phytoestrogens.
Individual phytoestrogens were not associated with cycle length, although total phytoestrogens were associated with shorter cycles (-0.042 days; 95% confidence interval [CI], -0.080 to -0.003, per 10% increase). Each 1 nmol/L increase in enterolactone (odds ratio [OR] 0.88; 95% CI, 0.79-0.97) and total lignans (OR 0.85; 95% CI, 0.76-0.95) was associated with reduced irregularity, and each 1 nmol/L increase in genistein with irregularity (OR 1.19; 95% CI, 1.02-1.38).
Phytoestrogens were not meaningfully associated with cycle length but may be associated with menstrual regularity, among women with self-reported regular cycles. These results highlight differences between isoflavones and lignans and are reassuring for women attempting pregnancy.
植物雌激素可能会影响受孕能力，但其生物学机制仍不清楚。由于据推测植物雌激素可能通过影响激素水平发挥作用，因此我们在尝试怀孕的健康女性中研究了植物雌激素与月经周期长度（一种激素环境的替代指标）之间的关联。
一项基于人群的前瞻性队列研究，对326名年龄在18至40岁、自我报告月经周期为21至42天的女性进行随访，直至怀孕或尝试怀孕12个月。
入组时测量尿中染料木黄酮、大豆苷元、O-去甲基安哥拉紫檀素、雌马酚、肠二醇和肠内酯的含量。月经周期长度由生育监测器和日常记录确定。线性混合模型评估与连续月经周期长度的关联，并以观察到的周期数的倒数加权。逻辑回归模型评估月经规律性（标准差>第75百分位数与≤第75百分位数）。模型对年龄、体重指数、种族、肌酐、运动、补充剂、血脂、铅、镉、可替宁、产次、酒精和其他植物雌激素进行了校正。
尽管总植物雌激素与较短的月经周期相关（每增加10%，-0.042天；95%置信区间[CI]，-0.080至-0.003），但单个植物雌激素与月经周期长度无关。肠内酯每增加1 nmol/L（比值比[OR] 0.88；95% CI，0.79 - 0.97）和总木脂素每增加1 nmol/L（OR = 0.85；95% CI，0.76 - 0.95）与月经不规律减少相关，而染料木黄酮每增加1 nmol/L与月经不规律增加相关（OR = 1.19；95% CI，1.02 - 1.38）。
在自我报告月经周期规律的女性中，植物雌激素与月经周期长度无显著关联，但可能与月经规律性有关。这些结果突出了异黄酮和木脂素之间的差异，对尝试怀孕的女性来说是令人安心的。
