Cancer Research Center of Hawaii, 1236 Lauhala Street, Honolulu, HI 96813, USA.
Cancer Epidemiol Biomarkers Prev. 2010 Jul;19(7):1775-83. doi: 10.1158/1055-9965.EPI-10-0116.
Isoflavonoids (IFL) may protect against chronic diseases, including cancer. IFL exposure is traditionally measured from plasma (PL), but the reliability of urine is uncertain. We assessed whether IFL excretion in overnight urine (OU) or spot urine (SU) reliably reflects IFLs in PL and the usefulness of the three matrices to determine soy intake compliance.
In a randomized, double-blind, placebo-controlled soy intervention trial with 350 postmenopausal women, IFLs (daidzein, genistein, glycitein, equol, O-desmethylangolensin, dihydrodaidzein, dihydrogenistein) were analyzed by liquid chromatography/mass spectrometry in OU, SU, and PL collected at baseline and every 6 months over 2.5 years.
High between-subject intraclass correlations between all three matrices (median, 0.94) and high between-subject Pearson correlations (median r(OU-PL) = 0.80; median r(SU-PL) = 0.80; median r(OU-SU) = 0.92) allowed the development of equations to predict IFL values from any of the three matrices. Equations developed from a randomly selected 87% of all available data were valid because high correlations were found on the residual 13% of data between equation-generated and measured IFL values (median r(OU-PL) = 0.86; median r(SU-PL) = 0.78; median r(OU-SU) = 0.84); median absolute IFL differences for OU-PL, SU-PL, and OU-SU were 8.8 nmol/L, 10.3 nmol/L, and 0.28 nmol/mg, respectively. All three matrices showed highly significant IFL differences between the placebo and soy intervention group at study end (P < 0.0001) and highly significant correlations between IFL values and counted soy doses in the intervention group.
OU and SU IFL excretion reflect circulating PL IFL levels in healthy postmenopausal women accurately.
Noninvasively-collected urine can be used to reliably determine systemic IFL exposure and soy intake compliance.
异黄酮（IFL）可能对包括癌症在内的慢性疾病具有保护作用。IFL 的暴露传统上是从血浆（PL）中测量的，但尿液的可靠性尚不确定。我们评估了 overnight urine（OU）或 spot urine（SU）中 IFL 的排泄是否能可靠地反映 PL 中的 IFL，以及这三种基质在确定大豆摄入量依从性方面的有用性。
在一项针对 350 名绝经后妇女的随机、双盲、安慰剂对照的大豆干预试验中，在基线时以及 2.5 年内每 6 个月采集 OU、SU 和 PL，并使用液相色谱/质谱法分析 IFL（大豆苷、染料木素、黄豆苷元、黄豆黄素、O-去甲安哥拉紫檀素、二氢大豆苷、二氢染料木素）。
三种基质之间的受试者内组内相关系数均较高（中位数，0.94），受试者内 Pearson 相关系数也较高（中位数 r（OU-PL）=0.80；中位数 r（SU-PL）=0.80；中位数 r（OU-SU）=0.92），这允许我们开发从任何三种基质预测 IFL 值的方程。从所有可用数据中随机选择的 87%的数据中开发的方程是有效的，因为在剩余的 13%的数据中，方程生成的和测量的 IFL 值之间存在高度相关性（中位数 r（OU-PL）=0.86；中位数 r（SU-PL）=0.78；中位数 r（OU-SU）=0.84）；OU-PL、SU-PL 和 OU-SU 的 IFL 差异中位数分别为 8.8 nmol/L、10.3 nmol/L 和 0.28 nmol/mg。在研究结束时，所有三种基质在安慰剂和大豆干预组之间均显示出 IFL 差异具有统计学意义（P<0.0001），并且在干预组中 IFL 值与计数的大豆剂量之间存在高度显著的相关性。
健康绝经后妇女的 OU 和 SU 中 IFL 的排泄能准确反映循环 PL 中的 IFL 水平。
非侵入性采集的尿液可用于可靠地确定系统性 IFL 暴露和大豆摄入量的依从性。
