Table 2.

Geometric mean (95% confidence interval) urinary concentrations of estrogens and estrogen metabolites measured by LC-MS/MS and either ELISA or RIA

Estrogen metabolite measure (assay)Mean (95% confidence interval) urinary concentration (pmol/mg creatinine)
Premenopausal women luteal phase (n = 264)Premenopausal women nonluteal phase (n = 98)Postmenopausal women (n = 168)
Parent estrogens
    E1 (RIA)41.9 (39.1-45.0)27.9 (23.1-33.6)6.9* (6.4-7.5)
    E1 (LC-MS/MS)23.4 (21.7-25.3)14.6 (12.0-17.9)2.6 (2.4-2.9)
    E2 (RIA)17.6 (16.4-19.0)12.0 (9.9-14.6)2.1 (1.9-2.3)
    E2 (LC-MS/MS)10.9 (10.2-11.7)7.7 (6.4-9.2)1.5 (1.3-1.7)
2-Hydroxylation pathway
    2-OHE1 (ELISA)47.8 (44.7-51.2)31.0 (26.6-36.2)18.6§ (16.9-20.5)
    2-Hydoxyestrone (LC-MS/MS)24.6 (22.4-26.9)13.8 (11.1-17.1)2.9 (2.6-3.3)
16α-Hydroxylation pathway
    16α-OHE1 (ELISA)32.2 (30.6-33.9)23.8 (21.3-26.7)14.1 (13.2-15.0)
    16α-OHE1 (LC-MS/MS)11.0 (10.2-11.9)6.5 (5.3-8.0)1.2 (1.1-1.4)
    E3 (RIA)77.2 (71.6-83.3)50.1 (42.3-59.4)12.9 (12.0-14.0)
    E3 (LC-MS/MS)55.5 (50.7-60.9)31.2 (25.3-38.5)5.7 (5.0-6.4)
2-OHE1:16α-OHE1
    ELISA ratio1.5** (1.4-1.6)1.3 (1.2-1.5)1.3§ (1.2-1.4)
    LC-MS/MS ratio2.2 (2.0-2.5)2.1 (1.8-2.5)2.4 (2.1-2.8)

NOTE: Early morning, 12-h urines.