Comparability of serum, plasma, and urinary estrogen and estrogen metabolite measurements by sex and menopausal status

The comparability between serum, plasma, and urinary measurements of estrogen metabolites via liquid chromatography-tandem mass spectrometry (LC-MS/MS) has not been largely explored, and it is unclear if urinary LC-MS/MS measurements are suitable surrogates of circulating levels.Serum, plasma (EDTA and heparin), and urinary estrogen/estrogen metabolite levels were measured via LC-MS/MS in paired samples from 64 healthy volunteers (18 men, 20...