Pharmaceutical Sciences Faculty Publications
Stability of 15 estrogens and estrogen metabolites in urine samples under processing and storage conditions typically used in epidemiologic studies.
Document Type
Article
Publication Date
10-1-2010
Journal Title
The International Journal of Biological Markers
ISSN
1724-6008
Volume
25
Issue
4
First Page
185
Last Page
194
PubMed ID
21161939
PubMed Central® ID
PMC3131741
Abstract
BACKGROUND: In preparation for large-scale epidemiologic studies of the role of estrogen metabolism in the etiology of breast and other cancers, we examined the stability of estrogens and estrogen metabolites (EM) in urine during processing and storage protocols.
METHODS: Fifteen EM were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in first morning urines from 3 premenopausal women. Linear regression was used to model log EM concentrations for each woman, with and without adding ascorbic acid (0.1% w/v), during storage at 4°C (7-8 time points, up to 48 hours), during long-term storage at -80°C (10 time points, up to 1 year), and by freeze-thaw cycles (up to 3).
RESULTS: Without ascorbic acid, concentrations (pmol/mL) of nearly all EM changed
CONCLUSIONS: Given the large inter-individual variability in urinary EM concentrations, changes of the magnitude observed here are unlikely to cause substantial misclassification. Furthermore, processing and storage conditions studied here are adequate for use in epidemiologic studies.
Keywords
Ascorbic acid, epidemiologic methods, estrenes, estrogens, premenopause, preservation, biological, temperature, time factors
Recommended Citation
Fuhrman, Barbara J.; Xu, Xia; Falk, Roni T.; Hankinson, Susan E.; Veenstra, Timothy D.; Keefer, Larry K.; and Ziegler, Regina G., "Stability of 15 estrogens and estrogen metabolites in urine samples under processing and storage conditions typically used in epidemiologic studies." (2010). Pharmaceutical Sciences Faculty Publications. 262.
https://digitalcommons.cedarville.edu/pharmaceutical_sciences_publications/262