Variability of urinary creatinine, specific gravity, and osmolality over the course of pregnancy: Implications in exposure assessment among pregnant women.

Autor: Lee G; School of Public Health, Seoul National University, Seoul, Republic of Korea., Kim S; School of Public Health, Seoul National University, Seoul, Republic of Korea; Institute of Health and Environment, Seoul National University, Seoul, Republic of Korea; Chemical Safety Research Center, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea., Park H; Department of Laboratory Medicine, Seoul National University Boramae Medical Center, Seoul, Republic of Korea., Lee J; Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea., Lee JP; Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea., Kho Y; Department of Health, Environment & Safety, Eulji University, Seongnam, Republic of Korea., Choi G; Department of Obstetrics and Gynecology, Soonchunhyang University Hospital, Seoul, Republic of Korea., Park J; Cheongdam Yeon & Nature Obstetrics & Gynecology, Seoul, Republic of Korea., Worakhunpiset S; Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand., Moon HB; Department of Marine Sciences and Convergent Technology, Hanyang University, Ansan, Republic of Korea., Choi K; School of Public Health, Seoul National University, Seoul, Republic of Korea; Institute of Health and Environment, Seoul National University, Seoul, Republic of Korea. Electronic address: kyungho@snu.ac.kr.
Jazyk: angličtina
Zdroj: Environmental research [Environ Res] 2021 Jul; Vol. 198, pp. 110473. Date of Electronic Publication: 2020 Nov 13.
DOI: 10.1016/j.envres.2020.110473
Abstrakt: Due to dilution status of the urine, chemical concentrations measured in spot urine are frequently adjusted using correction factors, such as creatinine, specific gravity (SG), or osmolarity of the urine. Urinary correction factors, however, can be influenced dramatically by physiological changes such as pregnancy. Details about the variation of urine dilution over the course of pregnancy are not well characterized. In the present study, we investigated the variation of urine correction factors over time among the pregnant women of Korea (n = 69) and Thailand (n = 102). Creatinine, SG, and osmolality were determined in the urine samples obtained in each trimester of the participating women, and were compared by sampling time and by nationality. Implication of the variation in these correction factors was studied using phthalate metabolites measured in the urine samples as model chemicals. Urinary correction factors significantly varied across the trimesters especially in Korean pregnant women: urinary creatinine and osmolality were significantly lower in the third trimester (T3) urine than the first trimester (T1) urine. Urinary creatinine and SG of the T3 urine of Korean pregnant women were also significantly lower than those reported from the non-pregnant women who participated in Korean National Environmental Health Survey (KoNEHS) 2015-2017. Among Thai women, however, these correction factors were rather stable across the pregnancy. Differences in ethnicity, or in behavior such as water consumption amount may partly explain the differences. Temporal changes in these urine correction factors influenced the urinary phthalate metabolite concentrations adjusted for dilution, in both Korean and Thai pregnant women. The present observations show that the variations of urinary correction factors should be considered in exposure assessment of urinary chemicals for pregnant women, in order to circumvent potential bias due to physiological changes occurring during pregnancy, and to reduce errors in exposure classification and association.
(Copyright © 2020 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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