Variability of urinary cadmium excretion in spot urine samples, first morning voids, and 24 h urine in a healthy non-smoking population: Implications for study design
(2014) In Journal of Exposure Science & Environmental Epidemiology 24(2). p.171-179- Abstract
- When selecting the least biased exposure surrogate, for example, the concentration of a biomarker in a urine sample, information on variability must be taken into consideration. We used mixed-effects models to estimate the variability and determinants of urinary cadmium (U-Cd) excretion using spot urine samples collected at six fixed times during 2 days about 1 week apart, from 24 healthy non-smokers. The urine samples were analysed for U-Cd, the concentrations were adjusted for dilution, and the excretion rates were calculated. Between-individual variability dominated the total variability for most measures of U-Cd excretion, especially for 24h urine and first morning samples. The U-Cd excretion showed a circadian rhythm during the day,... (More)
- When selecting the least biased exposure surrogate, for example, the concentration of a biomarker in a urine sample, information on variability must be taken into consideration. We used mixed-effects models to estimate the variability and determinants of urinary cadmium (U-Cd) excretion using spot urine samples collected at six fixed times during 2 days about 1 week apart, from 24 healthy non-smokers. The urine samples were analysed for U-Cd, the concentrations were adjusted for dilution, and the excretion rates were calculated. Between-individual variability dominated the total variability for most measures of U-Cd excretion, especially for 24h urine and first morning samples. The U-Cd excretion showed a circadian rhythm during the day, and time point of sampling was a significant factor in the mixed-effects models, thus a standardised sampling time, such as first morning urine samples, needs to be applied. Gender, urinary flow rate, age, and urinary protein excretions were also significant determinants for U-Cd excretion. The choice of biomarker for U-Cd excretion was found to be more important in individually-based studies of exposure-response relationships than in studies of comparing Cd levels of groups. When planning a study, this variability of U-Cd in spot samples must be acknowledged. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4363702
- author
- Akerstrom, Magnus ; Barregard, Lars ; Lundh, Thomas LU and Sallsten, Gerd
- organization
- publishing date
- 2014
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- variability, spot urine, urinary excretion, cadmium, 24h urine, study, design
- in
- Journal of Exposure Science & Environmental Epidemiology
- volume
- 24
- issue
- 2
- pages
- 171 - 179
- publisher
- Nature Publishing Group
- external identifiers
-
- wos:000331596000009
- scopus:84896706810
- pmid:24022669
- ISSN
- 1559-064X
- DOI
- 10.1038/jes.2013.58
- language
- English
- LU publication?
- yes
- id
- 088c60bb-5285-4729-8226-0386e79bdbeb (old id 4363702)
- date added to LUP
- 2016-04-01 13:49:04
- date last changed
- 2022-02-11 23:10:51
@article{088c60bb-5285-4729-8226-0386e79bdbeb,
abstract = {{When selecting the least biased exposure surrogate, for example, the concentration of a biomarker in a urine sample, information on variability must be taken into consideration. We used mixed-effects models to estimate the variability and determinants of urinary cadmium (U-Cd) excretion using spot urine samples collected at six fixed times during 2 days about 1 week apart, from 24 healthy non-smokers. The urine samples were analysed for U-Cd, the concentrations were adjusted for dilution, and the excretion rates were calculated. Between-individual variability dominated the total variability for most measures of U-Cd excretion, especially for 24h urine and first morning samples. The U-Cd excretion showed a circadian rhythm during the day, and time point of sampling was a significant factor in the mixed-effects models, thus a standardised sampling time, such as first morning urine samples, needs to be applied. Gender, urinary flow rate, age, and urinary protein excretions were also significant determinants for U-Cd excretion. The choice of biomarker for U-Cd excretion was found to be more important in individually-based studies of exposure-response relationships than in studies of comparing Cd levels of groups. When planning a study, this variability of U-Cd in spot samples must be acknowledged.}},
author = {{Akerstrom, Magnus and Barregard, Lars and Lundh, Thomas and Sallsten, Gerd}},
issn = {{1559-064X}},
keywords = {{variability; spot urine; urinary excretion; cadmium; 24h urine; study; design}},
language = {{eng}},
number = {{2}},
pages = {{171--179}},
publisher = {{Nature Publishing Group}},
series = {{Journal of Exposure Science & Environmental Epidemiology}},
title = {{Variability of urinary cadmium excretion in spot urine samples, first morning voids, and 24 h urine in a healthy non-smoking population: Implications for study design}},
url = {{http://dx.doi.org/10.1038/jes.2013.58}},
doi = {{10.1038/jes.2013.58}},
volume = {{24}},
year = {{2014}},
}