Variability of biomarkers in volunteer studies: The biological component

摘要: Biological monitoring has become one of the methods to measure exposure, with advantage that it gives information about concentration a substance actually enters body and reflects inter-individual differences in uptake metabolic variation. However, limited is available on inter- intra-individual variability biomarkers. The aim this study was gather biological component variation biomarkers using results from volunteer studies. Open literature other (internal) sources were searched find human studies utilizing monitoring. Ultimately 41 included our analysis, total 6747 observations for or more 223 volunteers. data these grouped basis study, under investigation, exposure route, matrix, duration, dose number events obtain 278 homogeneous groups (strata) statistical analysis. Variability assessed two ways. Firstly, estimates biomarker half-life calculated each individual, thereby allowing estimation half-lives within groups. Secondly, concentrations at given time point estimated. For estimated GSDs ranged 1.0 6.8. did not differ much different types substances. average strata 5.6. Again, (e.g., type substance). median 0.11 (range 0-3.0). In conclusion, enable both levels well-defined Comparison indicates due between people quite substantial relative contribution will be smaller when variance components are less groups, such as those occupational environmental settings.