title: Biological variations in cadmium, alpha 1-microglobulin, beta 2-microglobulin and N-acetyl-beta-D-glucosaminidase in adult women in a non-polluted area.
abstract: OBJECTIVE
  This study was initiated to investigate the extents of biological variations in cadmium and three common tubular dysfunction marker levels in blood and urine through repeated sampling.
  
  
  METHODS
  A 12-month survey and a 10-week survey were conducted in an area with no known cadmium pollution. In the 12-month survey, five adult women offered urine samples once every month and blood samples once in every season, respectively. In the 10-week survey, 17 adult women gave urine samples once every week. Blood and urine samples were analyzed for cadmium (Cd-B and Cd-U) by graphite-furnace atomic absorption spectrometry, and urine samples were analyzed also for alpha 1-microglobulin (alpha 1-MG-U), beta 2-microglobulin (beta 2-MG-U) and N-acetyl-beta-D-glucosaminidase (NAG-U) by conventional methods, all under strict quality control. The results were subjected to statistical analysis to examine the extents of biological variations through-out the study periods.
  
  
  RESULTS
  Variations in geometric means (GMs) for Cd-B, Cd-U, alpha 1-MG-U, beta 2-MG-U, and NAG-U were all small; the ratio of the largest GM over the lowest GM was 1.1 for Cd-B, 2 for Cd-U and 2 to 3 for alpha 1-MG-U, beta 2-MG-U, and NAG-U in the 12-month survey, and 1.7 at largest for all parameters in the 10-week survey. The within-subject variations during the 12-month or 10-week periods were however large, i.e., more than 4-5-fold difference between the smallest and the largest values obtained for the same subject. Effects of the correction for urine density to reduce the variations were limited. In contrast, within-subject variation in Cd-B was small with a ratio of 1.3.
  
  
  CONCLUSIONS
  Variations in GM values for Cd-U, alpha 1-MG-U, beta 2-MG-U, and NAG-U at different time of sampling are small so that single measurement would be acceptable as far as the evaluation on a group basis is the study objective. Within-subject variations are wide however, the ratio of the largest value over the smallest value being 4-5 or more, irrespective of correction for urine density. Therefore, care should be practiced when evaluation on an individual basis is intended. Very low within-subject variation in Cd-B may suggest the advantage of Cd-B over Cd-U for individual evaluation among general populations if blood sampling is accepted.
authors.affiliation: Hokuriku Health Service Association, Nishifutamata, Toyama 930-0177, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamagami
authors.forename: Tomoko
authors.initials: T
authors.lastname: Suna
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Fukui
authors.forename: Fumiko
authors.initials: F
authors.lastname: Ohashi
authors.forename: Shiro
authors.initials: S
authors.lastname: Takada
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Sakurai
authors.forename: Keiko
authors.initials: K
authors.lastname: Aoshima
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ikeda
mesh_terms: D000118:Acetylglucosaminidase / Q000032:analysis* / Q000097:blood / Q000652:urine; D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis; D002104:Cadmium / Q000032:analysis* / Q000097:blood / Q000652:urine; D004787:Environmental Pollution; D005260:Female; D006801:Humans; D007564:Japan; D008875:Middle Aged; D001613:beta 2-Microglobulin / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D015415:Biomarkers; D001613:beta 2-Microglobulin; D002104:Cadmium; D000118:Acetylglucosaminidase