Biological variations in cadmium, α1-microglobulin, β2-microglobulin and N-acetyl-β-d-glucosaminidase in adult women in a non-polluted area

Abstract

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.

Cadmium and tubular dysfunction marker levels in urine of residents in non-polluted areas with natural abundance of cadmium in Japan

“…This conclusion is in line with previous reports from this study group (Ezaki et al 2003a, b;Yamagami et al 2006Yamagami et al , 2008 that tubular function of general Japanese population [including residents in Toyama prefecture outside of the Jinzu river basin where once Itai-itai disease was endemic (Aoshima 1987)] stays unaltered despite relatively high dietary Cd intake (Ikeda 1992;Ikeda et al 2000Ikeda et al , 2004Watanabe et al 2000). It is also in agreement with the results from literature survey on possible Cd-induced health effects among general populations in non-polluted areas (Table 6).…”

“…a 1 -MG (mg/g cr) b 2 -MG NAG (Unit/g cr) Noonan et al (2002) 0.1 lg/g cr 120 lg/g cr 0.7 American (n = 144; probably men and women mixed) Satarug et al (2005) When similar (although not identical) data were employed in more than one study, priority was given to the study with more cases (e.g., Moriguchi et al 2005, rather than Moriguchi et al 2003Moriguchi et al , 2004 When the same data were presented in several units, e.g., as observed (per l) and after correction for CR (per g cr), priority was given to CRcorrected values for uniformity in the table (e.g., Reaves and Vanderpool 1997;Moriguchi et al 2005;Kowal and Zirkes 1983;Å kesson et al 2005;Suwazono et al 2006;Yamagami et al 2008) When values given in other units, e.g., in mmol, they were converted to lg/g cr by use of MW of 12.4 for Cd and 113.12 for creatinine (cr)…”

Cadmium Exposure in General Populations in Japan: a Review

“…It should be noted that benchmark response (BMR) = 5% (or BMR = 10%) was approximately equivalent to an increase of 0.12 (or 0.25) mg α 1 -MG-U/g cr and 31 (or 70) μg β 2 -MG-U/g cr when the procedure is taken into consideration that α 1 -MG-U cr and β 2 -MG-U cr were employed after logarithmic conversion, because the GM values were 2.54 mg α 1 -MG/g cr and 115 µg β 2 -MG/g cr for general populations in Japan 13) . These values are well within biological variations for individuals 57) , and the elevations may have only limited toxicological significance, even though it was statistically significant. In fact a population with Cd-U cr of 3 µg/g cr (corresponding to ca.…”

“…Nevertheless, the apparent discrepancy between the two estimates may need further discussion. Because within-individual variation (ie, variation observed after repeated measurement of Cd-B and Cd-U cr of the same subjects) was larger for Cd-U cr whereas Cd-B was stable (ie, the maximum/minimum ratio = 1.1 for Cd-B and 1.6 for Cd-U cr ) 57) , the Cd-B based estimate should be better respected than the Cd-U cr based estimate. Cd-B was however less available than Cd-U in literature, possibly reflecting the invasive nature of blood sampling.…”

Evidence of tubular damage in the very early stage of chronic kidney disease of uncertain etiology in the North Central Province of Sri Lanka: a cross-sectional study

“…To account for variations in urine concentrations among individuals, all concentrations were expressed in units per gram urinary creatinine excretion. Tentative cut-off values (5 mg/g creatinine for A1M, and 3.5 U/g creatinine for NAG) for screening were set based on previous publications so that even early stages of renal tubular damage could be identified [9,[16][17][18][19][20][21]. Table 1 shows the urinary concentrations of the two tubular markers in the CKDue patients at different clinical stages, in the relative controls, and in the Japanese controls.…”