Associations between proteins and heavy metals in urine at low environmental exposures: Evidence of reverse causality

详细信息	查看全文 | 推荐本文 |

• 作者：Agnè ; s Chaumont^a ; Marc Nickmilder^a ; Xavier Dumont^a ; Thomas Lundh^b ; Staffan Skerfving^b ; Alfred Bernard^a ; ^{alfred.bernard@uclouvain.be} ; ^{bernard@toxi.ucl.ac.be}
• 关键词：B-Cd ; cadmium in blood ; U-Cd ; cadmium in urine ; B-Pb ; lead in blood ; U-RBP ; retinol-binding protein in urine ; U-尾2m ; 尾2-microglobulin in urine ; U-Alb ; albumin in urine ; U-Creat ; creatinine in urine ; IQR ; interquartile range ; SD ; standard deviation ; BMI
• 刊名：Toxicology Letters
• 出版年：2012
• 期刊代码：49_03784274
• 类别：pha
• 出版时间：5 May, 2012
• 卷：210
• 期：3
• 页码：345-352
• 文件大小：572 K

摘要

Heavy metals can cause renal effects on vulnerable populations but it is uncertain whether these metals still pose health risks at the low exposure levels now prevailing in most industrialized countries.

In a cross-sectional study performed on 736 adolescents, we assessed the associations between the concentrations of cadmium and lead in blood and urine and the urinary concentrations of albumin and of low-molecular-weight (LMW) proteins, retinol-binding protein (RBP) and 尾₂-microglobulin. Multiple regression analyses were tested using urinary markers normalized to urinary creatinine or specific gravity.

Median metal concentrations were in blood (渭g/L): lead, 15.1, cadmium, 0.18 and in urine (渭g/g creatinine): cadmium, 0.09 and lead, 0.82. Multivariate analyses revealed significant associations in urine between RBP and cadmium as well as between 尾₂-microglobulin and lead whereas no associations were seen with metals in blood. These associations were completely abolished in subjects with increased urinary albumin, which may be explained by the competitive inhibition of LMW protein reabsorption by albumin.

Given the evidence that cadmium and lead circulate mainly bound to LMW proteins, these associations observed at low exposure might simply reflect the interindividual variations in the renal uptake of proteins sharing the same affinity for tubular binding sites.