Ikeda Masayuki, Ohashi Fumiko, Fukui Yoshinari, Takada Shiro, Moriguchi Jiro, Ezaki Takafumi
Kyoto Industrial Health Association, 67 Nishinokyo-Kitatsuboicho, Nakagyo-ku, Kyoto 604-8472, Japan.
Int Arch Occup Environ Health. 2007 Jan;80(3):171-83. doi: 10.1007/s00420-006-0117-4. Epub 2006 Jul 5.
This study was initiated to investigate if and to what extent the elevations in urinary alpha(1)- and beta(2)-microglobulins (alpha(1)-MG and beta(2)-MG, respectively) are specific to Cd nephro-toxicity.
Stored urine samples, collected from 1,000 adult women in 11 prefectures all over Japan, were analysed for eight elements (Ca, Cd, Co, Cu, Mg, Mn, Ni and Zn), alpha(1)-MG, beta(2)-MG, creatinine (CR) and specific gravity (SG); the data were cited from previous publications. The levels of eight elements and two MGs were expressed as observed and after correction for CR or SG (1.016). Age, CR and SG distributed normally, whereas two MGs and eight elements distributed log-normally. The 1,000 cases were classified into quartiles (i.e., 250 cases/group) of the lowest to the highest values (Groups A to D) for each element.
alpha(1)-MG and beta(2)-MG increased as a function of Ca, Cd and Cu when corrected for CR, and the two MGs increased in parallel only with Cd and Cu after SG correction. Prevalence of alpha(1)-MG-uria (cut-off values; 5.3 and 6.5 mg/g cr or l) and beta(2)-MG-uria (cut-off values; 300 and 400 microg/g cr or l) was elevated with increasing Ca, Cd and Cu when corrected for CR, but only with Cd and Cu when corrected for SG. Multiple regression analysis of 353 cases of 50-59 year-old women with the eight element levels as independent variables and one of the two MGs as a dependent variable showed that Cu was the most influential element, and both Cd and Zn were less influential.
Urinary levels of alpha(1)-MG and beta(2)-MG among women with no environmental Cd exposure correlated more closely with Cu levels than Cd levels in urine. The observation suggests that sub-clinical elevation in alpha(1)-MG and beta(2)-MG is not always attributable to nephro-toxicity of Cd, and that consideration on possible effects of other elements such as Cu is necessary.
开展本研究以调查尿中α1-微球蛋白和β2-微球蛋白（分别为α1-MG和β2-MG）升高是否以及在何种程度上对镉肾毒性具有特异性。
对从日本全国11个县的1000名成年女性收集的储存尿液样本进行8种元素（钙、镉、钴、铜、镁、锰、镍和锌）、α1-MG、β2-MG、肌酐（CR）和比重（SG）分析；数据引自先前发表的文献。8种元素和两种微球蛋白的水平以观察值以及校正CR或SG（1.016）后的值表示。年龄、CR和SG呈正态分布，而两种微球蛋白和8种元素呈对数正态分布。将1000例病例按每种元素从最低到最高值分为四分位数（即每组250例）（A组至D组）。
校正CR后，α1-MG和β2-MG随钙、镉和铜水平升高而增加，校正SG后，两种微球蛋白仅随镉和铜水平平行增加。校正CR时，α1-MG尿（临界值；5.3和6.5mg/g肌酐或升）和β2-MG尿（临界值；300和400μg/g肌酐或升）的患病率随钙、镉和铜水平升高而升高，但校正SG时仅随镉和铜水平升高。以8种元素水平为自变量、两种微球蛋白之一为因变量，对353例50 - 59岁女性进行多元回归分析表明，铜是最具影响力的元素，镉和锌的影响力较小。
未接触环境镉女性尿中α1-MG和β2-MG水平与尿中铜水平的相关性比与镉水平的相关性更密切。该观察结果表明，α1-MG和β2-MG的亚临床升高并不总是归因于镉的肾毒性，有必要考虑其他元素如铜的可能影响。
