title: [Long-term effect of cadmium exposure on residents' renal dysfunction: An epidemiologic study].
abstract: OBJECTIVE
  To study long-term effect on renal function exposed to environmental cadmium.
  
  
  METHODS
  Stratified random sampling and cluster sampling method of epidemiological investigations were carried out in northern Guangdong province between April, 2011 and August, 2012. A total of 167 residents who lived in high cadmium exposure area for more than 15 years, aged above 40 were selected in exposed group. Moreover, A total of 145 residents who had similar living and economic conditions and lived in local for more than 15 years, aged above 40 were selected in control group. We used health questionnaires and medical examinations in order to acquire their health status. Home-harvested rice and vegetables were collected using quartering method for detection of cadmium level. Urine specimens of residents were collected for detection of cadmium level and creatinine as well as renal dysfunction biomarkers, namely, N-acetyl-beta-D-glucosamidase (NAG), β2-microglobulin (β2-MG), and retinol binding protein(RBP), respectively. The analysis of spearman rank correlation and multiple regression were used to investigate the relationships between age, urinary cadmium levels and renal injury biomarkers.
  
  
  RESULTS
  The cadmium levels in rice and vegetables of exposed group were 0.75 and 0.10 mg/kg, both were significantly higher than 0.07 and 0.01 mg/kg in the control group (Z values were -6.32 and -7.84, all P values < 0.001). The urinary cadmium level of exposed group was 8.29 µg/g · cr, which was higher than that of the control group 2.03 µg/g · cr with significant difference (Z value was -11.39, P < 0.001). After stratified the total population by age, the urinary cadmium level in 40-49 years, 50-59 years and ≥ 60 years subgroups were 7.22, 8.71, and 13.10 µg/g · cr, which both were significantly higher than 1.80, 2.04, and 2.05 µg/g · cr in the control group (Z values were -5.22, -7.41, and -7.14, all P values < 0.001). After stratified the total population by gender, the urinary cadmium level of male and female were 5.12 and 12.36 µg/g · cr, which both were significantly higher than 1.79 and 2.16 µg/g · cr in the control group (Z values were -7.68 and -9.03, all P values < 0.001). Comparing the differences of renal dysfunction biomarkers (NAG, β2-MG, RBP) between two groups. The level of urinary β2-MG and RBP of exposed group were 0.21 and 0.04 µg/g · cr, which were higher than 0.05 and 0.00 µg/g · cr of the control group with significant difference (Z value was -7.08 and -9.65, all P values < 0.001). Pearson correlation analysis showed that NAG, β2-MG and RBP were positively correlated with urinary cadmium and age, the correlation coefficients were 0.57, 0.49, 0.21 and 0.22, 0.26, 0.23 respectively (all P values < 0.001). After adjusting the effect of age, it was appeared that urinary cadmium levels contributed most to the alteration of NAG, β2-MG and RBP, the standardized regression coefficients were 0.57, 0.49 and 0.20 (all P values < 0.001), and suggested that the cadmium body burden was one of the most important factors for renal dysfunction.
  
  
  CONCLUSIONS
  Residents, who had cadmium contaminated rice and vegetables for a long time, would take the risk of increasing body burden of cadmium and urinary early biomarkers of renal tubular injury that referred to occurrence of renal dysfunction.
authors: Medical School, Jinan University, Guangzhou 510632, China.
authors: Yunrui
authors: Y
authors: Zhang
authors: Institute of Public Health Service Testing, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 510632, China.
authors: Xuxia
authors: X
authors: Liang
authors: Wencai
authors: W
authors: Chen
authors: Jing
authors: J
authors: Wang
authors: Qiong
authors: Q
authors: Huang
authors: Zihui
authors: Z
authors: Chen
authors: Ping
authors: P
authors: Wang
authors: Rui
authors: R
authors: Huang
authors: Shuguang
authors: S
authors: Hu
authors: Zhixue
authors: Z
authors: Li
authors: Liuying
authors: L
authors: Tang
authors: Guian
authors: G
authors: Wang
authors: Fei
authors: F
authors: Yang
authors: Xiaowei
authors: X
authors: Li
authors: Yunfeng
authors: Y
authors: Zhao
authors: Email: yangxingfen@cdcp.org.cn.
authors: Xingfen
authors: X
authors: Yang
authors: Email: wuyongning@cfsa.net.cn.
authors: Yongning
authors: Y
authors: Wu
mesh_terms: D000328:Adult; D000368:Aged; D002104:Cadmium; D003404:Creatinine; D004781:Environmental Exposure; D016021:Epidemiologic Studies; D005260:Female; D005506:Food Contamination; D006801:Humans; D007674:Kidney Diseases; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012275:Oryza; D012306:Risk; D013995:Time; D014675:Vegetables
chemical_list: D002104:Cadmium; D003404:Creatinine