Associations between arsenic in drinking water and the progression of chronic kidney disease: A nationwide study in Taiwan.

To evaluate the associations between exposure to arsenic in drinking water and the progression of chronic kidney disease (CKD), we conducted a study in Taiwan. We recruited 8854 participants from a nationwide health screening program from 2000 to 2009 who were at least 20 years old and had two checkups in a 24-month period with at least 12 months apart. We defined CKD as having an estimated glomerular filtration rate (eGFR)<90ml/min/1.73m2 or renal dysfunction demonstrated by proteinuria and a rapid progression of CKD as a decline in eGFR>5ml/min/1.73m2/year. Arsenic levels were assessed on the basis of a governmental nationwide survey. Of the 8854 participants, 1341 exhibited rapid progression. Participants who lived in areas with arsenic levels≥50μg/L had a higher risk of rapid progression, with an odds ratio of 1.22 (95% confidence interval: 1.05-1.42, p<0.01) after adjusting for hypertension, diabetes mellitus, proteinuria, and anemia. The results showed that a high arsenic level in drinking water was a risk factor for rapid progression of CKD, independent of most of the documented risk factors. Screening and intervention programs should be implemented in endemic areas of exposure to reduce the risk.