The association of urine arsenic with prevalent and incident chronic kidney disease: evidence from the Strong Heart Study.
BACKGROUND
Few studies have evaluated associations between low to moderate arsenic levels and chronic kidney disease (CKD). The objective was to evaluate the associations of inorganic arsenic exposure with prevalent and incident CKD in American Indian adults.


METHODS
We evaluated the associations of inorganic arsenic exposure with CKD in American Indians who participated in the Strong Heart Study in 3,851 adults ages 45-74 years in a cross-sectional analysis, and 3,119 adults with follow-up data in a prospective analysis. Inorganic arsenic, monomethylarsonate, and dimethylarsinate were measured in urine at baseline. CKD was defined as estimated glomerular filtration rate ≤ 60 ml/min/1.73 m, kidney transplant or dialysis.


RESULTS
CKD prevalence was 10.3%. The median (IQR) concentration of inorganic plus methylated arsenic species (total arsenic) in urine was 9.7 (5.8, 15.7) μg/L. The adjusted odds ratio (OR; 95% confidence interval) of prevalent CKD for an interquartile range in total arsenic was 0.7 (0.6, 0.8), mostly due to an inverse association with inorganic arsenic (OR: 0.4 [0.3, 0.4]). Monomethylarsonate and dimethylarsinate were positively associated with prevalent CKD after adjustment for inorganic arsenic (OR: 3.8 and 1.8). The adjusted hazard ratio of incident CKD for an IQR in sum of inorganic and methylated arsenic was 1.2 (1.03, 1.41). The corresponding HRs for inorganic arsenic, monomethylarsonate, and dimethylarsinate were 1.0 (0.9, 1.2), 1.2 (1.00, 1.3), and 1.2 (1.0, 1.4).


CONCLUSIONS
The inverse association of urine inorganic arsenic with prevalent CKD suggests that kidney disease affects excretion of inorganic arsenic. Arsenic species were positively associated with incident CKD. Studies with repeated measures are needed to further characterize the relation between arsenic and kidney disease development.
From the aDepartment of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD; bMedStar Health Research Institute, Hyattsville, MD; cGeorgetown-Howard Universities Center for Clinical and Translational Science, Washington, DC; dCollege of Public Health, University of Oklahoma, Oklahoma City, OK; eInstitute of Chemistry-Analytical Chemistry, Karl-Franzens University, Graz, Austria; fDepartment of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD. gDepartment of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; hWelch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD; iArea of Epidemiology and Population Genetics, National Center for Cardiovascular Research (CNIC), Madrid, Spain; and jDepartment of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD.
Laura Y
LY
Zheng
Jason G
JG
Umans
Fawn
F
Yeh
Kevin A
KA
Francesconi
Walter
W
Goessler
Ellen K
EK
Silbergeld
Karen
K
Bandeen-Roche
Eliseo
E
Guallar
Barbara V
BV
Howard
Virginia M
VM
Weaver
Ana
A
Navas-Acien
D000368:Aged; D001130:Arizona / Q000453:epidemiology; D001151:Arsenic / Q000652:urine*; D001152:Arsenicals / Q000652:urine; D002101:Cacodylic Acid / Q000652:urine; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D015994:Incidence; D007198:Indians, North American / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009658:North Dakota / Q000453:epidemiology; D009825:Oklahoma / Q000453:epidemiology; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology*; D013023:South Dakota / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
D001152:Arsenicals; D002101:Cacodylic Acid; C020300:monomethylarsonic acid; D001151:Arsenic