Creatinine, Diet, Micronutrients, and Arsenic Methylation in West Bengal, India

• Published in: Environmental health perspectives Vol. 119; no. 9; pp. 1308 - 1313
• Main Authors: Basu, Arin, Mitra, Soma, Chung, Joyce, Mazumder, D.N. Guha, Ghosh, Nilima, Kalman, David, von Ehrenstein, Ondine S., Steinmaus, Craig, Liaw, Jane, Smith, Allan H.
• Format: Journal Article
• Language: English
• Published: Research Triangle Park, NC National Institute of Environmental Health Sciences 01.09.2011; US Department of Health and Human Services
• Subjects: Adolescent; Adult; Animal fats; Arsenic; Arsenic - metabolism; Arsenic - toxicity; Arsenic - urine; Arsenicals - metabolism; Arsenicals - urine; Biological and medical sciences; Blood plasma; Chemical and industrial products toxicology. Toxic occupational diseases; Creatinine; Creatinine - urine; Cross-Sectional Studies; Diet; Environment. Living conditions; Environmental Monitoring; Female; Humans; India; Lesions; Male; Measurement; Medical sciences; Metabolism; Metals and various inorganic compounds; Methylation; Micronutrients; Micronutrients - blood; Micronutrients - metabolism; Middle Aged; Nutritional aspects; Potable water; Public health. Hygiene; Public health. Hygiene-occupational medicine; Selenium; Toxicology; Urine; Water Pollutants, Chemical - metabolism; Water Pollutants, Chemical - urine; Young Adult; Asia; West Bengal; India; Creatinine; Micronutrient; Health and environment; Arsenic; Diet; West Bengal; micronutrients; Methylation; Feeding; India
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.1003393

Background: Ingested inorganic arsenic (InAs) is methylated to monomethylated (MMA) and dimethylated metabolites (DMA). Methylation may have an important role in arsenic toxicity, because the monomethylated trivaient metabolite [MMA(III)] is highly toxic. Objectives: We assessed the relationship of creatinine and nutrition—using dietary intake and blood concentrations of micronutrients—with arsenic metabolism, as reflected in the proportions of InAS, MMA, and DMA in urine, in the first study that incorporated both dietary and micronutrient data. Methods: We studied methylation patterns and nutritional factors in 405 persons who were selected from a cross-sectional survey of 7,638 people in an arsenic-exposed population in West Bengal, India. We assessed associations of urine creatinine and nutritional factors (19 dietary intake variables and 16 blood micronutrients) with arsenic metabolites in urine. Results: Urinary creatinine had the strongest relationship with overall arsenic methylation to DMA. Those with the highest urinary creatinine concentrations had 7.2% more arsenic as DMA compared with those with low creatinine (p < 0.001). Animal fat intake had the strongest relationship with MMA% (highest tertile animal fat intake had 2.3% more arsenic as MMA, p < 0.001). Low serum selenium and low folate were also associated with increased MMA%. Conclusions: Urine creatinine concentration was the strongest biological marker of arsenic methylation efficiency, and therefore should not be used to adjust for urine concentration in arsenic studies. The new finding that animal fat intake has a positive relationship with MMA% warrants further assessment in other studies. Increased MMA% was also associated, to a lesser extent, with low serum selenium and folate.