Environmental exposure to arsenic, AS3MT polymorphism and prevalence of diabetes in Mexico

• Published in: Journal of exposure science & environmental epidemiology Vol. 23; no. 2; pp. 151 - 155
• Main Authors: Drobná, Zuzana, Del Razo, Luz M, García-Vargas, Gonzalo G, Sánchez-Peña, Luz C, Barrera-Hernández, Angel, Stýblo, Miroslav, Loomis, Dana
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.03.2013; Nature Publishing Group
• Subjects: 631/208/457/649; 692/699/2743/137; 692/700/478/174; 704/172/169/895; Adolescent; Adult; Arsenic; Arsenic - metabolism; Arsenic - toxicity; Blood; Confidence intervals; Contamination; Development and progression; Diabetes; Diabetes mellitus; Diabetes Mellitus - epidemiology; Drinking water; Environmental aspects; Environmental Exposure; Epidemiology; Exposure; Fasting; Female; Gene polymorphism; Genetic aspects; Genotypes; Genotyping; Glucose; Glucose tolerance; Health aspects; Humans; Immunological tolerance; Male; Medicine; Medicine & Public Health; Metabolism; Metabolites; Methylation; Methyltransferase; Methyltransferases - genetics; Mexico - epidemiology; Middle Aged; original-article; Oxidation; Physiological aspects; Polymorphism; Polymorphism, Single Nucleotide; Prevalence; Risk factors; Single nucleotide polymorphisms; Statistical analysis; Urine; Valence; Young Adult; Mexico; metals; biomonitoring; disease; emerging contaminants
• ISSN: 1559-0631; 1559-064X
• DOI: 10.1038/jes.2012.103

Exposure to arsenic in drinking water is associated with increased prevalence of diabetes. We previously reported an association of diabetes and urinary concentration of dimethylarsinite (DMAs III ), a toxic product of arsenic methylation by arsenic (+3 oxidation state) methyltransferase (AS3MT). Here we examine associations between AS3MT polymorphism, arsenic metabolism and diabetes. Fasting blood glucose, oral glucose tolerance and self-reported diagnoses were used to identify diabetic individuals. Inorganic arsenic and its metabolites were measured in urine. Genotyping analysis focused on six polymorphic sites of AS3MT. Individuals with M287T and G4965C polymorphisms had higher levels of urinary DMAs III and were more frequently diabetic than the respective wild-type carriers, although the excess was not statistically significant. Odds ratios were 11.4 (95% confidence interval (CI) 2.2–58.8) and 8.8 (95% CI 1.6–47.3) for the combined effects of arsenic exposure >75th percentile and 287T and 4965C genotypes, respectively. Carriers of 287T and 4965C may produce more DMAs III and be more likely to develop diabetes when exposed to arsenic.