title: Environmental exposure to arsenic, AS3MT polymorphism and prevalence of diabetes in Mexico.
abstract: 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.
authors.affiliation: Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Drobná
authors.forename: Luz M
authors.initials: LM
authors.lastname: Del Razo
authors.forename: Gonzalo G
authors.initials: GG
authors.lastname: García-Vargas
authors.forename: Luz C
authors.initials: LC
authors.lastname: Sánchez-Peña
authors.forename: Angel
authors.initials: A
authors.lastname: Barrera-Hernández
authors.forename: Miroslav
authors.initials: M
authors.lastname: Stýblo
authors.forename: Dana
authors.initials: D
authors.lastname: Loomis
mesh_terms: D000293:Adolescent; D000328:Adult; D001151:Arsenic / Q000378:metabolism / Q000633:toxicity*; D003920:Diabetes Mellitus / Q000453:epidemiology*; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008780:Methyltransferases / Q000235:genetics*; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence; D055815:Young Adult
chemical_list: D008780:Methyltransferases; C505756:AS3MT protein, human; D001151:Arsenic