Inorganic Arsenic Exposure is not Associated with Type-2 Diabetes Prevalence in Cycle 2 of the Canadian Health Measures Survey

Abstract

Introduction: A positive association between arsenic exposure and the occurrence of type-2 diabetes (T2D) has been reported and there is biological plausibility for this relationship. We examined this association among participants of the second cycle of the Canadian Health Measures Survey (CHMS-C2). Methods: The association was assessed in a random sample of 932 Canadians (20-79 year-old) who participated in the CHMS-C2 between 2009-2011. T2D status was determined by means of fasting blood glucose, glycated haemoglobin or self-declared diagnosis/medication. Concentrations of arsenic species and creatinine were determined in spot urine samples. Other variables were determined during a medical exam (blood pressure and height and weight) or by questionnaire (age, sex, ethnicity, smoking, sea food consumption). Urinary inorganic arsenic index (UIAs) – the sum of arsenite, arsenate, dimethylarsenic acid and monomethyl arsenic acid – was divided into quartiles. The Odds Ratio (OR) of T2D was estimated by means of multiple logistic regressions with adjustment for potential confounders using non diabetics as controls and the first quartile of UIAs as the reference group of exposure. Results: Weighted prevalence of type-2 diabetes in this sample of Canadian adults was 9.3% (95% confidence intervals (CI):6.1-12.4). Adjusted OR of diabetes for the fourth quartile of UIAs was 0.47 (95% CI:0.2-2.10) without adjustment for creatinine and 0.18 (95% CI: 0.02-1.14) after adjustment for creatinine. There was no dose-response relationship. Conclusion: No relationship was found between exposure to inorganic arsenic and T2D in this sample of Canadian adults who participated to CHMS-C2. The small sample size and the cross-sectionnal design are limitations of this study.