Introduction
Inorganic arsenic and its metabolites are considered dangerous to human
health. Although several studies have reported associations between low-level arsenic
exposure and diabetes mellitus in the United States and Mexico, this association has not
been studied in the Canadian population. We evaluated the association between arsenic
exposure, as measured by total arsenic concentration in urine, and the prevalence of type
2 diabetes (T2D) in 3151 adult participants in Cycle 1 (2007–2009) of the Canadian
Health Measures Survey (CHMS).
Methods
All participants were tested to determine blood glucose and glycated
hemoglobin. Urine analysis was also performed to measure total arsenic. In addition,
participants answered a detailed questionnaire about their lifestyle and medical history.
We assessed the association between urinary arsenic levels and T2D and prediabetes
using multivariate logistic regression while adjusting for potential confounders.
Results
Total urinary arsenic concentration was positively associated with the prevalence
of T2D and prediabetes: adjusted odds ratios were 1.81 (95% CI: 1.12–2.95) and 2.04
(95% CI: 1.03–4.05), respectively, when comparing the highest (fourth) urinary arsenic
concentration quartile with the lowest (first) quartile. Total urinary arsenic was also
associated with glycated hemoglobin levels in people with untreated diabetes.
Conclusion
We found significant associations between arsenic exposure and the
prevalence of T2D and prediabetes in the Canadian population. Causal inference is
limited due to the cross-sectional design of the study and the absence of long-term
exposure assessment.