Long-term exposure to low-level arsenic in drinking water and diabetes incidence: a prospective study of the diet, cancer and health cohort

• Published in: Environmental health perspectives 2014-10, Vol.122 (10), p.1059-1065
• Main Authors: Bräuner, Elvira Vaclavik, Nordsborg, Rikke Baastrup, Andersen, Zorana Jovanovic, Tjønneland, Anne, Loft, Steffen, Raaschou-Nielsen, Ole
• Format: Article
• Language: English
• Subjects: Aquifers; Arsenic; Arsenic - toxicity; Cancer; Cohort Studies; Contamination; Denmark - epidemiology; Diabetes; Diabetes Mellitus - chemically induced; Diabetes Mellitus - epidemiology; Diet - statistics & numerical data; Drinking water; Drinking Water - chemistry; Emigration; Environmental Exposure - statistics & numerical data; Environmental health; Exposure; Female; Geographic information systems; Glucose; Groundwater; Health; Health aspects; Health risk assessment; Health risks; Health services; Humans; Incidence; Male; Medical research; Medicine, Experimental; Middle Aged; Neoplasms - epidemiology; Outdoor air quality; Personal identification numbers; Proportional Hazards Models; Prospective Studies; Remote sensing; Risk; Risk factors; Studies; Water Pollutants, Chemical - toxicity; Water Pollution, Chemical - statistics & numerical data; Water supply; Water Supply - statistics & numerical data
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.1408198

Established causes of diabetes do not fully explain the present epidemic. High-level arsenic exposure has been implicated in diabetes risk, but the effect of low-level arsenic exposure in drinking water remains unclear. We sought to determine whether long-term exposure to low-level arsenic in drinking water in Denmark is associated with an increased risk of diabetes using a large prospective cohort. During 1993-1997, we recruited 57,053 persons. We followed each cohort member for diabetes occurrence from enrollment until 31 December 2006. We traced and geocoded residential addresses of the cohort members and used a geographic information system to link addresses with water-supply areas. We estimated individual exposure to arsenic using all addresses from 1 January 1971 until the censoring date. Cox proportional hazards models were used to model the association between arsenic exposure and diabetes incidence, separately for two definitions of diabetes: all cases and a more strict definition in which cases of diabetes based solely on blood glucose results were excluded. Over a mean follow-up period of 9.7 years for 52,931 eligible participants, there were a total of 4,304 (8.1%) diabetes cases, and 3,035 (5.8%) cases of diabetes based on the more strict definition. The adjusted incidence rate ratios (IRRs) per 1-μg/L increment in arsenic levels in drinking water were as follows: IRR = 1.03 (95% CI: 1.01, 1.06) and IRR = 1.02 (95% CI: 0.99, 1.05) for all and strict diabetes cases, respectively. Long-term exposure to low-level arsenic in drinking water may contribute to the development of diabetes.