Open Access Research article

A prospective study of dietary selenium intake and risk of type 2 diabetes

Saverio Stranges1*, Sabina Sieri2, Marco Vinceti3, Sara Grioni2, Eliseo Guallar45, Martin Laclaustra45, Paola Muti6, Franco Berrino7 and Vittorio Krogh2

Author Affiliations

1 Health Sciences Research Institute, University of Warwick Medical School, Coventry, UK

2 Nutritional Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy

3 Department of Public Health Sciences, University of Modena and Reggio Emilia, Modena, Italy

4 Departments of Epidemiology and Medicine, and Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA

5 Department of Cardiovascular Epidemiology and Population Genetics, National Center for Cardiovascular Research (CNIC), Madrid, Spain

6 Epidemiology and Prevention Unit, "Regina Elena" Italian National Cancer Institute, Rome, Italy

7 Etiological and Preventive Epidemiology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy

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BMC Public Health 2010, 10:564  doi:10.1186/1471-2458-10-564

Published: 21 September 2010

Abstract

Background

Growing evidence raises concern about possible associations of high selenium exposure with diabetes in selenium-replete populations such as the US. In countries with lower selenium status, such as Italy, there is little epidemiological evidence on the association between selenium and diabetes. This study examined the prospective association between dietary selenium intake and risk of type 2 diabetes.

Methods

The ORDET cohort study comprised a large sample of women from Northern Italy (n = 7,182). Incident type 2 diabetes was defined as a self-report of a physician diagnosis, use of antidiabetic medication, or a hospitalization discharge. Dietary selenium intake was measured by a semi-quantitative food-frequency questionnaire at the baseline examination (1987-1992). Participants were divided in quintiles based on their baseline dietary selenium intake.

Results

Average selenium intake at baseline was 55.7 μg/day. After a median follow-up of 16 years, 253 women developed diabetes. In multivariate logistic regression analyses, the odds ratio for diabetes comparing the highest to the lowest quintile of selenium intake was 2.39, (95% CI: 1.32, 4.32; P for linear trend = 0.005). The odds ratio for diabetes associated with a 10 μg/d increase in selenium intake was 1.29 (95% CI: 1.10, 1.52).

Conclusions

In this population, increased dietary selenium intake was associated with an increased risk of type 2 diabetes. These findings raise additional concerns about the association of selenium intake above the Recommended Dietary Allowance (55 μg/day) with diabetes risk.