Impact of endocrine disruptors on the incidence of type 2 diabetes: results from a case-control study in Liege

Objective Today, incidence of type 2 diabetes is increasing sharply, and the disease is being diagnosed in younger subjects. For several years now, endocrine disruptors have been held responsible for the increase in the incidence of various pathologies. In vitro and in vivo (animal studies) evidences on their impact on type 2 diabetes are now very strong but epidemiological data in humans are still lacking. The aim of this work was to study the link between the contamination by endocrine disruptors and the onset of type 2 diabetes in a Belgian population. Material and method Eleven phthalates and benzophenone were measured using liquid chromatography coupled to mass spectrometer while six bisphenols, five organophosphorus pesticides and triclosan were measured by gas chromatography coupled to mass spectrometer in urine of one hundred diabetics and healthy volunteers paired for age and gender. Dichlorodiphenyldichloroethylen, and twelve polychlorobiphenyls were measured using gas chromatography coupled to mass spectrometer and nine perfluoroalkyl substances were measured using liquid chromatography coupled to mass spectrometer in the serum of both populations. Statistical correlations with the diseases were explored by monovariate models and multivariate logistic regression models including sociodemographic parameters. Results Contamination frequencies for the various compounds will be presented, along with basic descriptive statistics (mean, median, P95). In urine, a significant correlation was found between ethylparaben contamination and type 2 diabetes status but only in monovariate model. In blood, with these models, concentrations of PCB 128, 158 and 167 but also of DDE were significantly associated with type 2 diabetes status. When multivariate models including socio-demographic parameters were used, the diabetic status was positively correlated with PCB 167 and PFHxS blood concentrations Conclusion Our results suggest correlations between contaminations by legacy environmental pollutants and type 2 diabetes. However, results need to be enhanced by enquiring cocktail effect of the multi-pollutants exposure.