Historical exposure to non-persistent environmental pollutants and risk of type 2 diabetes in a Spanish sub-cohort from the European Prospective Investigation into Cancer and Nutrition study.

ABSTRACT

BACKGROUND: Environmental factors are believed to account for a substantial burden of type 2 diabetes mellitus (T2DM). Non-persistent environmental pollutants (npEPs) are a group of widely-used chemicals identified as endocrine/metabolic disrupting chemicals and obesogens. The aim of this study was to analyse the potential associations of serum levels of three groups of npEPs with the risk of incident T2DM. METHODS: This is a longitudinal study within a sub-sample of Granada EPIC-Spain cohort (n = 670). We quantified serum concentrations of 7 npEPs four parabens (Methylparaben (MP) ethylparaben (EP), propylparaben (PP) and butilparaben (BP); two benzophenones Benzophenone 1 (BP1), Benzophenone 3 (BP3); and Bisphenol A (BPA). Exposure was assessed by means of chemical analyses of serum samples collected at recruitment, and information on potential confounders was gathered by using validated questionnaires at baseline. Follow-up was performed by review of patients' clinical records. Cox Proportional Hazards Models were used for the statistical analyses. RESULTS: Median follow-up time was 23 years. There were 182 (27%) incident T2DM diagnoses in our sub-cohort. MP was the most frequently detected npEP, 88.42% samples above the limit of detection, and BP showed the lowest percentage of detection (19.21%). Those individuals within the fourth PP quartile (0.53-9.24 ng/ml) showed a statistically significant increased risk of T2DM (HR = 1.668 p = 0.012), while BP1 concentrations showed an inverse non-significant trend with the risk. CONCLUSIONS: We evidenced a potential contribution of npEP exposure on T2DM, but no clear trend was observed. However, limitations in relation to exposure estimation might influence our findings and further research is warranted to confirm our results.