Association between polychlorinated biphenyls and diabetes mellitus in the German HELPcB cohort.

Abstract

The aim of the present study was to examine whether there is an association between the prevalence of diabetes mellitus, the levels of HbA1c and the internal PCB burden of the initial 263 participants of HELPcB (Health Effects in High-Level Exposure to PCB). Four waves of follow ups were examined with a cross sectional and a longitudinal approach between 2010 and 2013. HELPcB is a surveillance program for formerly PCB-exposed workers of a capacitor recycling company and other potentially affected people. During 4 waves of follow up, medical history and blood samples were taken. Biomonitoring for PCB was conducted by gas chromatography coupled with mass spectrometry. Serum analysis of blood glucose, HbA1c, GAD, IAA, IA-2 and ICA were conducted at the centre of laboratory diagnostics of the local university hospital. The mean levels of PCB were comparable to other investigations of occupational cohorts like Persky et al. (2012). A logistic regression model showed higher prevalence rates in comparison to the German general population for diagnosed or undiagnosed diabetes mellitus for several PCB congeners in the second, third or fourth quartile of PCB burden. The adjusted odds ratio was significantly increased for PCB 52 at the third quartile (7.6; 95% CI: 1.4-41.0). A multiple linear regression model showed a significant influence of several PCB congeners on the HbA1c level at year 3 and 4. The development of HbA1c over time was examined with the same regression model applied to a longitudinal data set of 119 participants who met all 4 follow ups. An analysis of the autoantibodies GAD, IAA, IA-2 and ICA showed no association to PCB burden. In summary there is a detectable association between internal PCB burden and glucose metabolism in the cohort of HELPcB, however it is difficult to find a possible mechanism or a congener with outstanding influence. Further research and more follow ups for the HELPcB cohort are scheduled.