Exposure to organochlorine compounds in relation to weight maintenance

BACKGROUND The purpose was to test the hypothesis that exposures to organochlorine compounds are associated with body weight increases in a dietary intervention study. METHODS In the DioGenes trial, adults with obesity who had at first lost at least 8% of their body weight then completed at least 26 weeks on a specific diet. Concentrations of major organochlorine compounds were assessed in plasma samples obtained at study baseline. RESULTS A total of 372 participants with complete data were examined for plasma concentrations of major organochlorine compounds. A doubling in total-PCB in plasma was associated with an increase in weight (in kg) at 26 weeks by 0.43 (0.04;0.83), independent of diet group and sex. Associations for most individual organochlorines were in the same direction, though mostly not statistically significant, especially after adjustment. However, p,p’ -DDE showed opposite effects. Adjustment for exposure to perfluorinated alkyl substances (PFASs) only minimally affected the findings. CONCLUSIONS Elevated plasma concentrations of some organochlorine compounds were weakly associated with increased weight gain, although most individual associations did not reach statistical significance after adjustment for PFAS exposure. However, p,p’-DDE concentrations showed a clear association with lowered body weight. Overall, the halogenated pollutants examined are likely to contribute to the obesity pandemic. TRIAL REGISTRATION: The original RCT is with ClinicalTrials.gov number NCT00390637.