Exposure to airborne polychlorinated biphenyls and type 2 diabetes in a Danish cohort

Laura Deen; Alice Clark; Karin Sørig Hougaard; Kajsa Ugelvig Petersen; Marie Frederiksen; Lauren A Wise; Amelia K Wesselink; Harald William Meyer; Jens Peter Bonde; Sandra Søgaard Tøttenborg

doi:10.1016/j.envres.2023.117000

Exposure to airborne polychlorinated biphenyls and type 2 diabetes in a Danish cohort

Environ Res. 2023 Nov 15;237(Pt 2):117000. doi: 10.1016/j.envres.2023.117000. Epub 2023 Aug 25.

Affiliations

¹ Department of Occupational and Environmental Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg Hospital, Denmark; Department of Public Health, The Faculty of Health Sciences, University of Copenhagen, Denmark. Electronic address: Laura.deen@regionh.dk.
² Real World Science, Novo Nordisk, Denmark.
³ Department of Public Health, The Faculty of Health Sciences, University of Copenhagen, Denmark; National Research Centre for the Working Environment, Denmark.
⁴ Department of Occupational and Environmental Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg Hospital, Denmark.
⁵ National Research Centre for the Working Environment, Denmark.
⁶ Department of Epidemiology, School of Public Health, Boston University, United States.
⁷ Department of Occupational and Environmental Medicine, Copenhagen University Hospital - Bispebjerg and Frederiksberg Hospital, Denmark; Department of Public Health, The Faculty of Health Sciences, University of Copenhagen, Denmark.

PMID: 37634693
DOI: 10.1016/j.envres.2023.117000

Abstract

Background: Previous research indicates an association between higher-chlorinated polychlorinated biphenyls (PCBs) and type 2 diabetes (T2D). However, less is known about the extent to which PCB exposure in indoor air, composed primarily of lower-chlorinated PCBs, affects T2D risk. We assessed the association between indoor air exposure to PCBs in residential buildings and T2D incidence.

Methods: The register-based 'Health Effects of PCBs in Indoor Air' (HESPAIR) cohort comprises 51,921 Danish residents of two residential areas with apartments built with and without PCB-containing materials (reference apartments). We assessed exposure status by combining register-based information on relocation history with extrapolated values of exposure based on PCB-measurements in indoor air from subsets of the apartments. T2D cases were identified in the Danish registers during 1977-2018. We estimated adjusted hazard ratios (HR) and 95% confidence intervals (CI) using Cox regression analyses with time-varying exposure.

Results: We identified 2737 incident T2D cases during the follow-up. Exposure to ≥3300 ng/m³ PCB × year (3rd tertile of PCB_year) was associated with higher risk of T2D (HR 1.15, 95% CI 1.02-1.30) compared with exposure to <300 ng/m³ PCB × year (reference). However, among individuals with lower cumulated PCB_year, the risk was similar to residents with exposure <300 ng/m³ PCB × year (300-899 ng/m³ PCB × year: HR 0.98, 95% CI 0.87-1.11; 900-3299 ng/m³ PCB × year: HR 0.96, 95% CI 0.83-1.10).

Discussion: We observed a marginally higher risk of T2D, but there was no evidence of an exposure-response relationship. The results should be interpreted with caution until confirmed in other independent studies of PCB exposure in indoor air.

Keywords: Environmental pollutants; Lower-chlorinated PCBs; PCBs; Volatile PCBs.