Enhanced occupational noise exposure and reduced telomere length with enhanced risk of heart disease: evidence from two populations.

BACKGROUND: Occupational noise exposure has been linked to cardiovascular risk, but its associations with emerging lipid-related cardiovascular predictors and the potential role of leukocyte telomere length (LTL) remain unclear. AIM: This study aimed to investigate associations of occupational noise exposure with the atherogenic index of plasma (AIP) and the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR), and to explore the potential involvement of LTL. DESIGN AND METHODS: This cross-sectional study included 765 Chinese workers and 131,214 participants from the UK Biobank. In the occupational cohort, cumulative noise exposure (CNE) was calculated using occupational histories and workplace noise monitoring data. AIP and NHHR were derived from lipid biomarkers, and LTL was measured by qRT-PCR. Generalized linear models, restricted cubic splines, interaction analyses and mediation analyses were performed. RESULTS: CNE was positively and nonlinearly associated with AIP and NHHR (both P for overall < 0.01 and P for nonlinear < 0.01); negatively associated with LTL (P for overall < 0.01 and P for nonlinear = 0.017). LTL was negatively associated with AIP (β: -0.008; 95% CI: -0.015, -0.002) and NHHR (β: -0.056; 95% CI: -0.078, -0.033). LTL explained the associations of noise level and CNE with NHHR, with the proportions of 16.51% and 34.90%, respectively. Similar associations of occupational noise exposure with AIP and LTL were observed in UKB. CONCLUSION: Our study demonstrates positive associations of occupational noise exposure with AIP and NHHR, and suggests that LTL plays an important role in those associations.