Objectives Environmental and occupational noise exposure have been related to increased risk of cardiovascular disease. Activation of the physiological stress response and altered serum lipid levels have been proposed as alternative causal pathways. The objective of this study was to investigate the relation between occupational noise exposure and serum levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides when taking account of the use of hearing protection devices (HPD) and well-established predictors of lipid levels.

Methods This cross-sectional study included 460 Danish industrial workers and 69 financial workers included as a reference. They provided a serum sample and lipid levels were determined. All participants wore portable dosimeters that recorded noise exposure levels at the dominant shoulder every 5 seconds for a 24 hour period. We extracted measurements obtained during work and calculated the L_Aeq value. For 341 workers who kept a HPD diary we subtracted 10 dB from every noise recording obtained during HPD use and estimated the noise exposure level at the ear.

Results The mean measured noise exposure level was 80.0 dB(A) [range: 55.0–98.9] and the mean estimated level at the ear 77.8 dB(A) [range:55.0–94.2]. The measured level was strongly associated with increasing levels of triglycerides (p = 0,01), cholesterol-HDL ratio (p < 0,01) and decreasing levels of HDL-cholesterol (p = 0,01), but only in unadjusted analyses that did not account for HPD use. In analyses of estimated noise exposure level at the ear that were adjusted for body mass index and smoking status among others no effects were seen.

Conclusion No association between current occupational noise exposure level and serum lipid levels was observed. This does not indicate that a causal pathway between occupational and environmental noise exposure and cardiovascular disease, if such a relation exists, includes alteration of lipid levels.