Oxidative stress markers in occupational noise exposure: a systematic review and meta-analysis.

Background: Exposure to occupational noise could lead to detrimental health outcomes by inducing oxidative stress mechanisms. In this study, we sought to investigate the impact of occupational noise exposure on serum and/or plasma levels of oxidative stress markers.

Methods: We performed a thorough search across PubMed, Web of Science, and SCOPUS for articles comparing oxidative stress markers, including malondialdehyde (MDA) and/or superoxide dismutase (SOD) and/or glutathione peroxidase (GPx) and/or total antioxidant capacity (TAC), in individuals occupationally exposed to high noise and unexposed controls. The random-effects model was applied to determine the standardized mean difference (SMD) and the associated 95% confidence interval (CI).

Results: Seven primary studies were included. The analysis encompassed a total of 989 workers, including 537 individuals exposed to occupational noise levels exceeding 85 dB and 452 workers exposed to noise below 85 dB. Meta-analysis indicated that workers with high noise exposure exhibited significantly elevated TAC levels (SMD, 2.74; 95% CI: 1.87 to 3.61; p = 0.00; I² = 88.75%) and SOD levels (SMD, 0.90; 95% CI, 0.47 to 1.33; p = 0.00; I² = 69.32%), while no significant differences were observed among the groups regarding MDA levels (SMD, 1.03; 95% CI, -0.12 to 2.18; p = 0.08; I² = 97.30%) and GPx levels (SMD, 1.35; 95% CI, -0.41 to 3.11; p = 0.13; I² = 98.63%).

Conclusion: Our results suggest that TAC and SOD levels are elevated in workers exposed to high noise, potentially indicating heightened free radical production. However, no significant differences were found in MDA and GPx levels, warranting further investigation. Early detection and intervention may help reduce the harmful health impacts of noise exposure.