Relationship between occupational noise exposure and hypertension: A cross-sectional study in steel factories

Abstract

Background: Hazardous exposure to occupational noise may be associated with an increased risk of cardiovascular disease and hypertension. This study was performed to assess the relationship between noise exposure and hypertension prevalence in steelworkers.

Methods: A cross-sectional survey using self-reported noise exposure and audiometrically measured hearing loss was performed. One thousand eight hundred and seventy-four workers were interviewed. Multiple logistic regression was used to calculate odds ratios for hypertension by noise exposure. Linear regression analysis was used to test associations between noise exposure and systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Results: Occupational noise-exposed subjects had significantly higher blood pressure levels than nonexposed subjects (SBP: 123.18 ± (standard deviation) 12.44 vs 119.80 ± 12.50 mm Hg; DBP: 77.86 ± 9.34 vs 75.49 ± 8.73 mmHg). The prevalence of hypertension was approximately 5% in the control group without noise exposure or hearing impairment and increased from 6% to 21% across the range of increasing degree of hearing loss and, separately, of cumulative exposure time. Noise exposure (any) was associated with an increase in the prevalence of hypertension (odds ratio, 2.03, 95% confidence interval [CI]: 1.15-3.58). Noise-induced hearing loss and cumulative noise exposure time were positively correlated with BP (hearing loss: SBP: β = .09, 95% CI: 0.04-0.15 mm Hg, DBP: β = .11, 95% CI: 0.06-0.17 mm Hg; cumulative exposure time: SBP: β = .10, 95% CI: 0.04-0.15 mm Hg, DBP: β = .09, 95% CI: 0.04-0.15 mm Hg).

Conclusions: Noise exposure measured in two different ways was strongly associated with the prevalence of hypertension in steelworkers. Reducing noise in the steel factory could be a way of decreasing the risk of hypertension in this population.

Keywords: cardiovascular disease; hearing loss; hypertension; occupational noise; steelworkers.