Noise exposure and hypertension: investigation of a silent relationship

Abstract

BackgroundNoise is an important occupational hazard worldwide and hypertension a well-known risk factor for cardiovascular disease, which is currently the greatest cause of disability retirement worldwide. The association between noise exposure and auditory effects is well documented in the biomedical literature, but the same is not true about exposure to different levels of noise and extra-auditory effects. It has been shown that noise exposure levels to be considered for non-auditory effects may not be the same as in the case of auditory effects. The frequent presence of noise in workplace environments, the high prevalence of hypertension worldwide, the biological plausibility of the association between noise exposure and high blood pressure and the need for more studies investigating the non-auditory effects of exposures to less than 85 dB(A), were the reasons that led us to develop this study. We aimed at investigating the hypothesis that exposure to different levels of noise is associated with hypertension.MethodsWe used a cross-sectional design to study the association between occupational noise exposure (≤75, 75–85, and ≥ 85 dB(A)) and hypertension (use of anti-hypertensive medication and/or blood pressure of ≥140/90 mmHg) in 1,729 petrochemical workers at Rio de Janeiro, Brazil. Data were collected from obligatory annual health evaluation records and from environmental measurements of noise and heat levels. We used logistical regression analysis to study the association while controlling for key confounding variables, such as smoking and body mass index.ResultsUsing the ≤75 dB(A) as reference category, noise exposure was independently associated to hypertension both at the 75–85 dB(A) (OR 1.56; 95% CI 1.13–2.17) and the ≥85 dB(A) levels (OR 1.58; 95% CI 1.10–2.26). Age, gender and body mass index were also independently associated to high blood pressure.ConclusionHerein, we were able to demonstrate that noise exposure is independently associated to hypertension. Our results are consistent with other studies that used similar methodology and enabled us to verify the occurrence of non-auditory effects in workers exposed to noise levels considered safe for auditory effects.

Is aircraft noise exposure associated with cardiovascular disease and hypertension? Results from a cohort study in Athens, Greece

“…However, most studies find results broadly consistent to ours. De Souza et al ,29 in an occupational noise exposure study at higher noise exposure levels (>75 dB) and including younger subjects compared with the present study, found an OR for hypertension of 1.56 (95% CI 1.13 to 2.17). A recent meta-analysis of five studies on the effect of noise on the prevalence/incidence of hypertension,6 which did not include the HYENA study, found an OR of 1.63 for exposure to aircraft noise versus non-exposure, a finding consistent with ours (although it should be noted that the definition of ‘exposure’ was differently defined between studies).…”

Effects of environmental noise exposure on DNA methylation in the brain and metabolic health

“…However, the effect of noise exposure upon blood pressure is still inconclusive as both hypertension and hypotension has been reported (de Souza et al, 2015;Lercher and Widmann, 2013;Lercher et al, 2014). This inconsistency may be the product of limitations in adjustment for confounders such as air pollution exposure, which is a key risk factor for increased blood pressure.…”

The Association between Risk Factors and Blood Pressure in the Textile Industry Workers

“…29 Similarly, with an opinion that suggests getting older, the higher the likelihood of developing high blood pressure. As we age, blood pressure increases gradually as the elasticity of the vessels diminishes.…”