Association between occupational noise and obesity: a retrospective cohort study in China

To determine the relationship between occupational noise, and obesity and body mass index (BMI) changes.

Baseline data were collected from participants (n = 1264) who were followed for 6 years in a retrospective study. The noise exposure level (L_Aeq,8h) was determined by equivalent continuous weighted sound pressure levels using the fixed-point surveillance method for noise monitoring. The cumulative noise exposure (CNE) level was determined using the equal energy formula, which is based on exposure history and level.

The incidence of obesity at low (RR = 2.364, 95% CI 1.123-4.739]), medium (RR = 3.921, 95% CI 1.946-7.347]), high (RR = 5.242, 95% CI 2.642-9.208]), and severe noise levels (RR = 9.322, 95% CI 5.341-14.428]) was higher risk than the L_Aeq,_8h control level. The risk of obesity among participants exposed to low (RR = 2.957, 95% CI 1.441-6.068]) and high cumulative noise levels (RR = 7.226, 95% CI 3.623-14.415]) was greater than the CNE control level. For every 1 dB(A) increase in L_Aeq,8h, the BMI increased by 0.063 kg/m² (95% CI 0.055-0.071], SE = 0.004). For every 1 dB(A) increase in the CNE, the BMI increased by 0.102 kg/m² (95% CI 0.090-0.113], SE = 0.006).

Occupational noise is related to the incidence of obesity. The occupational noise level and occupational noise cumulative level were shown to be positively correlated with an increase in BMI.