Association between noise exposure and diabetes in hearing loss: a retrospective cohort study with workers from the sugarcane industry in the State of São Paulo, Brazil

The aim is to evaluate the association between noise exposure and diabetes mellitus in the early onset of occupational hearing loss in individuals exposed to occupational noise from different work environments and different intensities. Retrospective cohort study with workers at a sugar-ethanol plant in the region of Dracena, SP, Brazil. The reference and sequential audiological exams were compared. The outcome dependent variable was the presence of hearing loss and the independent variables were age, environmental sound pressure level, type of workplace and presence of diabetes mellitus. 547 workers were evaluated. The univariate assessment showed a chance of finding individuals older than 39 years old with hearing loss triggering was 4.25 times greater compared to individuals aged between 19 and 28 years. The presence of diabetes increases the chance of hearing loss when compared to individuals without the disease. In the multivariate model, when adjusting for the predictors, there was a reduction in the chance of having diabetes, since part of the observed effect would be linked to the age. There is an association between diabetes mellitus and onset of hearing loss in individuals exposed to occupational noise below 85 dB.