The Effects of Hyperlipidemia on sensory neural hearing loss

Regarding the high incidence rate of hyperlipidemia in the society and the adverse effects of its complications including the occurrence of hearing loss in some of the patients, we decided to do this research. This is a cohort study, in cooperation with ENT units of Islamic Azad University Mashhad Hospitals, which was carried out in 2008-2009 in Mashhad to assess the effect of hyperlipidemia on hearing. Ninety hyperlipidemic cases and 90 controls that were matched in terms of both age (two groups 30-50 years and 50-70 years) and sex entered the study. All the cases answered the questionnaire before the tests of audiometry. Then, those who were diagnosed with impaired hearing due to other factors rather than hyperlipidemia were excluded from the study. Audiologic exams on 180 cases (including both the case and control groups) included pure tone audiometry, diapasonic tests and otoscopy. This study revealed that there was a significant difference in hearing loss in 5 frequencies (250, 1000, 2000, 4000, 8000 HZ) between two groups of case and control (P<0.05). Hypertriglyceridemic patients showed a distinct hearing loss in 4 frequencies (250, 2000, 4000, 8000 HZ) comparing the control group and hypercholesterolemic patients (P<0.05). Hypercholesterolemic patients were found to have hearing loss just in 1000 HZ of frequency, as compared to the control group and hypertriglyceridemic patients. Also, the findings of this study suggest that the sex of the patients had no influence on hearing loss (P>0.05).According to our results, regular and periodic tests of audiometry are recommended for the hyperlipidemic patients to find out a history of audiologic problems and ultimately prevent the subsequent complications.