Auditory Acuity as a Reflection of Dyslipidemia

Communication is a crucial aspect of human life and auditory sense is very important for communication of any kind. Dyslipidemia, being a silent disease has been hypothesized as an independent risk factor for hearing loss due to atherosclerotic changes in vessel wall leading to vascular obstruction and end organ hypoxia. Cochlea, whose blood supply is by an end artery, is highly sensitive to these changes.

A) To perform Pure Tone Audiometry and compare hearing frequencies between cases and controls. B) To assess lipid levels among different degrees of hearing loss

A Case control study was done. 30 cases with abnormal serum lipid levels, 30 controls with normal serum lipid levels of age 30–50 yrs were selected after appropriate inclusion-exclusion criteria. Informed consent was taken. Serum lipid levels were assessed. Audiometric test for hearing acuity using ASHA 2005 guidelines was done in all subjects. Results were compiled and statistically analysed.

Cases were found to have sensorineural hearing loss compared to controls in the hearing frequency of 500- 4000Hz (p<0.001). Serum levels of Total cholesterol and triglycerides showed no significant relationship among different degree of sensorineural hearing loss. Significant rise in LDL and decrease in HDL was found as sensorineural hearing loss increased from mild to severe degree (p<0.01). Degree of hearing loss increased with increasing duration of dyslipidemia.

Dyslipidemic subjects were found to have sensorineural hearing loss. Low density lipoprotein levels directly correlate whereas high density lipoproteins negatively correlate with severity of sensorineural hearing loss. Reduced auditory acuity does reflect about severity and duration of dyslipidemia.