Evaluation of the Auditory Effects of
Hyperlipidaemia and Diabetes Mellitus
by Using Audiometry
S Anandhalakshmi, MD,
Department of Physiology,
SRM Medical College Hospital and Research Centre,
SRM University, Kattankulathur,
Background: Hyperlipidaemia is a common disease of lipid metabolism, whereas diabetes mellitus (DM) is a chronic disease which is caused due to the relative or absolute lack of insulin, which results in elevated blood glucose levels. Hearing loss is the total or partial inability in hearing sound in one or both the ears. Although the relationship between hearing loss and hyperlipidaemia or diabetes mellitus has been shown in many clinical investigations, this concept is still controversial.
Objective: The aim of the study was to evaluate the auditory effects of hyperlipidaemia and diabetes mellitus by using audiometry.
Materials and Methods: The study group consisted of 30 normal subjects (group I), 30 subjects with hyperlipidaemia (group II), 30 Type II diabetic patients (group III) and 30 subjects with both diabetes and hyperlipidaemia (group IV) of the age group of 40- 50 years, who attended the Diabetology Outpatients Department and the Master Health Check Up Scheme at the Stanley Medical College and Hospital, Chennai. The subjects underwent blood pressure examination and the laboratory evaluation of the serum lipid profile, fasting and post prandial blood glucose levels, serum urea levels and creatinine levels. Pure tone audiometry was done for both the ears of all the subjects.
Results: The prevalence of hearing loss in group IV was 63.3%, in group III, it was 56.7%, in group II, it was 40% and in group I, it was 6.7%. There was also an increased association of hearing loss in people with high total cholesterol, high triglycerides and high LDL levels. The audiogram analysis showed a high frequency of hearing loss.
Conclusion: Our study reports that the prevalence of sensorineural deafness was increased in the subjects with diabetes and in subjects with hyperlipidaemia and the subjects having both diabetes and hyperlipidaemia had the highest risk of developing sensorineural deafness. The hearing loss was a progressive, bilateral, sensorineural deafness of gradual onset, which affected mainly the higher frequencies.