Effects of Hyperlipidemia on Noise Induced Hearing Loss (NIHL)

Likelihood of developing noise induced hearing loss (NIHL) is affected by some factors such as genes, nutrition and healthy hearing habits. We investigated this study to determine the effect of hyperlipidemia on NIHL. In a case-control study, 144 workers who exposed to continuous noise more than 85 dBA (88-89 dBA) from a textile factory in Tehran were examined. Serum Blood test results as index for dyslipidemi, were collected and audiometry tests were carried out to analyze the association of hyperlipidemian and NIHL. The mean ±SD of Cholesterol level for NIHL and control were 188.19 (28.46) and 159.00 (26.66) mg/dL respectively. Also the mean ±SD of Triglyceride level for NIHL and control were 203.75 (53.92) and 105.00 (30.50) mg/dL consecutively. After adjusting odds ratio (OR) for NIHL, only hypertriglyceridemia had association with NIHL. (aOR = 1.07; 95 % CI 1.04-1.10), and there wasn't any relation between hypercholestomia and NIHL (aOR = 1.02; 95 % CI 0.99-1.05). Workers with hypertriglyceridemia are at increased risk for NIHL. In factories with elevated noise levels, besides hearing conservation programs, attention to blood serum level of workers and healthy diet are proposed to help in preserving hearing threshold.