Serum fatty acids and cardiovascular risk factors in sudden hearing loss: a case control study.

OBJECTIVES: We analyzed the relationships between sudden sensorineural hearing loss (SSNHL) and serum levels of fatty acids, total cholesterol, low-density lipoproteins (LDLs), and the antioxidant coenzyme Q10. METHODS: Forty-three patients with SSNHL and 43 healthy subjects were enrolled in the study. The main outcome measures were serum levels of fatty acids, coenzyme Q10, total cholesterol, and LDLs. RESULTS: On univariate logistic regression analysis, high levels of total cholesterol (p < 0.001), LDLs (p = 0.024), behenic acid (p < 0.001), docosahexaenoic acid (p < 0.001), linolenic acid (p = 0.017), and oleic acid (p < 0.001) and low levels of coenzyme Q10 (p < 0.001) and nervonic acid (p < 0.001) were associated with an elevated risk of SSNHL. On multivariate analysis, only hypercholesterolemia (p = 0.15) and low levels of coenzyme Q10 (p = 0.02) and nervonic acid (p = 0.005) were significantly associated with SSNHL. CONCLUSIONS: This is the first report of low serum levels of nervonic acid as an independent risk factor for SSNHL. Considering that hypercholesterolemia, high serum levels of LDL, and low serum levels of the antioxidant coenzyme Q10 were associated with SSNHL as well, we hypothesize that saturated fatty acids may play a role in determining the dysmetabolic state in a subset of SSNHL patients. Together, these findings suggest that not only total cholesterol and LDL levels, but also fatty acid determination, may help identify SSNHL patients with cardiovascular risk factors.