Low serum folate levels: a risk factor for sudden sensorineural hearing loss?

Abstract

ObjectiveIschemic vascular damage of the inner ear is one of the known causes of sensorineural sudden hearing loss (SSHL). Folate is an emerging risk factor associated with an increased risk of vascular damage. The aim of this study was to investigate whether low serum folate levels are associated with SSHL.Material and MethodsSerum folate levels were determined in 43 patients with SSHL and in 24 controls.ResultsFolate levels were found to be significantly lower in SSHL patients than in controls (mean difference −1.96 ng/ml; 95% CI −3.31, −0.59 ng/ml; p=0.006). No significant relationship between folate levels and either sex, age, cigarette smoking, alcohol consumption or hypertension was observed, while a significant relationship was found between low folate levels and high homocysteine (HCY) levels in all 43 patients (p<0.01). The potential influence of low folate levels on hearing impairment in SSHL patients can be explained by the effects on HCY metabolism and the diminution of folate antioxidant capacity.ConclusionFurther studies are needed to elucidate whether low folate levels can be considered a risk factor for SSHL.