Metabolic Syndrome Increases the Risk of Sudden Sensorineural Hearing Loss in Taiwan: A Case-Control Study

Objective Sudden sensorineural hearing loss has been reported to be associated with diabetes mellitus, hypertension, and hyperlipidemia in previous studies. The aim of this study was to examine whether metabolic syndrome increases the risk of sudden sensorineural hearing loss in Taiwan. Study Design A case-control study. Setting Tertiary university hospital. Subjects and Methods We retrospectively investigated 181 cases of sudden sensorineural hearing loss and 181 controls from the Department of Otorhinolaryngology, Kaohsiung Medical University Hospital, in southern Taiwan from 2010 to 2012, comparing their clinical variables. We analyzed the relationship between metabolic syndrome and sudden sensorineural hearing loss. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III with Asian modifications. The demographic and clinical characteristics, audiometry results, and outcome were reviewed. Results Subjects with metabolic syndrome had a 3.54-fold increased risk (95% confidence interval [CI] = 2.00-6.43, P < .01) of having sudden sensorineural hearing loss compared with those without metabolic syndrome, after adjusting for age, sex, smoking, diabetes mellitus, hypertension, and hyperlipidemia. With increases in the number of metabolic syndrome components, the risk of sudden sensorineural hearing loss increased (P for trend <.01). Vertigo was associated with a poor outcome (P = .02; 95% CI = 1.13 +/- 5.13, adjusted odds ratio = 2.39). The hearing loss pattern may influence the outcome of sudden sensorineural hearing loss (P < .01). Conclusion These results suggest that metabolic syndrome is an independent risk factor for sudden sensorineural hearing loss in Taiwan. Vertigo and total hearing loss were indicators of a poor outcome in sudden sensorineural hearing loss.