Sudden Sensorineural Hearing Loss Predicts Ischemic Stroke: a Longitudinal Follow-Up Study.

Objectives: To investigate the risk of stroke in SSNHL patients.
Study Design: A longitudinal follow-up cohort study.
Setting: The Korean National Health Insurance Service-National Sample Cohort from 2002 to 2013.
Patients: The 4,944 SSNHL participants were matched with 19,776 controls for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia. The SSNHL subjects were diagnosed (International Classification of Disease [ICD]-10: H91.2), underwent an audiometry examination, and were treated with steroids. The history of hemorrhagic stroke, ischemic stroke, hypertension, diabetes, dyslipidemia, ischemic heart disease, and depression was investigated based on the ICD-10.
Main Outcome Measures: The hazard ratios (HRs) for hemorrhagic and ischemic stroke were analyzed using a Cox proportional hazard model. Subgroup analyses were conducted according to age (< 50 vs. ≥ 50 yr old) and sex.
Results: Participants diagnosed with ischemic stroke included 4.2% of SSNHL subjects and 3.5% of control subjects (p = 0.013). The adjusted HR of SSNHL for ischemic stroke was 1.22 (95% confidence interval [95% CI] = 1.05 - 1.43, p = 0.012). The ≥ 50-year-old male SSNHL subgroup showed 1.40 adjusted HRs for ischemic stroke (95% CI = 1.10 - 1.78, p = 0.006). The rate of hemorrhagic stroke was 0.7% for SSNHL and 0.6% for control subjects. SSNHL did not elevate the risk of hemorrhagic stroke (p = 0.310).
Conclusion: SSNHL elevated the risk of ischemic stroke in the general population. Older males with SSNHL demonstrated a high risk for ischemic stroke; however, SSNHL did not increase the risk of hemorrhagic stroke.