Laboratory Assessment of Sudden Sensorineural Hearing Loss: A Case-Control Study

Objectives/Hypothesis: Sudden sensorineural hearing loss (SSHL) is an otologic emergency that affects five to 30 subjects per 100,000/year. The cause of SSHL remains unknown or uncertain in 70% to 90% of cases, and treatment decisions are usually made without knowing the etiology. Study Design: Prospective case-control study. Methods: One hundred thirty-one idiopathic SSHL patients were recruited from January 2014 to June 2015 in concordance with the Statements of Clinical Practice Guideline and divided into groups according to the disease severity. A clinical laboratory assessment was completed on blood samples collected from SSHL patients and control subjects. Multivariable regression analysis was performed to investigate the association between laboratory data and SSHL basis. Results: Only a few SSHL patients were positive for autoimmunity or viral infection. Statistically significant (P <. 05) higher levels of blood glucose, glycated hemoglobin (HbA1C), lipoprotein (a), and factor VIII were found in SSHL patients compared to controls. Furthermore, blood glucose, HbA1C, uric acid, factor VIII, and homocysteine were significantly associated to disease severity. Conclusions: Gluco-metabolic, lipidic, and coagulative laboratory data support the vascular hypothesis for SSHL and its severity.