Objective: Sudden hearing loss is mostly a unilateral sensorineural hypoacusis with the highest incidence in young adults. The aim of this study was to determine the differences in homocysteine and serological marker levels in sudden sensorineural hearing loss and to define the importance of these markers in diagnosis.

Methods: After audiological examination, 52 patients were considered as having sudden hearing loss. Serological markers (C3, C4, anti-streptolysin-O, C-reactive protein, rheumatoid factor) and homocysteine were examined. The patients were divided into two groups, as patients above and below 40 years of age. Statistical analysis was performed using SPSS version 15 software. P values less than 0.05 were considered statistically significant.

Results: Fifty-two patients were included in the study, and the study group consisted of 33 men and 19 women. The mean age was 43.5 years and the age range was 14-82 years. According to the survey results, 63% of the patients had higher than normal homocysteine levels. It was observed that 60.8% of homocysteine levels were increased in patients below 40 years of age and 69% in patients over 40 years of age. There was no statistically significant difference between the two groups (p=0.49). In the evaluation of immunological serological markers, no parameter was observed except for C3c. Fifty-four percent of all patients were considered to have a C3c parameter below normal limits. C3c levels were decreased in 52% of patients below 40 years of age and 55% of patients over 40 years of age. There was no statistically significant difference between the two groups (p=0.31).

Conclusion: It is thought that microvascular and immunological pathogenesis develops in sudden hearing loss. Homocysteine and C3 levels are valuable but age-related parameters following diagnosis and treatment.