Microvascular dysfunction affects the development and prognosis of sudden idiopathic hearing loss.

OBJECTIVE: The aim of our study is to investigate whether systemic microvascular function affects the development and prognosis of sudden idiopathic hearing loss (SHL). TYPE OF STUDY: A prospective case-control study. MATERIALS AND METHODS: Fifty patients diagnosed with SHL at our hospital between September 2015 and May 2016 were included as the SHL group, and 50 healthy volunteers who came to the hospital for medical screening were included in the control group. Thirty-one patients from the SHL group who responded to treatment and 19 patients who did not respond to treatment were identified according to the Siegel criteria and were grouped. Patients with comorbid disorders were excluded from the study. To determine microvascular function, the videocapillaroscopic examination was conducted from the nailfold, measuring the capillary density (CD) and post-occlusive reactive hyperaemia (PORH) values and statistical analysis was performed between the groups. RESULT: While CD was an average of 83.1 ± 6 in the SHL group, it was measured as 96.2 ± 10 in the control group. The CD value was significantly lower in the SHL group than the control group (P < 0.05). While the average PORH value in the SHL group was 80.5 ± 7.7, it was measured as 97.5 ± 10 in the control group. The PORH value was significantly lower in the SHL group than the control group (P < 0.05). The CD value did not differ significantly (P > 0.05) between the group that responded to treatment (83.4 ± 5.5) and the group that did not respond to treatment (82.7 ± 6.9). The PORH value was significantly lower (P < 0.05) in the group that did not respond to treatment (75.2 ± 7.9) than the group that did (83.8 ± 5.6). CONCLUSION: To our best knowledge, our study is the first study in the literature. Although the role of specific mechanisms in SHL is not entirely understood, the capillaroscopic examination can show the importance of microvascular function in SHL. CD and PORH values were found to be low in SHL patients, and a low PORH value was found to be a factor of poor prognosis.