Abstract
Introduction Idiopathic sudden sensorineural hearing loss (ISSHL) is a disabling otologic urgency
whose ethiopathogenesis is still controversial. Only in recent years metabolic syndrome
(MetS) has been implicated as a possible aggravating factor in the prognosis of recovery
from ISSHL.
Objective To assess whether the preexistence of MetS interferes on hearing recovery levels.
Methods Retrospective cohort study composed of adult (> 18 years old) ISSHL patients admitted
for treatment between January 2015 and December 2019. To diagnose ISSHL, we used pure-tone
audiometry, and identified MetS patients based on the criteria of the United States
National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III). The
treatment protocol comprised hospitalization for five days for the intravenous administration
of dexamethasone, audiometric surveillance, imaging and blood analyses, and, based
on recovery, the planning of rescue treatments (intratympanic administration of dexamethasone
and/or hyperbaric oxygen). The Siegel criteria were used to evaluate the hearing outcomes.
Results The final sample was composed of 81 patients, 48 without MetS (nMetS) and 33 with
MetS. Regarding the Siegel recovery category, the nMetS group had significantly better
results (p = 0.001), with 44% of complete recoveries against 6% in the MetS, and 58% of the
MetS patients had the worst outcome, contrasting with 27% in the nMetS group. The
nMetS group had an overall better evolution in terms of hearing recovery and had a
significant improvement in the median hearing gain (20.6 dB versus 8.8 dB; p = 0.008). Additionally, the multivariate analysis revealed that the presence of MetS
is a significant risk factor for a worse outcome (odds ratio [OR] = 0.30; 95% confidence
interval [95%CI] = 0.10–0.85).
Conclusion Regardless of age, gender, the initial audiometry threshold, and autoimmunity, MetS
is a clear risk factor for a worse outcome regarding the recovery of hearing after
ISSHL.
Keywords
hearing loss - idiopathic sudden sensorineural hearing loss - metabolic syndrome -
hearing recovery
