Sudden sensorineural hearing loss associated with iron-deficiency anemia: a population-based study.

IMPORTANCE Vascular events play a big part in the development of sudden sensorineural hearing loss (SSNHL), but only those associated with sickle-cell anemia have been previously associated with SSNHL. This study demonstrates an association between SSNHL and prior iron-deficiency anemia (IDA).OBJECTIVE To evaluate the association between IDA and SSNHL using a nationwide population-based database.DESIGN, SETTING, AND PARTICIPANTS In this case-control study in Taiwan, participants with SSNHL (n = 4004) were identified, and controls (n = 12 012) were randomly selected.MAIN OUTCOMES AND MEASURES Conditional logistic regression was used to calculate the ORs (95%CIs) for IDA in participants with SSNHL vs controls.RESULTS Of the 16 016 sampled participants, 533 (3.3%) had previously been diagnosed with IDA, including 172 (4.3%) participants with SSNHL and 361 (3.0%) controls. The χ2 test revealed a significant difference (P < .001) in the prevalence of prior IDA between participants with SSNHL and controls. By conditional logistic regression, we found that the OR for previous IDA among the participants with SSNHL was 1.34 (95%CI, 1.11-1.61) (P < .01)after adjusting for monthly income, geographic region, urbanization level, and comorbidities(ie, hypertension, diabetes, hyperlipidemia, renal disease, and coronary heart disease). The significant relationship between SSNHL and prior IDA was most pronounced among those 44 years or younger (adjusted OR, 1.91; 95%CI, 1.35-2.72) (P < .001) for the participants with SSNHL compared with controls, and the strength of this relationship decreased with age.CONCLUSIONS AND RELEVANCE There is an association between SSNHL and prior IDA.Patients with IDA, especially those younger than 60 years, should be more aggressively surveyed and managed to reduce hearing-related morbidities.