Comorbid Diabetes Mellitus Type II, Hypercholesterolemia May Predict Pure-Tone Average Improvements in ISSNHL Patients

Do comorbid diseases significantly affect the prognosis of idiopathic sudden sensorineural hearing loss (ISSNHL)?

Background: ISSNHL is usually defined as a loss of greater than 30 dB of hearing sensitivity in three contiguous frequencies in less than three days. Several studies have discussed the presumed prognostic factors of ISSNHL, and many ISSNHL medical risk factors have been proposed. Reports on the effect of these major comorbidities on ISSNHL prognosis contain contradictions, however.

Study design: Retrospective cohort study of 781 patients newly diagnosed with ISSNHL and treated with the steroid prednisolone in a tertiary referral center between January 2003 and December 2013.

Setting: Chi Mei Medical Center, Yongkang District, Tainan City, Taiwan.

Synopsis: Seven comorbid major diseases (diabetes mellitus type II [DM], hypertension [HTN], coronary artery disease [CAD], hypercholesterolemia [Hch], cerebrovascular disease [CVD], chronic kidney disease [CKD], and anemia) were examined. The initial pure-tone average (PTA) of the affected ear at ISSNHL onset was calculated for all 781 patients. Major PTA improvements occurred in 345 patients, moderate improvements in 139, and minor improvements in 297. Major word recognition score (WRS) improvements occurred in 460 patients, moderate improvements in 248, and minor improvements in 83. The pretreatment PTA was significantly different for patients of different ages and with different comorbidities. The pretreatment PTA mean was significantly higher in patients older than 65 years old than in those from 12 to 64 years old and in patients with comorbid HTN and Hch. There was a significantly higher probability of a major PTA improvement for better pretreatment hearing, less treatment delay time, and no comorbid DM, and a significantly higher probability of a major to moderate PTA improvement for better pretreatment hearing, less treatment delay time and no comorbid Hch. We found no significant effect of the comorbid diseases on the probability of a major or moderate WRS improvement. One limitation was a varied follow-up period after the initiation of ISSNHL treatment.

Bottom line: Comorbid DM or Hch may indicate a smaller probability of major or moderate PTA improvement for patients with ISSNHL.

Citation: Lin CF, Lee KJ, Yu SS, Lin YS. Effect of comorbid diabetes and hypercholesterolemia on the prognosis of idiopathic sudden sensorineural hearing loss. Laryngoscope. 2016;126:142-149.