title: Increased prevalence of early cochlear damage in young patients with type 1 diabetes detected by distortion product otoacoustic emissions.
abstract: OBJECTIVE
  To evaluate the hearing of adolescents with diabetes mellitus type 1(DM1) by otoacoustic emissions (OAEs), and by comparing different tests with pure-tone audiometry to identify potential early cochlear impairments.
  
  
  METHODS
  Pure-tone audiometry, transient evoked otoacoustic emissions (TEOAEs), and distortion product otoacoustic emissions (DPOAEs) were performed in a group of adolescents with and without DM1. Clinical characteristics, disease duration, and glycated haemoglobin levels were studied.
  
  
  METHODS
  Participants were 40 adolescents with DM1 and 40 healthy subjects.
  
  
  RESULTS
  Sensorineural hearing loss, affecting frequencies of 6000 and 8000 Hz, was found only in DM1 subjects when compared to the controls (7.7% vs. 0%, p < 0.05). A higher prevalence of cochlear damage was detected by DPOAE responses, 32% belonging from the diabetic group, vs. 3.7% in the control group. Absent TEOAE responses were observed in only three individuals, all from the diabetic group (5.1% of the tests performed in the diabetic group). Additionally, hearing thresholds were better in diabetic subjects with good control when compared to ones with regular or poor control (p = 0.00). Hearing thresholds were higher in poorly controlled diabetics when compared to subjects with good (p = 0.000) or regular control (p = 0.006).
  
  
  CONCLUSIONS
  Early evidence of cochlear damage was detected in adolescents with DM1 leading to hearing loss at high frequencies. Abnormal DPOAEs responses were found more frequently than the alterations in TEOAEs and pure-tone audiometry, suggesting that DPOAEs evaluation is the most sensitive and it could be used for monitoring the progression of cochlear damage during the early stages of hearing impairment.
authors.affiliation: * Post-Graduate Student, Medical School, Federal University of Minas Gerais , Brazil.
authors.forename: Carla Tomaz
authors.initials: CT
authors.lastname: Botelho
authors.forename: Sirley Alves da Silva
authors.initials: SA
authors.lastname: Carvalho
authors.forename: Ivani Novato
authors.initials: IN
authors.lastname: Silva
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D001938:Brazil / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D003051:Cochlea / Q000503:physiopathology*; D015834:Cochlear Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D018450:Disease Progression; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006309:Hearing; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous; D015995:Prevalence; D012307:Risk Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: Diabetes mellitus; cochlea; hearing loss; sensorineural; type 1