Audiological profile of patients with type 2 diabetes mellitus

S Afr J Commun Disord. 2024 Jul 31;71(1):e1-e13. doi: 10.4102/sajcd.v71i1.1035.

Abstract

Background: South Africa shows a high prevalence of type 2 diabetes with reported association with auditory dysfunction.

Objectives: To describe the audiological profile of adults with this metabolic condition.

Method: Employing a descriptive research design, 35 individuals with type 2 diabetes, selected through purposive sampling, underwent a basic audiological assessment in addition to extended high-frequency (EHF) audiometry, distortion product otoacoustic emissions (DPOAE) testing and neurological auditory brainstem response (ABR) test.

Results: This study revealed a 31.4% prevalence of hearing loss with 81.8% being sensorineural in nature. Poor hearing thresholds were observed at 16 kHz (n = 19; 54.3%), 18 kHz (n = 24; 68.6%) and 20 kHz (n = 30; 85.7%) in the right ear and at 16 kHz (n = 20; 57.1%), 18 kHz (n = 24; 68.6%) and 20 kHz (n = 30; 85.7%) in the left ear. Absent DPOAEs were observed at 6 kHz (n = 20; 51.7%) and 8 kHz (n = 24; 68.6%) in the right ear and at 6 kHz (n = 17; 48.6%) and 8 kHz (n = 29; 82.9%) in the left ear, possibly indicating that type 2 diabetes specifically targets higher frequency hearing. The ABR results revealed a delayed absolute latency of wave III bilaterally (right ear -69%; left ear - 51%), suggesting an impact of this metabolic disease on retro-cochlear pathways.

Conclusion: Hearing loss should be recognised as a comorbidity accompanying type 2 diabetes, which indicates the need for routine comprehensive audiological assessments to facilitate early detection and intervention.Contribution: The present findings have implications for audiology clinical protocols; diabetes related health policies and patient education.

Keywords: adults; audiological profile; hearing loss; hypertension; type 2 diabetes mellitus.

MeSH terms

  • Adult
  • Aged
  • Audiometry
  • Audiometry, Pure-Tone
  • Auditory Threshold*
  • Diabetes Mellitus, Type 2* / complications
  • Diabetes Mellitus, Type 2* / epidemiology
  • Evoked Potentials, Auditory, Brain Stem*
  • Female
  • Hearing Loss / diagnosis
  • Hearing Loss / epidemiology
  • Hearing Loss / etiology
  • Hearing Loss, Sensorineural / diagnosis
  • Hearing Loss, Sensorineural / epidemiology
  • Humans
  • Male
  • Middle Aged
  • Otoacoustic Emissions, Spontaneous*
  • Prevalence
  • South Africa / epidemiology

Grants and funding

Funding information The research received no specific grant from any funding agency in the public or private sectors.