Severe diarrhea-dehydration in infancy permanently alters auditory function

Area of Science:

• Otolaryngology
• Pediatrics
• Metabolic Disorders

Background:

• Sensorineural hearing impairment (SHI) has numerous causes, but metabolic stress is often overlooked.
• Severe dehydration and hypoxia during infancy may induce lasting cochlear alterations.
• Previous research on otitis media suggests a link between infant hospitalization for diarrhea-dehydration and later auditory function.

Purpose of the Study:

• To investigate the hypothesis that transient metabolic stress from dehydration and hypoxia in infancy can lead to permanent SHI.
• To explore the potential impact on auditory thresholds and uncomfortable loudness levels.
• To examine the evolutionary consistency and verifiability of this hypothesis.

Main Methods:

• Analysis of a population-based prospective study of otitis media.
• Comparison of auditory thresholds and stapedius reflex thresholds in children with and without a history of infant hospitalization for diarrhea-dehydration.
• Consideration of descriptive studies in infants undergoing ECMO or treated for congenital diaphragmatic hernia, and animal studies for verification.

Main Results:

• Children hospitalized for diarrhea-dehydration as infants exhibited worse auditory thresholds at 4-8 years of age compared to those without otitis.
• Lower stapedius reflex thresholds were observed in children with a history of diarrhea-dehydration hospitalization, indicating reduced acoustic energy for arousal.
• The findings support the hypothesis linking infant metabolic stress to permanent SHI.

Conclusions:

• Transient metabolic stress, specifically severe dehydration and hypoxia in infancy, is a potential, underrecognized cause of permanent sensorineural hearing impairment.
• This condition may also reduce uncomfortable loudness thresholds.
• The hypothesis is biologically plausible and amenable to further investigation through clinical and animal studies.