Outer hair cell functioning in infants with iron deficiency anemia

Area of Science:

• Otoacoustic Emissions Research
• Pediatric Audiology
• Neonatal Health

Background:

• Distortion product otoacoustic emissions (DPOAE) assess cochlear status, particularly outer hair cell function, in infants.
• Iron deficiency anemia (IDA) is a common condition in infants, prompting investigation into its auditory effects.

Purpose of the Study:

• To analyze the presence and amplitude of DPOAE across various frequencies in infants with and without IDA.
• To determine if IDA affects the functioning of outer hair cells in the infant cochlea.

Main Methods:

• DPOAE measurements were conducted on 80 infants (6-24 months), comparing 40 with IDA to 40 healthy controls.
• Cubic DPOAEs were recorded at six frequencies (1500-8000 Hz) with specific stimulus intensities (L1=65 dBSPL, L2=55 dBSPL).
• Immittance audiometry confirmed normal middle ear function before DPOAE testing.

Main Results:

• DPOAEs were present in all infants, irrespective of IDA status, across all tested frequencies.
• No statistically significant differences in DP amplitude were found between infants with and without IDA (p < 0.05).
• Gender and age did not yield statistically significant differences in DPOAE measures between the groups.

Conclusions:

• Reduced iron levels in infants with IDA do not appear to influence outer hair cell function, as evidenced by unchanged DPOAE amplitude.
• Iron status in infancy does not seem to have a direct impact on the integrity of outer hair cell function.
• Further research using fine structure DPOAEs may be needed to detect subtle auditory changes related to iron deficiency.