Association Between the Development of Sensorineural Hearing Loss and Blood NAD⁺ Levels

Area of Science:

• Otolaryngology
• Biochemistry
• Gerontology

Background:

• Hearing loss is a prevalent condition, particularly in older adults.
• Sensorineural hearing loss (SNHL) affects a significant portion of the global population.
• The role of nicotinamide adenine dinucleotide (NAD+) in hearing loss is under investigation.

Purpose of the Study:

• To investigate the association between sensorineural hearing loss (SNHL) and blood nicotinamide adenine dinucleotide (NAD+) levels.
• To explore the relationship between SNHL, age-related hearing loss (ARHL), and oxidative stress markers.

Main Methods:

• An observational study included 80 patients aged 50 and older, categorized by hearing loss status and age.
• Whole-blood NAD+ levels, diacron-reactive oxygen metabolites (dROMs), and biological antioxidant potential (BAP) were measured.
• Statistical analyses, including analysis of covariance and multivariate analysis, were performed.

Main Results:

• Significantly lower NAD+ levels were observed in older adults (≥ 80 years) with hearing loss compared to those without.
• Increased dROMs levels correlated with a higher risk of developing SNHL.
• Age-related hearing loss (ARHL) was strongly associated with decreased whole-blood NAD+ levels.

Conclusions:

• Decreased NAD+ levels and increased dROMs are associated with an elevated risk of SNHL.
• Age-related hearing loss (ARHL) is particularly linked to reduced NAD+ levels.
• Further research with larger sample sizes is warranted to confirm these findings.