Author(s)
Kourosh Parham MD PhD
Affiliation(s)
University of Connecticut Health
Abstract:
Educational Objective: At the conclusion of this presentation, the participants should be able to discuss the implications of the relationship between two proposed circulatory otologic biomarkers, prestin and otolin-1.
Objectives: Circulatory biomarkers, based on inner ear specific proteins such as prestin and otolin-1, are showing great promise in the research setting. Prestin levels show sensitivity to noise and cisplatin induced hearing loss and to otoprotectants and prestin levels correlate strongly with hearing thresholds shortly after outer hair cell injury. Otolin-1 levels are higher in BPPV and Meniere's disease and show strong correlations with T-score and parathyroid hormone levels, factors which influence health of the otolithic membrane and consequently the function of the related sensorineural elements. Here we explore the relationship between levels of these biomarkers in circulation.
Study Design: Prospective observational investigation.
Methods: 79 healthy male and female subjects between ages of 20 and 95 years of age, without regard for hearing loss or dizziness participated in this study. Blood samples were collected and levels of prestin and otolin-1 were quantified using their respective ELISAs.
Results: Prestin and otolin-1 levels were 0.26-23.4 and 3.2-902 pg/mL, respectively. With the exception of one outlier, otolin-1 levels were on average 32 fold higher than that of prestin. The distribution of the two proteins were similar. The Pearson r correlation coefficient between otolin-1 and prestin levels was 0.99.
Conclusions: A strong correlation between these two biomarkers implies that factors that inner ear health affect both hearing and balance mechanisms. Consequently, measuring one protein can inform on the health of both mechanisms. An alternative interpretation is that the quantitative methods (e.g., ELISA) for inner ear biomarkers require refinement to improve specificity. Further work is needed to better understand this relationship.