Study on the Bone Metabolism Indices and Otoconin-90 in Benign Paroxysmal Positional Vertigo

Case-control study of otoconia proteins otolin-1 and otoconin-90 in patients with Meniere's disease

BACKGROUNDS

Otolin-1 and otoconin-90, the main otoconia matrix protein, can pass through the labyrinth-blood barrier and are detectable in the peripheral blood. Previous studies have shown that serum levels of these proteins well reflect otolith status, but none of concerning Meniere's disease (MD).

OBJECTIVES

This study aimed to evaluate the serum levels of otolin-1 and otoconin-90 in patients with MD.

MATERIAL AND METHODS

Patients with MD confirmed during an acute episode, and age- and sex-matched controls were recruited. Their demographic and clinical data were recorded. The serum levels of otolin-1 and otoconin-90 were measured and compared.

RESULTS

A total of 33 patients with MD and 176 healthy controls were recruited. In patients with MD, the median otolin-1 level was 284.96 pg/mL (interquartile range [IQR] 208.65-331.49 pg/mL) and the median otoconin-90 level was 60.50 ng/mL (IQR 40.61-85.62 ng/mL), which were significantly higher than those in the control group (p < 0.0001 and p = 0.005, respectively). Among patients with MD, serum otoconin-90 levels were correlated with the MD clinical grade (ρ = 0.487, p = 0.04), whereas serum otoconin-1 levels were not (ρ = 0.327, p = 0.063).

CONCLUSIONS

Serum levels of otolin-1 and otoconin-90 may serve as biomarkers of otolith lesions in patients with MD.

Serum Otoconin-90 and Otolin-1 Concentrations in Benign Paroxysmal Positional Vertigo

OBJECTIVE

The aim was to evaluate the value of otolith-associated protein otoconin-90 (OC90) and otolin-1 in the pathogenesis research and clinical treatment of benign paroxysmal positional vertigo (BPPV).

MATERIAL AND METHOD

The study included 50 patients with BPPV admitted to neurology and otorhinolaryngology departments and 30 healthy subjects with no history of dizziness as a control group.

RESULTS

BPPV and controls were similar in terms of gender and age. Otolin-1 concentration was significantly greater in the BPPV group than in the controls (710.44 [584.35-837.39] vs 280.45 [212.7-419.61]; p < 0.001). No statistical significance was found, although OC90 was higher in the BPPV group than in the controls. There was a strong positive correlation between otolin-1 and OC90, a moderate negative correlation between otolin-1 and vitamin D, and a strong negative correlation between OC90 and vitamin D in the BPPV patient group. Otolin-1 had high specificity and AUC values for BPPV (AUC: 0.933; 95% CI: 0.881-0.986, 79.2% sensitivity, 100% specificity with a cutoff greater than 525).

CONCLUSIONS

High serum concentrations of otolin-1 were associated with an increased risk of BPPV, but high concentrations of OC90 were not. Serum concentrations of otolin-1 can potentially be used as a biomarker for the acute onset of inner ear disorders due to the significant increase in patients with BPPV. Vitamin D has high specificity and sensitivity in patients with BPPV. It also provides evidence that BPPV patients with vitamin D deficiency may improve their symptoms with replacement therapy. More large-scale prospective studies are required to confirm these associations and clarify the exact mechanisms.

Preliminary study of the role of inner ear proteins in vestibular neuritis

Objective

To evaluate the plasma levels of the otoconial proteins, otoconin-90 and otolin-1, in individuals diagnosed with vestibular neuritis (VN) and determine the feasibility of using these proteins as biomarkers for VN.

Methods

In this preliminary study, 30 patients diagnosed with VN and 70 healthy individuals were recruited and followed to confirm whether they had benign paroxysmal positional vertigo (BPPV) during the following time. The recorded data included measurements of height, weight, and history of diabetes mellitus or hypertension. Additionally, levels of plasma otoconin-90, and otolin-1 were measured and compared.

Results

The plasma concentrations of otoconin-90 and otolin-1 may not be significantly different between patients with VN and healthy controls, nor among patients with BPPV secondary to VN and patients with VN without BPPV.

Conclusions

Plasma otoconin-90 and otolin-1 levels may not serve as biomarkers of acute VN episodes or predict BPPV occurrence secondary to VN.

Clinical Biomarkers in Otolaryngology-Head and Neck Surgery

OBJECTIVE

The purpose of this paper is to review the literature and compile promising and clinically relevant biomarkers in otolaryngology-head & neck surgery not related to autoimmune disorders.

STUDY DESIGN

Narrative review.

METHODS

PubMed and Google Scholar were queried using combined key words such as "biomarkers" and "otolaryngology." Additional queries were made with combined key words such as "biomarkers" and a particular subspecialty such as "rhinology" or "otology" to maximize yield of relevant titles. Subsequently, specific biomarkers identified, such as "beta-2 transferrin," were used as key words. Relevant titles were reviewed and selected for abstract review. Applicable abstracts were then selected for review of the full text.

RESULTS

Biomarkers currently in clinical use within the field of otolaryngology were included in this review. The compiled biomarkers were then detailed individually regarding their molecular characteristics, function, and clinical significance.

CONCLUSIONS

The number of biomarkers in use in otolaryngology is rapidly expanding representing a new diagnostic modality for our field. This review defines the key biomarkers that are currently or likely to be soon translated into clinical use within the field of otolaryngology. The majority of these biomarkers are in the form of proteins such as beta-2 transferrin, thyroglobulin, and P16. Given their growing impact on diagnosis, management and surveillance of otolaryngologic disorders periodic surveys are needed for education and to guide further advances and applications of otolaryngologic biomarkers.

Association between vitamin D deficiency and benign paroxysmal positional vertigo (BPPV) incidence and recurrence: a systematic review and meta-analysis

OBJECTIVES

The objective of this study is to determine the relationship between serum vitamin D level and the risk of developing benign paroxysmal positional vertigo (BPPV) incidence and recurrence in countries in the Northern Hemisphere.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Scopus and Web of Science databases were searched for studies published between January 2000 and February 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Participants located in the Northern Hemisphere aged 18 or over with at least one episode of BPPV, serum 25-hydroxyvitamin D levels measured and reported, no comorbidities or history of vitamin D supplementation.

DATA EXTRACTION AND SYNTHESIS

Data extraction and synthesis were performed by a single reviewer and checked by a second reviewer. Inclusion and exclusion criteria and risk of bias were assessed by two independent reviewers using the Newcastle Ottawa Tool for Cohort studies and Risk of Bias Assessment Tool for Nonrandomised Studies checklist for case-control studies. Meta-analysis was conducted using random effects models. Standard mean difference with a 95% CI was used to measure the relationship between vitamin D level and BPPV.

RESULTS

The 35 articles identified by the literature search reported data of 9843 individuals. 19 studies (7387 individuals) were included in the BPPV incidence meta-analysis while 7 studies (622 individuals) were included in the BPPV recurrence meta-analysis. Lower serum vitamin D levels were found in BPPV incidence compared with controls, but the relationship between vitamin D levels in recurrent BPPV compared with non-recurrent disease remained uncertain.

CONCLUSION

Results of this systematic review and meta-analysis demonstrated a negative correlation between serum vitamin D and BPPV incidence, while any relationship between serum vitamin D and BPPV recurrence remained uncertain. Risk of bias analysis revealed evidence of variable quality. There were insufficient data available to evaluate seasonal relationships between serum vitamin D and BPPV. Given the potential for this as a confounding factor, future research should aim to investigate this further.

PROSPERO REGISTRATION NUMBER

CRD42021271840.

Advances in otolith-related protein research

Otoliths are biological crystals formed by a layer of calcium carbonate crystal that adhere to the ciliary surface of the utricular and saccular receptors in the vestibule of all vertebrates inner ear, enabling the utricle and saccule to better perceive the changes in linear and gravitational acceleration. However, the molecular etiology of otolith related diseases is still unclear. In this review, we have summarized the recent findings and provided an overview of the proteins that play important roles in otolith formation and maintenance (Otoconin-90, Otolin-1, Otolith Matrix Protein-1, Cochlin, Otogelin, α-Tectorin, β-Tectorin, Otopetrin-1, and Otopetrin-2, PMCA2, etc.), providing new insight for the prevention and management of benign paroxysmal positional vertigo (BPPV) with basis for otolith-related proteins as potential biomarkers of vestibular disease.

High Serum Levels of Otolin-1 in Patients With Benign Paroxysmal Positional Vertigo Predict Recurrence

Background

Otolin-1 is an inner ear-specific protein that is exclusively expressed in otoconia and vestibule and cochlea cells. Recent investigations reported that otolin-1 can cross the blood-labyrinthine barrier and that the levels in serum well-reflected otolith status. Serum otolin-1 levels in patients with benign paroxysmal positional vertigo (BPPV) are significantly elevated compared with healthy controls. We aimed to explore whether otolin-1 can also serve as a biomarker for predicting BPPV recurrence.

Method

Patients at our institution with new-onset of idiopathic BPPV between May, 2017 and May, 2018 were recruited and followed up for 2 years. All demographic data of the patients were collected, and serum levels of otolin-1 and other laboratory indicators were measured and compared according to the recurrence status.

Results

A total of 74 patients, who met the inclusion criteria were enrolled in this study, of which 27 (36.5%) patients had suffered one or more episodes of recurrence after undergoing canal repositioning treatments during the study. The serum levels of otolin-1 in patients with recurrent BPPV were significantly higher than those in patients without recurrent BPPV (363.9 vs. 309.8 pg/ml, p = 0.001). In multivariate analysis comparing the second to fourth quartiles (Q2–Q4) against the first quartile (Q1) of otolin-1, the level of otolin-1 in Q4 could significantly predict BPPV recurrence, and the odds ratio (OR) was elevated by approximately 812% (OR = 9.12; 95% confidence interval [CI]: 1.44–57.9; p = 0.019).

Conclusion

High serum levels of otolin-1 were associated with an increased risk of BPPV recurrence, and further investigation is required to confirm this association and clarify the exact mechanism.