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

Abstract

BackgroundOtolin-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.MethodPatients 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.ResultsA 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).ConclusionHigh 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.

Residual dizziness after BPPV management: exploring pathophysiology and treatment beyond canalith repositioning maneuvers

“…Although low serum vitamin D values have been found to correlate with BPPV occurrence/recurrence (55,101) and abnormal vestibular evoked myogenic potential (VEMP) results (102), only one study has reported an association between low vitamin D levels and RD (93). Vitamin D supplementation might be beneficial in patients with RD and low serum vitamin D levels (103).…”

Advances in otolith-related protein research

“…In contrast, recent studies have found that Otoconin-90 can be quantitatively detected in peripheral blood and suggest that Otoconin-90 can be used as a biomarker for BPPV and has clinical significance for the diagnosis of certain patients with BPPV, such as elderly or posttraumatic patients who have difficulty performing diagnostic postural maneuvers, or patients who had nystagmu or satypical symptoms ( Bi et al, 2021 ). In addition, serum otolin-1 is quantifiable in BPPV patients, with elevated levels of Otolin-1 in BPPV patients, who are sensitive to BPPV ( Yadav et al, 2021 ), high serum otolin-1 levels associated with increased risk of BPPV recurrence ( Fan et al, 2022 ). A case-control study found that serum levels of otolin-1 were significantly higher in patients with BPPV than in patients with non-BPPV ( IIrugu et al, 2021 ).…”

Association between otolin-1 and benign paroxysmal positional vertigo: A meta-analysis

“…This is due to a high relapse rate of 7–50% ( 3 , 4 ), which consequently causes anxiety, reduces the quality of life, and increases the risk of fall from instability ( 23 , 24 ). Furthermore, BPPV comprises 24.1% of all clinical visits due to dizziness ( 2 ), and its medical burden is also known to be high ( 20 , 25 ).…”

“…From the clinical point of view, circulating biomarkers for otologic diseases are significant indicators for the investigation of inner ear damage, the diagnoses of inner ear disorders, tracking of treatment response, and the development of new treatments ( 11 ). Laboratory biomarkers should therefore be explored as tools to achieve a faster and more accurate diagnosis of BPPV, wherein otoconial degeneration may be utilised as a diagnostic modality ( 14 , 25 ). Several recent studies have shown that inner ear-specific proteins are present in the blood serum and can be quantified ( 10 , 29 , 30 ).…”

“…Elevated otolin-1 levels have also been reported in patients with BPPV, providing evidence for its potential as a biomarker for inner ear conditions and for predicting the risk of BPPV in the general population ( 17 ). Furthermore, studies have reported on the association between elevated serum otolin-1 levels and increased risk of BPPV relapse ( 25 ). The mechanism that the otolin-1 serum level is elevated in patients with BPPV is unclear.…”