Serum Vitamin D and Long-term Outcomes of Benign Paroxysmal Positional Vertigo

Clinical and Experimental Otorhinolaryngology Vol. 12, No. 3: 273-278, August 2019 https://doi.org/10.21053/ceo.2018.00381 pISSN 1976-8710 eISSN 2005-0720 Original Article Serum Vitamin D and Long-term Outcomes of Benign Paroxysmal Positional Vertigo Gu Il Rhim One Otorhinolaryngology Clinic, Paju, Korea Objectives. The purpose of the present study was to examine the effect of serum vitamin D concentrations on the longterm recurrence rates of benign paroxysmal positional vertigo (BPPV) patients. Methods. The present study was conducted with patients diagnosed with BPPV from June 2014 to April 2016. Whether the patients’ sex, age, types and locations of semicircular canals, diabetes, hypertension, hyperlipidemia, and vitamin D concentrations affect their recurrence rates was examined using Pearson chi-square tests, independent samples t-tests and Cox proportional hazards regression analyses. The effects of vitamin D concentrations on long-term recurrence rates were examined using Kaplan-Meier estimates and log-rank tests. Results. The recurrence rates obtained with Kaplan-Meier estimates were 18% and 50% at 12 months and 24 months, respectively. When the patients were divided into groups with vitamin D concentrations of <10 ng/mL and ≥10 ng/mL and the recurrence rates of the groups were compared, the difference was statistically significant (P =0.040). In addition, when the patients were divided into groups with vitamin D concentrations of <15 ng/mL and ≥15 ng/mL and the recurrence rates of the groups were compared, the difference was statistically quite significant (P =0.017). In a Cox regression model, variables such as age, sex, the types and locations of semicircular canals, hypertension, diabetes, hyperlipidemia, and 25-hydroxy vitamin D did not significantly affect recurrence. Conclusion. The present study investigated the recurrence rates of BPPV in patients for a long time without limiting the sex, age, or locations of semicircular canals and it could be seen that serum vitamin D concentrations significantly affected the recurrence of BPPV. Keywords. Benign Paroxysmal Positional Vertigo; Vitamin D Deficiency; Recurrence; Kaplan-Meier Estimate INTRODUCTION the standard treatment, but the 1-year recurrence rate is about 20% and recurrence rates of 30%–50% are shown within 3–5 years [1-3]. Age, otologic diseases, and the type of canal are factors that affect the recurrence of idiopathic BPPV, and recently, the association between idiopathic BPPV and metabolic disease/ vitamin D has been attracting attention [4,5]. Otoconia are composed of crystals of calcium carbonate (CaCO3) and glycoproteins, which are its main components, and is connected with protein fibers on hair cells. The formation, development, and degeneration processes of otoconia are known to be regulated by the active calcium metabolic process of the vestibular organ, in contrast to the low calcium concentration in the endolymph. Some study results have indicated that vitamin D-related epithelial calcium channel proteins are involved in the calcium metabolism of the vestibular organ [6]. Benign paroxysmal positional vertigo (BPPV) is known to be a disease in which otoconia, which has dropped out of the maculae of the utricle and saccule, enters the semicircular canal or adheres to the cupula and causes clinical symptoms according to position changes. Treatment with a particle repositioning maneuver (PRM) is ••Received March 18, 2018 Revised September 5, 2018 Accepted November 21, 2018 ••Corresponding author: Gu Il Rhim One Otorhinolaryngology Clinic, 1 Hugok-ro, Paju 10924, Korea Tel: +82-31-942-1275, Fax: +82-31-942-1278 E-mail: Copyright © 2019 by Korean Society of Otorhinolaryngology-Head and Neck Surgery. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 273 274 Clinical and Experimental Otorhinolaryngology Vol. 12, No. 3: 273-278, August 2019 Recently, there have been studies indicating that osteoporosis and osteopenia, which are representative calcium metabolic diseases, are associated with BPPV [7-9], and there have been reports indicating that patients with severely recurring BPPV had a quite serious vitamin D deficiency, along with study results indicating that BPPV patient groups have lower vitamin D concentrations [10-12]. The present study was conducted to examine the effect of serum 25-hydroxy (25-OH) vitamin D on the long-term recurrence of BPPV. MATERIALS AND METHODS Study subjects The subjects of the present study were selected from among patients diagnosed with BPPV at the One Otorhinolaryngology Clinic (Paju, Korea) from June 2014 to April 2016. In order to select the subjects for this study, 520 patients with BPPV were examined. Patient information on age, gender, comorbidities (diabetes, hypertension, and hyperlipidemia), 25-OH vitamin D concentrations, and the type and location of semicircular canals involved in the initial BPPV attacks were reviewed retrospectively. All patients had blood tests done upon first presentation, regardless of recurrence. As a serum test, the 25-OH vitamin D concentration was measured using chemiluminescence immunoassay (Centaur; Siemens Healthineers, Erlangen, Germany). The reference range of the serum test for 25-OH vitamin D concentrations used in this study was above 4 ng/mL. The serum vitamin D level was classified as normal (>20 ng/mL), insufficient (10–20 ng/mL), or deficient (<10 ng/mL). Whether the patients had any hypertension, diabetes, or hyperlipidemia was checked through questionnaire surveys. Among the patients, those with ear diseases such as homonymous Meniere disease, vestibular neuritis, and chronic otitis media, traumatic BPPV patients, multiple canal BPPV patients, patients who were taking vitamin D when they were first diagnosed with BPPV, and patients treated with vitamin D during their follow-up periods were excluded. Three hundred thirtytwo patients were retrospectively followed up until October 2017. Patient information was obtained from patient records, and direct telephone calls to patients were made to ensure the accuracy of the recurrence data. Informed consents from the pa- H I G H L I G H T S  he 24-month recurrence rate of benign paroxysmal positional T vertigo was 50%. The recurrence rate was higher in the low vitamin D supplement group. However, vitamin D supplement did not significantly decrease the recurrence rate in a multivariate model. tients are not needed because this is a retrospective study. Clinical diagnosis of BPPV All patients underwent physical examinations using pure tone audiometry, videonystagmography, and video Frenzel glasses when they first visited the hospital and were diagnosed and treated by one physician. Dix-Hallpike, su (...truncated)