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.

Assessment of vitamin D deficiency in recurrent BPPV patients: A cross-sectional study.

PURPOSE: This study aimed to investigate the vitamin D deficiency of patients with BPPV recurrence and to evaluate the differences of 25-hydroxy vitamin D (25(OH)D) and serum calcium levels among gender and age categories. METHODS: This cross-sectional study enrolled patients with BPPV. The diagnosis of BPPV was based on positional nystagmus and vertigo induced by certain head positions (The Dix-Hallpike maneuver and head roll tests). All patients' age, serum 25(OH)D, calcium measurements and recurrence data were collected and analyzed. RESULTS: The median of 25(OH)D was 15.32 (IQR 10.61, 20.90) ng/ml. The recurrent group showed lower 25(OH)D levels than that of non-recurrent group [13.28 (IQR 9.47, 17.57) ng/ml vs 16.21 (IQR 11.49, 21.13) ng/ml]. There were significant differences of 25(OH)D levels among age categories. The proportion of vitamin D deficiency in patients ≥60 years old was lower than that in the other two groups. CONCLUSION: Our study suggested that BPPV patients had a decreased 25(OH)D level and a high incidence of vitamin D deficiency. The 25(OH)D level of recurrent BPPV patients was lower than that in non-recurrent ones. Among them, the elderly group (≥60 years) took the preponderance, which had the lowest incidence of vitamin D deficiency and the highest incidence of vitamin D sufficiency.

Relation between vitamin D deficiency and benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of positional vertigo. Vitamin D deficiency may be one of the causes of its development. To assess the relation between recurrent attacks BPPV and Vitamin D deficiency. A case control study in which 40 patients were clinically diagnosed as posterior canal BPPV, Serum 25(OH) D was measured at 1st visit. Patients were divided into two groups; group A (20 patients) received Vitamin D supplementation in addition to canal repositioning maneuver and group B (20 patients) treated by canal repositioning maneuver only. Follow up of all patients for 6 months, neuro-otological assessment was repeated and recurrent attacks were recorded. Serum vitamin D was repeated after 6 month. This study included 14 males and 26 females age ranged from 35 to 61 years, Average serum of 25 (OH) D at the first visit was (12.4 ± 2 ng/ml) for group A, and (12.2 ± 1.7 ng/ml) for group B, all patients had low serum level of 25(OH) D (below 20 ng/ml). Recurrent BPPV episodes, were significantly lower in group A than that of group B. There is a relation between BPPV recurrence and low serum Vitamin D.

The role of low levels of vitamin D as a co-factor in the relapse of benign paroxysmal positional vertigo (BPPV).

BACKGROUND: Benign paroxysmal positional vertigo is characterized as brief episodes of vertigo that are exacerbated by the unexpected act of moving to a current provoking location. It is thought to be an otoconia-related balance disorder. Our objectives were to assess the serum concentrations of vitamin D and calcium (total and ionized) in cases with BPPV, determine if low vitamin D levels were regarded as a cause for BPPV relapse, and determine whether vitamin D supplementation would minimize the risk of BPPV relapse. RESULTS: Sixty cases with BPPV were included in the study; 53 cases had posterior canal BPPV, while seven had lateral canal BPPV. Canalithiasis was the most common type of BPPV pathology. Forty cases had abnormally low levels of vitamin D. There was a statistically significant positive correlation between the mean vitamin D assay for all cases with BPPV and serum calcium. There was statistically significant difference in comparing the relapse of BPPV for group that receive vitamin D after one year follow up. CONCLUSION: Abnormal vitamin D levels were linked with the incident and relapse of BPPV. Correction of low vitamin D levels was linked with the reduction of the relapse of BPPV.

Downregulation of VDR in benign paroxysmal positional vertigo patients inhibits otolith­associated protein expression levels.

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vertigo­associated disease. Vitamin D (VD) helps maintain normal otolith function and may be associated with BPPV. VD exerts its biological functions primarily via the VD receptor (VDR). The present study demonstrated that serum VD levels were significantly decreased in patients with BPPV compared with in controls. VDR, otolith­associated protein otoconin­90 (OC90) and NADPH oxidase 3 (NOX3) expression levels were also significantly decreased in patients with BPPV compared with in controls. Furthermore, a positive correlation was observed between VD levels and VDR expression. Receiver operating characteristic curve analysis identified VDR expression levels as a potential diagnostic marker for BPPV. OC90 and NOX3 expression levels were notably lower in the inner ear tissue of VDR knockout mice compared with in those of wild­type mice. In mice overexpressing VDR, OC90 and NOX3 were also overexpressed. Following intravenous injection of VD in VDR knockout mice, expression levels of OC90 and NOX3 were not significantly different from those in VDR knockout mice injected with saline. This indicated that VDR may be underexpressed in patients with BPPV and was associated with the expression levels of otolith­associated proteins. Moreover, VDR mediated VD activation, leading to otolith protein formation. The present study provided a novel theoretical basis for BPPV onset that may facilitate the development of more effective diagnostic and treatment options.

Serum otolin-1 as a biomarker for benign paroxysmal positional vertigo: a case-control study.

OBJECTIVES: This study aimed to evaluate serum otolin-1 levels in patients with benign paroxysmal positional vertigo and to compare these levels with healthy individuals. METHOD: This was a case-control study. After obtaining institutional ethical committee clearance, the serum level of otolin-1 was calculated in adult individuals (18-75 years old) who were divided into group 1 (patients presenting with benign paroxysmal positional vertigo) and group 2 (healthy patients without benign paroxysmal positional vertigo as the control group). Data analysis was carried out to compare the serum levels in the cases and controls. A p-value less than 0.05 was considered significant. RESULTS: A total of 70 age-matched individuals (cases, n = 40; controls, n = 30) were included in the study. The mean serum level of otolin-1 was 636.8 pg/ml (range, 259-981 pg/ml) in the group of patients with benign paroxysmal positional vertigo and 236.2 pg/ml (range, 189-370 pg/ml) in the control group. The difference was statistically significant (p = 0.0000). CONCLUSION: The serum levels of otolin-1 in patients with benign paroxysmal positional vertigo are significantly higher compared with individuals without benign paroxysmal positional vertigo.

An evaluation of serum Otolin-1 & Vitamin-D in benign paroxysmal positional vertigo.

BACKGROUND: Serum otolin-1 is an inner ear protein exclusively expressed in otoconia and cells of vestibule and cochlea. Serum otolin-1 is found to be quantifiable in patients with BPPV. Low Vitamin-D is associated with pathogenesis of BPPV. Since otoconia degeneration contributes to BPPV, lack of Vitamin-D may impact otoconia structure and integrity. OBJECTIVE: We aimed at studying the s.otolin-1 as biomarker and significance of vit-D in BPPV. MATERIAL AND METHOD: 23 patients in test and control groups respectively were chosen within the age of 20 to 65 years. All the patients were diagnosed using Dix Hallpike menouver and head roll test, patients were treated with appropriate Canal Reposition Menouver (CRM). RESULTS: Serum Otolin-1 levels among the test ranged from 366 to 882 pg/mL with mean of 585.17 pg/mL whereas in control group ranged from 223 to 462 pg/mL with mean of 335.26 pg/mL. Mean Vitamin-D levels among the test group was 22.67 ng/mL (Range = 6.3-68.4) and that of control 15.43 pg/mL (Range = 5.4-27.7) respectively. The relationship between the serum Otolin-1 and Vitamin-D was not statistically significant. CONCLUSION: Otolin-1 levels is increased in BPPV patients and is sensitive in BPPV, specificity needs to be validated. Role of vitamin-D with respect to inner ear proteins needs further investigation.

Investigation of Serum Calcium and 25-Hydroxy Vitamin D Levels in Benign Paroxysmal Positional Vertigo Patients.

OBJECTIVE: Benign paroxysmal positional vertigo (BPPV) is characterized by recurrent attacks of vertigo caused by head movements. It occurs as a result of otoconia falling into the semicircular canal. Calcium and 25 hydroxyvitamin D [25(OH)D] metabolism in the inner ear play an important role in otoconia formation and degeneration. Our aim in this study was to investigate the relationship between 25(OH)D levels and BPPV. METHODS: This retrospective, case-controlled study included 52 patients with posterior canal BPPV and 52 controls aged 18 to 80 years. Age, sex, serum calcium, corrected calcium, and 25(OH)D levels of the BPPV and control group were compared. RESULTS: Twenty-three of the patients were male (44.2%) and 29 were female (55.8%). The average age was 55.6 years. The 25(OH)D level was 15.3 ng/mL in the BPPV group and 20.2 ng/mL in controls. There was no significant difference in 25(OH)D and albumin-corrected calcium values (P = .394; P = .084, respectively). In 80.7% of the BPPV group and 61.5% of the controls, 25(OH)D levels were 20 ng/mL and below. 25 hydroxyvitamin D deficiency was found statistically significantly more frequently in patients with BPPV (P = .030). CONCLUSION: In our study, serum 25(OH)D levels were found to be lower in patients with BPPV, and the rate of vitamin D deficiency was higher in these patients. Based on these results, it is recommended to examine the 25(OH)D levels of patients with BPPV at the time of diagnosis.

Relationship between calcium metabolism and benign paroxysmal positional vertigo in north Sardinia population.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) has a reported recurrence ranging from 26.8 to 50%. Osteoporosis and Vitamin D deficiency seems to have an impact on recurrence of BPPV. OBJECTIVE: to evaluate the impact of osteoporosis and Vitamin D deficiency on recurrence of BPPV. METHODS: 73 consecutive patients were divided in two groups according to the presence (group 1) or absence (group 0) of a recurrent episode. BMD, femoral and lumbar T-scores and Vitamin D levels were recorded. Statistical analysis was performed to investigate correlations. RESULTS: patients in group 1 had statistically significant lower values of both femoral (-1,62±1,06 vs. -0,53±1,51; p = 0,001), lumbar T-score (-2,10±1,19 vs -0, 53±1.51, p = 0.001) and Vitamin D (19.53±15.33). The values of femoral T-score and Vitamin D could be combined in a model able to properly classify 65.8% of the cases (p = 0.002) as isolated or recurrent BPPV, with high accuracy (AUC 0.710 [0.590 -0.830]). CONCLUSION: present data show a probable correlation between osteoporosis and Vitamin D with recurrent BPPV.

Carotid imaging changes and serum IL-1ß, sICAM-1, and sVAP-1 levels in benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo. This study was performed to evaluate serum levels of inflammatory factors and changes in B-mode carotid ultrasound findings in patients with BPPV. The study population consisted of 90 BPPV patients and 90 age- and sex-matched controls. ELISA was used to compare the levels of inflammatory factors, such as interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α), soluble intercellular adhesion molecule-1 (sICAM-1), prostaglandin-E2 (PG-E2), and soluble vascular adhesion protein-1 (sVAP-1), between BPPV patients and controls. In addition, the results of ultrasonographic imaging to determine carotid intima-media thickness (C-IMT), carotid atheromatous plaque, and vertebral artery stenosis were also compared between the BPPV and control groups. Serum levels of IL-1ß, sICAM-1, and sVAP-1 were significantly higher in BPPV patients than controls (P < 0.001, P < 0.05, and P < 0.001, respectively). C-IMT and vertebral artery stenosis were significantly different in BPPV patients compared to controls (both P < 0.05). There were no significant relations between other parameters and BPPV. IL-1ß, sICAM-1, and sVAP-1 are potentially associated with the pathogenesis of BPPV, and C-ITM and carotid vertebral stenosis may be useful reference imaging findings for the diagnosis of BPPV.

Prevention of benign paroxysmal positional vertigo with vitamin D supplementation: A randomized trial.

OBJECTIVE: To assess the effect of vitamin D and calcium supplementation in preventing recurrences of benign paroxysmal positional vertigo (BPPV). METHODS: We performed an investigator-initiated, blinded-outcome assessor, parallel, multicenter, randomized controlled trial in 8 hospitals between December 2013 and May 2017. Patients with confirmed BPPV were randomly assigned to the intervention (n = 518) or the observation (n = 532) group after successful treatment with canalith repositioning maneuvers. The primary outcome was the annual recurrence rate (ARR). Patients in the intervention group had taken vitamin D 400 IU and 500 mg of calcium carbonate twice a day for 1 year when serum vitamin D level was lower than 20 ng/mL. Patients in the observation group were assigned to follow-ups without further vitamin D evaluation or supplementation. RESULTS: The intervention group showed a reduction in the ARR (0.83 [95% confidence interval (CI), 0.74-0.92] vs 1.10 [95% CI, 1.00-1.19] recurrences per 1 person-year) with an incidence rate ratio of 0.76 (95% CI, 0.66-0.87, p < 0.001) and an absolute rate ratio of -0.27 (-0.40 to -0.14) from intention-to-treat analysis. The number needed to treat was 3.70 (95% CI, 2.50-7.14). The proportion of patients with recurrence was also lower in the intervention than in the observation group (37.8 vs 46.7%, p = 0.005). CONCLUSIONS: Supplementation of vitamin D and calcium may be considered in patients with frequent attacks of BPPV, especially when serum vitamin D is subnormal. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for patients with BPPV, vitamin D and calcium supplementation reduces recurrences of BPPV.

Serum levels of superoxide dismutases in patients with benign paroxysmal positional vertigo.

OBJECTIVE: To investigate the possible role of superoxide dismutases (SODs) in the development of benign paroxysmal positional vertigo (BPPV) and recurrence events in a 1-year follow-up study. METHODS: This was a prospective one-center study. A total of 204 patients with BPPV and 120 age-and sex matched healthy subjects were included. The levels of SOD between patients and control cases were compared. The levels of SOD between posterior semicircular canal (PSC) and horizontal semicircular canal (HSC) were also compared. In the 1-year follow-up, recurrence events were confirmed. The influence of SOD levels on BPPV and recurrent BPPV were performed by binary logistic regression analysis. RESULTS: The serum levels of SOD in patients with BPPV were lower than in those control cases (P<0.001). Levels of SOD did not differ in patients with PSC and HSC (P=0.42). As a categorical variable, for per interquartile range (IQR) increment of serum level of SOD, the unadjusted and adjusted risks of BPPV would be decreased by 72% (with the odds ratio [OR] of 0.28 [95% confidence interval (CI): 0.21-0.37], P<0.001) and 43% (0.57 [0.42-0.69], P<0.001), respectively. Recurrent attacks of BPPV were reported in 50 patients (24.5%). Patients with recurrent BPPV had lower levels of SOD than in patients without (P<0.001). For per IQR increment of serum level of SOD, the unadjusted and adjusted risks of BPPV would be decreased by 51% (with the OR of 0.49 [95% CI: 0.36-0.68], P<0.001) and 24% (0.76 [0.60-0.83], P<0.001), respectively. CONCLUSION: Reduced serum levels of SOD were associated with higher risk of BPPV and BPPV recurrence events.

Effects of Peripheral Vertigo on Inflammatory and Immunologic Laboratory Markers.

The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) are markers of subclinical inflammation and atherothrombosis. We investigated whether these easily accessible blood count parameters are affected by peripheral vertigo (PV). We studied 142 patients who were diagnosed with PV and referred to our hospital along with 135 healthy patients who were free of inflammation as a control group. The patient group was divided into 3 study groups depending on the presence of benign paroxysmal positional vertigo (BPPV): BPPV, vestibular dysfunction (VD), and BPPV + VD. The total patient group and 3 subgroups were compared to the control group with respect to the NLR, PLR, and MPV. The NLR and PLR were calculated by dividing the neutrophil and platelet values by the lymphocyte value. Of 142 patients, 43, 71, and 28 patients comprised the BPPV, VD, and BPPV + VD groups, respectively. There was no statistically significant difference (P > .05) in the NLR, PLR, or MPV between the main patient group or the individual patient subgroups and the control group. Our findings suggest that NLR, PLR, and MPV do not change significantly either in BPPV or in other peripheral vestibular disorders.

Association between serum vitamin D levels and benign paroxysmal positional vertigo: a systematic review and meta-analysis of observational studies.

OBJECTIVE: Benign paroxysmal positional vertigo (BPPV) was the most common neuro-otological disorder manifests as recurrent positional vertigo, but its risk factors are elusive. Recent studies suggest that decreased Vitamin D level may be a risk factor, but the literature is inconsistent. METHODS: The databases PubMed, Web of Science, Chinese National Knowledge Infrastructure, Wanfang, SinoMed, and Embase were systematically searched for studies on the association between BPPV and  serum Vitamin D levels published up to June 2019. Data from eligible studies were meta-analyzed using Stata 12.0. RESULTS: A total of 18 studies were included in the analysis. Serum Vitamin D levels were significantly lower in individuals with BPPV than in controls (WMD - 2.46, 95% CI - 3.79 to - 1.12, p < 0.001). Subgroup analysis by geographical area showed that vitamin D level was significantly lower in BPPV than in controls in China (WMD - 3.27, 95% CI - 4.12 to - 2.43, p < 0.001), but not outside China (WMD - 0.90, 95% CI - 4.36 to 2.56, p = 0.611). Vitamin D levels were significantly lower in recurrent than non-recurrent BPPV across all countries in the sample (WMD 2.59, 95% CI 0.35-4.82, p = 0.023). Vitamin D deficiency emerged as an independent risk factor of BPPV (OR 1.998, 95% CI 1.400-2.851, p < 0.001). CONCLUSION: The available evidence suggests that BPPV is associated with decreased levels of serum Vitamin D, and vitamin D deficiency was an independent risk factor for BPPV.

Evaluation of bone mineral density and 25-(OH) vitamin D levels in middle-aged and elderly women with recurrent benign paroxysmal positional vertigo.

Background: Middle-aged and elderly perimenopausal women are prone to developing BPPV without definite cause. Objectives: This study aimed to investigate the correlation between bone mineral density (BMD), 25-(OH) vitamin D, and serum calcium levels in patients with benign paroxysmal positional vertigo (BPPV) in middle-aged and elderly women.Material and methods: A total of 103 women with two or more recurrent BPPV episodes (group A) and 80 age-matched healthy controls (group B) were recruited. All subjects had BMD and serum 25-(OH) D levels measurements taken, and the results were compared.Results: BMD was reduced in group A, and the proportion of osteoporosis was higher than in group B (p = .039). The BMD T-score and 25-(OH) vitamin D level were lower in group A than in group B (p = .004 and p < .0001, respectively). In group A, the BMD T-score was lower (p = .017) and serum 25-(OH) vitamin D level was higher (p < .0001) in premenopausal women than in menopausal women.Conclusions and Significance: Our study found that middle-aged and elderly women with recurrent BPPV, especially postmenopausal women, may present decreased BMD and serum vitamin D levels.

Seasonal variation of idiopathic benign paroxysmal positional vertigo correlates with serum 25-hydroxyvitamin D levels: a six-year registry study in Shanghai, China.

Seasonal variation of benign paroxysmal positional vertigo (BPPV) occurrence has been reported in recent years. Whether the seasonality of BPPV also exists in Chinese patients and whether it correlates with serum vitamin D levels is unexplored. We retrospectively analyzed the data of 1269 new-onset idiopathic BPPV patients registered in our vertigo outpatient clinic over a six-year period. Additionally, serum 25-hydroxyvitamin D levels during this period were measured in 877 patients by chemiluminescence immunoassay. We delineated the changing trend of the monthly BPPV patient numbers and serum 25-hydroxyvitamin D levels, and the correlation between them was explored. December to next March is the top 4 months with higher BPPV patient numbers. The median BPPV patient numbers in winter group were higher than those in summer group (20 vs. 16 patients, p < 0.05). Median 25-hydroxyvitamin D levels in winter group were much lower than those in summer group (16.3 vs. 20.8 ng/ml, p < 0.001) and autumn group (16.3 vs. 19.3 ng/ml, p < 0.05). A moderate negative correlation was observed between median serum 25-hydroxyvitamin D levels and BPPV patient numbers each month. The onset of BPPV also shows a seasonal fluctuation in Chinese patients. This phenomenon may be related to serum vitamin D levels.

Elevated serum macrophage migration inhibitory factor levels correlate with benign paroxysmal positional vertigo and recurrence events.

Objective: We aimed to assess the possible relations between serum levels of macrophage migration inhibitory factor (MIF), a central cytokine of the innate immunity and inflammatory response, and benign paroxysmal positional vertigo (BPPV) risk and BPPV recurrence events.Methods: In the present study, 154 patients with BPPV, and 100 age-and sex-matched control subjects were enrolled in the study. All the patients and controls underwent a complete audio-vestibular test battery including the Dix-Hallpike maneuver and supine roll test. In the BPPV group, measurements of MIF levels were repeated 1 month after the vertigo attack. The patients were also divided into the recurrence group and the nonrecurrence group in the 1-year follow-up.Results: The serum levels of MIF in patients with BPPV were higher than in those controls (13.9[interquartile range {IQR}, 8.9-18.4] ng/ml vs. 9.8[7.8-11.8]; P<0.001). As a continuous variable, MIF was associated with increased risk of BPPV (odds ratio [OR] 1.21, 95% confidence interval [CI]: 1.11-1.39; P=0.004) in multiple regression analyses. Recurrent attacks of BPPV were reported in 35 patients, and those patients had higher levels of MIF than those patients were not recurrence (18.0[IQR, 13.6-22.2] ng/ml vs. 12.6[9.3-16.8] ng/ml). In multivariate models comparing the second (Q2), third (Q3) and fourth(Q4) quartiles against the first (Q1) quartile of MIF, levels of MIF in Q4 were associated with recurrent BPPV, and the odds were increased by approximately 305% (OR = 4.05; 95%CI: 1.65-15.44; P=0.009).Conclusions: Elevated MIF is positively correlated with BPPV risk and BPPV recurrence events, requiring further efforts to clarify the exact mechanism.

[Relationship between the level of estrogen, calcium and phosphorus concentration in serum with benign paroxysmal positional vertigo].

Objective:To investigate relationship between the level of estrogen, calcium and phosphorus concentration in serum with benign paroxysmal positional vertigo(BPPV). Method:A total of 84 patients with idiopathic BPPV were enrolled in the experimental group, including 32 non-menopausal women, 24 menopausal women, and 28 males; 83 healthy people without vertigo and vestibular disease were selected as the control group consisted with 32 non-menopausal women, 24 menopausal women and 27 males. The levels of estradiol, serum calcium and serum inorganic phosphorus were measured in all participants. The difference of estrogen level, serum calcium and serum inorganic phosphorus concentration between the experimental group and the control group was analyzed by t test. Result:The total number, age distribution and gender composition of the experimental group and the control group were basically paired, and the age difference was not statistically significant (P=0.71). The overall estrogen level in the experimental group was lower than that in the control group (P<0.01). Among them, the female group's estrogen level, menopausal female estrogen level and male estrogen level in the experimental group were lower than the control group (P<0.01); there was no significant difference in serum calcium and serum inorganic phosphorus concentration between the experimental group and the control group (P=0.55, 0.11, respectively). Conclusion:The decrease of estrogen level may be a risk factor for idiopathic BPPV. The relationship between serum calcium and serum inorganic phosphorus concentration and BPPV needs further study.

[The correlations between serum vitamin D, parathyroid hormone, and bone mineral density with benign paroxysmal positional vertigo].

Objective:To detect serum 25-hydroxyvitamin D[25-（OH）2-VitD3], parathyroid hormone (PTH), and bone mineral density in patients with benign paroxysmal positional vertigo (BPPV), and to analyze their correlations with BPPV. Method:Fifty cases of BPPV were selected as the study group, 50 healthy persons were selected as control group. Chemiluminescence assay was used to detect serum VD level, chemiluminescence immunoassay was used to detect serum PTH level, dual energy X-ray absorptiometry was used to detect bone mineral density (BMD) and T value of lumbar vertebrae 1 to lumbar vertebrae 4 in two groups. Result:The serum 25-（OH）2-VitD3 level in the study group was significantly lower than that in the control group (P<0.05); the serum PTH level of the study group was significantly higher than that of the control group (P<0.05); there was no significant difference in T value between male BPPV patients and female BPPV patients younger than 48 years old with the control group (P>0.05), T value of female BPPV patients older than 48 years old was significantly lower than that of the control group (P<0.05). Logistic regression analysis showed that the decrease of serum 25-（OH）2-VitD3 level, the increase of PTH level, and the decrease of bone mineral density were risk factors for BPPV. Conclusion:The level of serum 25-（OH）2-VitD3 is decreased in BPPV patients, PTH level is increased and bone mineral density is decreased, they are risk factors for BPPV.

Serum levels of 25-hydroxy vitamin D correlate with idiopathic benign paroxysmal positional vertigo.

Background: The present study aimed to evaluate serum 25-hydroxy vitamin D (25(OH) D) levels in Chinese patients with idiopathic benign paroxysmal positional vertigo (BPPV) and to investigate the possible relationship between the occurrence and recurrence of idiopathic BPPV and low 25(OH) D levels. Methods: Between 1 January 2017 and 31 May, 2018, consecutively older patients (age, older than 50 years) with idiopathic BPPV were recruited in the present study. For each patient, 2:1 sex and age matched healthy people were assigned as the control group. The influence of 25(OH) D levels on BPPV and recurrent BPPV were performed by binary logistic regression analysis. Results: In the present study, 174 patients with BPPV and 348 controls were included. The serum levels of 25(OH) D in those patients were lower than in those controls (P<0.001). One hundred eight patients were found to have vitamin D deficiency; thus, the prevalence was 62.1%, which was higher than that in the controls (42.8%). The data showed that patients with recurrent BPPV (N = 31) had lower serum levels of 25(OH) D compared with those who were not (11.2 ng/ml [interquartile range, 7.2-20.8 ng/ml] vs 18.7 ng/ml [14.2-24.8 ng/ml]). The regression analyses demonstrated that vitamin D deficiency was associated with BPPV and recurrent BPPV with an odds ratio of 2.15 (95% confidence interval [CI], 1.30-4.32; P=0.006) and 5.16 (95% CI, 1.00-34.12; P=0.05). Conclusion: Decreased serum levels of 25(OH)D were associated with the occurrence and recurrence of BPPV in a Chinese population, independent of other baseline markers.