Abstract
BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is a common vestibular disorder characterized by brief episodes of vertigo triggered by changes in head position and is associated with displaced otoconia in the inner ear. Emerging evidence suggests that metabolic conditions, such as vitamin D deficiency, osteoporosis, and obesity, increase the risk of BPPV recurrence. This study investigated the associations between BPPV recurrence and these metabolic conditions using a large population-based dataset. METHODS: A nested case-control study was conducted using data from the Korean National Health Insurance Service cohort, including 507,744 individuals diagnosed with BPPV between 2005 and 2017. BPPV cases were identified by International Classification of Diseases, 10th revision, Clinical Modification codes, vestibular function tests, and canalith repositioning procedures. Univariate and multivariate analyses were performed to assess the impact of vitamin D deficiency, osteoporosis, body mass index (BMI), and supplementation on BPPV recurrence. RESULTS: The overall BPPV recurrence rate was 20.8%. Patients with vitamin D deficiency had a significantly higher recurrence rate (25.2%) compared with those with normal vitamin D levels (20.8%) (P < 0.001). Vitamin D supplementation significantly reduced the risk of recurrence (adjusted hazard ratio [aHR], 1.099; 95% confidence interval [CI], 1.003-1.203; P = 0.042), with a more pronounced effect in female patients (aHR, 1.110; 95% CI, 1.011-1.219; P = 0.029). Overweight individuals (BMI 25-30 kg/m²) with vitamin D deficiency had a significantly increased risk of recurrence compared with normal BMI (hazard ratio [HR], 1.207; 95% CI, 1.045-1.393; P = 0.010), whereas no significant difference in risk was observed in obese individuals (BMI ≥ 30 kg/m²) (HR, 1.096; 95% CI, 0.706-1.702; P = 0.682). Osteopenia and osteoporosis were not identified as an independent risk factor for BPPV recurrence. However, among postmenopausal women (age 50-69), osteopenia was a significantly associated with an increased risk of BPPV recurrence. Notably, combined calcium and vitamin D supplementation was associated with increased recurrence risk (HR, 1.122; 95% CI, 1.011-1.246; P = 0.030), especially in women aged 40-49 years (HR, 1.464; 95% CI, 1.030-2.082; P = 0.034). CONCLUSION: Vitamin D deficiency, osteopenia among postmenopausal women and higher BMI are significant risk factors for BPPV recurrence. Vitamin D supplementation reduces recurrence risk, particularly in women and younger individuals. However, combined calcium and vitamin D supplementation may be associated with an increased risk of recurrence in specific subgroups. These findings underscore the importance of metabolic health in the pathophysiology and management of BPPV and suggest that targeted interventions reduce the burden of recurrent vertigo in affected populations.