Abstract
BACKGROUND: This study aims to investigate the association between vitamin D levels and the risk of severe acute exacerbations of chronic obstructive pulmonary disease (AECOPD). METHODS: We conducted a prospective observational study with 636 COPD patients admitted for exacerbations between January 2021 and December 2022. Patients were categorized based on serum 25-hydroxyvitamin D levels: severe deficiency (<10 ng/mL), deficiency (10-20 ng/mL), insufficiency (20-30 ng/mL), or sufficiency (>30 ng/mL). Severe exacerbation was defined when the patient visits an emergency room or is hospitalized due to COPD exacerbation. Multivariate Cox regression was used to evaluate the risk associated with vitamin D deficiency. RESULTS: Over an 18-month follow-up, 178 (28.0%) patients experienced at least one severe exacerbation. The severe deficiency group had the highest exacerbation rate (40.6%), followed by deficiency (27.8%), insufficiency (22.5%), and sufficiency (18.1%) groups (P<0.01). Multivariate Cox regression analysis showed that severe vitamin D deficiency was significantly associated with an increased risk of severe exacerbations (HR=2.74, 95% CI: 1.55-4.84; P<0.01) compared to vitamin D sufficiency. CONCLUSION: Severe vitamin D deficiency is a significant predictor of severe COPD exacerbations, highlighting the importance of routine vitamin D assessment and supplementation in COPD management.