Severe vitamin D deficiency is associated with frequent exacerbations and hospitalization in COPD patients.

BackgroundAcute exacerbations of COPD (AECOPD) are common and strongly influence disease severity and relative healthcare costs. Vitamin D deficiency is frequent among COPD patients and its contributory role in disease exacerbations is widely debated. Our aim was to assess the relationship of serum vitamin D levels with COPD severity and AECOPD.MethodsSerum vitamin D (25-hydroxyvitamin D) levels were measured in 97 COPD patients and related to lung function, comorbidities, FEV1 decline, AECOPD and hospital admission during the previous year. Results Most patients (96%) had vitamin D deficiency, which was severe in 35 (36%). No significant relationship was found between vitamin D and FEV1 or annual FEV1 decline. No difference between patients with and without severe vitamin D deficiency was found in age, gender, BMI, smoking history, lung function, and comorbidities, apart from osteoporosis (60.9% in severe deficiency vs 22.7%, p<=0.001). In multiple logistic regression models, severe deficiency was independently associated with AECOPD [adjusted odds ratios (aOR) of 30.5 (95%CI 5.55, 168), p¿<¿0.001] and hospitalization [aOR 3.83 (95%CI 1.29, 11.4), p¿=¿0.02]. The odds ratio of being a frequent exacerbator if having severe vitamin D deficiency was 18.1 (95%CI 4.98, 65.8) (p¿<¿0.001), while that of hospitalization was 4.57 (95%CI 1.83, 11.4) (p¿=¿0.001). Conclusions In COPD patients severe vitamin D deficiency was related to more frequent disease exacerbations and hospitalization during the year previous to the measurement of vitamin D. This association was independent of patients¿ characteristics and comorbidities.