Association between vitamin D levels and frequency of disease exacerbations and hospitalizations in patients with COPD

Abstract

Introduction: Chronic obstructive pulmonary disease (COPD) is a debilitating disorder that restricts the physical activity of patients who are deprived of sunlight, which is a source of vitamin D. The purpose of this study was to assess the relationship between vitamin D and the frequency of exacerbation and hospitalization among patients with COPD. Material and Method: In the main analysis, 303 patients with COPD (stage GOLD A to D) were included in a retrospective cohort study in Turkey. Serum levels of vitamin D (25-hydroxyvitamin D) were measured in 303 patients with COPD and were associated with pulmonary function, AECOPD frequency and hospitalization in the previous year. Results: For COPD patients, the mean reference level of 25 hydroxyvitamin D in serum was 12.5 ng/dL. In comparison to patients with a serious 25-hydroxyvitamin D deficiency (< 10 ng/dL, n=119 [39,3%]), patients with a moderate deficiency (10-19.99 ng/dL, n=100 [33%]), inadequate levels (20-29.99 ng/dL, n=49 [16,2%]) presented a different risk of exacerbation (incidence rate ratio, 2.3 [95% CI, 1.9-2.6], 1.6 [95% CI, 1.2-2.0], and 0.8 [95% CI, 0.3-1.2] respectively). In patients with desirable levels (> 30 ng/dL, n=34 [11,2%]), the risk was lower but not significant (incidence ratio, 0.7 [95% CI, 0.2-1.2]. In COPD patients, 25-hydroxyvitamin D rates are low correlated with 1-s forced expiratory volume (FEV1) (r=0.187, p=0.0013). Conclusion: 25-hydroxyvitamin D deficiency is a frequent occurrence in COPD and is correlated with the frequency of exacerbation and hospitalization in COPD patients.