title: Severe vitamin D deficiency is associated with frequent exacerbations and hospitalization in COPD patients.
abstract: BACKGROUND
  Acute 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.
  
  
  METHODS
  Serum 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.
authors.affiliation: Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala, Sweden. andrei.malinovschi@medsci.uu.se.
authors.forename: Andrei
authors.initials: A
authors.lastname: Malinovschi
authors.affiliation: Department of Medical Sciences, University of Turin, Via Lamarmora 41, 10128, Turin, Italy. raerte@yahoo.it.
authors.forename: Monica
authors.initials: M
authors.lastname: Masoero
authors.affiliation: Department of Medical Sciences, University of Turin, Via Lamarmora 41, 10128, Turin, Italy. michela.bellocchia@libero.it.
authors.forename: Michela
authors.initials: M
authors.lastname: Bellocchia
authors.affiliation: Department of Medical Sciences, University of Turin, Via Lamarmora 41, 10128, Turin, Italy. antociu88@gmail.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ciuffreda
authors.affiliation: Cardiovascular and Thoracic Department, Città della Salute, Turin, Italy. psolidoro@cittadellasalute.to.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Solidoro
authors.affiliation: Cardiovascular and Thoracic Department, Città della Salute, Turin, Italy. amattei@cittadellasalute.to.it.
authors.forename: Alessio
authors.initials: A
authors.lastname: Mattei
authors.affiliation: Cardiovascular and Thoracic Department, Città della Salute, Turin, Italy. lmercante@cittadellasalute.to.it.
authors.forename: Lorena
authors.initials: L
authors.lastname: Mercante
authors.affiliation: Department of Medical Sciences, University of Turin, Via Lamarmora 41, 10128, Turin, Italy. heffler.enrico@gmail.com.
authors.forename: Enrico
authors.initials: E
authors.lastname: Heffler
authors.affiliation: Department of Medical Sciences, University of Turin, Via Lamarmora 41, 10128, Turin, Italy. giovanni.rolla@unito.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rolla
authors.affiliation: Department of Medical Sciences, University of Turin, Via Lamarmora 41, 10128, Turin, Italy. caterina.bucca@unito.it.
authors.forename: Caterina
authors.initials: C
authors.lastname: Bucca
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006760:Hospitalization; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000175:diagnosis
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D