Serum vitamin D in patients with chronic obstructive lung disease does not correlate with mortality--results from a 10-year prospective cohort study.
BACKGROUND
Recent studies have found vitamin D (25-OHD) deficiency and insufficiency to be common among patients with COPD. Serum level of 25-OHD seems to correlate to pulmonary function, COPD disease staging, and increased susceptibility to respiratory infections. We wanted to investigate whether vitamin D deficiency or insufficiency was associated with mortality rate in patients suffering from advanced COPD.


METHODS
25-OHD serum levels were measured in 462 patients suffering from moderate to very severe COPD. Patients were stratified into three groups according to serum levels of 25-OHD. Outcome measure was mortality in a 10 year follow-up period. Kaplan-Meier curves (KM) were plotted and mortality hazard ratios (HR) were calculated using Cox Proportional Hazard regression (Cox PH).


RESULTS
Serum 25-OHD deficiency and insufficiency were prevalent. We were unable to demonstrate any association between baseline serum levels of 25-OHD and mortality rate. We found an association between mortality and age [HR 1.05 (CI 95%: 1.03-1.06)], Charlson score [HR 1.49 (CI 95%: 1.06-2.09)], increasing neutrophil count [HR 1.05 (CI 95%: 1.02-1.09)], severe [HR 1.41 (CI 95%: 1.06-1.86)]/very severe COPD [HR 2.19 (CI 95%: 1.58-3.02)] and a smoking history of more than 40 pack years [HR 1.27 (CI 95%: 1.02-1.70)].


CONCLUSIONS
Serum level of 25-OHD does not seem to be associated with mortality rate, suggesting no or only a minor role of 25-OHD in disease progression in patients with moderate to very severe COPD.
Department of Infectious Diseases Q, Odense University Hospital, Odense, Denmark. Aesklepios@gmail.com
Dennis Back
DB
Holmgaard
Lone Hagens
LH
Mygind
Ingrid Louise
IL
Titlestad
Hanne
H
Madsen
Palle Bach Nielsen
PB
Fruekilde
Svend Stenvang
SS
Pedersen
C
C
Pedersen
D000368:Aged; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000401:mortality*; D014807:Vitamin D / Q000097:blood*
D014807:Vitamin D