SESSION TYPE: COPD Posters II
PRESENTED ON: Wednesday, October 24, 2012 at 01:30 PM - 02:30 PM
PURPOSE: Chronic obstructive pulmonary disease (COPD) has been shown to be associated with lower levels of serum 25-hydroxy vitamin D and the latter has been associated with total and cardiovascular disease (CVD) mortality. We examined whether lower vitamin D levels may further amplify the association of COPD and its severity with total and CVD mortality.
METHODS: We studied 7,474 U.S. adults ≥40 years from the National Health and Nutrition Examination Survey 1988-1994 with a mean age of 59.8 years and follow-up through 2006 (8.2±2.5 years) for total and CVD mortality. With vitamin D levels categorized into tertiles and COPD severity classified on the basis of forced expiratory volume in one second (FEV1): mild (FEV1 80%), moderate/severe (FEV1<80%), 24.3% of the subjects had COPD (FEV1/FVC ratio<70%). With Cox regression, we examined the hazard ratios (HR)( 95% confidence intervals) for total and CVD mortality according to COPD/vitamin D category, using those with no COPD in the highest tertile of vitamin D as reference group.
RESULTS: The HRs (unadjusted) increased successively by increasing COPD and decreasing vitamin D group to 4.5(3.3-6.1) for total and 3.4(2.2-5.3) for CVD mortality among those with moderate/severe COPD who were in the 1sttertile of vitamin D. After adjustment for age, gender, ethnicity, body mass index, total and HDL-cholesterol, triglycerides, systolic blood pressure, diabetes, and smoking, these associations were attenuated but remained increased (HR=2.1[1.5-2.9] for total mortality and HR=1.5[1.0-2.4] for CVD mortality). Lower vitamin D tertiles were associated with increasing HRs for total and CVD mortality within each COPD group.
CONCLUSIONS: Our study suggests lower levels of vitamin D may be associated with further increases in total and CVD mortality associated with COPD; however, age and cardiovascular risk factors appear to explain much of this association.
CLINICAL IMPLICATIONS: Measurement of serum vitamin D levels as only modest clinical utility for prognostic risk assessment in persons with COPD. Clinical trials would provide more definitive information about whether vitamin D may be protective in such persons.
DISCLOSURE: The following authors have nothing to disclose: Hwa Lee, Yanting Luo, Katherine Lee, Nathan Wong
No Product/Research Disclosure InformationHeart Disease Prevention Program, Division of Cardiology, School of Medicine, University of California, Irvine, Irvine, CA