The aim of this study was to determine the relationship between serum concentrations of 25-hydroxyvitamin D [25(OH)D] and chronic obstructive pulmonary disease (COPD) prevalence.
The analysis was performed using data from the Fifth Korean National Health and Nutrition Examination Survey, a cross-sectional survey of the Korean civilian population conducted from 2010 to 2012. The analyses were restricted to males who were 40 years of age and above. Complex sample multiple logistic regression analyses were used to examine the associations of COPD prevalence with 25(OH)D and other factors.
FEV1/FEV6 varied significantly with smoking status, age, household income, education level, occupation, body mass index (BMI), and physical activity (p < 0.05). In univariate analysis, smoking status, BMI, household income, education level, and occupation showed association with COPD (p < 0.05), but vitamin D was not associated with COPD (p = 0.078). However, when adjusted with smoking status, household income, education level, occupation, BMI, age, and smoking index, the lowest quartile of 25(OH)D showed OR 1.643 (95% CI 1.161-2.236) compared to 3rd quartile (p = 0.024).
A significant relationship was observed between serum concentration of 25(OH)D and COPD.
Serum 25-hydroxyvitamin D levels of males according to smoking status and the other factors in KNHANES V1)
Abbreviations: SE, standard error. N, unweighted frequency. FEV1, forced expiratory volume for 1 second. FEV6, forced expiratory volume for 6 seconds. BMI, body mass index
1) Data are expressed as estimates ± SE in ng/ml of 25-hydroxyvitamin D. 2) Calculated by complex sample general linear model (CSGLM)
Differences in FEV1 and FEV1/FEV6 by each variables for males in KNHANES V
Abbreviations: FEV1, forced expiratory volume for 1 second. FEV6, forced expiratory volume for 6 seconds. 25(OH)D, 25-hydroxyvitamin D. N, unweighted frequency. SE, standard error.
1) Calculated by complex sample general linear model (CSGLM).
Unadjusted and adjusted odds ratios of chronic obstructive pulmonary disease by vitamin D, demographic factors and smoking factors for males aged 40 or above in KNHANES V1)
Abbreviations: OR, odds ratio. CI, confidence interval. BMI, body mass index. SI, smoking index
1) Data are given as OR (95% confidence interval), unless otherwise indicated. 2) Calculated by complex sample logistic regression analysis