BACKGROUND:Vitamin C, as an antioxidant, has recently been suggested to provide protection against COPD; however, only few national cohort studies have investigated these effects. We aimed to confirm the protective effects of vitamin C against COPD in Korean patients.

PATIENTS AND METHODS:We analyzed the data of 3,283 adults aged≥40 years (representing 23,541,704 subjects) who underwent pulmonary function tests and responded to questionnaires on smoking history and vitamin C intake, with stratification variables and sampling weight designated by the Korea 2012 National Health and Nutrition Examination Survey.

RESULTS:Among all the subjects, 512 (representing 3,459,679 subjects; 15.6%) were diagnosed as having COPD based on pulmonary function test results. Male gender, old age, residence in suburban/rural regions, low household income, low educational level, an occupation in agriculture or fisheries, and heavy smoking were significantly associated with COPD. Low intake of nutrients, including potassium, vitamin A, carotene, retinol, and vitamin C, was significantly associated with COPD. The prevalence of COPD in heavy smokers with the lowest quartile (Q1,<48.50 mg; 63.0%) and low-middle quartile (Q2, 48.50-84.38 mg; 56.4%) of vitamin C intake was significantly higher than that in subjects with the high-middle quartile (Q3, 84.38-141.63 mg; 29.5%) and highest quartile (Q4,>141.63 mg; 32.6%) of vitamin C intake (P=0.015). In multivariate analysis, male gender, old age, heavy smoking, and a low intake of vitamin C were significant independent risk factors for COPD. A significant reduction of 76.7% in COPD risk was observed with a Q3 vitamin C intake compared to Q1 vitamin C intake (odds ratio, 0.233; 95% confidence interval, 0.094-0.576) in heavy smokers.

CONCLUSION:This large-scale national study suggests that dietary vitamin C provides protection against COPD, independent of smoking history, in the general Korean population.

BACKGROUND/AIM:Yoga is an ancient Indian science as well as the way of life. Pranayama is a part of yoga, which improves pulmonary function in combination of many pranayama, but the aim of our study is to evaluate the effect of only Bhramari pranayama and OM chanting on pulmonary function in healthy individuals.

MATERIALS AND METHODS:A total of 82 subjects were randomized into the study group (SG) (n = 41) and control group (CG) (n = 41). Baseline assessment was performed before intervention for both groups. SG practiced Bhramari pranayama and OM chanting for the duration of 10 min (5 min for each practice)/day for the period of 6 days/week for 2 weeks and CG did not practice so. After intervention post-assessment was performed for SG (n = 40) and CG (n = 39). Statistical analysis was performed by Independent samples t-test and Student's paired t-test with the use of Statistical Package for the Social Sciences version 16 (2007, USA).

RESULTS:The result showed a significant improvement in peak expiratory flow (PEF), forced expiratory flow (FEF)25% and maximal voluntary ventilation (MVV) along with a significant reduction in weight in SG compared with CG in independent samples t-test. Significant improvement in slow vital capacity (SVC), forced expired volume in 1 s (FEV1) along with PEF, FEF25% and MVV; Significant reduction in weight and body mass index were observed in SG unlike in CG in Student's paired t-test. No significant changes were found in forced vital capacity, FEV1 /SVC and FEF50% , between and within the group analysis of SG and CG.

CONCLUSION:Bhramari pranayama and OM chanting are effective in improving pulmonary function in healthy individuals.