title: Smokers With Adequate Vitamin C Intake Show a Preferable Pulmonary Function Test.
abstract: OBJECTIVE
  Airflow obstruction often results from the chronic inflammation caused by cigarette smoke. It has been concluded that cigarette smoke-induced oxidative damage is prevented by ascorbic acid on a cellular level. The purpose of the current study was to explore the effect of vitamin C intake on pulmonary function in established smokers (100 or more cigarettes) and never-smokers in a Korean population.
  
  
  METHODS
  The 2974 enrolled men and women over the age of 40 in the Korea National Health and Nutrition Examination Survey IV 2008 were divided into 4 groups based on smoking patterns (never-smoker vs established smoker) and vitamin C intake from dietary assessment (higher vs lower; median value: 77.18 mg/day).
  
  
  RESULTS
  Univariate analysis showed associations between forced expiratory volume in 1 second (FEV1), FEV/forced vital capacity (FVC) and age, gender, body mass index (BMI), pack-years, vitamin C intake, and additional micronutrient intake. On multiple logistic regression analysis, the odds ratios (95% confidence interval) for FEV1 < 80% predicted were 1.000 (never-smokers, higher vitamin C intake), 1.067 (0.823, 1.383; never-smokers, lower vitamin C intake), 1.224 (0.871, 1.721; established smokers, higher vitamin C intake), and 1.479 (1.057, 2.072; established smokers, lower vitamin C intake). The odds ratios for FEV1/FVC < 0.70 were 1.177 (0.821, 1.687; never-smokers, lower vitamin C intake), 1.637 (1.094, 2.445; established smokers, higher vitamin C intake), and 2.093 (1.403, 3.122; established smokers, lower vitamin C intake) after adjusting for confounding factors (p < 0.001).
  
  
  CONCLUSIONS
  Korean smokers with adequate vitamin C intake showed a preferable pulmonary function test.
authors.affiliation: a Department of Family Medicine, Samsung Medical Center, Sungkyunkwan University of Medicine, Yonsei University College of Medicine , Seoul , KOREA.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Shin
authors.affiliation: b Department of Family Medicine, Gangnam Severance HospitalYonsei University College of Medicine , Seoul , KOREA.
authors.forename: Jae Yong
authors.initials: JY
authors.lastname: Shim
authors.affiliation: c Department of Family Medicine, Severance Hospital, Yonsei University College of Medicine , Seoul , KOREA.
authors.forename: Duk Chul
authors.initials: DC
authors.lastname: Lee
authors.affiliation: b Department of Family Medicine, Gangnam Severance HospitalYonsei University College of Medicine , Seoul , KOREA.
authors.forename: Hye Ree
authors.initials: HR
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D016015:Logistic Models; D008168:Lung / Q000187:drug effects; D008297:Male; D018977:Micronutrients / Q000008:administration & dosage; D008875:Middle Aged; D015999:Multivariate Analysis; D015596:Nutrition Assessment; D009749:Nutrition Surveys; D018384:Oxidative Stress; D056910:Republic of Korea; D012129:Respiratory Function Tests; D012907:Smoking
chemical_list: D000975:Antioxidants; D018977:Micronutrients; D001205:Ascorbic Acid
keywords: antioxidants; ascorbic acid; pulmonary function test; smoking