title: Variability in proteinase-antiproteinase balance, nutritional status, and quality of life in stable chronic obstructive pulmonary disease due to tobacco and nontobacco etiology.
abstract: BACKGROUND
  Although the role of proteinase/antiproteinase imbalance in chronic obstructive pulmonary disease (COPD) due to tobacco is well established, information in COPD due to nontobacco etiology is sparse.
  
  
  OBJECTIVE
  To assess the variability in metalloproteinase activity in COPD related to tobacco and nontobacco causes.
  
  
  METHODS
  This is a hospital-based, prospective, observational study.
  
  
  METHODS
  Serum matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) were estimated in 200 subjects divided equally into four groups, i.e. COPD in tobacco smokers, COPD in nonsmokers but with exposure to biomass-related indoor air pollution, smokers without COPD, and nonsmoking healthy controls. Anthropometric skinfold measurements, quality of life (QOL) using St. George Respiratory Questionnaire, and exercise capacity using the 6-min walk test (6-MWT) were carried out. Groups were compared using analysis of variance and Kruskal-Wallis plus Mann-Whitney U-test to assess differences between groups. The Chi-square and Fisher's exact tests were used to evaluate associations among categorical variables. Spearman's rank correlation was calculated to assess the correlation between data.
  
  
  RESULTS
  Patients with COPD due to either tobacco or nontobacco etiology were older, more malnourished, had worse QOL, and poorer exercise capacity compared to non-COPD subjects. Triceps, subscapular, and suprailiac skinfold thicknesses were less in smokers with COPD than biomass-related COPD. MMP-9 and TIMP-1 levels were similar across all groups. TIMP-1 significantly correlated with 6-MWT among all groups.
  
  
  CONCLUSIONS
  The protease-antiprotease balance in COPD is similar irrespective of the presence or absence of tobacco exposure but is related to poor exercise capacity.
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: Anant
authors.initials: A
authors.lastname: Mohan
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: Mini
authors.initials: M
authors.lastname: Sharma
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: Arvind
authors.initials: A
authors.lastname: Uniyal
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: Rajlaxmi
authors.initials: R
authors.lastname: Borah
authors.affiliation: Department of Biochemistry, All Institute of Medical Sciences, New Delhi, India.
authors.forename: Kalpana
authors.initials: K
authors.lastname: Luthra
authors.affiliation: Department of Biostatistics, All Institute of Medical Sciences, New Delhi, India.
authors.forename: R M
authors.initials: RM
authors.lastname: Pandey
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: Karan
authors.initials: K
authors.lastname: Madan
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: Vijay
authors.initials: V
authors.lastname: Hadda
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: Randeep
authors.initials: R
authors.lastname: Guleria
keywords: Biomass; chronic obstructive pulmonary disease; matrix metalloproteinase-9; tissue inhibitor of metalloproteinases-1; tobacco