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BACKGROUND: Inflammatory and nutritional biomarkers have an important bearing on outcomes of acute exacerbations of chronic obstructive pulmonary disease (AECOPD), but the temporal profile of these compounds during an acute episode is unclear. PATIENTS AND METHODS: Plasma leptin, prealbumin, and tumor necrosis factor-alpha (TNF-α) were estimated at baseline and before hospital discharge in patients with AECOPD. RESULTS: A total of 82 patients were evaluated (66 males; mean (standard deviation) age, 61.6 (10.1) years. Of these, 74 subjects (90.2%) were current or former smokers, with median (range) pack-years of 15 (0-96), duration of COPD of 8 years (range, 2-25 years) and duration of current symptoms being 5 days (range, 1-30 days). Majority (41.5%) had type I (severe) exacerbation. During the current episode, 46 patients (58.9%) required mechanical ventilation for a median of 6 days (range, 1-34). The median duration of hospital stay was 13 days, (range, 1-110). At discharge, significant reduction was observed in dyspnea, total leukocyte count, erythrocyte sedimentation rate (ESR), partial pressure of carbon dioxide, hemoglobin, urea, creatinine, potassium, aspartate transferase, and TNF-α levels compared to baseline, whereas arterial pH, PO2, serum albumin, prealbumin, and leptin significantly improved. No difference was seen in leptin, prealbumin, and TNF-α between patients with mild/moderate and severe exacerbation, or between patients who required or did not require mechanical ventilation. Change in leptin correlated with body mass index and change in ESR; no associations were observed between leptin, prealbumin, and TNF-α with other clinico-laboratory variables. CONCLUSION: Plasma levels of novel inflammatory and nutritional biomarkers, i.e., leptin, TNF-α, and prealbumin are altered in AECOPD episodes and lag behind other parameters during recovery. These biomarkers are not reliable predictors of clinical outcomes in these patients.
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CONTEXT: 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. AIMS: To assess the variability in metalloproteinase activity in COPD related to tobacco and nontobacco causes. SETTINGS AND DESIGN: This is a hospital-based, prospective, observational study. SUBJECTS AND 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.