Putative Roles of Circulating Resistin in Patients with Asthma, COPD and Cigarette Smokers

AIMS To investigate the hypothesis that circulating resistin reflects the degree of pulmonary inflammation, this study explores putative roles of resistin in patients with acute and stable inflammatory obstructive airway diseases and cigarette smokers. METHODS We determined complements C3, C4, fasting resistin, insulin, glucose and lipid profile; calculated insulin resistance (homeostasis model assessment (HOMA-IR) in patients with acute asthma exacerbation (n=34); stable asthma (n=26) and stable chronic obstructive pulmonary disease (COPD; n=26), cigarette smokers (n=81), and healthy control subjects (n=42). We determined the associations between these variables and pulmonary function tests. RESULTS Patients with COPD, acute and stable asthma had significantly higher resistin and insulin than control subjects. Resistin, insulin, HOMA-IR, FEV1% and FEV1/FVC were significantly (p< 0.05) different between patients with acute asthma compared with stable asthma and COPD; smokers had similar levels of resistin, C3 and C4 as patients with asthma and COPD. In smokers, patients with asthma or COPD, resistin showed significant inverse correlations with FEV1%; FEV1/FVC% and positive significant correlations with BMI and HOMA-IR. Logistic regression showed that resistin is associated (p< 0.05) with inflammatory obstructive airways disease - odds ratio (OR)=1.22 and smoking OR=1.18. CONCLUSION Resistin may be a disease activity marker and may contribute to insulin resistance in smokers, asthma and COPD.