Adiponectin as a biomarker of systemic inflammatory response in smoker patients with stable and exacerbation phases of chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVE: Adiponectin is an adipose tissue-derived specific protein that has a role in energy homeostasis, that has a protective role against the development of insulin resistance and atherosclerosis and that exhibits anti-inflammatory properties. We investigated serum adiponectin as a biomarker of systemic inflammatory response and its relation with leptin, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and nitric oxide (NO) in chronic obstructive pulmonary disease (COPD) patients. MATERIAL AND METHODS: We studied 36 male patients with COPD (15 stable and 21 exacerbated) and 17 age and sex-matched healthy subjects. The adiponectin and leptin levels were measured by enzyme-linked immunosorbent assay. Serum CRP levels were measured using the nephelometric method. ESR was determined using the Westergren method and NO by the cadmium reduction method. RESULTS: Adiponectin levels in COPD patients were significantly higher than those in control subjects (p<0.001), whereas there were no differences in leptin or NO levels. Serum levels of CRP, ESR and adiponectin were significantly higher in the exacerbated COPD patients compared to the stable group (p<0.001, p = 0.033 and p = 0.024, respectively), whereas the differences in leptin and NO levels were not significant. Serum levels of adiponectin were not correlated with FEV(1), FEV(1)/FVC, dyspnoea score, BMI or other inflammatory parameters in the stable COPD group. CRP and ESR correlated negatively with FEV(1) in the stable COPD group. CONCLUSIONS: Adiponectin may be a marker of low-grade systemic inflammatory response in COPD. A further rise in serum adiponectin in the exacerbation period denotes that this may also be a biomarker of the exacerbation phase as well as CRP and ESR.