Research On The Relation Between Leptin And The Pathogenetic Condition In Chronic Obstructive Pulmonary Disease

Background:Malnutrition is prevalent in patients with COPD, which is concerned with acute exacerbation of COPD. Leptin, as a pleiotropic molecule, plays a role in regulating energy balance, immune function and inflammatory reaction. Some studies show that leptin can be taken as a inflammatory mark and cytokine-leptin link in pulmonary cachexia may be a cause of the poor response to nutritional support in some of the cachectic patients with COPD, but a few studies show that leptin doesn't relate to weight loss in patients with COPD, it is imcompatible that results of different researches on the relationship between leptin and inflammatory factor, so it is necessary to study further on the role of leptin in COPD.Objective:To explore the role of leptin in inflammatory reaction and malnutrition in patients with COPD and the value of leptin on evaluating the severity of condition in patients with COPD.Methods:Forty inpatients with COPD in acute exacerbation were selected , including 31 males and 9 females. The smoking informations were recorded. Routinely, the spirometry, arterial blood gas ,serum albumin and blood analysis, body height and weight were measured. The serum leptin and interleukin-6 levels were detected by ELISA. The correlation between the serum leptin level and interleukin-6 level, lung function, blood gas analysis index, nutrition index, and so on, were analyzed. The serum leptin and interleukin-6 levels of patients with COPD in acute exacerbation and symptomatic paracmasis were compared. The serum leptin levels of patients with different smoking status, nutritional status, severity of condition, were also compared. Results:1.The serum leptin level, interleukin-6 level, leucocyte count, percentage of neutrophil, partial pressure of arterial carbon dioxide in patients with COPD in the acute exacerbation were higher significantly than those in symptomatic paracmasis(P<0.05～0.01). The serum albumin, partial pressure of arterial oxygen and arterial oxygen saturation were lower significantly than those in symptomatic paracmasis(P<0.01).2.The serum leptin level in patients with COPD in the acute exacerbation had significantly positive correlation with interleukin-6 level, leucocyte count, percentage of neutrophil, partial pressure of arterial carbon dioxide(r=0.320～0.699,P<0.05～0.01), and had significantly negative correlation with partial pressure of arterial oxygen, arterial oxygen saturation, percentage of forced expiratory volume in first second(FEV1), serum albumin(r=-0.341～-0.422,P<0.05～0.01).There were no correlation between the serum leptin level and ratio of FEV1 to forced vital capacity, body mass index, smoking index, course of disease, sex, age.3.There was no difference in the serum leptin levels in groups with different nutritional status (P>0.05).4.The serum leptin level in smokers was higher significantly than that in ex-smokers(P<0.01).5.The serum leptin level in patients with severe and very severe COPD was higher significantly than that in mild and moderate COPD.Conclusion:Leptin is relation to the systemic inflammatory reaction in COPD and protein metabolism in patients with acute exacerbation of COPD . Leptin can be taken as a important inflammatory mark in the acute exacerbation of COPD. It can be used to evaluate the severity of condition in patients with COPD. Stop smoking can reduce serum leptin level in patients with COPD in the acute exacerbation .