Serum Uric Acid And Nutrition In Chronic Obstructive Pulmonary Disease

Background Chronic obstructive pulmonary disease (COPD)is a disease statecharacterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases.COPD is a leading cause of morbidity and mortality worldwide, which is a increasing global health problem. In our country, the respiratory disease ,the most of which is COPD, is already the fourth most common cause of death in the country and the first most common cause of death in the city . It is not all known about its pathogenesis . There is considerable evidence for increased oxidative stress in COPD.Reactive oxygen species (ROS) such as O_2·- ,·OH ,O·2 and H₂O₂ are enhancing and antioxidants such as uric acid(UA), vitamin C and vitamin E are declining.Objective To evaluate the significances of the ideal body weight percentage(IBM%) and serum UA in the patients with COPD, the level of serum UA , body weight and height of the patients with stable COPD were examined.Methods The level of serum uric acid , body weight and height were examined in 187 patients with stable COPD by GOLD and the revised diagnostic criteria of Chinese Respiratory College in 2002 . Electrocardiographs and spirometry measurements including forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), peak expiratory flow (PEF), maximal mid-expiratory flow (MMEF), residual volume (RV) , total lung capacity (TLC) and functional residual capacity (FRC) were undertaken for these patients , who were separated into three groups according to their FEV₁%( the predicted FEV₁ percentage ) : moderate A group , moderate B group and severe group . In addition, these patients were separated intotwo groups according to their electrocardiographs : A group with chronic cor pulmonale and B group without chronic cor pulmonale .Lastly, these patients were separated into two groups according to their IBM% : one group with malnutrition(lBM%<0.9)and the other group without malnutrition (IBM%>0.9). Software SPSS 10.0 was utilized for statistical analysis. Chi-square test was used for comparison about enumeration data. T test was used for comparison between two groups about measurement data .Analysis of variance was adopted in comparison of three groups about measurement data . Pearson product-moment correlation and partial correlation was used for correlation with FEVi%, FEV|/FVC, PEF%, FEF25%, FEF50%, MMEF% to the level of the serum UA.Results1. According to the diagnostic criteria set by the Chinese respiratory College in2002 and GOLD revise in 2004, 47 patients were identified as having moderate COPD; 90 patients were severe COPD; 50 patients were very severe COPD . There were 54 patients with malnutrition and 63 patients with chronic cor pulmonale in 187 patients.2. The parameters about spirometry:2.1 The parameters about spirometry such as FEV,%, FEVi/FVC, PEF%, FEF25%, FEF50%, MMEF%, RV%, TLC%, RV/TLC and FRC% were notably different between the three groups according to their FEVi%.2.2 The parameters about spirometry such as FEVi%, FEVi/FVC, PEF%, FEF25%, FEFso% and MMEF% were notably different between A group with chronic cor pulmonale and B group without chronic cor pulmonale.The parameters about spirometry such as RV%, TLC%, RV/TLC, FRC% in A group with chronic cor pulmonale were all bigger than one in B group without chronic cor pulmonale,but the differences between the two group were not significant.2.3 There were positive relationship with FEVi/FVC, PEF%, FEF25%, FEF50%, MMEF% to FEVi% (respectively r =0.784, P <0.01; r =0.710, P <0.01; r =0.889, P<0.01; r =0.868, P <0.01; r =0.876, P <0.01). There were negative relationship with RV%, TLC%, RV/TLC, FRC% to FEV,% (respectively r =-0.606. P <0.01; r =-0.343, P <0.01; r =-0.691, P <0.01; r =-0.594, P <0.01).3. IBM% in the groups:3.1 The incidence of the concomitancy with malnutrition in all the patients was notable different among the three groups according to their FEV|%( x 2 = 9.377 P<0.05).3.2 The incidence of the concomitancy with malnutrition in the patients was notably different between A group with chronic cor pulmonale and B group without chronic cor pulmonale ( x 2=25.555 P <0.01).3.3 The IBM% were notably different between the three groups according to their FEVt%.3.4 The IBM% of the group with chronic cor pulmonale were notably smaller than one of the group without chronic cor pulmonale.3.5 There were positive relationship with FEVt%, FEV,/FVC, FEF25%, FEF50%, MMEF% to IBM% (respectively r =0.207, P <0.01; r =0.228, P <0.01; r =0.133, P <0.05; r =0.199, P <0.01; r =0.156, P <0.05) and negative relationship with RV%, TLC% to 1BM% (respectively r =0.208, P <0.05; r=0.220, P<0.05). There were not significant relationship with PEF%, RV/TLC, FRC% to IBM% in all the patients.4. The serum UA in the groups:4.1 The level of the serum UA were notably different between the three groups according to their FEVi%.4.2 The level of the serum UA in the group with chronic cor pulmonale were notably smaller than one of the group without chronic cor pulmonale.4.3 There were positive relationship with FEVi%, FEVi/FVC, PEF%, FEF25%, FEF50%, MMEF% to the level of the serum UA (respectively r =0.255, P <0.01; r =0.274 , P <0.01; r =0.208, P <0.01; r =0.279, P <0.01; r =0.275, P O.01; r =0.247, P <0.01) and negative relationship with RV%, TLC%, RV/TLC, FRC% to the level of the serum UA (respectively r =-0.323, P <0.01; r =-0.344, P <0.01; r =-0.255, P<0.01; r =—0.299, P <0.01) in all the patients .4.4 After adjusting for age and nutrition , there were positive relationship with FEVi% , FEV,/FVC, PEF%, FEF25%, FEF50%, MMEF% to the level of the serum UA (respectively r'=0.215, P <0.01; r'=0.224, P <0.01; r'=0.192, P <0.05; r'=0.253, P <0.01; r'=0.233, P <0.01; r'=0.216, P <0.01) and negative relationship with RV%, TLC%, RV/TLC, FRC% to the level of the serum UA (respectively r'=-0.376, P <0.01; r'=-0.366, P <0.01; r'—0.292, P <0.01; r'--0.382, P <0.01) in all the patiets.Conclusion1. The airway limitation in the patients with COPD involves central airways and peripheral airways.In addion ,it is related to impairment of respiratory muscles.2. In the patients with COPD, FEVi% is not only an indication of the Airway limitation but also a hint of severity of emphysema.3. The incidence of the concomitancy with malnutrition in the patients was increasing when the airflow limitation was progressive and there came concomitancy with chronic cor pulmonale in them. There were positive relationship between the FEVi% and the IBM% in the all patients.In other words,more badly the nutrition in the patients with COPD is ,more severe the airway limitation in them is.There were negative relationship between the parameters about the spirometry such as RV%,TLC% and the IBM% in the all patients.Namely, more badly the nutrition in the patients with COPD is ,more severe the classification of severity of emphysema in them is.So, Malnutrition is one of the independent prognosis factors of COPD.4. The level of serum UA in the patients with COPD was decreasing when the airflow limitation was progressive or/and there came concomitancy with chronic cor pulmonale or/ and malnutrition in them. After adjusting for the age and the IBM% (nutrition),there were positive relationship with FEVi%, FEVi/FVC, PEF%, FEF25%, FEF5o%, MMEF% to the level of the serum UA.And there were negative relationship with RV%, TLC%, RV/TLC, FRC% to the level of the serum UA.So decrease in the level of serum UA is one hint about the bad prognosis ofcom.