| IntroductionIt has been proved that patients with chronic heart failure ( CHF) have insulin resistance(IR). Recently,the findings of the phenomenon that IR exist simultaneously with elevated serum levels of leptin in CHF patients has been described. The metabolic action of leptin is mediated through the different isofonns of the leptin receptor. To make clear that whether or not leptin resistance exists in CHF with elevated serum of leptin, we test the soluble leptin receptor in CHF and to institute the action of the leptin and other related factors in CHF.MethodsPatientsPatients( n = 50) with age ( 59. 6 2. 8 ) years, NYIIA fuctional class < IV as a result of dilated cardiomyopathy or ischemic heart disease were included in this study. All CHF patients had clinical, radiological and echocardiographic signs of CHF and a reduced left ventricular ejection fraction ( LVEF) of 60%. Exclusion criterias were primary valvular heart disease, uncontrolled hyperten-tion, chronic obstructive pulmonary disease, diabetes mellitus, renal failure and musculoskeletal conditions limiting exercise capacity such as rheumathoid arthritis. Patients with CHF were classified into two subgroups according to their peak oxygen consumption, they were moderate exercise capacity and severe exicise intolerance.A total of 10 age - matched patients( age 61 4.3years) , who were admit-ted with non - specific chest pain for exclusion of coronary artery disease, served as controls. They were classified as normal following physical examination, ECG, chest X - ray, echocardiography. No previous major medical illness was reported and they were on no medication during the study period.Measurements of blood samplesBlood samples were collected from both study groups in the morning . After immediate centrifugation , samples were stored at - 70 untile analysis . To detect soluble leptin receptor, insulin, glucose, lipid etc. Measure height, body weight, calculate ISI, BMI, and examine echocardiography, LVEF.Exercise testing and respiratory functionExercise testing was performed on a calibrated, electronically braked bicycle in an upright position with work load increasing progressively every 3 min in steps of 25 W beginning at 25 W. Respiratory gas exchange data were determined continuously throughout the exercise test .Statistical analysisMean value SD was calculated for all variables, inter group comparisons were performed using t - test. Correlation between serum parameters was assessed by linear regression analysis. A P -value of <0.05 was considered statistically significant. All calculations were performed using the computer program SPSS 11.5.ResultsFPS and sLPR in CHF are much higher than them in controls; LVEF, MV02, ISI are lower than them in controls. There is no difference in FPG and BMI.sLPR has positive correlation with the degree of seriousness of CHF. Patients with CHF were classified into two subgroups according to their peak oxygen consumption ( study group A - moderate exercise capacity if more than 14ml/min. kg or study group B - severe exercise intolerance if 14ml/min.kg). MV02 and ISI are higher in group A than them in group B, sLPR in group A is lower than it in group B. There is no difference of LVEF between two groups.sLPR in CHF has positive correlation with FPS and negative correlation with ISI and MVO2.DisscussionIt has been proved that serum leptin level elevates in CHF patients, but it has few articals about leptin receptor. Leptin carry out its physical action through leptin receptor, soluble leptin receptor is the major link protein with lep-tin in circulation. Serum leptin level rises and leptin receptor level descends in leptin resistance; the physical action of leptin is enhanced when leptin receptor rises. So soluble leptin receptor in circulation can reflect the action of leptin directly.We find that leptin is involved in metabolic abnormalities leading to a cata-bolic syndrome in advance CHF. The concentration of soluble leptin receptor was found to...
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