Study On Human Serum Leptin And Its Related Factors

1.Establishment of Human Serum Leptin RadioimmunoassayAIM:To establish human serum leptin RIA MATERAILS ANDMETHODS:The rabbit anti-human leptin antibody was used in the RIA of leptin 27 males and 24 females with normal 75gOGTT were included in the study RESULTS: 1.The leptin determinable range of this method was 0 5-24 ng /ml The CV of intra-assay and inter-assay were 2 94%-4 63% and 3 83%-5 64%, respectively The lowest determinable level of leptin was 0 45 ng/ml The rate of reabsorption was 90 65%-93 53%, the rate of reabsorption in dilution test was 93 46%-98 88% No cross-reaction was found with interleukin (IL)-1,2,3,6,8, tumor necrosis factor-a and GM-CS in this RIA The values of serum leptin measured by this method were similar to IRMA kit(DSL23100), r=0 98, p<0 01 2. The serum leptin[Median(25,75%)]level was 4 51(3 29,5 23)ng/ml in 27 men, and was 7 43(5 26, 9 99) ng/ml in 24 women, Z=3 878, p<0 01 3.Spearman analysis showed the fasting leptin was correlated with BMI and fasting insulin in men, and with BMI in women2 Human Serum Leptin Level and Its Related FactorsThe effect of sex, body weight, insulin and different glucose tolerance on human serum leptin was analyzed(1)The Serum Leptin Level and Its Related Factors in the Subjectsi1~~with Different Glucose ToleranceAIM:To study the serum leptin levels in different glucose tolerance subjects and its related factors SUBJECTS AND METHODS: 218 subjects were divided into 3 groups according to their 75g OGTT 104 were NGT, 76 were IGT, 28 were DM Among them 71 males and 77 females were non-obese, 36 males and 34 females were obese. The body weight, BMI, waist to hip ratio, blood pressure, FBS, CH, TG , HDL, lept in, fasting insulin and HOMA IR were measured in all subjects RESULTS3 The serum leptin[Median(25,75%)lwas 4 50(3 26,5 19)ng/ml in non-obese NGT men,7 24(5 04,8 99)ng/ml in non-obesewomen, p<0 01 The serum leptinwas5 50(4 46,8 78)ng/ml in obese NGT men, 4 50(3 26,5 19)ng/ml in non-obese men, p<0 01 The serum leptin was 9 85(8 87, 13 12) ng/ml in obese NGT women, 7 24(5 04,8 99) ng/ml in non-obese women, p<0 01 The serum leptin was 4.50(3 26,5 19),4 66(3 49,5 20),5 46(444,7 07)ng/ml inNGT, IGT, DM of non-obese men(p0 109) In non-obese women, the leptin was 7 24(5 04,8 99), 781(5 15,10 22), 11 03 (7 07,14 34)ng/ml, p<0 05 In men, fasting leptin was positively correlated with weight(WT), BMI, waist circumstance (WC), hip circumstance (HC), W/H, FBS, InsO and IR In women, fasting leptin was positively correlated with WT, BMI, IYC, HC, TG, CH, InsO and IR By stepwise regressionanalysis, theBMI, Ins0inmen, andBMI, InsO, TGinwomen were the independent affecting factors of serum leptin.(2)The Effect of Single-dosage Subcutaneous Injection of Insulin on Serum LeptinSAIM:To investigate the effect of single-dosage insulin injection subcutaneously on serum leptin SUBJECTS ANDMETHODS:Single-dosage of regular human insulin was injected subcutaneously in 11 healthy male volunteers The serum insulin and leptin concentrations were analyzed before and 30,60,90 minutes, 2, 4, 6, 8 hours after injection of insulin RESULTS: The serum insulin levels were significantly increased after injection of insulin, while the serum leptin levels were not changed remarkably, r20 045, p-0 513.The Effect of Genetic Factors on Serum Leptin levels and the other Metabolism Items in Subjects with Different Glucose ToleranceAIM:To study the effect of polymorphisms of the genes in relation to leptin signal action SUBJECTS AND METHODS: The subjects studied were as same as that in part2(1) The polymorphisms of OBRb (Gln223Arg), P i-AR (Trp64Arg )and PPARY2 (161 C→T) by PCR-RFLP were analyzed The leptin, BMI, WH, SBP, DBP, PBS, HDL, LDL, CH, TG, insulin and JR were compared between alleles carriers in different glucose tolerance groups RESULTS: 1. In males, Gln223 carriers of OBRb had higher WN/H in NGT, IGT and DM, higher SBP in IGT and DM, and higher DBP in DM CH was higher in IGT and...