Study On Relationship Among Leptin Receptor Gene Polymorphism (SNPsLys109Arg And SNPs Gln223Arg) With Serum Leptin Levels And Nutrition Of Patients With Chronic Obstructive Pulmonary Disease

Objective:To investigate the association between two single nucleotide polymorphisms(SNPs),Lys109Arg and Gln223Arg of leptin receptor gene with serum leptin levels,then discuss the relationship among leptin receptor phenotype, serum leptin concentration and chronic obstructive pulmonary disease.Materials and Methods:A total 257 subjects were enrolled in which lung function were performed in Shanghai HuaDong Hospital from Nov,2005 to Jun,2007.COPD group include 125 chronic obstructive pulmonary disease patients in stationary phase aged 60 to 92 years(average 80.37±5.77 years) who had FEV1/FVC＜70%.And COPD patients whose body mass index were less than 22kg/m~2 assigned in groupⅠ,the others in groupⅡ.Control group include 132 subjects aged 60 to 92 years(average 79.29±7.07 years) who had FEV1/FVC＞70%.Serum leptin concentration was evaluated by ELISA method.The genomic DNA was extracted using dielectric purification assay.The gene fractions in which these two mutations are located were selectively amplified from genomic DNA samples using a multiplex polymerase chain reaction(PCR),followed by multiplex ligase detection reaction (LDR).The fluorescence level of LDR-PCR products was detected by DNA sequencer.Result:In total 257 subjects,in regard to the frequencies of the Lysl09Arg polymorphisms in exon 3 of the leptin receptor gene,GG was183cases,A/G was 68 cases and AA was 6 cases,which was in compliance with Hardy-Weinberg equilibrium.In addition,regarding the frequency of the Gln223Arg genotype of leptin receptor exon 6,GG was 201cases,A/G was 50 cases and AA was 4 cases,which was also in compliance with Hardy-Weinberg equilibrium.At Lysl09Arg position,in COPD groupⅠ,the patients with GG was 40/54(74.0%),A/G was 13/54(24.1%), AA was 1/54(1.9%)respectively.In COPD groupⅡ,the patients with GG was 49/71(69.0%),A/G was 21/71(29.6%),AA was 1/71(1.5%).In control group,GG was 94/132(71.2%),A/G was 34/132(25.75%),AA was 4/132(3.03%),There was no significant association between the frequency of the genotype Lys109Arg and COPD underweight.And there were no significant difference in leptin levels between GG, A/G and AA genotype.At Gln223Arg position,,in COPD groupⅠ,the patients with GG was 45/54(83.3%),A/G was 8/54(14.8%),AA was 1/54(1.9%) respectively.In COPD groupⅡ,the patients with GG was 57/71(80.3%),A/G was 13/71(18.3%), AA was 1/71(1.4%).In control group,GG was 101/132(76.5%),A/G was 29/132(22%),AA was 2/132(1.5%).Similarly,There was no significant association between the frequency of the genotype Gln223Arg and COPD underweight.And there were no significant difference in leptin levels between GG,A/G and AA genotype. The levels of leptin were lower in patients with COPD underweight than that in normol weight patients and the healthy controls,and positively correlated with patients nutritional state.Conclusion:1.There was no relationship in leptin receptor gene SNPs Lysl09Arg and COPD underweight in elderly,there were no significant difference in leptin levels between GG,A/G and AA genotype.2.There was no significant association between the frequency of the genotype Gln223Arg and COPD underweight.And there were no significant difference in leptin levels between GG,A/G and AA genotype.3.Levels of leptin were lower in patients with COPDⅠthan that in COPDⅡand the healthy controls.,and positively correlated with patients nutritional state.