The Study Of Leptin Gene Polymorphisms-2548G/A In Patients With Premature Coronary Heart Disease

Objective:To study the distribution of single nucleotide polymorphism G/A in the promoter of leptin gene between normal and premature coronary heart disease (CHD) population in Chinese Han people of Tianjin.To explore whether leptin gene polymorphism is related to premature coronary heart disease.To evaluate the association between the serum leptin level with premature coronary heart disease, and to verify the correlation with the genotype distribution and the serum leptin level.Methods:(1)200patients with clinical diagnosis of premature coronary heart disease or positive findings for premature coronary heart disease in coronary angiography were grouped as premature coronary heart disease group, whereas100subjects with negative ECG changes for premature coronary heart disease and normal coronary angiography were grouped as normal control group.(2) Serum leptin levels in all subjects included in this study were measured by enzyme linked immunsorbent assay (ELISA) method.(3) The genotypes of leptin were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods in200premature coronary heart disease patients and100normal controls.Result:(1) The levels of serum leptin in the premature coronary heart disease patients were higher than those in the normal control.(2) The distribution genotype was in Hardy-Weinberg.(3) The genotype frequencies of AA,AG and GG were0.51,0.43and0.06in premature coronary heart disease;the distribution frequencies were0.45,0.38and0.17in the control group.The difference was statistically significant (x2=9.238, P=0.010).The relative risk suffering from premature coronary heart disease with genotype AA+AG was3.209times of those with genotype GG (OR=3.209CI=1.467～7.020).(4) The allele frequencies of’A’and’G’were0.725and0.275in premature coronary heart disease group and they were0.64and0.36in control group.The difference was statistically significant [χ2=4.559, P=0.033, OR(A/G)=1.483,95%CI:1.032～2.131].Multi-factor logistic regression analysis showed that the premature coronary heart disease morbidity of’A’allele carries is2.548times of non-’A’allele carries.(5) In premature coronary heart disease and normal control groups, patients with AA genotype showed higher fasting leptin level than those in the AG and GG genotype.Conclusion:1. In premature coronary heart disease group, leptin gene promoter had different distribution of genotypes compared with the normal controls.2. Leptin gene polymorphism-2548G/A was significantly correlated with premature coronary heart disease.’A’allele of leptin might be a genetic factor that may contribute to individual susceptibility for premature coronary heart disease.3. In all the tested patients, serum leptin level in AA genotype was higher than in AG and GG genotypes.