瘦素和瘦素基因G-2548A多态性与心力衰竭恶病质发生的相关性

The relationship of leptin and leptin G-2548A gene polymorphism in the development of cardiac cachexia

目的：探讨扩张型心肌病合并恶病质患者血清瘦素水平的变化，并从基因水平探讨其变化的原因，初步阐明心力衰竭恶病质的发生机制，为其治疗寻求新靶点。方法收集2012-2014年就诊于包头医学院第一附属医院，确诊为扩张型心肌病、心功能（NYHA）Ⅱ-Ⅳ级患者56例。根据体重下降程度分为心力衰竭恶病质（cCHF）组（n=24）和心力衰竭非恶病质（ncCHF）组（n=32）。于住院的第二天，采集空腹静脉血5 ml，经RFLP-PCR检测血液瘦素G-2548A基因型表达，并经ELISA法检测血清中瘦素的水平。结果 cCHF患者较ncCHF患者血清瘦素水平降低，差异有统计学意义（P＜0.05）；在所有入选者中瘦素基因型AA型携带者瘦素水平高于AG型及GG型，差异有统计学意义（P＜0.05）；所有心力衰竭患者中AA型基因表达较AG型及GG型增高，cCHF患者AA型表达较ncCHF患者高，但差异无统计学意义（P＞0.05）；cCHF患者瘦素基因型 AA型体内LEP水平低于ncCHF患者，差异有统计学意义（P＜0.05）。结论瘦素G-2548A基因AA型与扩张型心肌病心力衰竭的发生相关。瘦素水平降低参与cCHF的发生，但与瘦素G-2548A基因多态性无关。

Objective To investigate the change of serum level of leptin in dilated cardiomyopathy with cachexia patients, explore the reason from gene level, clarify the mechanism of cardiac cachexia patients preliminarily, and seek a new treatment target of chronic heart failure （CHF）. Methods We enrolled 56 subjects with dilated cardiomyopathy from 2012 to 2014 treated in the first affiliated hospital of Baotou Medical College whose heart function were valued in NYHA classⅡtoⅣlevel, and 5 ml limosis intravenous blood was drew in the following day morning. All subjects were divided into cachexia chronic heart failure （cCHF） group （n=24） and non-cachetic chronic heart failure （ncCHF） group （n=32） according to the level of weight loss. Their DNA was isolated from whole blood and leptin DNA polymorphism was detected with RFLP-PCR. The level of leptin was determined with ELISA. Results The contents of serum level of leptin in cCHF group were all lower than those in ncCHF group, and differences were all significant （P〈0.05）. The serum level of leptin of AA genotype was higher than AG and GG genotype among all of the subjects and differences were all significant （P〈0.05）. The expression ratio of leptin AA genotype was higher than AG and GG genotype among all of the subjects, and the expression ratio of AA genotype was higher in cCHF group than ncCHF group, but the difference was not statistically significant. The serum level of leptin of AA genotype in cCHF group was lower than the other, and difference was significant （P〈0.05）. Conclusion AA genotype of leptin gene G-2548A was significantly correlated with dilated cardiomyopathy CHF. A lower level of leptin may involves in the occurrence of cCHF, but it was not related to G-2548A gene polymorphism.