Influence of cardiovascular-associated genes on cardiac hypertrophy and arrhythmias in endurance athletes

耐力训练产生生理性左心室（LV）肥大和心动过缓。但相似训练的运动员心室大小并不相同，提示遗传因素可能影响心室质量。为探讨运动员左心室质量与肾素-血管紧张素系统基因多态性的关系，采用聚合酶链反应（PCR）技术检测了21名男性中长跑运动员基因组DNA中血管紧张素转换酶（ACE）基因插入/缺失（I/D）多态性和血管紧张素原（AGT）基因M235 T多态性。ACE和AGT基因DD、DI和II多态性的基因型频率分别为9.5%、42.9%和47.6%，TT和MT多态性的基因型频率分别为52.4%和47.6%。心电图心动过缓（49.4±7.7次/min），左室高电压，超声心动图左室巨大（263.3±47.3g）。而ACE和AGT基因型与运动员心脏无明显相关性。霍尔特心电图表现为心动过缓、房室传导阻滞和多个长的心脏停搏，但除极低心率外，心律失常与ACE和AGT基因型无相关性。AGT基因TT型最低心率（34.3±15.4/min）明显低于MT型（38.2±5.9/min）（P<0.05）。同时检测最大氧耗量（VO_2max），以探讨ACE和AGT基因多态性是否影响运动员的运动成绩。VO_2max（68.1 ± 5.4ml/kg/min）与ACE、AGT基因型无关。总之，我们不能找到显着的关系，没有最小的HR运动员的心脏和基因型的ACE和AGT的多态性。

Endurance training produces physiological left ventricular (LV) hypertrophy and bradycardia. However, similarity training athletes do not have same ventricular size, suggesting that genetic factors may affect ventricular mass. Therefore, we studied whether left ventricular mass in athletes associated with polymorphisms in renin-angiotensin system genes.Polymerase chain reaction with genomic DNA samples of 21 male distance runners was used to detect genotype of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and angiotensinogen (AGT) gene M235T polymorphism. Genotype frequencies of the ACE and AGT gene polymorphisms were found by 9.5%, 42.9% and 47.6% for DD, DI and II, and by 52.4% and 47.6% for TT and MT, respectively. Bradycardia (49.4±7.7/min) and high voltage in LV were shown in electrocardiography (ECG) and massive LV (263.3±47.3g) were observed in echocardiography. However, there was no significant relationship between athlete's heart and genotypes of the ACE and AGT polymorphisms. Holter ECG showed bradycardia, atrioventricular block and many long cardiac pauses, but there was no correlation without minimal heart rate (HR) between arrhythmias and genotypes of the ACE and AGT polymorphisms. TT genotype of AGT polymorphisms showed lower minimal HR (34.3±15.4/min) than that of MT genotype (38.2±5.9/min) (P<0.05). We also examined maximal oxygen consumption (VO_2 max) to detect whether the ACE and AGT gene polymorphisms affected athlete's performance. Subjects showed high VO_2 max (68.1 ± 5.4ml/kg/min), but there was no correlation to the ACE and AGT genotypes. In conclusion, we could not find significant relationship without minimal HR between athlete's heart and genotypes of the ACE and AGT polymorphisms.