Left ventricular function after exercise training in young men.

The effects of endurance training have been extensively studied in athletes, but longitudinal studies of exercise-induced cardiac changes in normal patients are limited. To assess the effects of 6 months of moderate-intensity aerobic training (1 hour/day, 3 times/week) on normal hearts, 23 sedentary men aged 31.1 +/- 3.5 years were studied by standard and tissue Doppler echocardiography. Left ventricular (LV) systolic function was assessed by the ejection fraction and Doppler-measured stroke volume, and diastolic function was assessed by transmitral and pulmonary venous flow. Tissue Doppler systolic (Sm), early (Em), and late (Am) myocardial velocities were obtained at the septal and lateral mitral annulus. After training, there was a 14.5% increase in peak oxygen consumption (p = 0.000002) and a decrease in heart rate (60 +/- 7 to 56 +/- 8 beats/min, p = 0.01). Septal and posterior wall thickness increased (8.7 +/- 1.0 to 9.4 +/- 1.3 mm, p = 0.002, and 8.2 +/- 0.7 to 8.8 +/- 1.1 mm, p = 0.0009, respectively), with a 15% increase in LV mass index (p = 0.0002). LV diameters, stroke volumes, and ejection fractions were unchanged. Mitral inflow showed a decrease in late-wave velocity (p = 0.00004), thus increasing the early (E)/A ratio. Septal and lateral Sm (p = 0.02) and Em velocities (p <0.05) increased after training. In conclusion, the physiologic increase in LV mass in response to regular exercise in healthy young men occurs in parallel with a decrease in atrial contribution to flow. LV function estimated by tissue Doppler is improved despite the lack of changes in standard echocardiographic indexes.

Influência do polimorfismo do gene da ECA e do angiotensinogênio na hipertrofia miocárdica e melhora da capacidade funcional provocados pelo treinamento físico / Influence of angiotensinogen and ACE polymorphisms on myocardial hypertrophy and gain of aerobic capacity caused by exercise training in young individuals

Diversos polimorfismos do sistema renina angiotensina têm sido descritos, mas o impacto dessa variação genética na expressão de fenótipos ainda é pouco conhecido. O objetivo desse estudo foi investigar a influência do polimorfismo da enzima conversora da angiotensina (ECA) e do angiotensinogênio na hipertrofia cardíaca e no ganho de capacidade funcional provocados pelo treinamento físico em indivíduos jovens e saudáveis da Polícia Militar de São Paulo, homozigotos para os alelos D e I do polimorfismo da ECA e para os alelos M e T do polimorfismo do angiotensinogênio. Foram estudados 83 policiais militares, genotipados para o polimorfismo da ECA e do angiotensonogênio. Realizaram avaliação ecocardiográfica e ergoespirométrica antes e após 17 semanas de treinamento físico aeróbio. O treinamento físico aumentou significativamente e semelhantemente o VO2 pico nos indivíduos homozigotos II e DD e nos indivíduos homozigotos TT e MM. Aumentou significativamente o IM nos indivíduos II e DD e nos indivíduos TT e MM. No entanto, o grau de hipertrofia ventricular nos indivíduos TT foi significativamente maior que nos indivíduos MM(P=0,04). A hipertrofia ventricular não foi diferente entre os indivíduos II e DD.

Some RAS polymorphisms has been identified. Although the impact of them in phenotype expression is less well-known yet. In this study, we investigated the effects of long-term physical exercise on left ventricular mass and aerobic power in young healthy individuals homozygous for the D or I allele of the angiotensin-converting enzyme (ACE) polymorphism and M or T allele of the angiotensinogen polymorphism.Eighty three policemen completed the study. They were genotyped for the M235T gene angiotensinogen polymorphism and for the ACE gene insertion/deletion (I/D) polymorphism. They were submitted to Echocardiography and treadmill tests before and after 17 weeks of aerobic physical exercise.Exercise training significantly and similarly increased the VO2 peak in homozigotous II/DD group and in homozigotous group TT /MM. The physical training increased significantly LVMI in II and DD group and in groups TT and MM. However the myocardial hypertrophy of TT subjects were significantly greater increase than in MM subjects(P=0,04). The ventricular hypertrophy was not diferent between II and DD subjects.