Prognostic value of cardiopulmonary exercise testing in children with heart failure secondary to idiopathic dilated cardiomyopathy in a non-beta-blocker therapy setting.

BACKGROUND: Peak oxygen consumption and resting left ventricular ejection fraction (LVEF) are independent predictors of survival in adult heart failure (HF) patients. AIM: To evaluate these factors in children. METHODS: We prospectively studied 31 children with NYHA class I to III HF (mean LVEF 26+/-10%; mean age 8.6+/-1.9 years). All had dilated cardiomyopathy and were awaiting heart transplantation. A cardiopulmonary treadmill exercise test was performed and LVEF determined by radionuclide ventriculography. RESULTS: During a median follow-up of 1282 days, 20 children reached at least one end-point (death or heart transplantation). Clinical data from the 11 children without events and the 20 children with events are as follows: NYHA class 1+/-0 vs. 2+/-0.9 (p<0.01); SBP 118+/-17 vs. 102+/-16 (p=0.01); DBP 70+/-10 vs. 61+/-10 (p=0.02); heart rate 165+/-22 vs. 148+/-22 (NS); double-product 19+/-4 vs. 15+/-4 (p=0.01); end-tidal carbon dioxide tension (PetCO2) 35+/-5 vs. 30+/-6 (NS); oxygen consumption (VO2) 22+/-5.4 vs. 18.3+/-5.7 (NS); exercise time 19+/-4 vs. 13+/-6 (p<0.003), and LVEF 31+/-8 vs. 22+/-10 (p=0.02). These variables all correlated with prognosis on univariate analysis. In multivariate analysis, only decreasing exercise time and LVEF were predictive of events during follow-up (p<0.001 and 0.04). CONCLUSION: These findings suggest that reduction in LVEF and exercise tolerance in children with heart failure is predictive of functional status.

Relationship of body fat distribution by waist circumference, dual-energy X-ray absorptiometry and ultrasonography to insulin resistance by homeostasis model assessment and lipid profile in obese and non-obese postmenopausal women.

OBJECTIVE: To correlate body fat distribution evaluated by waist circumference, dual-energy X-ray absorptiometry and ultrasonography to insulin resistance and lipid profile in obese and non-obese postmenopausal women. METHODS: We studied 40 obese and 47 non-obese postmenopausal women, assessing obesity by measuring waist circumference and fat tissue using dual-energy X-ray absorptiometry and ultrasonography, and examining their correlation with metabolic parameters: insulin resistance as determined by the homeostasis model assessment technique (HOMA-IR) and lipid profile including triglycerides (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), very-low-density lipoprotein, lipoprotein(a) (Lp(a)) and apoplipoprotein A-I (Apo A-I). RESULTS: There was no difference in lipid profile between the two groups. Insulin resistance was the metabolic disturbance of highest prevalence in the obese group, evaluated by HOMA-IR (obese: 3.38 +/- 2.2; non-obese: 1.20 +/- 0.7; p < 0.001). Obesity was not a confounding factor in linear regression analyses among HOMA-IR, HDL-C, TG, Lp(a), Apo A-I and the methods used to measure body fat distribution. Waist circumference was the method that best explained HOMA-IR (R(2) = 34.9%, p < 0.001) and TG concentration (R(2) = 10.9%, p = 0.002). HDL-C presented a positive association with subcutaneous fat evaluated by ultrasonography (R(2) = 12.5%, p < 0.001). Obesity was a confounding factor in multiple regression analyses between TC and LDL-C, when related to abdominal fat evaluated by ultrasonography, and resulted in a positive association among the obese and a negative association among the non-obese women. The sensibility of this method was related to the quantity of fat in the visceral region. CONCLUSIONS: Waist circumference showed the highest association with insulin resistance. Fat distribution evaluated by dual-energy X-ray absorptiometry and ultrasound was also associated with insulin resistance, but with lower intensity. The relationship of visceral fat distribution evaluated by ultrasound to TC cholesterol and LDL-C showed opposed results between obese and non-obese menopausal women.

Influência das variantes genéticas funcionais do sistema renina-angiotensina na doença arterial coronária / The influence of the functional gene variants of the renin angiotensin system in coronary artery disease

Um conjunto de evidências sugere que o sistema renina-angiotensina (SRA) está associado à modulação de vários processos envolvidos na gênese da aterosclerose. No presente estudo nós testamos a hipótese de que variantes funcionais do SRA podem influenciar a gravidade das lesões vasculares coronárias e de estar associadas a fatores de risco emergentes tais como obesidade e menopausa em portadores de doença arterial coronária.A great body of evidence suggests a link between the renin angiotensin system (RAS) and a variety of processes believed to play a role in the development of artherosclerosis. In the present study, we tested the hypothesis that functional gene variants of angiotensinogen and angiotensin converting enzyme(ACE)influence the degree of vascular lesion in patients with coronary artery disease(CAD)...

Interés, conocimientos, recursos y limitaciones de los estudiantes de medicina en la investigación científica / Interest, knowledge, resources and limitations of medical student in scientific research

Este artículo tiene como objetivo valorar la tendencia de los estudiantes de medicina de la Universidad Nacional Experimental "Francisco de Miranda" (Venezuela), hacia la investigación biomédica. Se diseño un estudio descriptivo longitudinal con una muestra aleatoria estratificada por cursos, en 113 alumnos de los últimos tres años de la carrera, se les aplicó una encuesta dividida en: interés, conocimientos, recursos físicos y humanos, y limitantes para realizar trabajos de investigación: 76,1 por ciento ha tenido la inquietud de investigar, paradójicamente 49,6 por ciento manifestó poca motivación; 29,2 por ciento ha presentado resultados en Congresos; ninguno ha publicado. Hay deficiencias en formulación de problemas, diseño de modelos experimentales y redacción científica. La inclinación de dos tercios de la población es favorable para investigar; ameritan capacitación paulatina desde el inicio de la carrera, con incentivos para docentes y alumnos, y así contribuir al estudio de la salud desde pregrado e intentar aumentar o mantener la producción científica actual