Mutación G972R del gen IRS-1 en individuos chilenos con enfermedad coronaria y controles / G972R mutation of the IRS-1 gene in chilean individuals with coronary artery disease and controls

El sustrato 1 del receptor de la insulina (IRS-1) es una de las moléculas más importantes en la transducción de señales, que permiten la incorporación de glucosa a la célula. Variaciones genéticas del IRS-1 han sido relacionadas con alteraciones de su función y diversas anormalidades metabólicas. Considerando la escasa información sobre las bases genéticas de las enfermedades cardiovasculares en nuestro país, el objetivo del presente estudio fue determinar la asociación entre la mutación G972R del gen IRS-1 y enfermedad coronaria en individuos de la población de la IX Región (Chile). Estudios de casos y controles, que evaluó 111 individuos (33 a 74 años), con enfermedad coronaria comprobada por angiografía y 116 controles (20 a 68 años). La genotipificación de la mutación G972R fue realizada mediante la técnica de PCR-RFLP. La mutación G972R fue más frecuente en individuos con enfermedad coronaria que en controles (17 por ciento vs. 6 por ciento, p=0,016). La OR asociada a esta mutación fue 3,21 (I.C. 95 por ciento, 1,28 - 8,06, p<0.05). Adicionalmente, el genotipo heterocigoto GR para la mutación G972R fue asociado a niveles más bajos de HDL-C (p=0,048) y a mayores niveles de glucosa (p=0,006) en los individuos controles. La mutación G972R del gen IRS-1 fue asociada a enfermedad coronaria en la población analizada, lo que sugiere un importante rol de IRS-1 en la patogénesis de desordenes metabólicos asociados a EC.

Prevalencia de factores de riesgo de enfermedad cardiovascular en una población de empleados chilenos / Prevalence of cardiovascular risk factor among chilean employees

Cardiovascular diseases are the main causes of death in Chile and there is a high prevalence of cardiovascular risk factors in the population. Aim: To assess the prevalence of those risk factors in a group of employees. Subjects and methods: We studied 2,219 individuals, 1,378 males with a mean age of 46.2ñ10.4 years and 841 females with a median age of 41.9ñ10.3 years. Results: High blood pressure was observed in 39.7 percent of men and in 21.8 percent of women. A serum cholesterol between 200 and 239 mg/dl was observed in 38 percent of men and 31.3 percent of women. A cholesterol over this value was seen in 23.7 percent of men and 18.8 percent of women. A low proportion of those with high blood pressure, or elevated cholesterol, were under treatment. Prevalence of smoking was high in men and women: 43.5 and 48.9.2 percent, respectively. Eighty four percent of men and 61.3 percent of women over 54 years were overweight or obese. The prevalence of diabetes mellitus was 4.5 percent. Twenty percent of men and 13 percent of women exercised regularly, at least 3 times a week. Conclusions: There is a high prevalence of untreated cardiovascular risk factors in this population

Reducción de la mortalidad por infarto del miocardio en hospitales chilenos / Reduction of acute myocardial infarction mortality in Chilean hospitals

Background: The characteristics of patients with acute myocardial infarction (MI) admitted to 37 Chilean hospitals (GEMI Registry Group), have been analyzed in the periods 1993-1995 and 1997-1998. Aim: To report the changes in hospital mortality between these 2 periods, with a particular emphasis on the impact of treatment. Patients and methods: Between 1993-1995 we collected information from 2,957 patients and between 1997-1998 we registered 1,981 patients with MI. Analysis of the changes in mortality between periods was adjusted by demographic variables, coronary risk factors, MI location, Killip class on admission and the different therapeutic strategies utilized. The effects of different treatments on hospital mortality were adjusted by the previously determined mortality risk variables. Results: Hospital mortality decreased from 13.3 percent to 10.8 percent between both periods (Odds Ratio (OR) 0.78, confidence intervals (95 percent) (CI) 0.65-0.93). A significant reduction in mortality was observed among patients below 60 years of age, in men, in diabetics and in subjects with an infarction classified as Killip class over II. The use of beta blockers (OR 0.65, CI 0.42-0.99) and intravenous nitrates (OR 0.78, CI 0.61-0.99) and the lower use of calcium channel blockers (OR 0.72, CI 0.60-0.87) were significantly associated with a lower mortality. The administration of angiotensin converting enzyme inhibitors was associated with a 29.3 percent mortality reduction (OR 0.69, CI 0.47-1.02). Conclusions: There has been a significant reduction in the mortality rate for MI in Chilean hospitals during the 2 registry periods analyzed, which was significant among some high risk patients and was related to treatment changes, according to evidence based guidelines

Cambios en los patrones de prescripción de medicamentos en el infarto agudo del miocardio: comparación de dos períodos / Changes in pharmacotherapy for acute myocardial infarction: comparison of 2 periods

Background: Pharmacotherapy of Chilean patients with acute myocardial infarction has been recorded in 37 hospitals since 1993. Aim: to compare pharmacotherapy for acute myocardial infarction in the period 1993 to 1995 with the period 1997-1998. Patients and methods: Drug prescription during hospital stay was recorded in 2957 patients admitted to Chilean hospitals with an acute myocardial infarction in the period 1993-1995 and compared with that of 1981 subjects admitted in the period 1997-1998. Results: When compared with the former period, in the lapse 1997-1998 there was an increase in the frequency of prescription of aspirin (93 and 96.1 percent respectively) ß blockers (37 and 55.2 percent respectively) and angiotensin converting enzyme inhibitors (32 and 53 percent). The prescription of thrombolytic therapy did not change (33 and 33.7 percent respectively). There was a reduction in the prescription of calcium antagonists and antiarrhythmic drugs. Conclusions: During the period 1997-1998, the prescription of drugs with a potential to reduce the mortality of acute myocardial infarction, increased. The diffusion of guidelines for the management of this disease may have influenced this change

Infarto agudo del miocardio en hospitales chilenos: resultados finales del estudio GEMI / Acute myocardial infarction in chilean hospitals: results of the GEMI study

Background: Acute myocardial infarction is the leading cause of death in Chile. Aim: To report the main features, hospital evolution, complications and pharmacological treatment of patients admitted to Chilean hospitals with the diagnosis of acute myocardial infarction. Patients and methods: Between 1993 and 1995, the GEMI group registered 2,957 patients admitted to 37 hospitals with the diagnosis of acute myocardial infarction. Results: Mean age of patients was 62 ñ 2 years old and 74 percent were male. Forty six percent had a history of hypertension and 40 percent were smokers. During the first five days of admission, 93 percent of patients received aspirin, 59 percent received intravenous nitrates, 59 percent intravenous heparin, 56 percent oral nitrates, 37 percent beta blockers, 32 percent angiotensin-converting enzyme inhibitors, 33 percent thrombolytic agents, 29 percent antiarrhythmics and 23 percent calcium antagonists. Coronary angiograms were performed in 28 percent of patients, angioplasty in 9 percent and 8 percent were subjected to a coronary bypass. Global hospital mortality was 13.4 percent (19.5 percent in women and 11.1 percent in men, p <0.001). Conclusions: This work gives a picture of myocardial infarction in Chilean hospitals. Pharmacological treatment is similar to that used abroad, but certainly it can be optimized

Niveles de lípidos y de presión arterial en población mapuche de la Región de la Araucanía, en Chile / Blood pressure and serum lipid levels in Chilean aboriginal populations (Mapuche) living in the Chilean region of Araucania

Background: Chilean aboriginal populations (Mapuche) predominantly live in the region of Araucanía, in the southern part of the country. Their cardiovascular risk factors have not been systematically assessed. Aim: To study the prevalence of cardiovascular risk factors in the Mapuche population. Subjects and methods: Blood pressure, weight, height, dietary habits, fasting serum total cholesterol, HDL cholesterol and triglycerides were measured in 1.948 adults living in 28 Mapuche communities. Results: Thirteen percent of males and 16 percent of females had high blood pressure. Body mass index was 25.5 kg/m2 in males and 28.1 kg/m2 in females. Forty five percent of women and 24 percent of men were classified as obese. Mean serum total cholesterol was 186.7ñ9.6 mg/dl, HDL cholesterol was 58.7ñ30.7 mg/dl, total cholesterol/HDL cholesterol was 3.4ñ2 and triglycerides were 155.2ñ91.2 mg/dl. Twenty eight percent of males and 9.6 percent of females smoked. Conclusions: Mapuche individuals have higher levels of HDL cholesterol, a better total cholesterol/HDL cholesterol ratio and lower frequency of smoking than non aboriginal Chileans subjects

Comparación de digoxina y enalapril en insuficiencia cardíaca secundaria a insuficiencia mitral / Comparison of the effects of digoxin or enalapril in the treatment of heart failure due to mitral insufficiency

Background: There is not much evidence about the usefulness of digoxin or enalapril in the treatment of heart failure due to mitral insufficiency. Aim: to compare digoxin and enalapril in the treatmen of heart failure due to mitral insufficiency. Patients and methods: Patients with mitral insufficiency, in sinus rhythm, with a heart failure grade II or III and with echocardiographic left ventricular dilatation were eligible for the study. They received sequentially, during 12 weeks each, digoxin 0.25 mg/day or enalapril in doses up to 20 mg/day, with a washout in-between period of 2 weeks. The order of the sequence was determined randomly. At the start and end of treatment, functional class according to NYHA and maximal exercise tolerance in the treadmil were assessed and a color Doppler echocardiogram was done to measure ventricular dimensions, function and degree of mitral insufficiency. Results: Nine patients on enalapril and 12 on digoxin improved their functional capacity. Digoxin improved exercise time in 76ñ168 sec (p= 0.022), whereas this change was not significant with enalapril (38ñ158 sec; p= 0.2). With enalapril treatmen, ventricular diastolic dimensiondecreased from 59.3ñ8.1 to 58ñ9.3 mm and the area of mitral insufficiency decreased from 8.1ñ3.5 to 6.6ñ3.1 cm2. Digoxin did not induce any significant echocardiographic change. Conclusions: In these patients, digoxin and enalapril improved functional class. Digoxin improved exercise time and enalapril reduced ventricular dimensions and mitral insufficiency

Comparación de digoxina y atenolol en fibrilación auricular crónica / Comparison between digoxin and atenolol in chronic atrial fibrillation

The benefits of digoxin in patients with atrial fibrillation may be reduced due to its limited effect on atrioventricular conduction. The aim of this work was to compare digoxin and etanolol on functional class, resting and exercise heart rate and exercise capacity in patients with atrial fibrillation. Thirteen subjects with this condition, normal echocardiographic left ventricular function and size, a resting heart rate less than 80 beats/min and with no contraindication for beta blocker or digoxin use, were studied. Patients were randomly assigned to receive initially digoxin 0.25 mg. o.d. or atenolol 100 mg o.d. in a double blind fashion. The doses were sdjusted to obtain a heart rate between 60 and 80 beats-min at the end of the first week of treatment. After 2 weeks of treatment, outcomes were assessed, patients were left without treatment for one week and crossed over to the other drug after that. Resting heart rates achieved with digoxin and atenolol were similar (67ñ11 and 65ñ23 beats/min respectively). However, maximal exercise heart rates and maximal exercise time were higher during digoxin treatment (166ñ23 vs 135ñ27 beats/min and 9.95ñ1.68 vs 8.5ñ2 min respectively). NYHA functional class deteriorated in 3 patients receiving atenolol. We conclude that atenolol achieves a better control of heart rate during exercise but also reduces maximal exercise capacity