Smoking and obesity in Chile’s Third National Health Survey: light and shade

[ABSTRACT]. The Chilean Ministry of Health recently disclosed the first results of the 2016–2017 National Health Survey (Encuesta Nacional de Salud, ENS). The survey was cross-sectional and used a multistage stratified random sampling strategy resulting in a final sample of 6 233 persons ≥ 15 years old, with national, regional, and urban/rural representativeness. The survey results show consistent reductions in tobacco consumption compared to previous national health surveys (ENS 2003 and ENS 2009–2010), most likely due to stringent tobacco control policies enacted in the last 10 years. However, the results also show that there were alarming increases in obesity in the last 15 years. Stronger regulatory policies may be needed to curb the obesity epidemic that besets Chile, along the lines of what was done with tobacco use. The lesson learned seems to be that pushing for stronger policy measures leads to good results, as seems to be the case for tobacco use, while weak measures may not be sufficient for the scale of the health epidemics Chile is now facing, such as excess weight.

[RESUMEN]. El Ministerio de Salud chileno divulgó recientemente los primeros resultados de la Encuesta Nacional de Salud 2016–2017 (ENS). Se trataba de una encuesta transversal, en la cual se usó una estrategia de muestreo polietápico aleatorio y estratificado, cuyo resultado fue una muestra final de 6 233 personas ≥ 15 años, con representatividad nacional, regional y urbana o rural. Los resultados de la encuesta muestran reducciones constantes en el consumo de tabaco en comparación con encuestas nacionales de salud anteriores (la ENS 2003 y la ENS 2009–2010), muy probablemente debido a las políticas estrictas de control del tabaco sancionadas en los últimos 10 años. Sin embargo, los resultados también indican que la obesidad aumentó de forma alarmante en los últimos 15 años. Es posible que se necesiten políticas regulatorias más firmes para reducir la epidemia de obesidad que se registra en Chile, de manera similar a lo que se hizo con el consumo de tabaco. Pareciera que la enseñanza extraída es que impulsar medidas políticas más firmes conduce a buenos resultados, como parece ser el caso del consumo de tabaco, mientras que las medidas débiles pueden ser insuficientes para la escala de las epidemias en el ámbito de la salud a las que Chile se enfrenta ahora, como el sobrepeso.

[RESUMO]. O Ministério da Saúde do Chile divulgou recentemente as conclusões preliminares da Pesquisa Nacional de Saúde (PNS) 2016–2017. Foi conduzida uma pesquisa de delineamento transversal com uma estratégia de amostragem aleatória estratificada com múltiplos estágios, resultando em uma amostra final de 6.233 indivíduos com 15 anos de idade ou acima de representatividade nacional, regional e urbana/rural. Os resultados de pesquisa demonstram uma redução constante do tabagismo em relação às pesquisas nacionais anteriores (PNS 2003 e PNS 2009–2010), provavelmente decorrente das políticas de controle rigoroso do tabagismo promulgadas na última década. Porém, os resultados também indicam um aumento alarmante da obesidade nos 15 últimos anos. Políticas de regulamentação mais rigorosas devem ser necessárias para conter a epidemia de obesidade que assola o país, na mesma linha do que foi feito com o tabagismo. O ensinamento a ser tirado parece ser o seguinte: a pressão para que sejam adotadas políticas mais duras leva a bons resultados, como no caso do tabagismo, e medidas brandas não são suficientes diante da magnitude das epidemias em saúde enfrentadas atualmente pelo país, como o excesso de peso.

Smoking and obesity in Chile's Third National Health Survey: light and shade / El tabaquismo y la obesidad en la tercera Encuesta Nacional de Salud de Chile: luces y sombras / Tabagismo e obesidade na Terceira Pesquisa Nacional de Saúde do Chile: luzes e sombras

ABSTRACT The Chilean Ministry of Health recently disclosed the first results of the 2016-2017 National Health Survey (Encuesta Nacional de Salud, ENS). The survey was cross-sectional and used a multistage stratified random sampling strategy resulting in a final sample of 6 233 persons ≥ 15 years old, with national, regional, and urban/rural representativeness. The survey results show consistent reductions in tobacco consumption compared to previous national health surveys (ENS 2003 and ENS 2009-2010), most likely due to stringent tobacco control policies enacted in the last 10 years. However, the results also show that there were alarming increases in obesity in the last 15 years. Stronger regulatory policies may be needed to curb the obesity epidemic that besets Chile, along the lines of what was done with tobacco use. The lesson learned seems to be that pushing for stronger policy measures leads to good results, as seems to be the case for tobacco use, while weak measures may not be sufficient for the scale of the health epidemics Chile is now facing, such as excess weight.

RESUMEN El Ministerio de Salud chileno divulgó recientemente los primeros resultados de la Encuesta Nacional de Salud 2016-2017 (ENS). Se trataba de una encuesta transversal, en la cual se usó una estrategia de muestreo polietápico aleatorio y estratificado, cuyo resultado fue una muestra final de 6 233 personas ≥ 15 años, con representatividad nacional, regional y urbana o rural. Los resultados de la encuesta muestran reducciones constantes en el consumo de tabaco en comparación con encuestas nacionales de salud anteriores (la ENS 2003 y la ENS 2009-2010), muy probablemente debido a las políticas estrictas de control del tabaco sancionadas en los últimos 10 años. Sin embargo, los resultados también indican que la obesidad aumentó de forma alarmante en los últimos 15 años. Es posible que se necesiten políticas regulatorias más firmes para reducir la epidemia de obesidad que se registra en Chile, de manera similar a lo que se hizo con el consumo de tabaco. Pareciera que la enseñanza extraída es que impulsar medidas políticas más firmes conduce a buenos resultados, como parece ser el caso del consumo de tabaco, mientras que las medidas débiles pueden ser insuficientes para la escala de las epidemias en el ámbito de la salud a las que Chile se enfrenta ahora, como el sobrepeso.

RESUMO O Ministério da Saúde do Chile divulgou recentemente as conclusões preliminares da Pesquisa Nacional de Saúde (PNS) 2016-2017. Foi conduzida uma pesquisa de delineamento transversal com uma estratégia de amostragem aleatória estratificada com múltiplos estágios, resultando em uma amostra final de 6.233 indivíduos com 15 anos de idade ou acima de representatividade nacional, regional e urbana/rural. Os resultados de pesquisa demonstram uma redução constante do tabagismo em relação às pesquisas nacionais anteriores (PNS 2003 e PNS 2009-2010), provavelmente decorrente das políticas de controle rigoroso do tabagismo promulgadas na última década. Porém, os resultados também indicam um aumento alarmante da obesidade nos 15 últimos anos. Políticas de regulamentação mais rigorosas devem ser necessárias para conter a epidemia de obesidade que assola o país, na mesma linha do que foi feito com o tabagismo. O ensinamento a ser tirado parece ser o seguinte: a pressão para que sejam adotadas políticas mais duras leva a bons resultados, como no caso do tabagismo, e medidas brandas não são suficientes diante da magnitude das epidemias em saúde enfrentadas atualmente pelo país, como o excesso de peso.

Efectividad y seguridad del tratamiento anticoagulante con acenocumarol en fibrilación auricular no valvular / Effectiveness and safety of oral anticoagulation treatment with acenocoumarol in non-valvular atrial fibrillation

Background: Vitamin K antagonists significantly decrease the incidence of stroke but increase the risk of bleeding. Aim: To assess the effectiveness and risk of bleeding of vitamin K antagonists in non-valvular atrial fibrillation. Material and Methods: Retrospective cohort study of 524 patients, 236 women (45%) and 288 men (55%) with non-valvular atrial fibrillation (NVAF) admitted to the oral anticoagulation treatment (OAT) clinic at four public hospitals, between 2009 and 2012. They were followed until March 2013, measuring the quality of OAT, ischemic and bleeding events. Results: The mean follow-up was 26.1 months, with 1,154.7 person-years of follow-up accrued. The percentage of time in therapeutic range (TTR) was 35.2 ± 18%; this was deemed to represent the quality of OAT. The cumulative incidence of ischemic events, either stroke or systemic embolism, was 2.25/100 person-years, being greater in patients with previous embolism (Risk ratio 5.21, 95% confidence intervals 2.31- 11.73, p < 0.01). The cumulative incidence of major bleeding events-extracranial and intracraneal-was 4.08/100 person-years. The main site of extracranial major bleeding was the gastrointestinal tract (32%). Conclusions: In our clinical practice, the effectiveness of OAT with acenocoumarol in NVAF patients is similar to that published abroad. However, the incidence of bleeding complications is higher. The quality of the OAT measured by the TTR was lower than abroad.

Características basales, manejo de terapias antitrombóticas y pronóstico de pacientes chilenos con FA no valvular. Lecciones del Registro GARFIELD AF en Chile / Features, management and prognosis of Chilean patients with non valvular atrial fibrillation: GARFIELD AF registry

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with high rates of death, ischemic stroke and systemic embolism (SE). There is scarce information about clinical characteristics and use of anti-thrombotic therapies in Chilean patients with non-valvular AF. Aim: To describe the characteristics and 1-year outcomes of patients with recently diagnosed AF recruited in Chile into the prospective global GARFIELD-AF registry. Material and Methods: Between 2011-2016, we prospectively registered information of 971 patients recruited at 15 centers, 85% of them from the public system and 15% from the private sector. Demographics, clinical characteristics and use of antithrombotic therapies were recorded for all patients. Adverse clinical outcomes were analyzed in 711 patients with 1-year follow-up. Results: The mean age was 71.5 years (66-79), 50% were men. Mean CHAD2S2 Vasc and HAS BLED scores for stroke risk were 3.3 (2.0-4.0) and 1.5 (1.0-2.0) respectively. Oral anticoagulants were prescribed in 82% of patients. Seventy percent received Vitamin K antagonists, 10% novel direct anticoagulants or antiplatelet therapy and only 8% did not receive any antithrombotic therapy. Mean time in optimal therapeutic range (an international normalized ratio of 2 to 3), was achieved in only 40.7% (23.0-54.8) of patients receiving Vitamin K antagonists. One year rates of death, stroke/systemic embolism and bleeding were 4.75 (3.36-6.71), 2.40 (1.47-3.92) and 1.64% (0.91-2.97) per 100 person-years. Ischemic stroke occurred in 1.8% and hemorrhagic stroke in 0.8% of patients at 1-year of follow up. Conclusions: Although the use of vitamin K antagonists at baseline was high, the mean time in optimal therapeutic range was low. Mortality and stroke rates are higher than those reported in other contemporary registries.

Evolución del riesgo cardiovascular y sus factores en Temuco entre 1989 y 2011-12 / Cardiovascular risk factors among males in 1989 and 2011-12 in a southern Chilean city

Background: A successful cardiovascular prevention program should induce a reduction of risk factors along time. Aim: To assess changes in cardiovascular risk factors among males aged between 35 and 65 years living in Southern Chile. Material and Methods: The results of two cross sectional household surveys, with a probability sampling stratified by socioeconomic status, were analyzed. Two hundred males were evaluated in 1989 and 800 in 2011-12, paired by age for selection. Results: In the second survey, a mean weight increase of 4.5 kg was recorded. Body mass index increased from 27.1 to 28.6 kg/m² (p < 0.01), especially in men younger than 45 years old. No changes in smoking prevalence were observed. The prevalence of hypertension and hypertensive patients in treatment increased from 32.7 to 38.1% and from 17 to 33%, respectively. The number of treated hypertensive patients with a well-controlled blood pressure did not change significantly. In 1989 and 2011-12, mean total cholesterol values were 192 and 201 mg/dl respectively (p < 0.01). The figures for mean non-HDL cholesterol were 152 and 160 mg/dl (p = 0.03). The frequency of people with total cholesterol over 240 mg/dl or using statins increased from 15 to 25% (p < 0.01). The estimated 10 years risk of myocardial infarction and coronary death using Framingham tables was 9,0 in both periods (p = 0.95). Conclusions: In a 22 years period an increase in the prevalence of obesity and elevated total cholesterol was observed. There was a higher proportion of individuals treated for hypertension and dyslipidemia, but without reduction in the estimated cardiovascular risk.

Prevención secundaria post infarto agudo de miocardio en hospitales públicos: implementación y resultados de las garantías GES / Universal health coverage and accomplishment of secondary prevention goals among patients with acute myocardial infarction

Background: In 2005, acute myocardial infarction (AMI) was included in a universal health plan (GES) to reduce inequity in care and optimize its diagnosis and treatment. Aim: To evaluate the effect of GES in risk factor control and therapeutic management among patients with AMI. Material and Methods: A survey was conducted in 2008-2009 in six public hospitals. Patients were identified from a hospital based registry of AMI and evaluated one year later with laboratory tests and an interview. Results: The registry enrolled 534 patients with ST and non ST segment elevation myocardial infarction. Of these, 416 patients aged 63 ± 12 years (25% women) were evaluated one year later. Eighty three percent were evaluated by a cardiologist and 37% by a general practitioner. Twenty two percent were evaluated by a nurse and 22% by a nutritionist. At the moment of the interview, 9% smoked, 78% were overweight or obese, 24% performed moderate or vigorous physical activity ≥ 150 min/week, 60% had systolic pressure > 130 mmHg and 63% a diastolic pressure > 80 mmHg. In 30%, LDL cholesterol was > 100 mg/dl and in 43%, triglycerides were > 150 mm/dl. Twenty two percent were diabetic and among them, 52% had a glycosilated hemoglobin > 7%. Forty five percent of non-diabetic patients had a fasting glucose > 100 mg/dl. Ninety three percent were in treatment with aspirin, 86% with statins, 66% with b-blockers, and 73% with angiotensin converting enzyme inhibitors or angiotensin receptor blockers and 20% with clopidogrel. Conclusions: Despite the high proportion of patients in treatment with evidence-based therapy, many do not achieve the targets for risk factor control with the new health care model.

Incidencia e importancia pronóstica del deterioro de la función renal en pacientes hospitalizados con insuficiencia cardiaca / Deterioration of kidney function as a risk factor for mortality among patients hospitalized for heart failure

Background: Acute deterioration of kidney function among patients admitted to the hospital for cardiac failure is associated with an increased mortality. Aim: To investigate the association between deterioration of kidney function and mortality among patients hospitalized for cardiac failure. Material and Methods: Patients admitted for decompensated cardiac failure to 14 Chilean hospitals between 2002 and 2009 were incorporated to the study. Clinical and laboratory features were registered. Serum creatinine values on admission and discharge were determined. Hospital and long term mortality was determined requesting death certificates to the National Identification Service at the end of follow up, lasting 635 ± 581 days. Results: One thousand sixty four patients were incorporated and 1100, aged 68 ± 13 years (45% females) had information about renal function. Seventy seven percent were hypertensive and 36% were diabetic. Mean ejection fraction was 41 ± 18% and 34% had an ejection fraction over 50%. Mean admission creatinine was 1.7 ± 1.6 mg/dl and 19% had a creatinine over 2 mg/dl. Serum creatinine increased more than 0.5 mg/dl during hospitalization in 9% of general patients and in 11% of diabetics. The increase in creatinine was associated with a higher risk of hospital mortality (odds ratio (OR) 12.9, 95% confidence intervals (CI) 6.7-27.6) and long term mortality (OR 2.1, 95% CI 1.6-3). Conclusions: The deterioration of renal function during hospitalization of patients with heart failure is a risk factor for hospital and long term mortality.

Nivel de actividad física medida a través del cuestionario internacional de actividad física en población Chilena / Levels of physical activity in an urban population from Temuco, Chile

Background: Physical activity plays a crucial role in the protection against cardiovascular diseases. Aim: To assess the level of physical activity in a group of subjects living in urban Temuco. Material and Methods: Cross sectional study in a random sample of 1091 women aged 52 ± 10 years and 444 men aged 54 ± 10 years , living in Temuco, Chile. The level of physical activity was measured using the long form of the International Physical Activity Questionnaire (IPAQ). Age, gender, educational and socioeconomic level were also determined in study subjects. Results: Median energy expenditure was 2150 and 1600 MET-minute/ week in men and women, respectively (p = 0,001). It decreased with age from a median of 1965 MET-minute/ week in those younger than 50 years old to 1647 MET-minute/ week among subjects aged between 51 and 60 years old and to 1485 MET-minute/ week among those older than 60 years. (p = 0,001). The frequency of high, moderate and low physical activity levels were 15.6, 66 and 18.4 percent respectively. These levels were associated with gender, age, educational and socioeconomic level. Conclusions: There was a high frequency of low and moderate levels of physical activity in the urban population of Temuco, associated with female gender, advanced age and middle socioeconomic level.

Influencia de factores socioculturales en la evolución alejada de pacientes con insuficiencia cardíaca / Influence of social and cultural factors in the late course of patients with congestive heart failure

Objetivo: Evaluar el impacto de los factores socioculturales (SC) en Las características del cuidado de la insuficiencia cardiaca (IC) y la evolución post alta en pacientes admitidos con diagnostico de IC descompensada a hospitales del registro ICARO en el periodo 2006-2008.Método: Registro prospectivo de 14 hospitales. Se incorporaron en forma consecutiva pacientes admitidos con el diagnostico de IC descompensada entre enero 2006 y mayo 2008. La mortalidad al fin del seguimiento se determino por la base de datos del Servicio Nacional del Registro Civil e Identificación. Se definió como terapia optima la combinación de en betabloqueador con cualquiera de los siguientes: inhibidores de la enzima convertidora de angiotensina (IECA), antagonistas del receptor de angiotensina Il (ARAlI), hidralazina/isosorbide o espironolactona. Las características de los pacientes se compararon mediante t de Student o chi cuadrado según correspondía. La sobrevida se evaluó mediante Kaplan-Meier.Resultados: Los pacientes de bajo nivel SC son do mayor edad (71 +/- 11 v/s 66 +/-15 años respectivamente, p<0.01). predomina el género femenino (52.2 por ciento v/s 26.1 por ciento, p<0,01), y su previsión fue mayoritariamente FONASA (90 por ciento). La etiología isquémica fue más frecuente en el estrato SC alto (34,5 vs. 16,6 por ciento) y la hipertensiva en el nivel SC bajo (30,3 v/s 16,6 por ciento). La utilización de ARA II fue más frecuente en el nivel SC alto con una tendencia a menor utilización de IECA, el uso de betabloqueadores espironolactona hidralazina e isosorbide amiodarona y anticoagulante fue menor en el estrato SC bajo.

Aim: to evaluate de impact of social and cultural (S-C) factors in the care and course of patients with congestive heart failure (CHF) enrolled in the ICARO study (national registry for patients with head failure). Methods: Patients were enrolled from 2006 through 2008. They were discharged from 14 hospitals participating in the prospectively designed ICARO study. Late mortality was obtained from the national Identification registry. Optimal medical therapy was defined as the use of a betablocker in addition to any of the following ACE inhibitors, ARA II. combination of hydralazine and nitrates, or spironolactone. Statistical analysis included Students t tesl. chi square and Kaplan Meir and Log-rank testing, as appropriate. Results: Patients with a low S-C level were older (71 +/- 11 vs 66 +/- IS years. p<0.01). more frequently females (52.2 percent vs 26.1 percent, p<0.01) and most of them belonged in the FONASA health insurance system (90 percent). Ischemic heart disease was more prevalent in the high S-C level (34.5 vs 16.6 percent) and hypertension in the low S-C level (30.3 vs 16.6 percent). ARA II rather than ACE inhibitors were more commonly used in the high S-C level: A CE inhibitors, betablockers, spironolactone, hydralazine-nitrates, amiodarone and anticoagulatioo were less frequently used in the low S-C level. After discharge a more intensive treatment of heart failure was observed; however, this was less seen in the low S-C level. Patients with decreased left ventricular ejection fraction were similarly treated in both groups. An optimal therapy for CHF was used in 43.7 percent, 43.3 percent and 51.1 percent in S-C levels low, intermediate and high, respectively (NS). Independent predictors for late mortality were age>70 years (HR 2.71 (CI 1.55-3.03), low S-C level (HR 1.57, CII. 17- 2.09), EF<50 percent (HR 1.49, CI 1.04-2.14) and absence of optimal medical therapy at discharge (HR 0.52, CI 0.41-0.66).

Riesgo individual y poblacional en infarto agudo del miocardio: Estudio INTERHEART Chile / Individual and population risk in acute myocardial infarction: The Chilean INTERHEART study

Acute myocardial infarction (AMI) is the first cause of death in Chile. Aim To assess the magnitude of risk of individuals and population associated with AMI risk factors. Material and methods: Case control study with incident cases and 2 controls paired by age and gender. History of diabetes, hypertension, smoking, stress, depression, diet, weight, height, hip and waist circumference, apolipoprotein (Apo) Al and B were determined. Odds ratio (OR) and population attributable risk (PAR) were calculated with 95 percent confidence interval. Results: Three hundred thirty two cases and 672 controls were included. Mean age was 61.6±12 years and 22 percent were women. The higher individual risk was associated with smoking: OR 3.1 (2.3-4.2), hypertension: 2.9 (2.1-3.9), permanent stress: 2.2 (1,3-2,8), increased apoB/ApoAl ratio: 2.1 (1.4-3.0) and diabetes: 2.0 (1.4-2.9). A protective effect of daily consumption of vegetables and/or fruits with and OR of 0.54 (0.4-0.8), was observed. The highest PAR was due to smoking: 42 percent (33.2-51.4), increased ApoB/ApoAl ratio: 35.2 (19.0-55.8) and hypertension: 32 percent (24.5-40.8). These three factors explained 71.3 percent of the AMI risk in Chile. A moderate effect on PAR was observed for abdominal obesity: 16.6 percent (2.4-61.2), permanent stress: 12.0 percent (2.3-44.1) and diabetes: 10.8 percent (6.1-18.3). Conclusions: Known risk factors ¡ike dyslipidemia, smoking and hypertension explain most of the AMI cases in Chile. The control of these risk factors should have a major effect on morbidity and mortality due to coronary artery disease in our country.

Mortalidad intrahospitalaria en hombres y mujeres según terapias de reperfusión en infarto agudo del miocardio con supradesnivel del ST / ln-hospital mortality after ST-segment elevation myocardial infarction according to reperiusion therapy

Primary angioplasty is considered the best reperiusion therapy in the treatment of ST-segment elevation myocardial infarction (STEMI). However, thrombolysis is the reperiusion method most commonly used, due to its wide availability, reduced costs and ease of administration. Aim: To compare inhospital mortality in STEMI patients according to reperiusion therapy. Material and Methods: Patients admitted to Chilean hospitals participating in the GEMI network, from 2001 to 2005, with STEMI were included. They were divided in three groups: a) treated with thrombolytics, b) treated with primary angioplasty, c) without reperiusion procedure. Inhospital mortality according to gender, was analized in each group, using a logistic regression method, to assess risk factors associated with mortality. Results: We included 3,255 patients. Global mortality was 9.9 percent (7.5 percent in men and 16.7 percent in women, p <0.001). Mortality in patients treated with thrombolytics, was 10.2 percent (7.6 percent in men and 18.7 percent in women, p <0.01). The figure for patients treated with primary angioplasty, was 4.7 percent (2.5 percent in men and 13 percent in women, p <0.01), and in patients without reperiusion, was 11.6 percent (9.8 percent in men and in 15.4 percent women, p <0.01). In each group women were older, had a higher prevalence of hypertension and a higher percentage of Killip 3-4 infarctions. Logistic regression showed that angioplasty, compared with no reperiusion, was associated with a reduced mortality only in men. The use oí thrombolytics in women was associated with a higher mortality. Conclusions: Primary angioplasty was the reperiusion therapy associated to the lower mortality in STEMI. Use of thrombolytics in women was associated with a higher mortality rate than in non reperfused women.

Evaluación del impacto de la variante genética C677T de la enzima metilentetrahidrofolato reductasa en el pronóstico de trombosis venosa profunda / Impact of the C677T genetic variant of metilentetrahydrofolate reductase on the prognosis of deep venous thrombosis

Introducción: Diversos estudios han relacionado diferentes factores trombofílicos al desarrollo de trombosis venosa profunda (TVP). Entre las alteraciones adquiridas y hereditarias asociadas a trombofilias destacan las relacionadas al metabolismo de la homocisteína. Sin embargo, los resultados observados son contradictorios e influenciados por diversos factores, entre ellos la etnia. Objetivo: Considerando la escasa información sobre las bases genéticas de la TVP en Chile, el objetivo del presente estudio fue investigar la posible asociación entre la mutación C677T del gen de la metilentetrahidrofolato reductasa (MTHFR) y TVP en individuos de nuestra región. Métodos: Fueron evaluados 60 pacientes con TVP (17 a 87 años) y 120 controles (21 a 81 años), de ambos sexos, todos provenientes a la IX Región de La Araucanía. La presencia de TVP fue confirmada mediante ecografía Doppler. La genotipificación de la mutación C677T fue realizada mediante la técnica de PCR-RFLP. Resultados: El genotipo homocigoto TT para la mutación C677T del gen MTHFR fue más frecuente en los individuos con TVP (28 por ciento vs. 15 por ciento, p=0.047). Similarmente, el alelo mutado 677T fue también más frecuente en los pacientes con TVP (0.53 vs. 0.39, p=0.018). La Odss ratio (OR) asociada a la variante 677T confirma la interacción encontrada(OR= 2.0, IC 95 por ciento 1.06 – 3.79, p<0.05). Conclusión: Los datos sugieren que la mutación C677T del gen MTHFR contribuye para el desarrollo de TVP en la población analizada. Sin embargo, hasta que más antecedentes sean reunidos, nosotros no recomendamos incluir la genotipificación de esta mutación en el screening de rutina de trombofilias.

Background: Several studies relate the presence of diverse thrombophilic factors to the development of deep venous thrombosis (DVT). Alteration of homocisteine metabolism has been associated to hereditary and acquired forms of thrombophilia. However, several factors may modify this relationship, among them the subject's ethnic origin. Aim: To investigate a possible association of the C677T mutation of metilentetrahydrofolate reductase (MTHFR) to DVT. Methods: Sixty patients with DVT, aged 17 to 87 years, and 120 control subjects (21 to 81 years old), males and females, all residents of the Araucania region were evaluated. DVT was confirmed by duplex ultrasonography. PCR-RFLP was used to determine de presence of the C677T mutation Results: The homozygous TT genotype for C677T was more frequent in DVT subjects (28 percent) as compared to controls (15 percent, p=0.047). The mutated alelle of C677T was also more frequent in the DVT group (53 percent vs 39 percent, p=0.018). The OR for DVT associated to C677T was 2.0 (95 percent CI 1.06 – 3.79, p<0.05) Conclusion: The data suggest that the C677T mutation of MTHFR is associated to DVT. However, more information is needed before making a recommendation for use of gene characterization of this mutation in screening for thrombophilia.