BACKGROUND: This is an update of a Cochrane review that was first published in 2011 of the effects of reducing dietary salt intake, through advice to reduce salt intake or low-sodium salt substitution, on mortality and cardiovascular events.OBJECTIVES: 1. To assess the long-term effects of advice and salt substitution, aimed at reducing dietary salt, on mortality and cardiovascular morbidity. 2. To investigate whether a reduction in blood pressure is an explanatory factor in the effect of such dietary interventions on mortality and cardiovascular outcomes.METHODS:Search methods: We updated the searches of CENTRAL (2013, Issue 4), MEDLINE (OVID, 1946 to April week 3 2013), EMBASE (OVID, 1947 to 30 April 2013) and CINAHL (EBSCO, inception to 1 April 2013) and last ran these on 1 May 2013. We also checked the references of included studies and reviews. We applied no language restrictions. Selection criteria: Trials fulfilled the following criteria: (1) randomised, with follow-up of at least six months, (2) the intervention was reduced dietary salt (through advice to reduce salt intake or low-sodium salt substitution), (3) participants were adults and (4) mortality or cardiovascular morbidity data were available. Two review authors independently assessed whether studies met these criteria. Data collection and analysis: A single author extracted data and assessed study validity, and a second author checked this. We contacted trial authors where possible to obtain missing information. We extracted events and calculated risk ratios (RRs) and 95% confidence intervals (CIs).MAIN RESULTS: Eight studies met the inclusion criteria: three in normotensives (n = 3518) and five in hypertensives or mixed populations of normo- and hypertensives (n = 3766). End of trial follow-up ranged from six to 36 months and the longest observational follow-up (after trial end) was 12.7 years. The risk ratios (RR) for all-cause mortality in normotensives were imprecise and showed no evidence of reduction (end of trial RR 0.67, 95% confidence interval (CI) 0.40 to 1.12, 60 deaths; longest follow-up RR 0.90, 95% CI 0.58 to 1.40, 79 deaths n = 3518) or in hypertensives (end of trial RR 1.00, 95% CI 0.86 to 1.15, 565 deaths; longest follow-up RR 0.99, 95% CI 0.87 to 1.14, 674 deaths n = 3085). There was weak evidence of benefit for cardiovascular mortality (hypertensives: end of trial RR 0.67, 95% CI 0.45 to 1.01, 106 events n = 2656) and for cardiovascular events (hypertensives: end of trial RR 0.76, 95% CI 0.57 to 1.01, 194 events, four studies, n = 3397; normotensives: at longest follow-up RR 0.71, 95% CI 0.42 to 1.20, 200 events; hypertensives: RR 0.77, 95% CI 0.57 to 1.02, 192 events; pooled analysis of six trials RR 0.77, 95% CI 0.63 to 0.95, n = 5912). These findings were driven by one trial among retirement home residents that reduced salt intake in the kitchens of the homes, thereby not requiring individual behaviour change. Advice to reduce salt showed small reductions in systolic blood pressure (mean difference (MD) -1.15 mmHg, 95% CI -2.32 to 0.02 n = 2079) and diastolic blood pressure (MD -0.80 mmHg, 95% CI -1.37 to -0.23 n = 2079) in normotensives and greater reductions in systolic blood pressure in hypertensives (MD -4.14 mmHg, 95% CI -5.84 to -2.43 n = 675), but no difference in diastolic blood pressure (MD -3.74 mmHg, 95% CI -8.41 to 0.93 n = 675). Overall many of the trials failed to report sufficient detail to assess their potential risk of bias. Health-related quality of life was assessed in one trial in normotensives, which reported significant improvements in well-being but no data were presented.AUTHORS' CONCLUSIONS: Despite collating more event data than previous systematic reviews of randomised controlled trials, there is insufficient power to confirm clinically important effects of dietary advice and salt substitution on cardiovascular mortality in normotensive or hypertensive populations. Our estimates of the clinical benefits from advice to reduce dietary salt are imprecise, but are larger than would be predicted from the small blood pressure reductions achieved. Further well-powered studies would be needed to obtain more precise estimates. Our findings do not support individual dietary advice as a means of restricting salt intake. It is possible that alternative strategies that do not require individual behaviour change may be effective and merit further trials.

OBJETIVE: To estimate prevalence of type 2 diabetes (diabetes) and impaired fasting glucose (IFG) in the border region between the United States of America and Mexico, by ethnic origin and country of residence; identify risk factors associated with both conditions; and explore the extent to which these factors account for cross-border or ethnic disparities in prevalence. METHODS: From April 2001 to November 2002, Phase I of the U.S.-Mexico Border Diabetes Prevention and Control Project, a prevalence study of diabetes and its risk factors, was conducted at the U.S.-Mexico border using multistage cluster sampling. A questionnaire was administered on diabetes (self-reported) and lifestyle and a physical examination and blood sample were obtained. A total of 4 027 adults participated in the study: 2 120 Hispanics from the Mexican side of the border and 1 437 Hispanics and 470 non-Hispanics (of whom 385 were classified as "white") from the U.S. side of the border. RESULTS: The age-adjusted prevalence of self-reported and unrecognized diabetes in Hispanics was 15.4% (16.6% on the Mexican side of the border and 14.7% on the U.S. side). The age-adjusted prevalence of IFG was similar on both sides of the border (14.1% on the Mexican side and 13.6% on the U.S. side). CONCLUSIONS: Established risk factors for diabetes (e.g., age, obesity, and family history) were relevant and there was an inverse relationship between diabetes and education and socioeconomic level. While diabetes prevalence is high on both sides of the U.S.-Mexico border, one-fourth of the cases remain undiagnosed, suggesting a need for development and implementation of a public health program for prevention, diagnosis, and control of diabetes in the region.

OBJETIVO: Calcular la prevalencia de la diabetes de tipo 2 (diabetes) y de la alteración de la glucosa en ayunas en la zona fronteriza entre México y los Estados Unidos, por origen étnico y país de residencia; identificar los factores de riesgo asociados a ambas afecciones, y explorar en qué grado estos factores explican las diferencias transfronterizas o étnicas en la prevalencia. MÉTODOS: Entre abril del 2001 y noviembre del 2002, se realizó la fase I del Proyecto de Prevención y Control de la Diabetes en la Frontera México-Estados Unidos, un estudio de prevalencia de la diabetes y sus factores de riesgo, mediante un muestreo por conglomerados en varias fases. Se utilizó un cuestionario acerca de la diabetes (autonotificada) y el modo de vida, se realizó una exploración física y se extrajo una muestra de sangre. En total, participaron 4 027 adultos en el estudio: 2 120 hispanos del lado mexicano de la frontera, y 1 437 y 470 no hispanos (de los cuales, 385 se clasificaron como "blancos") del lado estadounidense de la frontera. RESULTADOS: La prevalencia (ajustada según la edad) de la diabetes autonotificada y no diagnosticada en los hispanos fue de 15,4% (16,6% en el lado mexicano de la frontera y 14,7% en el lado estadounidense). La prevalencia (ajustada según la edad) de la alteración de la glucosa en ayunas fue similar en ambos lados de la frontera (14,1% en el lado mexicano y 13,6% en el lado estadounidense). CONCLUSIONES: Los factores de riesgo conocidos para la diabetes (por ejemplo edad, obesidad y antecedentes familiares) resultaron relevantes y hubo una relación inversa entre la diabetes y el nivel socioeconómico y la escolaridad. Si bien la prevalencia de la diabetes es alta en ambos lados de la frontera entre México y los Estados Unidos, un cuarto de los casos sigue sin diagnóstico, lo que indica la necesidad de crear y ejecutar un programa de salud pública para la prevención, el diagnóstico y el control de la diabetes en la zona.

OBJECTIVE: To determine the extent of secondary prevention of coronary heart disease (CHD) and cerebrovascular disease (CVD) in low- and middle-income countries. METHODS: A descriptive cross-sectional survey of a sample of 10 000 CHD (85.2%) and CVD (14.8%) patients (6252 men; 3748 women) was conducted over 6 months in geographically defined areas. The mean age was 59.2 years (standard deviation (SD), 10.8). Consecutive patients were recruited from a stratified random sample of primary, secondary and tertiary care facilities in defined areas in 10 countries (Brazil, Egypt, India, Indonesia, Islamic Republic of Iran, Pakistan, Russian Federation, Sri Lanka, Tunisia and Turkey). The main outcome measures were levels of lifestyle and physiological risk factors, and the use of drugs for secondary prevention of CHD and CVD. FINDINGS: Approximately 82%, 89% and 77% of patients were aware of the cardiovascular benefits of quitting smoking, a heart-healthy diet and regular physical activity, respectively. About half (52.5%) engaged in less than 30 minutes of physical activity per day, 35% did not follow a heart-healthy diet and 12.5 % were current tobacco users. Blood pressure had been measured in 93.8% (range 71-100%), blood cholesterol in 85.5% (range 29-97%) and blood sugar in 75.5% (range 65-99%) in the preceding 12 months. The proportions who had received medications among CHD and CVD patients were: aspirin, 81.2%, 70.6%; beta-blockers, 48.1%, 22.8%; angiotensin-converting enzyme inhibitor, 39.8%, 37.8%; statins, 29.8%, 14.1%, respectively. About one-fifth of patients with CHD had undergone revascularization. CONCLUSION: A significant proportion of patients did not receive appropriate medications. About 47% of patients had at least two or more modifiable risk factors (smoking, physical inactivity, hypertension, diabetes or hypercholesterolaemia). There are considerable missed opportunities for prevention of recurrences in those with established CVD in low- and middle-income countries.

OBJETIVO: Determinar el grado de prevención secundaria de la cardiopatía coronaria (CC) y las enfermedades cerebrovasculares (ECV) en los países de ingresos bajos y medios. MÉTODOS: A lo largo de 6 meses se llevó a cabo un estudio transversal descriptivo de una muestra de 10 000 casos de CC (85,2%) y de ECV (14,8%) (6252 hombres; 3748 mujeres) en varias zonas geográficas delimitadas. La media de edad era de 59,2 años (desviación estándar: 10,8). Se seleccionó a pacientes consecutivos en una muestra aleatoria estratificada de establecimientos de atención primaria, secundaria y terciaria de zonas concretas de 10 países (Brasil, Egipto, India, Indonesia, República Islámica del Irán, Pakistán, Federación de Rusia, Sri Lanka, Túnez y Turquía). Las principales medidas de resultado fueron los niveles de diversos factores de riesgo fisiológicos o relacionados con el modo de vida, y el uso de medicamentos de prevención secundaria de la CC y la ECV. RESULTADOS: Aproximadamente el 82%, el 89% y el 77% de los pacientes conocían los beneficios cardiovasculares que conllevan dejar de fumar, una dieta cardiosaludable y la actividad física regular, respectivamente. Alrededor de la mitad (52,5%) hacían menos de 30 minutos de actividad física al día, el 35% no seguía una dieta cardiosaludable, y el 12,5% eran fumadores habituales en el momento del estudio. La tensión arterial había sido determinada en un 93,8% de los casos (intervalo: 71%-100%), el colesterol sanguíneo en un 85,5% (intervalo: 29%-97%) y la glucemia en un 75,5% (intervalo 65%-99%) durante los 12 meses precedentes. El porcentaje de pacientes que habían recibido medicamentos entre quienes habían sufrido CC y ECV fueron los siguientes: aspirina, 81,2% y 70,6%; betabloqueantes, 48,1% y 22,8%; inhibidores de la enzima conversora de la angiotensina, 39,8% y 37,8%; y estatinas, 29,8% y 14,1%, respectivamente. Alrededor de una quinta parte de los pacientes con CC habían sido sometidos a revascularización. CONCLUSIÓN: Una proporción considerable de los pacientes no recibía la medicación adecuada. Alrededor del 47% de los enfermos presentaban dos o más factores de riesgo modificables (tabaquismo, inactividad física, hipertensión, diabetes o hipercolesterolemia). Se están desaprovechando muchas oportunidades para prevenir las recidivas en las personas que han sufrido un accidente cerebrovascular en los países de ingresos bajos y medios.

OBJECTIF: Déterminer l'ampleur de la prévention secondaire des cardiopathies coronariennes et des accidents vasculaires cérébraux (AVC) dans les pays à revenus faibles et moyens. MÉTHODES: Une étude descriptive transversale d'un échantillon comprenant 10 000 cas d'AVC (85,2 %) et de cardiopathies coronariennes (14,8 %) et composé de 6252 hommes et 3748 femmes a été menée sur 6 mois dans des zones définies géographiquement. L'âge moyen des malades était de 59,2 ans (écart type : 10,8). Les malades ont été successivement recrutés à partir d'un échantillon stratifié d'installations de soins de santé primaires, secondaires et tertiaires, situées dans des zones définies de 10 pays (Brésil, Égypte, Inde, Indonésie, République Islamique d'Iran, Pakistan, Fédération de Russie, Sri Lanka, Tunisie et Turquie). Les principaux critères d'évaluation utilisés étaient le mode de vie, les facteurs de risque physiologiques et l'utilisation de médicaments pour la prévention secondaire des cardiopathies coronariennes et des AVC. RÉSULTATS: Environ 82 %, 89 % et 77 % respectivement des malades étaient conscients des bénéfices sur le plan cardiovasculaire d'un arrêt du tabac, d'un régime alimentaire sain pour le cœur et d'une activité physique régulière. Environ la moitié (52,5 %) avaient pratiqué moins de 30 min d'activité physique par jour, 35 % n'avaient pas suivi de régime sain pour le cœur et 12,5 % étaient encore consommateurs de tabac. Au cours des 12 mois précédents, on avait mesuré la tension artérielle chez 93,8 % en moyenne (71 à 100 % des sujets), le taux de cholestérol sanguin chez 85,5 % en moyenne (29 à 97 %) des sujets et le taux de sucre dans le sang chez 75,5 % en moyenne (65 à 99 %) d'entre eux. Parmi les personnes ayant souffert d'un AVC ou d'une cardiopathie coronarienne, 81,2 et 70,6 % respectivement avaient reçu de l'aspirine, 48,1 et 22,8 % respectivement, des bêtabloquants, 39,8 et 37,8 % respectivement, de l'inhibiteur de l'enzyme de conversion et 29,8 et 14,1 % respectivement, des statines. Environ un cinquième des personnes victimes d'un AVC avaient subi une revascularisation. CONCLUSION: Une proportion importante des malades n'avait pas reçu de médication appropriée. Environ 47 % d'entre eux présentaient au moins deux facteurs de risque ou plus modifiables (tabagisme, inactivité physique, hypertension, diabète ou hypercholestérolémie). Dans les pays à revenus faibles et moyens, les possibilités non exploitées de prévenir les récidives chez les personnes ayant subi un AVC sont donc considérables.