How predictive of SARS-CoV-2 infection are clinical characteristics at presentation among individuals with COVID-like symptoms treated at the Mexican Institute of Social Security.

BACKGROUND: The COVID-19 pandemic has progressed rapidly, with the emergence of new virus variants that pose challenges in treating infected individuals. In Mexico, four epidemic waves have been recorded with varying disease severity. To understand the heterogeneity in clinical presentation over time and the sensitivity and specificity of signs and symptoms in identifying COVID-19 cases, an analysis of the changes in the clinical presentation of the disease was conducted. AIM: To analyze the changes in the clinical presentation of COVID-19 among 3.38 million individuals tested for SARS-CoV-2 at the Mexican Social Security Institute (IMSS) from March 2020 to October 2021 and evaluate the predictivity of signs and symptoms in identifying COVID-19 cases. METHODS: A retrospective analysis of clinical presentation patterns of COVID-19 among individuals treated at IMSS was performed, contrasting the signs and symptoms among SARS-CoV-2-positive individuals with those who tested negative for the virus but had respiratory infection symptoms. The sensitivity and specificity of each sign and symptom in identifying SARS-CoV-2 infection were estimated. RESULTS: The set of signs and symptoms reported for COVID-19-suspected patients treated at IMSS were not highly specific for SARS-CoV-2 positivity. The signs and symptoms exhibited variability based on age and epidemic wave. The area under the receiver operating characteristic (ROC) curve was 0.62 when grouping the five main symptoms (headache, dyspnea, fever, arthralgia, and cough). Most of the individual symptoms had ROC values close to 0.5 (16 out of 22 between 0.48 and 0.52), indicating non-specificity. CONCLUSIONS: The results highlight the difficulty in making a clinical diagnosis of COVID-19 due to the lack of specificity of signs and symptoms. The variability of clinical presentation over time and among age groups highlights the need for further research to differentiate whether the changes are due to changes in the virus, who is becoming infected, or the population, particularly with respect to prior infection and vaccination status.

Changes in the epidemiological profile of SARS-CoV-2-positive individuals in Mexico across pandemic waves as an explanation of fatality reduction: a retrospective observational study.

OBJECTIVES: We aim to quantify shifts in hospitalisation and mortality and how those were related to the first three phases of the epidemic and individuals' demographics and health profile among those with a positive test for SARS-CoV-2 treated at the Mexican Social Security Institute's facilities from March 2020 to October 2021. DESIGN: Retrospective observational study using interrupted time series analysis to identify changes in hospitalisation rate and case fatality rate (CFR) by epidemic wave. SETTING: Data from the Mexican Institute of Social Security's (IMSS) Online Influenza Epidemiological Surveillance System (SINOLAVE) that include all individuals that sought care at IMSS facilities all over Mexico. PARTICIPANTS: All individuals included in the SINOLAVE with a positive PCR or rapid test for SARS-CoV-2. PRIMARY AND SECONDARY OUTCOME MEASURES: Monthly test positivity rates, hospitalisation rates, CFRs and prevalence of relevant comorbidities by age group. RESULTS: From March 2020 to October 2021, the CFR declined between 1% and 3.5%; the declines were significant for those 0-9, 20-29, 30-39, 40-49 and 70 and older. The decline was steep during the first wave and was less steep or was temporarily reversed at the beginning of the second and third waves (changes in the trend of about 0.3% and 3.8%, and between 0.7% and 3.8%, respectively, for some age groups), but then continued to the end of the analytical period. Prevalence of diabetes, hypertension and obesity among patients testing positive also declined-two for most age groups (reductions of up to 10 percentage points for diabetes, 12 percentage points for hypertension and 19 percentage points for obesity). CONCLUSION: Data suggest that the decrease in COVID-19 fatality rate is at least partially explained by a change in the profile of those contracting the disease, that is, a falling proportion of individuals with comorbidities across all age groups.

Evolution of differences in clinical presentation across epidemic waves among patients with COVID-like-symptoms who received care at the Mexican Social Security Institute.

Background: Timely monitoring of SARS-CoV-2 variants is crucial to effectively managing both prevention and treatment efforts. In this paper, we aim to describe demographic and clinical patterns of individuals with COVID-19-like symptoms during the first three epidemic waves in Mexico to identify changes in those patterns that may reflect differences determined by virus variants. Methods: We conducted a descriptive analysis of a large database containing records for all individuals who sought care at the Mexican Social Security Institute (IMSS) due to COVID-19-like symptoms from March 2020 to October 2021 (4.48 million records). We described the clinical and demographic profile of individuals tested (3.38 million, 32% with PCR and 68% with rapid test) by test result (positives and negatives) and untested, and among those tested, and the changes in those profiles across the first three epidemic waves. Results: Individuals with COVID-19-like symptoms were older in the first wave and younger in the third one (the mean age for those positive was 46.6 in the first wave and 36.1 in the third wave; for negatives and not-tested, the mean age was 41 and 38.5 in the first wave and 34.3 and 33.5 in the third wave). As the pandemic progressed, an increasing number of individuals sought care for suspected COVID-19. The positivity rate decreased over time but remained well over the recommended 5%. The pattern of presenting symptoms changed over time, with some of those symptoms decreasing over time (dyspnea 40.6 to 14.0%, cough 80.4 to 76.2%, fever 77.5 to 65.2%, headache 80.3 to 78.5%), and some increasing (odynophagia 48.7 to 58.5%, rhinorrhea 28.6 to 47.5%, anosmia 11.8 to 23.2%, dysgeusia 11.2 to 23.2%). Conclusion: During epidemic surges, the general consensus was that any individual presenting with respiratory symptoms was a suspected COVID-19 case. However, symptoms and signs are dynamic, with clinical patterns changing not only with the evolution of the virus but also with demographic changes in the affected population. A better understanding of these changing patterns is needed to improve preparedness for future surges and pandemics.

The Past, Present, and Future of Mexico's National Bioethics Commission.

The establishment of Mexico's National Bioethics Commission (Comisión Nacional de Bioética), in 1992, was conceived within the context of a global movement aimed at raising awareness of the ethical implications of technological and scientific development, especially in biomedicine. In 2005, a new decree put the commission under the scope of the Secretariat of Health and granted it technical and operational autonomy, allowing it to become a regulatory agency aimed at promoting a culture of bioethics, encouraging reflection on human health, and developing guidelines for health care, research, and education, through a global, secular, and democratic perspective. The commission became the leading actor in the strategy for institutionalizing bioethics in Mexico after reforms to the country's General Health Act in 2011, which required that public, social assistance, or private health care facilities establish a hospital bioethics committee to address bioethical dilemmas or issues and, when relevant, a research ethics committee to address research with human subjects. This assignment has shifted the focus of the activities and goals of the National Bioethics Commission toward establishing these committees in line with current regulations and developing mechanisms to ensure that they operate with the highest standards of ethical conduct, performance, and accountability.

[Improvement of child survival in Mexico: the diagonal approach]. / Aumento de la sobrevida en menores de cinco años en México: la estrategia diagonal.

Public health interventions aimed at children in Mexico have placed the country among the seven countries on track to achieve the goal of child mortality reduction by 2015. We analysed census data, mortality registries, the nominal registry of children, national nutrition surveys, and explored temporal association and biological plausibility to explain the reduction of child, infant, and neonatal mortality rates. During the past 25 years, child mortality rates declined from 64 to 23 per 1000 livebirths. A dramatic decline in diarrhoea mortality rates was recorded. Polio, diphtheria, and measles were eliminated. Nutritional status of children improved significantly for wasting, stunting, and underweight. A selection of highly cost-effective interventions bridging clinics and homes, what we called the diagonal approach, were central to this progress. Although a causal link to the reduction of child mortality was not possible to establish, we saw evidence of temporal association and biological plausibility to the high level of coverage of public health interventions, as well as significant association to the investments in women education, social protection, water, and sanitation. Leadership and continuity of public health policies, along with investments on institutions and human resources strengthening, were also among the reasons for these achievements.

Aumento de la sobrevida en menores de cinco años en México: la estrategia diagonal / Improvement of child survival in Mexico: the diagonal approach

Las intervenciones en salud pública dirigidas a niños en México han ubicado a este país entre los siete países encaminados a cumplir las metas de reducción de la mortalidad infantil para 2015. La información para este estudio se ha tomado de diferentes fuentes: los censos poblacionales; los registros de mortalidad de la Secretaría de Salud y del Instituto Nacional de Estadística, Geografía e Informática; el registro nominal de niños recolectado por el Programa de Vacunación Universal; y las encuestas nacionales de nutrición. Con estos datos se estudió la asociación temporal y la plausibilidad biológica de las diferentes intervenciones en salud pública, para explicar la reducción de las tasas de mortalidad entre niños, infantes y recién nacidos. Las tasas de mortalidad en menores de cinco años han descendido de casi 64 muertes a menos de 23 por cada 1 000 niños nacidos vivos registrados en los últimos 25 años. Se observó una reducción drástica en las tasas de mortalidad por diarrea, junto con la eliminación de polio, difteria y sarampión. El estado nutricional de los niños mejoró de manera significativa en cuanto a bajo peso para la talla, baja talla para la edad y bajo peso para la edad. En los últimos 25 años, se mantuvieron intervenciones altamente costo-efectivas que acercaron los servicios de salud de atención primaria a los hogares, lo que aquí se ha llamado estrategia diagonal. A pesar de que no es posible establecer una relación de causalidad entre la reducción de la mortalidad en menores de cinco años y los factores investigados, se presenta evidencia basada en la asociación temporal y en la plausibilidad biológica que indica que la alta cobertura de las intervenciones de salud pública, los avances en educación de las mujeres, protección social, disponibilidad de agua potable y saneamiento, así como nutrición, impactaron en el resultado observado. Por otro lado, el liderazgo y la continuidad de las políticas de salud pública junto...

Public health interventions aimed at children in Mexico have placed the country among the seven countries on track to achieve the goal of child mortality reduction by 2015. We analysed census data, mortality registries, the nominal registry of children, national nutrition surveys, and explored temporal association and biological plausibility to explain the reduction of child, infant, and neonatal mortality rates. During the past 25 years, child mortality rates declined from 64 to 23 per 1000 livebirths. A dramatic decline in diarrhoea mortality rates was recorded. Polio, diphtheria, and measles were eliminated. Nutritional status of children improved significantly for wasting, stunting, and underweight. A selection of highly cost-effective interventions bridging clinics and homes, what we called the diagonal approach, were central to this progress. Although a causal link to the reduction of child mortality was not possible to establish, we saw evidence of temporal association and biological plausibility to the high level of coverage of public health interventions, as well as significant association to the investments in women education, social protection, water, and sanitation. Leadership and continuity of public health policies, along with investments on institutions and human resources strengthening, were also among the reasons for these achievements.

Improvement of child survival in Mexico: the diagonal approach.

Public health interventions aimed at children in Mexico have placed the country among the seven countries on track to achieve the goal of child mortality reduction by 2015. We analysed census data, mortality registries, the nominal registry of children, national nutrition surveys, and explored temporal association and biological plausibility to explain the reduction of child, infant, and neonatal mortality rates. During the past 25 years, child mortality rates declined from 64 to 23 per 1000 livebirths. A dramatic decline in diarrhoea mortality rates was recorded. Polio, diphtheria, and measles were eliminated. Nutritional status of children improved significantly for wasting, stunting, and underweight. A selection of highly cost-effective interventions bridging clinics and homes, what we called the diagonal approach, were central to this progress. Although a causal link to the reduction of child mortality was not possible to establish, we saw evidence of temporal association and biological plausibility to the high level of coverage of public health interventions, as well as significant association to the investments in women education, social protection, water, and sanitation. Leadership and continuity of public health policies, along with investments on institutions and human resources strengthening, were also among the reasons for these achievements.

Design and validation of a population-based definition of the metabolic syndrome.

OBJECTIVE: The National Cholesterol Education Program (NCEP) definition of the metabolic syndrome was modified to be described as a continuous variable and adapted to the characteristics of a Hispanic population. RESEARCH DESIGN AND METHODS: Age/sex population percentiles for every component of the NCEP criteria were included in this approach using population-based data from a Mexican nationwide survey (2,158 subjects). One point was given per decile for every component. The total number of points accumulated was used to classify subjects. The predictive power for incident diabetes was evaluated using the 7-year follow-up results of the Mexico City Diabetes Study. RESULTS: Our population-based method had a significantly better prognostic power compared with the original and the updated NCEP definitions (area under the receiver operating characteristic curve 0.746 vs. 0.697 and 0.723, respectively, P < 0.05). Using individuals with /=39 points) (12.71 [95% CI 5.67-28.49]) compared with that calculated for the original (9.52 [4.69-19.31]) and the updated (11.14 [5.33-23.30]) NCEP criteria. The major advantage of our approach is the detection of subjects at the extremes of the range of diabetes risk and the ability to estimate this risk as a continuum. CONCLUSIONS: Our method adapts the NCEP criteria to the characteristics of a Hispanic population. It improves the predictive power of the NCEP criteria for future diabetes.

[Gender violence prevalence in female users of health services in Mexico]. / Prevalencia de diferentes tipos de violencia en usuarias del sector salud en México.

OBJECTIVE: To identify the prevalence of violence against females among those who are health service beneficiaries in Mexico. MATERIAL AND METHODS: The National Survey on Violence against Women (ENVIM, per its Spanish abbreviation) was applied in 2003 to female users of public primary and secondary health care services. The sampling framework was based on a stratified, probabilistic sample in two stages. First the health care units were selected with probability proportional to the number of physicians' offices in the unit, from a list of possible care units. Second, women 15 years and older who sought care at the health care unit were selected for participation in the study through systematic sampling. Univariate analysis and then bivariate analysis were carried out on the data collected with a questionnaire. RESULTS: The sample included 26 042 women between 15 and 92 years of age, with a mean age of 35.8 years. Physical violence during childhood was reported by 42% of the women. Only 7.8% answered yes to a general question about whether they experienced domestic partner violence, but 21.5% reported experiencing violence of any type during the last 12 months as measured by a scale including specific acts of psychological, economic, physical and sexual violence. The most frequently reported type of violence was psychological (19.6%). Of the women who had been pregnant, 14.1% reported having experienced violence during pregnancy, and 4.4% reported being hit in the abdomen. The prevalence of sexual violence was 17.3% and close to half reported being victims of this type of violence before age 15. Higher prevalence of violence was found among women with lower levels of formal education, living in a rented home, in areas with higher overcrowding indices, and users of Ministry of Health care services. CONCLUSIONS: Identifying and measuring violence is complex, given the diverse types of violence and how they are perceived and therefore reported by women themselves. This is an important public health problem, in view of the high frequency observed in this study and the immediate implications. These findings indicate the urgent need for interventions to prevent and treat violence.

[Methodological design for the National Survey Violence Against Women in Mexico]. / Diseño metodológico de la Encuesta Nacional sobre Violencia contra las Mujeres en México.

OBJECTIVE: To describe the methodology, the research designs used, the estimation and sample selection, variable definitions, collection instruments, and operative design and analytical procedures for the National Survey Violence Against Women in Mexico. MATERIAL AND METHODS: A complex (two-step) cross-sectional study was designed and the qualitative design was carried out using in-depth interviews and participant observation in health care units. RESULTS: We obtained for the quantitative study a total of 26 240 interviews in women users of health services and 2 636 questionnaires for health workers; the survey is representative of the 32 Mexican states. For the qualitative study 26 in-depth interviews were conducted with female users and 60 interviews with health workers in the States of Quintana Roo, Coahuila and the Federal District.

Obesity among children residing in Mexico City and its impact on lung function: a comparison with Mexican-Americans.

BACKGROUND: The objective of the study was to describe the prevalence of obesity among Mexican children and its impact on ventilatory lung function. METHODS: We studied cross-sectionally 6784 students between 8 and 20 years of age attending schools located <2 km away from ten air pollution monitors located throughout metropolitan Mexico City. The comparison group was made up of 1924 Mexican-Americans of the same age, studied during the NHANES-III examination, which included information on spirometry and body mass index (BMI). RESULTS: Of all our subjects, 9.7% had a BMI >95(th) percentile of CDC growth charts (compared to 15.1% in Mexican-Americans) and 6.6% fulfilled the obesity criteria of the International Obesity Task Force (vs. 12.2%). Obesity was related to male gender, asthma and passive smoking. At the same height and gender, lung function was higher in Mexicans than in Mexican-Americans, perhaps due to altitude. In children 8-11 years of age, lung function increased in heavier subjects but, in older children and youths, function reached a plateau and decreased among children with highest BMI (inverted U pattern, seen in adults). CONCLUSIONS: Obesity is higher in Mexican-American children and youths than in Mexicans. Spirometric function is affected adversely by obesity, especially in young people.

Prevalencia de diferentes tipos de violencia en usuarias del sector salud en México / Gender violence prevalence in female users of health services in Mexico

OBJETIVO: Identificar la prevalencia de la violencia contra las mujeres en usuarias del sector salud en México. MATERIAL Y MÉTODOS: En 2003 se levantó la Encuesta Nacional sobre Violencia contra las Mujeres 2003 (ENVIM 2003) en usuarias de los servicios médicos de primer y segundo nivel. El esquema de muestreo se basó en una muestra probabilística estratificada en dos etapas: a) de un listado de unidades médicas elegibles, se seleccionaron aquellas con probabilidad proporcional al número de consultorios de la unidad; b) mediante muestreo sistemático se seleccionó a mujeres de 15 años y más que acudieron a la unidad médica. Se realizó un análisis univariado y posteriormente uno bivariado. RESULTADOS: Participaron 26 042 mujeres de 15 a 92 años de edad. La media de edad fue de 35.8 años. La violencia física durante la niñez, notificada, fue de 42.2 por ciento. Sólo 7.8 por ciento de las mujeres respondieron afirmativamente a la pregunta general de violencia de pareja. Sin embargo, al aplicar la escala de violencia, la prevalencia de cualquier tipo de violencia en los últimos 12 meses fue de 21.5 por ciento. El tipo de violencia más frecuente fue la psicológica (19.6 por ciento). De las mujeres que tuvieron antecedente de embarazo, 14.1 por ciento señalaron violencia y 4.4 por ciento refirieron haber sido golpeadas en el abdomen. La prevalencia de violencia sexual fue de 17.3 por ciento y cerca de la mitad de este porcentaje la padecieron antes de los 15 años de edad. La violencia se presenta en mayor prevalencia en las usuarias de la SSA, entre las de menor escolaridad, entre aquellas que no viven en casa propia y entre las que viven en mayor hacinamiento. CONCLUSIONES: La identificación y la medición de la violencia constituyen un fenómeno complejo en consideración a los diversos tipos de violencia que existen y a la manera en que las mujeres mismas la perciben y la notifican. La violencia es un problema importante de salud, tanto por la alta prevalencia como por sus consecuencias inmediatas y acumulativas sobre la salud. Los resultados indican la necesidad urgente de prevenir y atender este problema.

OBJECTIVE: To identify the prevalence of violence against females among those who are health service beneficiaries in Mexico. MATERIAL AND METHODS: The National Survey on Violence against Women (ENVIM, per its Spanish abbreviation) was applied in 2003 to female users of public primary and secondary health care services. The sampling framework was based on a stratified, probabilistic sample in two stages. First the health care units were selected with probability proportional to the number of physicians' offices in the unit, from a list of possible care units. Second, women 15 years and older who sought care at the health care unit were selected for participation in the study through systematic sampling. Univariate analysis and then bivariate analysis were carried out on the data collected with a questionnaire. RESULTS: The sample included 26 042 women between 15 and 92 years of age, with a mean age of 35.8 years. Physical violence during childhood was reported by 42 percent of the women. Only 7.8 percent answered yes to a general question about whether they experienced domestic partner violence, but 21.5 percent reported experiencing violence of any type during the last 12 months as measured by a scale including specific acts of psychological, economic, physical and sexual violence. The most frequently reported type of violence was psychological (19.6 percent). Of the women who had been pregnant, 14.1 percent reported having experienced violence during pregnancy, and 4.4 percent reported being hit in the abdomen. The prevalence of sexual violence was 17.3 percent and close to half reported being victims of this type of violence before age 15. Higher prevalence of violence was found among women with lower levels of formal education, living in a rented home, in areas with higher overcrowding indices, and users of Ministry of Health care services. CONCLUSIONS: Identifying and measuring violence is complex, given the diverse types of violence and how they are perceived and therefore reported by women themselves. This is an important public health problem, in view of the high frequency observed in this study and the immediate implications. These findings indicate the urgent need for interventions to prevent and treat violence.

Diseño metodológico de la Encuesta Nacional sobre Violencia contra las Mujeres en México / Methodological Design for the National Survey Violence Against Women in Mexico

OBJETIVO: Describir la metodología utilizada en la Encuesta Nacional sobre Violencia contra las Mujeres 2003 (ENVIM 2003) en México, junto con el diseño de investigación, la estimación y la selección de muestras, la definición de variables, los instrumentos de recolección, el diseño operativo para su instrumentación y los procedimientos de análisis. MATERIAL Y MÉTODOS: En la parte cuantitativa se recurrió a un diseño transversal en dos etapas. En el componente cualitativo se realizaron entrevistas en profundidad y observación participante en unidades médicas. RESULTADOS: Se obtuvo un total de 26 240 entrevistas, aplicadas a usuarias de los servicios de salud; y 2 636 cuestionarios correspondientes a proveedores, que abarcaron los 32 estados de la República. En el estudio cualitativo se llevó a cabo un total de 26 entrevistas de profundidad a usuarias y 60 entrevistas de profundidad a prestadores de servicios de salud en los estados de Quintana Roo, Coahuila y el Distrito Federal.

OBJECTIVE: To describe the methodology, the research designs used, the estimation and sample selection, variable definitions, collection instruments, and operative design and analytical procedures for the National Survey Violence Against Women in Mexico. MATERIAL AND METHODS: A complex (two-step) cross-sectional study was designed and the qualitative design was carried out using in-depth interviews and participant observation in health care units. RESULTS: We obtained for the quantitative study a total of 26 240 interviews in women users of health services and 2 636 questionnaires for health workers; the survey is representative of the 32 Mexican states. For the qualitative study 26 in-depth interviews were conducted with female users and 60 interviews with health workers in the States of Quintana Roo, Coahuila and the Federal District.

Applicability of the National Cholesterol Education Program III (NCEP-III) guidelines for treatment of dyslipidemia in a non-Caucasian population: a Mexican nation-wide survey.

We assessed the impact of the NCEP-III recommendations in a population-based, nation-wide Mexican survey. Information was obtained from 15,607 subjects aged 20 to 69 years. In this report, only samples obtained after a 9 to 12 hours fast are included (2,201 cases). A cardiovascular risk equivalent was found in 10.5% and > or = 2 risk factors were present in 41.7% of the population. In 10% of cases, the LDL-C concentration was high enough to be an indication for a lipid-lowering drug (> 160 mg/dL), independent of the presence of risk factors. A quarter of the population was eligible for some form of treatment (lifestyle modifications in 15.9%, drug therapy in an additional 11.7%). Among cases with > or = 2 risk factors, a small percentage (1.8%) were identified as having a 10 year-risk > 20% and 86.3% were considered as having a 10 year-risk < 10%. The majority of the metabolic syndrome cases (84%) were identified as low-risk subjects. As a result, only 17.6% of them qualified for drug-based LDL-C lowering. Our data helps to estimate of the magnitude of the burden imposed on the Mexican health system, of lowering LDL-C for cardiovascular prevention. If we apply our results to the 2,000 Mexican population census more than 5.8 million cases nationwide may require LDL lowering drug therapy following the NCEP-III criteria.

Epidemiology of type 2 diabetes in Mexico.

The epidemiology of diabetes in Mexico is reviewed. In less than four decades, diabetes has become the main health problem in Mexico. It is the principal cause of death in women and the second among men since the year 2000. It is the primary cause of premature retirement, blindness, and kidney failure. By the year 2025, close to 11.7 million Mexicans are expected to be diagnosed with diabetes. In the year 2000, diabetes was the 11th most frequent cause of hospitalization but the second most common cause of hospital mortality. The number of cases reported in children has also increased since 1995. The results of population-based, nationwide surveys have detected a 25% increment over a 7-year period. Fourteen percent of people with diabetes are <40 years of age, and a large proportion of patients have other conditions that determine the appearance of macrovascular complications and kidney failure. In addition, many cases do not reach treatment goals. In conclusion, the growing number of cases and the significant health burden imposed on affected subjects makes diabetes a disease that needs to be prevented. Well-planned strategies are urgently needed to modify the lifestyle of the population and to increase their physical activity. In addition, an enormous effort will be required to educate the population and physicians to improve the diagnosis and treatment of patients with diabetes.

The metabolic syndrome: a concept hard to define.

The metabolic syndrome integrates, in a single diagnosis, the manifestations of insulin resistance that may lead to increased cardiovascular morbidity and precedes type 2 diabetes. Here we discuss the strengths and limitations of the definitions of the metabolic syndrome and the epidemiology of the syndrome including information from non-Caucasian populations. The definitions proposed by the World Health Organization (WHO) and the National Cholesterol Education Program (NCEP) are the most frequently used. The relative risk of having long-term complications is greater for the WHO definition; this is explained by the inclusion of the insulin resistance criteria. The cut-off points used in these definitions should be, but are not, adjusted for ethnicity; as a result, in non-Caucasian subjects, there is lack of agreement among these criteria. In a Mexican population-based survey the prevalence was 13.61% using the WHO definition and 26.6% using the NCEP-III criteria. Cases identified by the WHO criteria had a more severe form of the disease. We propose that the metabolic syndrome should be viewed as a progressive long-term process that leads to major complications. Its definition should reflect the continuous nature of the disease; the categorical approach of the current criteria oversimplifies the complexity of the syndrome. The threshold for defining abnormality should be based on the associated risk of the identified phenotype. Refinement of the definition of both affected and nonaffected subjects is required. The available definitions include, in each of these categories, heterogeneous groups with a broad range of risk of future complications.

Applicability of the National Cholesterol Education Program III (NCEP-III) Guidelines for treatment of dyslipidemia in a non-Caucasian population: A Mexican Nation-Wide Survey / Aplicabilidad del III Programa Nacional de Educación en Colesterol (NCEP-III). Guías para el tratamiento de la dislipidemia en una población no caucásica: Un estudio en toda la nación mexicana

We assessed the impact of the NCEP-III recommendations in a population-based, nation-wide Mexican survey. Information was obtained from 15,607 subjects aged 20 to 69 years. In this report, only samples obtained after a 9 to 12 hours fast are included (2,201 cases). A cardiovascular risk equivalent was found in 10.5% and > 2 risk factors were present in 41.7% of the population. In 10% of cases, the LDL-C concentration was high enough to be an indication for a lipid-lowering drug (> 160 mg/dL), independent of the presence of risk factors. A quarter of the population was eligible for some form of treatment (lifestyle modifications in 15.9%, drug therapy in an additional 11.7%). Among cases with > 2 risk factors, a small percentage (1.8%) were identified as having a 10 year-risk > 20% and 86.3% were considered as having alO year-risk < 10%. The majority of the metabolic syndrome cases (84%) were identified as low-risk subjects. As a result, only 17.6% of them qualified for drug-based LDL-C lowering. Our data helps to estimate of the magnitude of the burden imposed on the Mexican health system, of lowering LDL-C for cardiovascular prevention. If we apply our results to the 2,000 Mexican population census more than 5.8 million cases nationwide may require LDL lowering drug therapy following the NCEP-III criteria.

Evaluamos el impacto de las recomendaciones del Programa Nacional de Educación en Colesterol (NCEP-III) en muestra poblacíonal. La información proviene de 2,201 sujetos de 20 a 69 años cuyas muestras se obtuvieron después de un ayuno de 9 a 12 horas. Una condición con riesgo cardiovascular equivalente al de la cardiopatía isquémica se encontró en 10.5%; > 2 factores de riesgo se encontraron en 41.7%. El colesterol LDL (LDL-C) fue suficientemente alto (> 160 mg/dL) para indicarse tratamiento hipolipemiante con medicamentos, en ausencia de otros factores de riesgo en 10% de los participantes. El 25% de la población calificó para recibir tratamiento hipolipemiante (cambios del estilo de vida 15.9% y tratamiento farmacológico en 11.7%). En casos con > 2 factores de riesgo, un pequeño porcentaje (1.8%) fue identificado con riesgo mayor a > 20% de tener un evento cardiovascular a 10 años; 86.3% fue identificado con bajo riesgo (< 10% a 10 años). La mayoría de los casos con síndrome metabólíco (84%) fueron identificados en el grupo de bajo riesgo. Como resultado, sólo 17.6% de ellos calificó para disminuir su LDL-C con medicamentos. Nuestros datos demuestran el reto que representa la prevención de complicaciones cardiovasculares por medio de la reducción de la concentración del LDL-C. Extrapolando nuestros datos al censo 2000, más de 5.8 millones de mexicanos califican para recibir tratamiento farmacológico de acuerdo con los criterios del NCEP-III.

Management of the metabolic syndrome as a strategy for preventing the macrovascular complications of type 2 diabetes: controversial issues.

The metabolic syndrome is known to increase cardiovascular morbidity and precede the development of type 2 diabetes. Even before the appearance of hyperglycemia, the components of the metabolic syndrome play a crucial role in the pathogenesis of the macrovascular complications. Thus, the recognition and treatment of the metabolic syndrome may be a strategy to prevent the most likely cause of death (i.e. cardiovascular events) in cases that eventually develop type 2 diabetes. In this review, controversial issues regarding the treatment of the two main components of the metabolic syndrome (i.e dyslipidemia and arterial hypertension) are discussed. Several disparities in the current NCEP-ATPIII recommendations, when applied to patients with the metabolic syndrome, are pointed out. In population-based studies, the number of individuals with the metabolic syndrome who would need LDL cholesterol lowering treatment following these guidelines is remarkably low compared to subjects belonging to the same risk strata (10 year risk 10-20%). Subjects with the metabolic syndrome do not fall into the same risk category, resulting in differing LDL-C targets. Also, the Framingham tables underestimate the cardiovascular risk associated with the metabolic syndrome; hence fewer cases qualify for drug therapy. In addition, LDL-C underestimates the number of atherogenic particles and is therefore not the ideal target for these patients. The selection of antihypertensive medication in the metabolic syndrome is also controversial. Thus, there is sufficient evidence for a review of the current management of the metabolic syndrome as part of a strategy to prevent the macrovascular complications in type 2 diabetes.

Nutrition transition in Mexico and in other Latin American countries.

Mexico and other Latin American countries are currently undergoing important demographic, epidemiologic and nutrition transitions. Noncommunicable chronic diseases such as obesity, type 2 diabetes mellitus, and high blood pressure are becoming public health problems as the population experiences an important reduction in physical activity and an increase in energy-dense diets. In contrast, the prevalence of undernutrition is declining in most countries, although several decades will be needed before the prevalence drops to acceptable values. The objective of this article is to discuss the characteristics of the nutrition transition with emphasis in data from Mexico, Brazil, and Chile.