Early identification of peripheral neuropathy based on sudomotor dysfunction in Mexican patients with type 2 diabetes.

BACKGROUND: Type 2 Diabetes in Mexico has a high prevalence, 16-87% of patients may experience peripheral neuropathy. Early detection can prevent or halt its progression. The performance of Sudoscan in detecting neuropathy was compared to the Michigan Neuropathy Screening Instrument (MNSI). The aim was to identificate small fibers neuropathy. METHODS: Patients type 2 diabetes received both MNSI and sudomotor function assessment through measurement of electrochemical skin conductance (ESC) in the hands and feet. RESULTS: Two hundred twenty-one patients with neuropathy according to MNSI B had lower hands and feet ESC, regardless of diabetes duration. Among the 170 patients who had had diabetes for at least 5 years, 76 of them with normal MNSI B had abnormal hands or feet ESC; this was also the case in 28 out of 51 patients with diabetes than 5 or more years. In contrast, only 5 patients in the first group and 1 in the second group had abnormal MNSI B with normal ESC. Using MNSI B as a reference, abnormal hands or feet ESC (< 60 µS and 70 µS respectively) had a sensitivity of 97%, positive predictive value of 87% to detect neuropathy in patients with longer diabetes duration. The group with shorter diabetes duration, the sensitivity of abnormal hands or feet ESC to detect neuropathy was 91% while the positive predictive value was 88%. CONCLUSIONS: The Sudoscan device, which does not require any preparation, is noninvasive, easy and rapid to perform, can be useful in the early diagnosis peripheral neuropathy in type 2 diabetic.

Indices of anti-dengue immunoglobulin G subclasses in adult Mexican patients with febrile and hemorrhagic dengue in the acute phase.

Heterologous secondary infections are at increased risk of developing dengue hemorrhagic fever (DHF) because of antibody-dependent enhancement (ADE). IgG subclasses can fix and activate complement and bind to Fcɣ receptors. These factors may also play an important role in the development of ADE and thus in the pathogenesis of DHF. The aim of this study was to analyze the indices of anti-dengue IgG subclasses in adult patients with febrile and hemorrhagic dengue in the acute phase. In 2013, 129 patients with dengue fever (DF) and 57 with DHF in Veracruz, Mexico were recruited for this study and anti-dengue IgM and IgG determined by capture ELISA. Anti-dengue IgG subclasses were detected by indirect ELISA. Anti-dengue IgG2 and IgG3 subclasses were detected in patients with dengue. IgG1 increased significantly in the sera of patients with both primary and secondary infections and DHF, but was higher in patients with secondary infections. The IgG4 subclass index was significantly higher in the sera of patients with DHF than in that of those with DF, who were in the early and late acute phase of both primary and secondary infection. In conclusion, indices of subclasses IgG1 and IgG4 were higher in patients with DHF.

Clinical practice guidelines for diagnostic and treatment of the chronic heart failure.

Chronic heart failure continues to be one of the main causes of impairment in the functioning and quality of life of people who suffer from it, as well as one of the main causes of mortality in our country and around the world. Mexico has a high prevalence of risk factors for developing heart failure, such as high blood pressure, diabetes, and obesity, which makes it essential to have an evidence-based document that provides recommendations to health professionals involved in the diagnosis and treatment of these patients. This document establishes the clinical practice guide (CPG) prepared at the initiative of the Mexican Society of Cardiology (SMC) in collaboration with the Iberic American Agency for the Development and Evaluation of Health Technologies, with the purpose of establishing recommendations based on the best available evidence and agreed upon by an interdisciplinary group of experts. This document complies with international quality standards, such as those described by the US Institute of Medicine (IOM), the National Institute of Clinical Excellence (NICE), the Intercollegiate Network for Scottish Guideline Development (SIGN) and the Guidelines International Network (G-I-N). The Guideline Development Group was integrated in a multi-collaborative and interdisciplinary manner with the support of methodologists with experience in systematic literature reviews and the development of CPG. A modified Delphi panel methodology was developed and conducted to achieve an adequate level of consensus in each of the recommendations contained in this CPG. We hope that this document contributes to better clinical decision making and becomes a reference point for clinicians who manage patients with chronic heart failure in all their clinical stages and in this way, we improve the quality of clinical care, improve their quality of life and reducing its complications.

La insuficiencia cardiaca crónica sigue siendo unas de las principales causas de afectación en el funcionamiento y en la calidad de vida de las personas que la presentan, así como una de las primeras causas de mortalidad en nuestro país y en todo el mundo. México tiene una alta prevalencia de factores de riesgo para desarrollar insuficiencia cardiaca, tales como hipertensión arterial, diabetes y obesidad, lo que hace imprescindible contar con un documento basado en la evidencia que brinde recomendaciones a los profesionales de la salud involucrados en el diagnóstico y el tratamiento de estos pacientes. Este documento establece la guía de práctica clínica (GPC) elaborada por iniciativa de la Sociedad Mexicana de Cardiología (SMC) en colaboración con la Agencia Iberoamericana de Desarrollo y Evaluación de Tecnologías en Salud, con la finalidad de establecer recomendaciones basadas en la mejor evidencia disponible y consensuadas por un grupo interdisciplinario y multicolaborativo de expertos. Cumple con estándares internacionales de calidad, como los descritos por el Institute of Medicine de los Estados Unidos de América (IOM), el National Institute of Clinical Excellence (NICE) del Reino Unido, la Intercollegiate Network for Scottish Guideline Development (SIGN) de Escocia y la Guidelines International Network (G-I-N). El grupo de desarrollo de la guía se integró de manera interdisciplinaria con el apoyo de metodólogos con experiencia en revisiones sistemáticas de la literatura y en el desarrollo de GPC. Se llevó a cabo y se condujo metodología de panel Delphi modificado para lograr un nivel de consenso adecuado en cada una de las recomendaciones contenidas en esta GPC. Esperamos que este documento contribuya para la mejor toma de decisiones clínicas y se convierta en un punto de referencia para los clínicos que manejan pacientes con insuficiencia cardiaca crónica en todas sus etapas clínicas, y de esta manera logremos mejorar la calidad en la atención clínica, aumentar la calidad de vida de los pacientes y disminuir las complicaciones de la enfermedad.

Dried Serum Samples for Antibody Detection in Arthropod-Borne Virus Infections Are an Effective Alternative to Serum Samples.

The disease burden of arthropod-borne infections is particularly high in low- and middle-income countries, where the availability of resources for surveillance and testing is limited. The lack of local infrastructure demands that biological samples be sent to central laboratories by refrigerated transport, which increases costs and the risk of sample degradation. Dried blood spot samples are an alternative for ensuring sample integrity during transportation and storage. They can be used for the detection of nucleic acids and proteins, such as antigens or antibodies. Here, we compared anti-chikungunya IgM, anti-dengue IgM, anti-dengue IgG, and anti-Zika IgG detection between paired serum and dried serum samples (DSSs); the agreement between results was found to be 90.6%, 94.1%, 85.9%, and 95.5%, respectively, indicating a strong correlation. Our results suggest that DSSs provide a reliable alternative for detection of specific antibodies in arthropod-borne infections.

Effect of 3D-MOT training on the execution of manual dexterity skills in a population of older adults with mild cognitive impairment and mild dementia.

Computerized cognitive training tools are an alternative to preventive treatments related to cognitive impairment and aging. In this study, the transfer of 3D multiple object tracking (3D-MOT) training on manual dexterity concerning fine and gross motor skills in 38 elderly participants, half of them with mild cognitive impairment (MCI) and the other half with mild dementia (MD) was explored. A total of 36 sessions of the 3D-MOT training program were administered to the subjects. The Montreal Cognitive Assessment (MoCA) test was used to assess the baseline cognitive status of the participants. Two batteries of manual motor skills (GPT and MMDT) were applied before and after the 3D-MOT training program. The results showed an interaction effect of training and improvement in manual dexterity tests, from the first training session until the fifteenth session, and after this range of sessions, the interaction effect was lost. However, the training effect continued to the end of the thirty-six-session program. The experimental results show the effect of cognitive training on the improvement of motor skills in older adults. This type of intervention could have a broad impact on the aging population in terms of their attention, executive functions, and therefore, their quality of life.

The Short-Term Effects of Roux-en-Y Gastric Bypass on Renal Excretion of Sodium and Its Association with Blood Pressure.

INTRODUCTION: Bariatric surgery has been shown to be effective in reducing weight and has benefits, such as lowering blood pressure. An increase in urinary sodium excretion has been suggested as a possible mechanism. This study explored changes in sodium excretion and their correlation with blood pressure after Roux-en-Y gastric bypass. MATERIALS AND METHODS: This study was conducted on 28 obese participants with body mass index (BMI) of 44.54 ± 7.81 kg/m2 who underwent gastric bypass. Before surgery and at the third and sixth months after gastric bypass, blood pressure, urinary sodium concentration, 24-hour (24-h) urinary sodium excretion, and fractional excretion of sodium were evaluated. In addition, serum sodium and potassium levels were determined. Nonparametric tests were used to analyze the data. RESULTS: Blood pressure decreased after surgery and remained at low levels over the 3- and 6-month periods. The urinary sodium concentration increased at 3 months after surgery; however, the 24-h urinary sodium excretion and urine volume decreased. Interestingly, although some associations between variables were observed, significant correlations between the 24-h urinary sodium excretion and the systolic, diastolic, and mean blood pressures were found. In addition, the urine volume was higher in the sixth month than in the third month following surgery. CONCLUSIONS: In the months immediately following surgery, a low-salt and low-volume diet favors decreases in urine volume and 24-h urinary sodium excretion. In addition, in the sixth month after surgery, an association between blood pressure and 24-h urinary sodium excretion was observed.

Association of Genetic Polymorphisms in TLR3, TLR4, TLR7, and TLR8 with the Clinical Forms of Dengue in Patients from Veracruz, Mexico.

Dengue manifestations range from a mild form, dengue fever (DF), to more severe forms such as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). The ability of the host to present one of these clinical forms could be related to polymorphisms located in genes of the Toll-like receptors (TLRs) which activate the pro-inflammatory response. Therefore, the genotyping of single nucleotide genetic polymorphisms (SNPs) in TLR3 (rs3775291 and rs6552950), TLR4 (rs2737190, rs10759932, rs4986790, rs4986791, rs11536865, and rs10983755), TLR7 (rs179008 and rs3853839), and TLR8 (rs3764880, rs5741883, rs4830805, and rs1548731) was carried out in non-genetically related DHF patients, DF patients, and general population (GP) subjects. The SNPs were analyzed by real-time PCR by genotyping assays from Applied Biosystems®. The codominance model showed that dengue patients had a lower probability of presenting the TLR4-rs2737190-G/G genotype (odds ratio (OR) (95% CI) = 0.34 (0.14-0.8), p = 0.038). Dengue patients showed a lower probability of presenting TLR4-rs11536865-G/C genotype (OR (95% CI) = 0.19 (0.05-0.73), p = 0.0092) and had a high probability of presenting the TACG haplotype, but lower probability of presenting the TGCG haplotype in the TLR4 compared to GP individuals (OR (95% CI) = 0.55 (0.35-0.86), p = 0.0084). In conclusion, the TLR4-rs2737190-G/G and TLR4-rs11536865-G/C genotypes and TGCG haplotype were associated with protection from dengue.

Seven and 3.5-day rhythms in the incidence of myocardiopathies in Mexico.

BACKGROUND: There is recent evidence about the existence of 7- and 3.5-day rhythms in some biological systems, particularly in human diseases. The objective of this work was to analyze and compare health data from various sources in Mexico to find this rhythm and a plausible explanation. METHODS: We analyzed the hourly number of myocardial infarctions (MI), angina, arrhythmias, hypertension, and heart failure registered at the Clinical Research Department of Hospital de Cardiología of Centro Medico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, in Mexico City for a period of 1 year (1996), with a total of 4947 cases. We used two methods based on the Fast Fourier Transform algorithm to determine the periodicities of this data. RESULTS: A predominant 1-day rhythm was found in the hourly data, and important periodicities of approximately 7- and 3.5-day among other rhythms. These periodicities were also found in other medical data from different sources in Mexico, particularly a long database of MI mortality for the whole country. CONCLUSIONS: The explanation of the 7-day rhythm may be related to the social week of human activity, but the 3.5-day rhythm has no easy explanation. Here we discuss the possibility that these rhythms may be related to environmental conditions, particularly to the solar activity that has periods close to the 3.5 and 7 days. Regardless of the modest number of data, the finding of these rhythms on the incidence of MI and other cardiac-related diseases in Mexico confirms previous investigations concerning medical data from other Mexican health care institutions.

What to know before raising a research question? / ¿Qué saber antes de plantear una pregunta de investigación?

With the purpose of establishing a research question adequately, it is necessary to update the state of knowledge in scientific publications, in order to verify the originality of the hypothesis; for this it is necessary to have acquired the training that allows to read and adequately criticize the methodology and the analysis of the medical literature.

Para plantear una pregunta de investigación de forma adecuada es necesario actualizar el estado del conocimiento en las publicaciones científicas, esto con el objeto de verificar la originalidad de la hipótesis; para ello es necesario haber adquirido la capacitación que permita leer y criticar adecuadamente la metodología y el análisis de la literatura médica.

Hemorrheologic effect of diuretics in the control of blood pressure in the hypertensive patient / Efecto hemorreológico de los diuréticos en el control de la presión arterial en el paciente hipertenso

Background: Diuretics are the first choice as an antihypertensive, because of its efficacy and cost, however its mechanism of action is not well understood. The aim of this work was to analyze the hemorrheological effect of the diuretics as vasodilators in patients with newly diagnosed arterial hypertension. Methods: Patients with hypertension were given diet and exercise recommendations and 25 mg of chlorthalidone per day were prescribed; Hemoglobin/hematocrit, viscosity, and basal nitric oxide (ON) were determined at 15 and 45 days and compared with healthy subjects. Results: We included 28 patients with average age of 48 years old; systolic blood pressure in the treated patients decreased from baseline at 15 days from 130 to 119 mm Hg and at 114 mmHg at 15 to 45 days; diastolic blood pressure decreased from baseline at 15 days from 103 to 97 mm Hg, and at 93 mmHg at 15 to 45 days. The hematocrit increased in both men and women with a statistical significance of the baseline period at 15 days, after that, it remained without significative changes. The viscosity increased similarly to the hematocrit, which conditioned the ON elevation. Conclusions: The increase in hematocrit due to diuretic caused an increase in blood viscosity, which led to an increase in nitric oxide, resulting in lower blood pressure.

Introducción: Los diuréticos son la primera elección como antihipertensivo por su eficacia y costo, sin embargo su mecanismo de acción no está bien esclarecido. El objetivo de este trabajo fue analizar el efecto hemorreológico del diurético como vasodilatador en pacientes con hipertensión arterial de reciente diagnóstico. Métodos: A los pacientes con hipertensión arterial se les dieron recomendaciones de dieta, ejercicio y se prescribió 25 mg de clortalidona al día; se determinaron hemoglobina/hematocrito, viscosidad y óxido nítrico (ON) basal, a los 15 y 45 días y se compararon con sujetos sanos. Resultados: Se incluyeron 28 pacientes, con edad promedio de 48 años; la presión arterial sistólica en los pacientes tratados descendió de la cifra basal a los 15 días de 130 a 119 mmHg, y a 114 mmHg de los 15 a los 45 días; la presión arterial diastólica descendió de la basal a los 15 días de 103 a 97 mmHg, y a 93 mmHg de los 15 a los 45 días . El hematocrito se incrementó en ambos géneros, con significancia estadística del período basal a los 15 días de tratamiento, posteriormente permaneció sin cambios. La viscosidad se incrementó de forma similar al hematocrito, lo que condicionó elevación del ON. Conclusiones: El incremento del hematocrito debido al diurético causó elevación de la viscosidad sanguínea, lo que condujo a incremento del óxido nítrico, repercutiendo en el descenso de la presión arterial.

Blood group incompatibility as risk of corneal rejection / Incompatibilidad de grupo sanguíneo como riesgo de episodio de rechazo corneal

Background: There is a high risk of rejection of a corneal transplant known as a "rejection episode" in our Hospital conditioned by multiple variables. The aim of this article is to analyze the different risk factors of "corneal rejection episode" in post-transplant patients at one year of follow-up and in particular to consider the presence of donor blood incompatibility during the first year of post-surgical follow-up. Methods: A nested case-control study was designed in a cohort: observational, longitudinal, analytical and retrospective from year 2012 to 2013. We performed OR and logistic regression of the variables that influenced rejection. Results: We included 101 consecutive transplants from multiorgan donation. The variables that influenced the rejection episode were: preoperative high risk group, graft size, blood incompatibility, female gender and age over 60 years old. Other variables such as the presence of comorbidities, combined surgery, surgical time greater than one hour and postoperative complications did not show significant differences. Conclusions: It is advisable to perform routine blood compatibility to reduce the risk of rejection.

Introducción: Existe un elevado riesgo de rechazo de trasplante corneal conocido como "episodio de rechazo" en nuestro Hospital condicionado por múltiples variables. El objetivo de este trabajo fue analizar las diferentes causas de riesgo de episodio de rechazo corneal en pacientes postrasplantados a un año de seguimiento y en particular considerar la presencia con incompatibilidad sanguínea del donador durante el primer año de seguimiento posquirúrgico. Métodos: Se diseñó un estudio de casos y controles anidados en una cohorte: observacional, longitudinal, analítico y retrospectivo del año 2012 al 2013. Se realizó OR y regresión logística de las variables que influyeron en rechazo. Resultados: Se incluyeron 101 trasplantes consecutivos procedentes de donación multiorgánica. Las variables que influyeron en el episodio de rechazo fueron: grupo prequirúrgico de riesgo alto, tamaño del injerto, incompatibilidad sanguínea, género femenino y mayores de 60 años. Otras variables como la presencia de comorbilidades, cirugía combinada, tiempo quirúrgico mayor a una hora y complicaciones postquirúrgicas no mostraron diferencias significativas. Conclusiones: Es recomendable realizar de rutina la compatibilidad sanguínea para disminuir el riesgo de episodio de rechazo.

Relationship of receptors of adipokines with hypertension and obesity. Murine model

Background: The aim of this paper is to investigated the contribution of adipose tissue thought the adipokines and kidney failure (KF) Methods: In male rats were fed with a standard lab diet (C) or a hypercaloric diet including 30% sucrose; obese group (Ob) and obese with kidney failure group (Ob/KF). We evaluated the changes of adipokines under conditions of obesity and KF, using 5/6 surgery to induce vascular injury. The anterior and media branches of the left kidney artery were tied together, leaving the posterior branch viable to enable the kidney to function. The right kidney was removed. Results: A 90% survival rate of the animals was achieved due to special care taken. Kidney function progressively decreased after surgery. Compared with the control group, in the other two groups (Ob and Ob/KF) the level of leptin increased and that of adiponectin decreased (p < 0.01). Post-surgery increases were observed in blood pressure, lipids, creatinine and insulin (p < 0.01). Conclusion: This model is proposed for the study pathophysiological mechanisms that lead to obesity and complications of kidney or cardiovascular function.

Introducción: El objetivo de este trabajo es investigar la contribución del tejido adiposo y las adipocinas y la insuficiencia renal (KF). Métodos: Ratas machos se alimentaron con una dieta estándar de laboratorio (C) o una dieta hipercalórica incluyendo 30% de sacarosa; Grupo obeso (Ob) y obeso con grupo de insuficiencia renal (Ob/KF). Se evaluaron los cambios de adipocinas en condiciones de obesidad y KF, utilizando cirugía 5/6 para inducir lesión vascular. Las ramas anterior y media de la arteria renal izquierda fueron unidas, dejando la rama posterior viable para permitir sobreviviencia y función renal. El riñón derecho fue removido. Resultados: Se logró una tasa de supervivencia del 90% de los animales debido a un cuidado especial. La función renal disminuyó progresivamente después de la cirugía. En comparación con el grupo control, en los otros dos grupos (Ob y Ob/KF) el nivel de leptina aumentó y el de adiponectina disminuyó (p < 0.01). Se observaron aumentos postquirúrgicos en la presión arterial, los lípidos, la creatinina y la insulina (p < 0.01). Conclusión: Este modelo se propone para el estudio de los mecanismos fisiopatológicos que conducen a la obesidad y las complicaciones de la función renal o cardiovascular.

Serum Dried Samples to Detect Dengue Antibodies: A Field Study.

BACKGROUND: Dried blood and serum samples are useful resources for detecting antiviral antibodies. The conditions for elution of the sample need to be optimized for each disease. Dengue is a widespread disease in Mexico which requires continuous surveillance. In this study, we standardized and validated a protocol for the specific detection of dengue antibodies from dried serum spots (DSSs). METHODS: Paired serum and DSS samples from 66 suspected cases of dengue were collected in a clinic in Veracruz, Mexico. Samples were sent to our laboratory, where the conditions for optimal elution of DSSs were established. The presence of anti-dengue antibodies was determined in the paired samples. RESULTS: DSS elution conditions were standardized as follows: 1 h at 4°C in 200 µl of DNase-, RNase-, and protease-free PBS (1x). The optimal volume of DSS eluate to be used in the IgG assay was 40 µl. Sensitivity of 94%, specificity of 93.3%, and kappa concordance of 0.87 were obtained when comparing the antidengue reactivity between DSSs and serum samples. CONCLUSION: DSS samples are useful for detecting anti-dengue IgG antibodies in the field.

Increased Cardiovascular Risk Using Atherogenic Index Measurement Among Healthcare Workers.

BACKGROUND AND AIMS: Cardiovascular diseases are one of the leading causes of death worldwide. This burden of disease is particularly high among healthcare workers. The aim of the study was to identify determinants that increase atherogenic index among healthcare workers. METHODS: In 1,678 healthcare workers, cardiovascular risk factors were analyzed: body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, glucose, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. Atherogenic index was calculated and determinants were identified. RESULTS: Mean (SD) age was 41.2 (8.4) years; body mass index 28.4 (4.8); waist-hip-ratio 0.88 (0.07); glucose 96.6 (22.2) µg/dL; TC 195.3 (50.3) mg/dL; HDL 49.0 (16.3) mg/dL; LDL 112.7 (35.0) mg/dL; triglycerides 171.7 (121.2) mg/dL; and atherogenic index 3.3 (1.5). Overweight and obesity prevalence was 77.2%. In the multiple linear regression model, the coefficients for AI were being a physician ß = 0.381, male gender = 0.443, BMI ß = 0.35, waist-to-hip ratio ß = 2.15, age = 0.014, and triglycerides ß = 0.915. CONCLUSIONS: The main contributors to atherogenic index increase were male sex, increased age, waist-to-hip ratio increase, overweight and obesity, high triglyceride levels and working as a physician. Although waist-to-hip ratio was the most powerful determinant, the physician occupational category added risk factors such as stress and adverse psychosocial working conditions, which may potentiate cardiovascular diseases.

Seroprevalence of Pandemic A(H1N1) pmd09 Virus Antibodies in Mexican Health Care Workers Before and After Vaccination.

BACKGROUND AND AIMS: In April 2009, a new strain of influenza A(H1N1) was identified in Mexico and in the U.S. In June 2009, WHO declared this a pandemic. Health care workers constituted a risk group for their close contact with infected individuals. The aim was to estimate seropositivity for A(H1N1)pdm09 in health staff at the Instituto Mexicano del Seguro Social. METHODS: A two-stage cross-sectional study, before and after vaccination in the same workers, was performed on a random sample of health-care workers. A socio-occupational questionnaire was applied and serum antibodies against influenza A(H1N1)pdm09 were determined through neutralization of retroviral pseudotypes; two logistic regression models for both were constructed. RESULTS: The average (median/mean) age of 1378 participants from 13 work centers was 41.7 years and 68.7% (947) were women. Seroprevalence for the first stage was 26.5% (365) (7.4-43%) vs. 20.8% (11) in a control group from the blood bank; for the second stage, the vaccinated group was 33% (215) (18.2-47%) and 27% (196) (11.6-50%) for the unvaccinated group. In regression models, seropositivity was associated with occupational exposure to suspected influenza infected patients, being physicians, and being vaccinated. CONCLUSIONS: Seropositivity against pandemic virus is similar to what was reported, both for vaccinated (2.8-40.9%) and unvaccinated (18.8-64.7%). Low seroprevalence in the vaccinated group indicates that between 67% and 73% were susceptible to infection. Given the relatively low vaccine-induced seropositivity, it is imperative to increase, hygiene and safety for health staff and at-risk populations, and strengthen epidemiological surveillance.

Influence of serological factors and BMI on the blood pressure/hematocrit association in healthy young men and women.

The association between mean arterial blood pressure (MAP) and hematocrit (Hct) as a surrogate for blood viscosity was investigated in a young (average 20.0±2.3 years), healthy population of 174 men and 442 women. Health status was assessed by clinical examination and serological evaluation. Individuals with severe anemia or hemoconcentration, prior traumas or major surgical intervention, smokers, and pregnant or lactating women were excluded from the study. The MAP/Hct association was positive and significant (P=0.04) for women and negative, albeit not significantly so, for men. The MAP/Hct association was also evaluated in subgroups of the same population with a progressive step-by-step exclusion of: individuals with cholesterol >200 mg/dL; triglycerides >200 mg/dL; body mass index >25 kg/m(2); and glucose >100 mg/dL. This consecutively reduced the strength of the positive MAP/Hct association in women, which became negative - although not significantly so - when all anomalously high factors were excluded. The same trend was found in men. Our study indicates that previously reported positive trends in the relationship between the MAP and Hct in the population are not present in a young, healthy population of men or women that excludes individuals with the confounding factors of above normal serological values and BMI.

[Demographic factors and comorbidity associated to prehypertension]. / Factores demográficos y de comorbilidad asociados a prehipertensión arterial.

BACKGROUND: prehypertension is the category established in JNC-7, which designates the individuals that present diastolic blood pressure of 80-89 mm Hg and systolic blood pressure of 120-139 mm Hg, and it is associated to high rates of cardiovascular disease. The purpose of the study was to identify prevalence rates and their correlation with sociodemographic factors and comorbidity in a sample of a population of Veracruz, Mexico. METHODS: a cross-sectional and representative survey was chosen by means of probability sampling. Sociodemographic factors, lifestyle and anthropometric characteristics were assessed. Odds ratios and 95 % confidence intervals were obtained. RESULTS: the prehypertension prevalence found was 33.8 %, with an average age of 40.9 ± 14.2 years in prehypertensive subjects, and 50.6 ± 12.7 in hypertension subjects (p < 0.05). In relation with prehypertension, males presented a 1.48 (1.18-1.86) OR. Also, those who had more than 40 years had an OR of 1.9 (1.51-2.38); the ones with basic schooling, an OR of 1.73 (1.38-2.17); subjects with hyperglycemia, OR 3.0 (1.5-3.75); with overweight, OR 1.41 (1.01-1.68); and those with other comorbidities an OR of 1.61 (1.09-2.36). CONCLUSIONS: a high prevalence of prehypertension was found in the sample, and it was associated to male gender subjects, aged above 40 years, with basic schooling and relevant comorbidities, such as diabetes and cardiovascular disease.

Introducción: la prehipertensión arterial es la categoría establecida en el JNC-7 para definir las cifras de presión arterial diastólica de 80-89 y sistólica de 120-139 mm Hg que se asocian a riesgo cardiovascular. El objetivo del estudio fue determinar su prevalencia y su asociación con factores sociodemográficos y de comorbilidad en una muestra representativa de la población del estado de Veracruz. Métodos: por medio de muestreo probabilístico y una encuesta transversal, se registraron variables sociodemográficas, estilo de vida, antropometría, presión arterial y glucosa. Se obtuvieron razones de momios (RM) e intervalos de confianza (IC) del 95 % para los factores de riesgo mencionados. Resultados: la prevalencia de prehipertensión fue de 33.8 %, con edad promedio de 40.9 ± 14.2 años en prehipertensos y 50.6 ± 12.7 en hipertensos (p < 0.05). Para prehipertensión, el sexo masculino presentó RM de 1.48 (1.18-1.86). Asimismo, aquellos mayores de 40 años tuvieron una RM de 1.9 (1.51-2.38); los que tenían escolaridad básica, RM de 1.73 (1.38-2.17); aquellos con hiperglucemia de ayuno, RM de 3.0 (1.5-3.75); con sobrepeso, RM de 1.41 (1.01-1.68); y con otras comorbilidades, una RM de 1.61 (1.09-2.36). Conclusiones: se encontró una elevada prevalencia de prehipertensión en esta muestra de la población y su asociación de riesgo fue con las personas de sexo masculino que eran mayores de 40 años y que tenían escolaridad básica y comorbilidades como diabetes y enfermedad cardiovascular.

[Homocysteine after a methionine load in healthy subjects with adequate B-vitamin status]. / Homocisteína plasmática posterior a carga oral de metionina en sujetos sanos con nivel adecuado de vitaminas B.

BACKGROUND: Plasma homocysteine (Hcy) determination at 6-8 h after an oral methionine load (OML) allows for identification of some, but not all, individuals at risk to develop cardiovascular disease. It is probable that in some cases the Hcy increases occur later, or it elevates between normal ranges but in a sustained manner. However, the entire Hcy response curve has not been described. We undertook this study to determine Hcy concentrations from baseline to 24- and 48-h after an OML in non-B-vitamin deficient adult subjects with other risk factors for high levels of Hcy such as smoking and overweight. METHODS: In a cross-over, clinical design, Hcy concentrations were determined at 2-h intervals throughout 12 h and at 24 h and 48 h after an OML (0.1 g/kg). Hcy and vitamin B6 (VB6) concentrations were measured by high-performance liquid chromatography (HPLC). Folic acid (FA) and vitamin B12 (VB12) were measured by radioimmunoassay (RIA). Statistical analysis included delta values and areas under the curve. Student t-test and repeated measurement analyses were conducted to control for confounders. RESULTS: Twenty-nine subjects with adequate Hcy, FA, VB6 and VB12 status were included. The maximum Hcy concentration occurred 8 h after the load and returned to baseline concentrations after 24 h. All subjects presented Hcy after the load within normal ranges, but smoking and overweight synergistically influenced the response to the challenge, producing a sustained elevation after the dose. CONCLUSIONS: Hcy concentrations after an OML remained above baseline for at least 24 h. Smoking and overweight affected the response to the methionine challenge.