La resistina se asocia con la proteína C reactiva y marcadores de riesgo cardiovascular en niños obesos / Resistin is associated with C reactive protein and cardiovascular risk markers in obese children / A resistina associa-se à proteína C reativa e aos marcadores de risco cardiovascular em crianças obesas

El objetivo del trabajo fue evaluar los niveles de resistina sérica y su asociación con la proteína C reactiva (PCR-hs), óxido nítrico (NO) y lípidos plasmáticos (LP) en sujetos de edad pediátrica. Participaron 366 niños y adolescentes (10-16 años), agrupados en eutróficos (n=162) y obesos (n=204). Se les estudió peso, talla, circunferencia de la cintura, resistina sérica, glucosa e insulina basal, LP, NO, PCR-hs, malondialdehído y tensión arterial. Se calculó el IMC, el índice cintura-talla (IC/T) y el HOMA-IR. Se utilizaron las pruebas t de Student, ANOVA, U de Mann y Whitney o Kruskal- Wallis para comparar entre grupos y la correlación de Spearman para determinar asociación entre variables. Los obesos masculinos presentaron niveles superiores de resistina (p<0,05). El género femenino presentó valores más altos de resistina en eutróficos (p=0,012) y con IC/T normal (p=0,011). A mayor concentración de resistina los eutróficos presentaron niveles más altos de triacilglicéridos, pero los obesos mostraron niveles más bajos de triacilglicéridos, HDLc y NO, más altos de PCR-hs y mayor IMC. Los resultados sugieren que la resistina podría ser un factor de riesgo para la enfermedad cardiovascular por su asociación positiva con la PCR-hs e inversa con el NO y la HDLc, parámetros involucrados en la inflamación y la disfunción endotelial.

The aim of this study was to evaluate seric levels of resitin and their association with high-sensitivity C Reactive Protein (hs-CRP), nitric oxide (NO) and plasmatic lipids (PL) in a pediatric age population. A total of 366 children and adolescents (between 10-16 years old) participated, and were grouped into eutrophic (n=162) and obese (n=204). Weight, height, waist circumference, resistin, fasting blood glucose and insulin levels, PL, hs-CRP, NO, malondialdehyde and blood pressure were measured. BMI, waist to height ratio (W/HR) and HOMA-IR were calculated. T-student, ANOVA, Mann-Whitney U-value or Kruskal-Wallis were used to compare between groups and Spearman correlation was used to determine association among variables. Male obese subjects showed higher resistin levels (p<0.05). Female subjects showed higher resistin values in the eutrophic group (p=0.012) and in the normal W/HR (p=0.011). At higher levels of resistin, the eutrophic group showed higher levels of triacylglycerides, but the obese group showed lower triacylglycerides, HDLc and NO levels and higher hs-CRP levels and BMI. These results suggest that resistin could be a risk factor for cardiovascular disease because of its positive association with hs-CRP and inverse association with NO and HDLc, parameters involved in inflammation and endothelial dysfunction.

O objetivo da pesquisa foi avaliar os níveis séricos de resistina sérica e sua associação com a proteína C-reativa (PCR-hs), óxido nítrico (NO) e lipídios plasmáticos (LP) em crianças e adolescentes. O estudo envolveu 366 crianças e adolescentes (10-16 anos), agrupados em eutróficos (n=162) e obesos (n=204). Os sujeitos foram estudados em relação ao peso, altura, circunferência da cintura, resistina sérica, glicose e insulina basal, LP, NO, PCR-hs, malondialdeído e pressão arterial. Os IMC, índice cintura-altura (IC/A) e HOMA-IR foram calculados. Foram utilizados os Testes t de Student, ANOVA, U de Mann e Whitney ou Kruskal-Wallis para comparar entre os grupos e a correlação de Spearman para verificar a associação entre variáveis. Os obesos masculinos mostraram níveis mais elevados de resistina (p<0,05). O sexo feminino apresentou valores mais altos de resistina em eutróficos (p=0,012) e com IC/T normal (p=0,011). À maior concentração de resistina, os eutróficos apresentaram maiores níveis de triacilglicerídeos, mas os obesos apresentaram níveis mais baixos de triacilglicerídeos, HDLc e NO, mais altos de PCR-hs e maior IMC. Os resultados sugerem que a resistina poderia ser um fator de risco para a doença cardiovascular devido à sua associação positiva com a PCR-hs e inversa com o NO e a HDLc, parâmetros envolvidos na inflamação e disfunção endotelial.

DE LA OBESIDAD A LA DIABETES: LA INSULINO- RESISTENCIA ES UN MECANISMO DE DEFENSA TISULAR Y NO UNA ENFERMEDAD / FROMOBESITYTODIABETES:INSULIN-RESISTANCE IS A DEFENSE MECHANISM AND NOT A DISEASE ABSTRACT

La capacidad de almacenamiento del tejido adiposo es limitada y determinada genéticamente, así, hay individuos delgados con poca capacidad de almacenamiento que tienen marcadores metabólicos alterados (hiperinsulinismo, hiperglucemia, dislipidemia, esteatosis hepática, etc.), y otros sujetos con gran capacidad de almacenamiento que incrementan su peso hasta llegar a obesidad mórbida y sin embargo tienen marcadores metabólicos normales. A medida que el tejido adiposo se va acercando a su máxima capacidad de almacenamiento, el adipocito se va haciendo menos sensible a la insulina, para evitar su muerte por apoptosis debido al acúmulo excesivo de triglicéridos (TG). El grado de insulino-resistencia (IR) del tejido adiposo y el tiempo que dure determina tres situaciones diferentes. Una inicial donde el individuo incrementa su peso. La segunda en la cual el individuo mantiene su peso constante, ya que la cantidad de TG almacenados es igual a la cantidad que se hidrolizan. Y la tercera, cuando la IR es permanente, se desencadena la Diabetes Mellitus tipo 2 (DM2) que cursa con pérdida de peso y marcadores metabólicos alterados. La IR del tejido adiposo incrementa los ácidos grasos libres circulantes y estos tienen tres destinos: en el tejido hepático se acumulan causando esteatosis; la célula beta pancreática sufre apoptosis y disminuye la síntesis y secreción de insulina; y el músculo esquelético desarrolla IR para protegerse de una acumulación anormal de glucógeno que conllevaría a degeneración y muerte de la célula muscular. En este artículo se explican las modificaciones moleculares que estos órganos utilizan para mantener su indemnidad.

The storage capacity of adiposetissueislimitedand determined genetically, so therearethin people with small storage capacity that have altered metabolic markers (hyperinsulinemia, hyperglycemia, dyslipidemia, hepatic steatosis, etc.), and other people with large storage capacity that are able to increase weight until becoming morbidly obese and yet have normal metabolic markers. As adipose tissue approaches its maximum storage capacity, the adipocyte becomes less sensitive to insulin, to avoid death by apoptosis due to excessive accumulation of triglycerides (TG). The degree of insulin resistance (IR) in the adipose tissue and its duration determines three different situations. First of all, the patient increases weight. Second, the patient remains in a constant weight, since the amount of stored TG equals the amount that is hydrolyzed. And finally, when the IR is permanent, Type 2 Diabetes Mellitus (DM2) develops, causing weight loss and altered metabolic markers. Adipose tissue IR increases circulating free fatty acids, which have three destinations: liver, where they accumulate causing steatosis; pancreatic beta cell, which undergoes apoptosis and decreases synthesis and secretion of insulin; and skeletal muscle which develops IR to protect itself against an abnormal accumulation of glycogen that would lead to degeneration and death of the muscle cell. This article explains the molecular modifications that these organs use to maintain their indemnity.

[Association between resistin serum levels and dimension and body composition variables in children and adolescents]. / Asociación de la resistina con variables de dimensión y composición corporal en eutróficos y obesos.

BACKGROUND: Resistin is an adipokine secreted in adipose tissue that may be associated with the metabolic and endocrine disorders of obesity. AIM: To assess the association between serum resistin levels and body composition variables, in children and adolescents. MATERIAL AND METHODS: Cross-sectional assessment of 302 subjects, aged 10-16 years. According to body mass index, 124 were classified as eutrophic and 178 as obese. A clinical examination and pubertal assessment were performed. Body weight, height, waist and arm circumferences were measured. Serum resistin levels were measured using an immunoenzymatic assay. RESULTS: Male obese children had significantly higher resistin levels than their eutrophic counterparts. Eutrophic women had higher levels than eutrophic males. No significant association between resistin and pubertal status was observed. In the whole sample and among obese subjects, resistin levels correlated with body mass index, tricipital skinfold, arm circumference, arm fat area and fat mass. CONCLUSIONS: There is a significant association between resistin levels and body composition variables, particularly with indicators of fat accretion.

Asociación de la resistina con variables de dimensión y composición corporal en eutróficos y obesos / Association between resistin serum levels and dimension and body composition variables in children and adolescents

Background: Resistin is an adipokine secreted in adipose tissue that may be associated with the metabolic and endocrine disorders of obesity. Aim: To assess the association between serum resistin levels and body composition variables, in children and adolescents. Material and Methods: Cross-sectional assessment of 302 subjects, aged 10-16 years. According to body mass index, 124 were classified as eutrophic and 178 as obese. A clinical examination and pubertal assessment were performed. Body weight, height, waist and arm circumferences were measured. Serum resistin levels were measured using an immunoenzymatic assay. Results: Male obese children had significantly higher resistin levels than their eutrophic counterparts. Eutrophic women had higher levels than eutrophic males. No significant association between resistin and pubertal status was observed. In the whole sample and among obese subjects, resistin levels correlated with body mass index, tricipital skinfold, arm circumference, arm fat area and fat mass. Conclusions: There is a significant association between resistin levels and body composition variables, particularly with indicators of fat accretion.

Percentiles de circunferencia de cintura en niños y adolescentes del municipio maracaibo del estado zulia: venezuela / Waist circumference percentiles in children and adolescents of Maracaibo municipality of zulia state: venezuela

El exceso de grasa visceral constituye un importante predictor de riesgo metabólico y cardiovascular en niños y adolescentes, y la circunferencia de cintura (CC) es la mejor variable antropométrica que la estima. El objetivo de este estudio fue estimar los percentiles de circunferencia de cintura específicos por edad y género para niños y adolescentes, utilizando una muestra obtenida del Municipio Maracaibo del Estado Zulia, Venezuela. Se analizó una muestra de 1787 niños y adolescentes (884 del género masculino y 903 del género femenino) con edades comprendidas entre 2 y 18 años, seleccionados por muestreo aleatorio por conglomerado. A cada individuo se le realizó un examen físico y evaluación antropométrica para confirmar su estado de salud. Para la construcción de las curvas suavizadas de los percentiles de CC se utilizó el método LMS. La media de la circunferencia de cintura aumentó con la edad, y se mantuvo similar en ambos géneros hasta la edad de 8 años, despues de los cuales comenzó a verse un ligero incremento en el género masculino. Los valores de CC en cada percentil se incrementaron con la edad. Al compararlo con otros países, los valores de CC en el percentil 50 para ambos grupos, se mostraron cercanos pero levemente superiores a los valores registrados por Colombia, Canadá, USA, Hong Kong y Londres hasta la edad de 9 años, a partir de la cual se evidencia un incremento constante en promedio de 2,5 cm de un año a otro. Las curvas de ambos géneros se acercan suficientemente a las curvas que dibuja USA. Sin embargo, se observó un aumento en los valores de CC en el grupo masculino desde los 10 años en adelante, comparado con los otros países, incluso USA. Estas primeras estimaciones de percentiles de CC y sus curvas correspondientes para niños y adolescentes del Municipio Maracaibo, permitirá identificar individuos con obesidad abdominal (una vez establecidos los puntos de corte en futuras investigaciones); y así definir no solo las estrategias de atención, sino también las de prevención de riesgo cardiovascular y metabólico en este grupo vulnerable(AU)

The excess of visceral fat constitutes important predictor of metabolic and cardiovascular risk in children and adolescents, and the waist circumference (WC) is the best anthropometric variable to estimate it. The objective was to estimate the specific WC percentiles by age and gender for children and adolescents, using data obtained from Maracaibo Municipality of Zulia State, Venezuela. For this purpose, a sample of 1787 children and adolescents (884 boys and 903 girls) from 2 until 18 years old, were selected by conglomerate random sampling. A complete physical examination and anthropometric evaluation was performed to each patient to confirm their healthy state. Construction of the smoothed centile curves was performed using the LMS method. Mean WC increased with age, with the values being similar between males and females until 8 years old, after which values are slightly higher in males. For both genders, the values of WC in each percentile increased with the age. Compared with other countries, our values of WC in percentile 50 for both groups were similar, but slightly superior to the values registered by Colombia, Canada, USA, Hong Kong and London until age 9, after this age a constant increase in average of 2.5 cm from one year to another was observed. Both gender curves approach the USA curves. Nevertheless, an increase in the values of WC in the male group from the 10 years was observed, compared with the other countries, even USA. These first estimations of percentiles of WC and their corresponding curves for children and adolescents from Maracaibo Municipality, will allow to identify subjects with abdominal obesity (after cut-off points are established in future investigations) and thus to define not only the strategies for attention, but also for prevention cardiovascular and metabolic risk in this vulnerable group(AU)

Effect of cigarette smoking on the oxidant/antioxidant balance in healthy subjects.

BACKGROUND AND PURPOSE: Cigarette smoking has been associated with the development of cardiovascular disease and cancer. Even though the molecular mechanism(s) are not clear, the pathology has been related to oxygen free radicals present in cigarette smoke. Thus, the main objective of this study was to establish the changes in the oxidation/antioxidation balance induced by cigarette smoking. METHODS: Thirty healthy subjects (15 smokers and 15 nonsmokers) of both sexes were studied. The smokers group had smoked a mean of 14 cigarettes per day for an average of 4.5 years. Fasting serum levels of malondialdehyde (MDA), a marker of oxidative stress, nitric oxide (NO), reduced glutathione (GSH), and vitamin C (ascorbic and dehydroascorbic acids) were measured. RESULTS: Fasting NO concentration was significantly higher in smokers (51.3 +/- 5.3 microM) than in nonsmokers (35.2 +/- 4.8 microM, P < 0.05). The smokers had significantly higher serum dehydroascorbic acid levels (2.4 +/- 0.5 mg/dL, P < 0.03) than the nonsmokers (1.08 +/- 0.08 mg/dL). No significant differences were observed in the levels of ascorbic acid, MDA, and GSH between the smokers and nonsmokers. CONCLUSIONS: Our results suggest that exposure to cigarette smoke increases NO synthesis, such that NO may act in a compensatory way as an inhibitor of lipid peroxidation. Smoking also activates other antioxidative mechanisms such as involving vitamin C. These protective mechanisms appear to be enough in preventing accumulation of oxidative products such as MDA and avoiding oxidative damage.

Metformin plus low-dose glimeperide significantly improves Homeostasis Model Assessment for insulin resistance (HOMA(IR)) and beta-cell function (HOMA(beta-cell)) without hyperinsulinemia in patients with type 2 diabetes mellitus.

OBJECTIVE: Type 2 diabetes mellitus is characterized by insulin resistance and defects in insulin secretion from pancreatic beta-cells, which have been studied by using euglycemic/hyperinsulinemic clamps. However, it is difficult to study insulin resistance and beta-cell failure by these techniques in humans. Therefore, the aim of this study was to evaluate the effect of three different antidiabetic therapeutic regimens on insulin resistance and beta-cell activity by using a mathematical model, Homeostasis Model Assessment for insulin resistance (HOMA(IR)) and beta-cell function (HOMA(beta-cell)). RESEARCH DESIGN AND METHODS: Seventy type 2 diabetic patients were randomly assigned to one of three therapeutic regimens: (A) metformin + American Diabetic Association (ADA)-recommended diet + physical activity; (B) metformin + low-dose glimepiride + ADA diet + physical activity; or (C) ADA diet + physical activity (no drugs). Blood samples were obtained before and after the treatment to determine serum levels of fasting and post-prandial blood glucose, fasting insulin, and glycosylated hemoglobin (HbA1c), and HOMA(IR) and HOMA(beta-cell) were calculated. RESULTS: Fasting and post-prandial levels of glucose, HbA1c, and fasting insulin and calculated HOMA(IR) and HOMA(beta-cell) values before treatment were significantly higher than the respective values after treatment for all groups of patients (P < 0.01). Significant differences were also found when comparing the treatment-induced reduction in fasting blood glucose (51.8%; P < 0.01), post-prandial blood glucose (55.0%; P < 0.05), and HOMA(IR) (65.3%; P < 0.01) in patients of Group B with that in patients receiving other therapeutic options (Groups A and C). CONCLUSIONS: Metformin plus low-dose glimepiride (plus ADA diet and physical activity) is a more effective treatment for type 2 diabetes than either metformin plus ADA diet and physical activity or ADA diet and physical activity alone. Determination of HOMA(IR) and HOMA(beta-cell) values is an inexpensive, reliable, less invasive, and less labor-intensive method than other tests to estimate insulin resistance and beta-cell function in patients with type 2 diabetes mellitus.

Oat-derived beta-glucan significantly improves HDLC and diminishes LDLC and non-HDL cholesterol in overweight individuals with mild hypercholesterolemia.

OBJECTIVE: To investigate the effect of bread formulated with 6 g of beta-glucan (oat soluble fiber) on serum lipids in overweight normotensive subjects with mild to moderate hypercholesterolemia. DESIGN: Thirty-eight male subjects [mean age 59.8 +/- 0.6 yr, mean body mass index (BMI) 28.3 +/- 0.6 kg/m(2)] who were eligible for the study ate an isocaloric diet for a 1-week period. They were then divided into 2 groups: group A (n = 19), who were maintained on American Heart Association (AHA) Step II diet, including whole wheat bread, and group B (n = 19), who were maintained on AHA Step II diet containing high levels of monounsaturated fatty acids plus bread containing 6 g of beta-glucan (Nutrim-OB) for 8 weeks. Plasma lipids and glucose were measured at baseline and after weeks 8 in all subjects. All subjects were advised to walk for 60 minutes every day. RESULTS: There was a significant increase (upward arrow 27.8%) in plasma high density lipoprotein (HDL) cholesterol in the beta-glucan group (group A) from 39.4 +/- 2.0 to 49.5 +/- 2.1 mg/dL (P < 0.001), but there was no change in group B. There was a significant reduction in total cholesterol in the 2 groups to approximately the same extent: group A, from 232.8 +/- 2.7 mg/dL to 202.7 +/- 6.7 mg/dL; P < 0.001; and group B, from 231.8 +/- 4.3 mg/dL to 194.2 +/- 4.3 mg dL; P < 0.001. Plasma low density lipoprotein (LDL) cholesterol also decreased significantly in the two groups: group A, from 160.3 +/- 2.8 mg/dL to 133.2 +/- 5.4 mg/dL; P < 0.001; group B, from 167.9 +/- 4.3 mg/dL to 120.9 +/- 4.3 mg/dL; P < 0.001; however, the beta-glucan fortified diet was significantly more effective (downward arrow 27.3% vs. downward arrow 16.8%; P < 0.04). There was a small and insignificant reduction in plasma very LDL (VLDL) cholesterol and triglycerides in the two groups. Similarly, non-HDL cholesterol levels were also decreased, with beta-glucan diet producing significantly higher effect (downward arrow 24.5% vs. downward arrow 16.1%; P < 0.04). The beta-glucan diet also produced higher reduction in total cholesterol/HDL cholesterol ratio (downward arrow 33.3% vs. downward arrow 8.4%; P < 0.003) and LDL cholesterol/HDL cholesterol ratio (downward arrow 42.1% vs. downward arrow 13.3%; P < 0.001) than the diet without beta-glucan. The beta-glucan diet also decreased fasting plasma glucose (P < 0.4), whereas the other diet had no effect. Interestingly, both diets reduced body weight and BMI significantly, with beta-glucan diet having a greater effect. CONCLUSIONS: Six grams of beta-glucan from oats added to the AHA Step II diet and moderate physical activity improved lipid profile and caused a decrease in weight and, thus, reduced the risk of cardiovascular events in overweight male individuals with mild to moderate hypercholesterolemia. The diet with added beta-glucan was well accepted and tolerated.

Ciprofibrate treatment decreases non-high density lipoprotein cholesterol and triglycerides and increases high density lipoprotein cholesterol in patients with Frederickson type IV dyslipidemia phenotype.

OBJECTIVE: The combination of hypertriglyceridemia and low high density lipoprotein (HDL) cholesterol is one of the most common lipid abnormalities. Thus, the aim of this study was to determine the effects of ciprofibrate on lipid profile in patients with Frederickson's type IV dyslipidemia phenotype. RESEARCH DESIGN AND METHODS: Seventy-five patients with type IV dyslipidemia were assigned at random to 1 of 2 therapeutic options: group A (control), American Heart Association (AHA) Step II diet and physical activity; and group B, AHA diet, physical activity, and ciprofibrate 100 mg daily for 8 weeks. The lipid profile of all patients was determined at baseline and after therapeutic intervention. RESULTS: Patients in group B (treated with ciprofibrate) compared with group A (control) had significantly higher reductions in total cholesterol (downward arrow 14.2% vs. downward arrow 4.8%; P < 0.02), triglycerides (downward arrow 38.0% vs. downward arrow 21.6%; P < 0.007), very low density lipoprotein cholesterol (downward arrow 38.0% vs. downward arrow 21.6%; P < 0.007), non-HDL cholesterol (downward arrow 20.5% vs. downward arrow 7.1%; P < 0.007), and total cholesterol/high density cholesterol ratio (downward arrow 25.6% vs. downward arrow 9.4%; P < 0.01). The ciprofibrate group had a significantly higher increase in HDL cholesterol levels compared with the other group (upward arrow 25.0% vs. upward arrow 9.6%, P < 0.02). CONCLUSIONS: Ciprofibrate treatment effectively reduced triglyceride-rich particles and non-HDL cholesterol, and significantly increased HDL cholesterol, proving its effectiveness in patients with low HDL cholesterol and type IV Frederickson's hyperlipidemia.

Adición de mayonesa a la dieta de rata Sprague-Dawley incrementa la glicemia y los triacilglicéridos con disminución del HDL-colesterol / Adding mayonnaise to the diet of Sprague-Dawley rats increases with triacilglycerides glycemia and decreased HDL-cholesterol

El objetivo del presente estudio fue evaluar el efecto del consumo de mayonesa, sobre algunos factores determinantes del riesgo de enfermedad cardiovascular (ECV). Para ello se utilizaron 24 ratas macho Sprague-Dawley a las cuales se les suministró por un período de 5 semanas, ratarina mezclada con mayonesa ad libitum en proporción de 25 por ciento. Antes y después de recibir la dieta modificada se les determinó, previo ayuno de 12 horas, las concentraciones séricas de glucosa, colesterol total, colesterol de HDL, VLDL y LDL, y triacilglicéridos. Los resultados mostraron un incremento significativo en la glicemia basal (101,3 ± 3,9 vs. 126,4 ± 4,5 mg/dl, p< 0,0001), triacilglicéridos (49,9 ± 3,4 vs. 117,4 ± 27,6 mg/dl; p<0,02) y colesterol de VLDL (10,0 ± 0,7 vs. 23,5 ± 5,5 mg/dl; p<0,02), y una disminución en la concentración de HDL-colesterol (40,8 ± 1,7 vs. 35,8 ± 1,0 mg/dl; p<0,001) sin cambios significativos en el colesterol total y LDL-colesterol. Podemos concluir que una ingesta elevada de aditivos alimenticios con alto contenido graso como la mayonesa, incrementa en las ratas los marcadores del riesgo de ECV lo cual llama a la reflexión por el efecto que dicho aditivo podría también tener en los humanos.

Influencia del hábito de fumar sobre las concentraciones séricas de zinc, cobre y selenio en adultos jóvenes / Influence of smoking on serum concentrations of zinc, copper and selenium in young adults

Zinc, cobre y selenio son cofactores de enzimas antioxidantes, por lo que una disminución de sus niveles séricos, compromete su papel preventivo de enfermedades degenerativas. En este estudio se planteó evaluar la influencia del hábito de fumar cigarrillo sobre las concentraciones séricas de estos cofactores en adultos jóvenes. La muestra estuvo conformada por 40 individuos sanos del sexo masculino, con edades entre 18 y 25 años, índice de masa corporal normal y consumo de nutrientes acorde con sus requerimientos nutricionales, divididos en grupo control (n=20) y grupo de fumadores crónicos (n=20), a los cuales se les cuantificó los niveles séricos de zinc, cobre, selenio y se les estimó la ingesta de nutrientes a través del recordatorio de 24 horas y la frecuencia de consumo de alimentos. En los fumadores los niveles séricos de zinc se mostraron severamente disminuidos (0,36 + 0,10 mg/L) y significativamente inferiores a los encontrados en los controles (0,71 + 0,09 mg/L), mientras que los niveles sérico de cobre y selenio no mostraron diferencia significativa. Los resultados indican que aún cuando el consumo de minerales en los fumadores fue adecuado, la dieta habitual no logró mantener la concentración sérica de zinc en los rangos normales, haciéndolos más susceptibles al estrés oxidativo.

Actividad de la enzima antioxidante superóxido dismutasa y niveles de cobre y zinc en pacientes con diabetes mellitus tipo 2 / Activity of the antioxidant enzyme superoxide dismutase and copper and zinc levels in patients with type 2 diabetes mellitus

Los seres vivos han desarrollado diversos mecanismos moleculares, donde participan antioxidantes enzimáticos y cofactores minerales, los cuales permiten la estabilización de estas especies reactivas y ofrecen protección contra sus efectos dañinos. Se ha determinado que en la diabetes existe una mayor producción de radicales libres, razón por la cual el objetivo del presente estudio fue determinar la actividad de la enzima superóxido dismutasa (SOD) y su relación con los niveles de cobre (Cu) y zinc (Zn) en pacientes con diabetes mellitus tipo 2 (DM2). Fueron tomadas muestras sanguíneas en ayuno de 34 pacientes diabéticos y 30 sujetos no diabéticos (controles), para medir la actividad de la Cu /Zn-SOD eritrocitaria y cuantificar Cu y Zn en suero y eritrocitos, mediante métodos espectrofotométricos. Los pacientes con DM2 presentaron una actividad de la Cu /Zn-SOD significativamente inferior (1839±101 U/g Hb) a los controles (2573±161 U/g Hb) (p<0,05). En diabéticos, los niveles de cobre sérico (59,50±6,02 µg/dL) y eritrocitario (1,76±0,14 µg/g Hb) fueron significativamente mayores que en los controles (55,45±5,80 µg/dl y 1,27±0,13 µg/g Hb) (p<0,05). El Zn sérico en diabéticos (119,59±6,73 µg/dl) fue significativamente bajo en comparación con los controles (134,74±9,43 µg/dl), pero los diabéticos tenían más Zn en eritrocitos (39,13±1,05 µg/g Hb) que los controles (31,62±1,75 µg/g Hb) (p<0,05). La actividad de la Cu /Zn-SOD sólo se correlacionó positivamente con el Zn sérico en controles (r=0,712; p<0,05). Los resultados sugieren que los pacientes con DM2 presentan una alteración en el sistema de defensa antioxidante endógeno mediado por la SOD y sus cofactores.

Elevados niveles séricos de lipoproteína (a) en una población afro-venezolana / High serum (a) in a afro-venezuelan population

Altas concentraciones de Lipoproteína (a) [Lp)a)] son consideradas un factor de riesgo independiente para la enfermedad cardiovascular, sin embargo su determinación no se realiza como prueba de rutina en la evaluación de dicho riesgo. El propósito de este estudio fue determinar los niveles séricos de Lp(a) en individuos de las poblaciones de Maracaibo, una localidad con predominio blanco-hispánico, y de Bobures, una localidad afrovenezolana, ambas ubicadas en el Estado Zulia, Venezuela. para ello se seleccionaron al azar un total de 112 individuos, 57 de Maracaibo (edad promedio 41,8 ± 13,5 años), y 55 de Bobures (edad promedio 31,4 ± 17,4 años) a los cuales se les determinó en condiciones basales glicemia, perfil lípidico y Lp(a). Para la cuantificación sérica de Lp(a) fue utilizado un Kit comercial basado en ELISA de doble anticuerpo monoclonal contra apo-B100 y contra apo(a) (Heber Biotech BioSCREEN Lp(a), La Habana, Cuba). El colesterol total y el colesterol de HDL fueron significativamente más elevados en los individuos de Maracaibo que en los de Bobures (p<0.009 y p<0.001 respectivamente), mientras que los niveles de Lp(a) séricos fueron significativamente más elevados (p<0.001 en la población afrovenezolana (media de 59,0 mg/dl) que en los blancos hispánicos) (media de 29,0 mg/dl). Nuestros rsultados sugieren que la población afrovenezolana estudiada al tener concentraciones de Lp(a) dos veces más elevada que la muestra de blancos-hispánicos estudiados y por encima del rango normal de 30 mg/dl, tienen un mayor riesgo de enfermedad cardiovascular, por lo tanto deben ser realizados estudios destinados a determinar de los subtipos de Lp(a) presentes en esta población(AU)

High serum Lipoprotein (a) [Lp(a)] concentrations are considered an independent risk factor for cardiovascular disease. Lp(a) is not usually included as a marker in the routine measurement of the evaluation and management of cardiovascular disease. The goal of this study was to determine the serum Lp(a) levels in two Venezuelas population, Maracaibo, a white-hispanic population, and Bobures, an afro-venezuelan population which has a high prevalence of cardiovascular disease. A total of 112 subjects, 57 from Maracaibo (aged 41,8 ± 13,5 years) and 55 from Bobures (aged 31,4 ± 17,4 years), were selected randomly. Fasting glycemia, lipid profile and Lp(a) concentrations were measured throughout. Serum Lp(a) was measured using a commercial kit (Heber Biotech BioSCREEN Lp(a), La Habana, Cuba). Serum total cholesterol and HDL cholesterol levels were significantly higher in Maracaibo than Bobures subjects (p<0.009 and p<0.001 respectively); whereas Lp(a) levels were significantly higher (p<0.001) in afro-venezuelan (mean 59.0 mg/dl) than in white-hispanic subjects (mean 29.0 mg/dl). Our results suggest that afro-venezuelan population had high serum Lp(a) and low HDL-cholesterol concentrations which could be related with the high prevalence of mortality from cardiovascular disease in this population(AU)

Elevados niveles séricos de lipoproteína (a) en una población afro-venezolana / High serum (a) in a afro-venezuelan population

Altas concentraciones de Lipoproteína (a) [Lp)a)] son consideradas un factor de riesgo independiente para la enfermedad cardiovascular, sin embargo su determinación no se realiza como prueba de rutina en la evaluación de dicho riesgo. El propósito de este estudio fue determinar los niveles séricos de Lp(a) en individuos de las poblaciones de Maracaibo, una localidad con predominio blanco-hispánico, y de Bobures, una localidad afrovenezolana, ambas ubicadas en el Estado Zulia, Venezuela. para ello se seleccionaron al azar un total de 112 individuos, 57 de Maracaibo (edad promedio 41,8 ± 13,5 años), y 55 de Bobures (edad promedio 31,4 ± 17,4 años) a los cuales se les determinó en condiciones basales glicemia, perfil lípidico y Lp(a). Para la cuantificación sérica de Lp(a) fue utilizado un Kit comercial basado en ELISA de doble anticuerpo monoclonal contra apo-B100 y contra apo(a) (Heber Biotech BioSCREEN Lp(a), La Habana, Cuba). El colesterol total y el colesterol de HDL fueron significativamente más elevados en los individuos de Maracaibo que en los de Bobures (p<0.009 y p<0.001 respectivamente), mientras que los niveles de Lp(a) séricos fueron significativamente más elevados (p<0.001 en la población afrovenezolana (media de 59,0 mg/dl) que en los blancos hispánicos) (media de 29,0 mg/dl). Nuestros rsultados sugieren que la población afrovenezolana estudiada al tener concentraciones de Lp(a) dos veces más elevada que la muestra de blancos-hispánicos estudiados y por encima del rango normal de 30 mg/dl, tienen un mayor riesgo de enfermedad cardiovascular, por lo tanto deben ser realizados estudios destinados a determinar de los subtipos de Lp(a) presentes en esta población

Sweeteners and beta-glucans improve metabolic and anthropometrics variables in well controlled type 2 diabetic patients.

UNLABELLED: The introduction of fat and carbohydrates replacers has been a revolutionary advance in treating obesity and diabetes mellitus. Since these materials have shown to have beneficial effects on the metabolic profiles of diabetic patients, they should be useful in designing specific foods for patients with diabetes. OBJECTIVE: To compare metabolic and anthropometric improvements elicited by a diet based on the American Diabetic Association's nutrition recommendations with a modified, low-energy diet incorporating fat replacers and non-sucrose sweeteners. DESIGN: A total of 16 male, well controlled type 2 diabetes patients were divided into two groups of eight; one group received the diet based on the American Diabetic Association's nutrition recommendations, and the other was fed a modified, low-calorie diet containing a fat replacer (beta-glucans derived from oats) and the sweeteners, sucralose and fructose. Both groups were maintained on their respective diets for 4 weeks. All patients performed daily aerobic exercise consisting of walking for 60 minutes. Body weight, body mass index, basal glycemia, hemoglobin HbA1C, and lipid profile were determined in each patient before starting the diets and after 4 weeks of dietary intervention. RESULTS: Both diets produced significant improvements in weight, body mass index, lipid profile, basal glucose, and HbA1C. However, the experimental diet was superior to the American Diabetic Association's diet in improving metabolic and anthropometric profile: greater increase in HDL cholesterol and larger decreases in HbA1C, weight, and body mass index. CONCLUSIONS: A diet incorporating a fat replacer and non-sucrose sweeteners produced a greater improvement in metabolic and anthropometric variables in well controlled type 2 diabetic patients when compared with a diet based on American Diabetic Association's nutrition recommendations.

Increased serum malondialdehyde and decreased nitric oxide within 24 hours of thrombotic stroke onset.

BACKGROUND AND PURPOSE: Ischemia/reperfusion generates free oxygen radicals, which react with the unsaturated lipids of biomembranes resulting in the generation products such as malondialdehyde. Malondialdehyde could be a sensor for tissue damage and reperfusion. Nitric oxide, released due to the early arrival of leukocytes in the brain parenchyma, could be a sensor for nonflow phenomenon. Thereby, the purpose of this research was to evaluate the behavior of malondialdehyde and nitric oxide within the 24 hours after the stroke onset. METHODS: Fifteen patients up to an age of 49 years, admitted to the emergency of University Hospital and Chiquinquirá Hospital in Maracaibo, Venezuela, were examined by a neurologist and underwent 12-lead electrocardiograms and computed tomography for the diagnosis of thrombotic stroke. Serum malondialdehyde and nitric oxide were measured as thiobarbituric acid adducts and total nitrites. Data were collected within the 24 hours after the stroke onset. RESULTS: Malondialdehyde for patients with stroke had a significant increase (P<0.001) when compared with healthy controls (47.9 +/- 7.1 vs. 1.7 +/- 0.2 micromol/L). Conversely, serum nitric oxide for patients with stroke had a significant decrease (P<0.001) when compared with the control group (14.5 +/- 1.4 vs. 41.3 +/- 3.7 micromol/L). The lowest values of malondialdehyde and the highest values of nitric oxide were observed in two patients, who died. CONCLUSIONS: Serum levels of malondialdehyde increase, and serum levels of nitric oxide diminish within 24 hours after the onset of thrombotic stroke onset. This suggests that serum malondialdehyde level could be used as potentially reliable and sensitive marker for reperfusion, whereas nitric oxide levels could acts as potential biochemical sensor for nonreflow phenomenon.

Trimetazidine diminishes fasting glucose in rats with fasting hyperglycemia: a preliminary study.

Trimetazidine is a drug with cardioprotective properties used in coronary artery disease. Its effect has been attributed to the inhibition of the long chain fatty acids intramitochondrial transport via carnitine-palmitoyl-transferase-1. Clinical evidence supports the possibility that trimetazidine is able to improve the fasting glycemia in diabetic patients. For this reason, the objective of the present study was to determine the effect of trimetazidine on serum glucose of Sprague-Dawley rats with fasting hyperglycemia. All animals received water and food "ad libitum." Blood glucose was measured weekly to confirm fasting hyperglycemia in rats. The rats were treated for 1 month with trimetazidine (1 mg/kg), and blood samples were collected (in the fasting period) on the last day of treatment (the 30th day); and then on the 15th day posttreatment, measurements of plasma glucose were taken. Fasting plasma levels after 30 days of trimetazidine administration decreased significantly from 141.2 +/- 3.3 mg/dL (pre-drug) to 120.9 +/- 5.8 mg/dL (P<0.01). 15 days after the end of treatment, fasting plasma glucose levels (137.0 +/- 7.0 mg/dL) were close to the pretreatment levels but significantly different (P<0.05) from levels on day 30 of treatment. These data suggest that trimetazidine improved blood glucose utilization in rats with fasting hyperglycemia.

Comportamiento del perfil lipídico en una muestra de población adulta de la ciudad de Maracaibo / Behavior of the profile lipid in a specimen of population adult of the city of Maracaibo

Las enfermedades isquémicas representan un gran porcentaje de morbi-mortalidad en la población, Investigaciones han establecido la relación perfil lipídico alterado-mayor riesgo para enfermedades isquémicas. Estas cifras corresponden en su mayoría a poblaciones de adultos en otras regiones, por lo cual se considero necesario conocer el comportamiento para estos grupos etarios en nuestra región y el país. Se escogieron 186 individuos de ambos sexos (94 hombres y 92 mujeres) mayores de 40 años de la ciudad de Maracaibo. Fueron divididos en grupos etarios (40 a 49 a, 50 a 59a y 60a y más) y sexo (H y M). Se determinaron concentraciones de Colesterol Total (Ct), Triglicéridos (TG) y HDL colesterol (cHDL), a partir del suero; para el resto de las fracciones fue utilizada la formula de Friedewald. Las diferencias se consideraron como significativas cuando el valor de p<0,05. El Ct mostró diferencia significativa con relación al sexo en el grupo de 60a y más (176,9 ± 4,7 mg/dl-H Vs 200,1 ± 4,9 mg/dl-M). También entre hombres para cada grupo etario (193,5 ± 9,0 mg/dl Vs 192,2 ± 11,2 mg/dl Vs 176,9 ± 4,7 mg/dl). Niveles de TG mostraron significancia entre grupos etarios para hombres (221,15 ± 21,84 mg/dl Vs 170,96 ± 17,94 mg/dl Vs 131,45 ± 6,87 mg/dl), y comparando sexos en grupos de 40-49a (221,1 ± 21,8 mg/dl-H Vs 149,8 ± 9,7 mg/dl-M) y 60 años y más (131,4 ± 6,8 mg/dl-H Vs 157,7 ± 9,8 mg/dl-M. Niveles de cHDL mostraron diferencias entre sexos por cada grupo etario, 40-49a (39,3 ± 1,5 mg/dl-H Vs 48,3 1,7 mg/dl-M), 50-59a (37,3 ± 1,21 mg/dl-HVs 45,2 ± 1,7 mg/dl-M), 60a y más (41,4 ± 1,4 mg/dl-HVs 45,8 ± 1,21 mg/dl-M). Concentraciones de VLDL mostraron diferencia en los tres grupos etarios para hombres (44,2 ± 4,3 mg/dl Vs 34,1 ± 3,5 mg/dl Vs 26,3 ± 1,3 mg/dl), entre sexos para grupos 40-49a (44,2 ± 4,3 mg/dl-H Vs 29,9 ± 1,9 mg/dl-M) y 60a y más (26,2 ± 1,3 mg/dl-H Vs 31,5 ± 1,9 mg/dl-M). El estudio mostró descenso en niveles de Ct y TG en grupos etarios de 60a y más; al igual que diferencias significativas en los niveles de cHDL entre sexos para todos los grupos etarios estudiados

Influencia de la edad y el sexo en el balance oxidación/antioxidación / Age and sex influence in the oxidation/antioxidation balance

El metabolismo oxidativo es el mecanismo de mayor relevancia involucrado en la producción de energía en los animales superiores. La falta de control en este proceso conduce a una sobreproducción de radicales libres de oxígeno, los cuales pueden ocasionar daño a las estructuras celulares. El malondialdehído (MDA) es un marcador de la peroxidación lipídica, cuya producción puede ser compensada por el óxido nítrico (NO), vitamina C y glutatión reducido (GSH) como integrantes del sistema antioxidante del organismo. El objetivo de este estudio fue establecer la influencia de la edad y el sexo en el sistema oxidante/antioxidante en un grupo de sujetos sanos. El MDA fue determinado como producto del ácido tiobarbitúrico, el NO como nitritos totales, la vitamina C oxidada y reducida, utilizando el método de Scharz y Williams y el GSH mediante kit colorimétrico del GSH-400 Assaytm. No se observaron diferencias significativas en las concentraciones de oxidante (MDA), así como tampoco en el sistema antioxidante (NO, vitamina C, GSH) cuando se compararon sujetos de 13 a 19 años con sujetos de 20 a 38 años. Sólo se encontró diferencia significativa al analizar los valores de NO entre sexos, presentando las mujeres un valor significativamente superior (p<0,012). Estos resultados sugieren que el MDA, NO, vitamina C y GSH no cambian en el intervalo de edad estudiado (13-38 años) y que la concentración de NO, sólo se ve afectada por el sexo

Heparinas de bajo peso molecular en la cardiopatía isquemica metab¢lica: bases moleculares: experiencia clínica y resultados / Heparin of low weight molecular in the cardiopatic ischemic metabolic: base molecular: experience clinical and result

Las Heparinas de Bajo Peso Molecular (HBPM) se aíslan a partir de la heparina no fraccionada, siendo su mecanismo de acción el efecto inhibitorio que ejerce sobre el factor Xa por la antitrombina. Las HBPM más utilizadas a nivel mundial son la enoxaparina (Clexane), nadroparina (Fraxiparina) y la dalteparina sodica (Fragmin). Un considerable numero de ensayos clínicos ha comparado el efecto de las HBPM con la NHF en el tratamiento de la trombosis venosa profunda y del tromboembolismo pulmonar donde se confirma la eficacia de las HBPM sobre las NHF. Con base a estudios anteriores, utilizamos la dalteparina sodica a dosis de 5000 Ul/día durante 10 días; indofubeno a dosis de 400 mg/día y trimetazidina a dosis 60 mg/día durante 3 meses en pacientes con cardiopatía isquémico-metabolica. Nuestros resultados muestran una mejoría significativa en la mayoría de los pacientes observándose estabilización en la frecuencia cardíaca, desaparición del dolor precordial y desaparición de los signos de isquémia, lesión y necrosis en el electrocardiograma, por lo que sugerimos la utilización de esta terapéutica no invasiva y ambulatoria en pacientes con cardiopatía Isquémico-metabolica