Resultados clínicos en la reparación artroscópica de manguito rotador con la técnica de Mason-Allen modificada / Clinical results in arthroscopic rotator cuff repair with the modified Mason-Allen technique

Resumen: Introducción: la lesión del manguito de los rotadores es una de las lesiones más comunes del hombro. El tratamiento por elección es la reparación artroscópica con uso de anclas. La técnica Mason-Allen modificada, que integra los beneficios de las suturas puente y colchonero, ha demostrado resultados satisfactorios. El propósito de este estudio es reportar y analizar los resultados clínicos del uso de dicha sutura en rupturas del manguito de los rotadores. Resultados: flexión activa media 126o inicial, 169o a tres meses, 175o a 12 meses (p < 0.0001), abducción activa 98o, tres meses 159o y 167o a 12 meses (p < 0.0001), rotación interna valor prequirúrgico 4.4 ± 3, a los tres meses 7.1 ± 1.7 (p < 0.05) y 12 meses 7.6 ± 1.1 (p < 0.001). Constant Score 45.76 ± 16.35 con un valor de p < 0.0001, a tres meses 87.27 ± 10.94 y 12 meses 91.30 ± 6.00. SSV 41.30 ± 20.89, tres meses 81.43 ± 18.31 y 12 meses 94.37 ± 6.90 (p = 0.0001). EVA media inicial 6.6 ± 1.6 y 12 meses 0.63 ± 1.02 (p < 0.0001). Conclusión: en rupturas del manguito de los rotadores, el uso de hilera simple con técnica Mason-Allen modificada es una opción recomendada y replicable con resultados satisfactorios y mejoría clínica estadísticamente significativa a los tres y 12 meses postquirúrgicos.

Abstract: Introduction: rotator cuff tears are one of the most common shoulder injuries. The treatment of choice is arthroscopic repair with the use of anchors. The modified Mason-Allen technique, which combines the benefits of suture bridge and mattress sutures, has shown satisfactory results. This study aims to report and analyze the clinical results using these suture techniques in rotator cuff tears. Results: preoperative mean active flexion 126o, 169o at three months, 175o at 12 months (p < 0.0001), active abduction 98o, 159o at three months and 167o at 12 months (p < 0.0001), internal rotation preoperative value 4.4 ± 3, at three months 7.1 ± 1.7 (p < 0.05) and 12 months 7.6 ± 1.1 (p < 0.001). Constant score 45.76 ± 16.35 (p < 0.0001) at three months 87.27 ± 10.94 and 12 months 91.30 ± 6.00. SSV 41.30 ± 20.89, three months 81.43 ± 18.31 and 12 months 94.37 ± 6.90 (p = 0.0001). Initial mean VAS 6.6 ± 1.6 and 12 months 0.63 ± 1.02 (p < 0.0001). Conclusion: in rotator cuff tears, using a single row with the modified Mason-Allen technique is a recommended and replicable option with satisfactory results and statistically significant clinical improvement at three and 12 months post-surgery.

[Clinical results in arthroscopic rotator cuff repair with the modified Mason-Allen technique]. / Resultados clínicos en la reparación artroscópica de manguito rotador con la técnica de Mason-Allen modificada.

INTRODUCTION: rotator cuff tears are one of the most common shoulder injuries. The treatment of choice is arthroscopic repair with the use of anchors. The modified Mason-Allen technique, which combines the benefits of suture bridge and mattress sutures, has shown satisfactory results. This study aims to report and analyze the clinical results using these suture techniques in rotator cuff tears. RESULTS: preoperative mean active flexion 126o, 169o at three months, 175o at 12 months (p < 0.0001), active abduction 98o, 159o at three months and 167o at 12 months (p < 0.0001), internal rotation preoperative value 4.4 ± 3, at three months 7.1 ± 1.7 (p < 0.05) and 12 months 7.6 ± 1.1 (p < 0.001). Constant score 45.76 ± 16.35 (p < 0.0001) at three months 87.27 ± 10.94 and 12 months 91.30 ± 6.00. SSV 41.30 ± 20.89, three months 81.43 ± 18.31 and 12 months 94.37 ± 6.90 (p = 0.0001). Initial mean VAS 6.6 ± 1.6 and 12 months 0.63 ± 1.02 (p < 0.0001). CONCLUSION: in rotator cuff tears, using a single row with the modified Mason-Allen technique is a recommended and replicable option with satisfactory results and statistically significant clinical improvement at three and 12 months post-surgery.

INTRODUCCIÓN: la lesión del manguito de los rotadores es una de las lesiones más comunes del hombro. El tratamiento por elección es la reparación artroscópica con uso de anclas. La técnica Mason-Allen modificada, que integra los beneficios de las suturas puente y colchonero, ha demostrado resultados satisfactorios. El propósito de este estudio es reportar y analizar los resultados clínicos del uso de dicha sutura en rupturas del manguito de los rotadores. RESULTADOS: flexión activa media 126o inicial, 169o a tres meses, 175o a 12 meses (p < 0.0001), abducción activa 98o, tres meses 159o y 167o a 12 meses (p < 0.0001), rotación interna valor prequirúrgico 4.4 ± 3, a los tres meses 7.1 ± 1.7 (p < 0.05) y 12 meses 7.6 ± 1.1 (p < 0.001). Constant Score 45.76 ± 16.35 con un valor de p < 0.0001, a tres meses 87.27 ± 10.94 y 12 meses 91.30 ± 6.00. SSV 41.30 ± 20.89, tres meses 81.43 ± 18.31 y 12 meses 94.37 ± 6.90 (p = 0.0001). EVA media inicial 6.6 ± 1.6 y 12 meses 0.63 ± 1.02 (p < 0.0001). CONCLUSIÓN: en rupturas del manguito de los rotadores, el uso de hilera simple con técnica Mason-Allen modificada es una opción recomendada y replicable con resultados satisfactorios y mejoría clínica estadísticamente significativa a los tres y 12 meses postquirúrgicos.

Intracardiac impedance response during acute AF internal cardioversion using novel rectilinear and capacitor-discharge waveforms.

Intracardiac impedance (ICI) is a major determinant of success during internal cardioversion of atrial fibrillation (AF). However, there have been few studies that have examined the dynamic behaviour of atrial impedance during internal cardioversion in relation to clinical outcome. In this study, voltage and current waveforms captured during internal cardioversion of acute AF in ovine models using novel radiofrequency (RF) generated low-tilt rectilinear and conventional capacitor-discharge based shock waveforms were retrospectively analysed using a digital signal processing algorithm to investigate the dynamic behaviour of atrial impedance during cardioversion. The algorithm was specifically designed to facilitate the simultaneous analysis of multiple impedance parameters, including: mean intracardiac impedance (Z M), intracardiac impedance variance (ICIV) and impedance amplitude spectrum area (IAMSA) for each cardioversion event. A significant reduction in ICI was observed when comparing two successive shocks of increasing energy where cardioversion outcome was successful. In addition, ICIV and IAMSA variables were found to inversely correlate to the magnitude of energy delivered; with a stronger correlation found to the former parameter. In conclusion, ICIV and IAMSA have been evidenced as two key dynamic intracardiac impedance variables that may prove useful in better understanding of the cardioversion process and that could potentially act as prognostic markers with respect to clinical outcome.

Electrocardiographic waveforms fitness check device technique for sudden cardiac death risk screening.

A novel cardiac health device technique development for reliable, non-invasive and cost-effective heart screening in preventive cardiovascular healthcare is presented. In particular, identification of apparently healthy individuals involved in sports activities (particularly in the young, age <; 35 years) who may be at-risk of sudden-cardiac-death (SCD) is mainly focused here. Nevertheless, the same device technique may be prospectively extended for detecting cardiovascular abnormalities in children and adolescents with type1-diabetes, and also in detecting patients with Brugada syndrome. The device system has been aimed to provide a single figure diagnostic output, thus, not requiring highly-skilled medical personnel. The principles of the required ECG-waveform analysis algorithm have been reported in previous clinical studies. A prototype system platform design that will enable low-cost, portability and key user-friendly characteristics was implemented and in-vitro tested. Real-time firmware integrity and cardiac fitness detection algorithm performed reliably with an in-vitro positive SCD ECG-waveform modelling technique.

Perfil lipídico en mujeres embarazadas sanas de tres regiones de Chile / Lipid profile in healthy pregnant women in three regions of Chile

Antecedentes: Los lípidos plasmáticos maternos durante el embarazo pueden influir en el crecimiento fetal, particularmente en pacientes con diabetes gestacional; estos lípidos cambian su concentración plasmática materna a lo largo de la gestación. Objetivo: Calcular tablas y curvas de lípidos normales según edad gestacional en una población de embarazadas chilenas. Método: Se midió el colesterol total (CT), colesterol LDL (LDL-C) triglicéridos (TG), Colesterol-HDL (HDL-C), y ácidos grasos no esterificados (NEFA), en 94 embarazadas sanas y jóvenes (<33 años, edad media de 27,6 +/- 6,2 años), con peso pregestacional normal (Índice de Masa Corporal entre 20 y 24,9 Kg/m2 y medio de 23,3 +/- 2,0 Kg/m2). Las pacientes provenían de: Hospital Parroquial de San Bernardo, Santiago (n=55), Hospital de Talca (n=2); Hospital del Profesor, Santiago (n=18); Hospital Regional de Concepción (n=9) y Hospital Clínico de la Pontificia Universidad Católica de Chile (n=10). Resultados: Calculamos, para cada uno de los cuatro lípidos, las curvas de percentil 50, percentil 90 y percentil 10, en mg/dL y mmol/l. Los NEFA solo fueron expresados en mmol/l. Incluimos las funciones matemáticas de las curvas de regresión polinomial de los cuatro lípidos con el fin que sean fácilmente reproducibles en otros tamaños. Conclusiones: Calculamos las tablas y curvas de lípidos maternos normales a lo largo del embarazo, que sean aplicables a la población de embarazadas chilenas.

Background: In normal human pregnancy, maternal lipids can modify the rate of fetal growth, particularly in pregnancies with Gestational Diabetes Mellitus (GDM). These lipids change continuously their serum concentration in the mother along the pregnancy. Aim: To calculate tables and curves of normal serum lipids, according to gestational age, in healthy Chilean pregnant women. Methods: We measured total cholesterol (CT), LDL-cholesterol (LDL-C), triglycerides (TG), HDL-Cholesterol (HDL-C), and Non-Esterified Fatty Acids (NEFA) in 94 young and healthy pregnant women (< 33 years, mean age 27.6 +/- 6.2 years), with normal pregestational Body Mass Index (BMI, 20.0-24.9 Kg/m2 , mean value= 23.3 +/- 2.0 Kg/m2). The women of the study were patients of 5 hospitals: Hospital Parroquial de San Bernardo, Santiago (n=55), Hospital de Talca (n=2); Hospital del Profesor, Santiago (n=18); Hospital Regional de Concepción (n=9) and Hospital Clínico de la Pontificia Universidad Católica de Chile (n=10). Results: For each one of the lipids, we calculated curves of 50th, 90th and 10th percentiles, both in mg/dL and mmol/L (the NEFA were expressed only in mmol/L). The mathematical functions of the curves of polynomial regression of all lipids were included in the manuscript, in order to facilitate their reproduction. Conclusions: We calculated tables and curves of normal maternal serum lipids in relation to gestational, in order to make these available for use in the care of Chilean pregnant women.

Use of frequency analysis on the ECG for the prognosis of low energy cardioversion treatment of atrial fibrillation.

Electric cardioversion is the most effective therapy for restoring sinus rhythm in patient with atrial fibrillation (AF), however, there is not a guiding criteria for advising on when and in whom it will be successful. The objective of this study was to employ frequency analysis on the surface electrocardiogram (ECG) to predict the outcome of low energy internal cardioversion in patients with AF. Thirty nine patients with AF, for elective DC cardioversion were included in this study. One catheter was positioned in the right atrial appendage and another in the coronary sinus. A voltage step-up protocol (50-300 V) was used for patient cardioversion. Prior to shock delivery, residual atrial activity signal (RAAS) was derived from 60 seconds of surface ECG from defibrillator pads, by bandpass filtering and ventricular activity (QRST) cancellation. Dominant atrial fibrillatory frequency (DAFF) was estimated from the RAAS power spectrum as the dominant frequency within the 3-12 Hz band. DAFF was calculated from whole 60 seconds segment (DAFF_L) and from the finals 10 seconds segment (DAFF_S) of the RAAS. Lower DAFF_L and DAFF_S were found in successfully cardioverted patients than in those nonsuccessful ones, with energy < or =3 and < or =6 joules. Therapy result (employing 3J or less) was predicted in 35/39 (89.7%) patients with DAFF_L=5.40Hz, and DAFF_L was > or =5.75Hz in a 100% of noncardioverted patients. In conclusion, frequency analysis of the RAAS could be useful for predicting success of low energy internal cardioversion of patients with atrial fibrillation.

Automatización en el laboratorio clínico / Automation in the clinical laboratory

La automatización de los laboratorios clínicos es un fenómeno que va en aumento, un proceso aplicable a todas las etapas del proceso analítico; el uso de la computación, la incorporación de autoanalizadores y otros elementos automáticos proporciona una serie de ventajas mejorando la eficiencia y la capacidad productiva en beneficio de los pacientes, de los profesionales y del propio laboratorio, reconocer el momento adecuado en que debe aplicarse la automatización así como el grado y etapas en las que se puede intervenir reporta una serie de beneficios, este cambio debe hacerse en forma planificada considerando elementos tales como los costos, la capacitación del personal y las tecnologías disponibles.

The automation of the clinical laboratories is a phenomenon that increases, a process applicable to all the stages of the analytical process, the use of the computation, the incorporation of autoanalyzers and other automatic elements provide a series of advantages improving the efficiency and the productive capacity to the benefit of the patients, of the professionals and the own laboratory, to recognize the suitable moment in which it must be applied to the automation as well as the degree and stages in which it is possible to be taken part reports a series of benefits, this change must be made in planned form considering elements such as the costs, the qualification of the personnel and the technologies available.

Nonlinear analysis of the ECG during atrial fibrillation in patients for low energy internal cardioversion.

The goal of this study was to investigate the usefulness of nonlinear analysis in determining the success of low energy internal cardioversion (IC) in patients with atrial fibrillation (AF). Nonlinear analysis has previously been used for characterizing AF patterns, and spontaneous termination in its paroxysmal form. However, the relationship between the probability to restore sinus rhythm by IC and quantitative nonlinear analysis based electrocardiographic (ECG) markers has not been explored before. Thirty nine patients with AF, for elective DC cardioversion at the Royal Victoria Hospital in Belfast, were included in this study. One catheter was positioned in the right atrial appendage and another in the coronary sinus, to deliver a biphasic shock waveform. A voltage step-up protocol (50-300 V) was used for patient cardioversion. Residual atrial fibrillatory signal (RAFS) was derived from 60 seconds of surface ECG from defibrillator pads, prior to shock delivery, by bandpass filtering and ventricular activity (QRST) cancellation. QRST complexes were cancelled using a recursive least squared (RLS) adaptive filter. The maximal Lyapunov exponent (lambda), correlation dimension (course grained estimation, CDcg) and approximate entropy (ApEn) were extracted from the RAFS. These variables were calculated from 10 s of the RAFS before shock delivery. 26 patients were successfully cardioverted, employing a maximum energy of 11.84 joules. A lower lambda (0.037+/-0.006 vs. 0.044+/-0.008, P=0.01) and CDcg (5.552+/-2.075 vs. 6.592+/-1.130, P=0.049) were found in successfully cardioverted patients than in those non successful ones, with an energy

Determinación de anticuerpos anticélulas beta mediante un método cualitativo por enzima inmunoensayo (ELISA): comparación con técnica de inmunofluorescencia indirecta (IFI) / Determination of islet cell antibodies by qualitative enzyme linked immunosorbent assay (ELISA): comparison with indirect immunofluorescence techniques (IFI)

La diabetes mellitus tipo 1 (DM1) es una enfermedad autoinmune caracterizada por la presencia de autoanticuerpos dirigidos contra la célula beta del páncreas; la presencia de tales marcadores pueden ser detectados en la etapa preclínica de la enfermedad. Entre estos anticuerpos se encuentran los anticuerpos citoplasmáticos antiislote (ICA) los que se han asociado directamente con la aparición de diabetes mellitus tipo 1. El método de referencia es la inmunofluorescencia indirecta (IFI) y en la actualidad existe un método cualitativo por enzima inmunoensayo (ELISA) para determinarlos. El objetivo de este trabajo fue determinar en un grupo de 167 sujetos los ICA mediante ELISA y comparar sus resultados con el método IFI. Se encontraron 10 ICA positivos por IFI y 9 por ELISA, el 70 por ciento de los ICA positivos por IFI se encontraban entre los individuos de menor edad. ELISA tuvo concordancia solo en 2 pacientes. Considerando que los ICA han sido preferentemente utilizados para identificar a los individuos en riesgo de desarrollar DM1 y que la presencia de altos títulos de ICA se asocian a un rápido descenso en los niveles de péptido C, parece adecuado determinar los ICA mediante IFI, a pesar de lo laborioso de la técnica y de la dificultad para procesar volúmenes grandes de muestras.

Diabetes mellitus type I (DM1) is an autoimmune disease characterized by the presence of antibodies on the surface of pancreatic beta cell, these antibodies can also be detected in the preclinic stage before onset of the disease. Among these antibodies are islet cells cytoplasmic antibodies (ICA) who have been directly associated with the onset of type I diabetes mellitus The reference method is the indirect immuno fluorescence (IFI) and by today, there is a qualitative enzyme-linked imnjunosorbent assay (ELISA) for the detection of ICA. The aim of this study was to determine in a group of 167 subiects ICA by ELISA and compare their results with 161. RESULTS: We found 10 positive for ICA with IFI and 9 by Elisa, 70 percent of ICA positive IFI were among individuals younger. Elisa was matched only 2 patients. CONCLUSIONS: Whereas the ICA have been primarily used for identifying individuals at risk for developing DM1 and that the presence of high-titer ICA at diagnosis is associated with a rapid decrease in C-peptide levels seems appropiate to determine the ICA through IFI, despite laborious nature of the technical and difficult to process large volumes of samples.

The effect of internal DC shocks on the atrial fibrillation frequency.

The objective of this study, was to investigate the effect of internal DC shocks on the atrial fibrillation frequency (AFF). AFF has previously been shown to predict the success and energy requirements in patients undergoing internal cardioversion (IC) of atrial fibrillation (AF). However the possibility that unsuccessful shocks during IC may influence the AFF has not been before studied. Thirty eight patients with AF, suggested for DC cardioversion at the Royal Victoria Hospital in Belfast, were included in our study. Two catheters were positioned in the right atrial appendage (RAA) and the coronary sinus (CS), to deliver a biphasic shock waveform, synchronized with the R wave of the electrocardiogram (ECG) signal. A voltage step-up protocol (50-300 V) was used for patient cardioversion. The ECG was analyzed for a mean of 52,8+/-10.1 seconds (corresponding to segments before and after nonsuccessful shocks). Atrial fibrillatory activity was extracted by means of bandpass filtering and ventricular activity (QRST) cancellation. QRST complexes were cancelled using a recursive least squared (RLS) adaptive filter. FFT was applied to the residual atrial fibrillatory signal. AFF was estimated from the dominant frequency within the 3-12 Hz band of the power spectrum. R-R intervals during the segments were also analyzed. A total of 26 patients were successfully cardioverted, employing 167 shocks (141 nonsuccessful). AFF, computed with 10 s of signal, showed significant reduction (mean 0.3052 +/- 1.1055 Hz, P=0.028) comparing segments immediately before and after shocks, and AFF significantly increases (mean 0.2582 +/- 0.609 Hz, P=0.007) between segments immediately after shocks and those 35 s after. AFF showed distinct behavior according to the energy level of the shocks. In conclusion, intracardiac electric shocks could cause transitory changes in the AFF of patients with atrial fibrillation.

Medición del gasto energético basal o en reposo / Basal or rest energy expenditure determination

Las funciones vitales del organismos requieren un determinado gasto energético, que debe ser compensado por los alimentos y bebidas de la dieta. Así. Las necesidades energéticas se definen como la cantidad de energía necesaria para mantener la salud, el crecimiento y un nivel apropiado de actividad física. En situaciones de equilibrio, el ajuste entre la energía ingerida y el consumo energético diario se alcanza a través de diferentes mecanismos, que regulan el apetito y el gusto energético, evitando grandes variaciones en el peso a lo largo del tiempo y, por tanto, la destrucción calórica y obesidad. La medición del gasto energético aporta un dato objetivo en el manejo nutricional de pacientes hospitalizados y ambulatorios. Una de las metodologías utilizadas para realizar la medición es la calorimetría directa o indirecta. La base teórica de la calorimetría asegura exactitud y confiabilidad cuando la medición se realiza bajo condiciones adecuadas. La calorimetría indirecta constituye el método de aplicación más frecuente en clínica, adaptándose para ser usado en todo tipo de pacientes mientras que la calorimetría directa es reservada para estudios de investigación y desarrollo.

Adiponectina en mujeres premenopausicas obesas y no obesas: su relación con la resistencia insulinica / Adiponectin levels in premenopause obese and non-obese women: its relationship with the insulin resistance

La adiponectina es una hormona producida exclusivamente por el adiposito. Se han reportado concentraciones plasmáticas reducidas en individuos con obesidad, hipertensión o dislipidemia. En este estudio se compararon los niveles de adiponectina en mujeres premenopáusicas no obesas y obesa, divididas en insulinosensibles (IS) e insulinorresistentes (IR). Se midió colesterol total, colesterol de lipoproteína de alta densidad (C-HDL), triglicéridos, glucosa de ayuno, insulina plasmática, adiponectina por RIA y el grado de adiposidad mediante índice de masa corporal (IMC). La resistencia a la insulina determinada por el modelo matemático HOMA IR se asoció negativamente con la adiponectina en mujeres no obesa y obesas independientemente del IMC. Las mujeres no obesa y obesas IS tuvieron los niveles de adiponectina más altos que la no obesas y obesas IR. Asimismo, la concentración de adiponectina se correlacionó positivamente con el C-HDL en ambos grupos de mujeres. En conclusión, encontramos que los niveles disminuidos de adiponectina se asociaron a resistencia a la insulina, hiperinsulinismo, concentración baja de C-HDL y mayores niveles de triglicéridos en mujeres premenopáusicas obesas y no obesas, independientemente de la obesidad.

Concentraciones plasmáticas de adiponectina en individuos normales y obesos correlacionadas con el perfil de lípidos plasmáticos / Plasma adiponectin concentration in normal weight and obese individual is associated with profile of plasma lipids

La adiponectina es una proteína del tejido adiposo que mejora la sensibilidad a la insulina y posee propiedades antiaterogénicas. Los niveles circulantes son más bajos en hombres que en mujeres y se encuentran disminuidos en la obesidad, diabetes tipo 2 y enfermedad cardiovascular. Este estudio investiga la relación entre los niveles de adiponectina con los líquidos plasmáticos y la resistencia a la insulina, en 180 individuos normales y obesos. Medimos adiponectina, mediante radioinmunoanálisis, colesterol total sérico, colesterol de HDL (C-HDL), triglicéricos, glicemia de ayuno e insulina plasmática. Las mujeres tenían la adiponectina más alta que los hombres (8,45 ± 3,82 versus 6,10 ± 2,62) y la resistencia a la insulina medida por HOMA IR se correlacionó negativamente con la adiponectina tanto en obesos como en no obesos, independientemente del índice de masa corporal (IMC). Asimismo, hubo una correlación positiva entre adiponectina y C-HDL (p = 0,01) y negativa con los triglicéridos (p = 0,05). Estos resultados indican que los niveles elevados de triglicéridos y los bajos niveles de C-HDL se asocian con concentraciones plasmáticas disminuidas de adiponectina. Se requieren mayores estudios para determinar si la adiponectina es la causante de estas anormalidades lipídicas.

Estudio del gasto energético basal mediante calorimetría indirecta y fórmulas tradicionales en una población de adultos obesos / Basal energetic expenditure study by means indirect calorimetric and traditionals formulas in a population of obese adults

La obesidad es una enfermedad compleja, multifactorial y crónica, asociada a una serie de patologías, con un alto índice de fracasos en su tratamiento, lo que la transforma en un problema de salud pública. Se postula que es producida por un desbalance entre la energía aportada y la requerida. El cálculo del gasto energético basal (GEB) puede ser estimado mediante fórmulas o medido por equipos especializados. El objetivo de este estudio fue comparar el GEB medido con el GEB estimado por fórmulas, en una población de adultos. No se encontraron diferencias significativas entre ambos métodos estudiados y con muy buenas correlaciones entre ellos. Se estima que el uso de fórmulas para estimar el GEB en aquellos lugares donde no es posible contar con equipos especializados, puede ser una muy buena ayuda para el profesional clínico.

Síndrome metabólico / Metabolic syndrome

El síndrome metabólico es definido como una serie de factores de riesgo metabólicos que incluyen resistencia insulínica, obesidad abdominal, hiperglicemia, hipertensión arterial y dislipidemia, los que aumentan tanto el riesgo de enfermedad cardiovascular como de diabetes tipo 2. Han sido varios los intentos por standarizar los criterios de diagnósticos del síndrome metabólico, los más divulgados son los de la Organización Mundial de la Salud y del Programa Nacional de Educación del Colesterol de EEUU. Variables grados de asociación se ha reportado entre el síndrome metabólico y los factores que lo componen pareciendo ser los más importantes, la resistencia insulínica y la obesidad seguidos por la dislipidemia y finalmente la hipertensión. El objetivo de este artículo es hacer una revisión del síndrome metabólico y su asociación con la resistencia insulínica y la obesidad.

La Hemoglobina glicosilada en el control de la diabetes mellitus / The glycosylated hemoglobin in the control of the mellitus diabetes

Uno de los principales exámenes en el manejo clínico de la diabetes lo constituye la determinación de hemoglobina glicosilada. Existen diferentes métodos para cuantificarla, algunos miden el total de las hemoglobinas glicosiladas (HbA1) y otros, exclusivamente la concentración de la hemoglobina A1c. El método de referencia propuesto por el Programa Nacional para la Estandarización de la Hemoglobina Glicosilada (NGSP) es el HPLC de intercambio catiónico. El objetivo de este trabajo fue comparar 2 técnicas para determinar hemoglobina glicosilada en pacientes diabéticos. Se estudiaron 222 pacientes diabéticos, de ambos sexos quienes concurrieron a control al Laboratorio de Nutrición de la Pontificia Universidad Católica de Chile. Se les midió HbA1 mediante el método de Gabbay y HbA1c mediante HPLC. El análisis de los datos se realizó utilizando SPSS para estadística descriptiva y correlaciones y Medcal para la estadística de Bland y Altman. El coeficiente de correlación entre ambos métodos fue de 0,93 y al aplicar el test de Bland y Altman se observó un muy buen nivel de concordancia entre ambas metodologías cuya ecuación de regresión es: por ciento HbA1c = por ciento HbA1 - 2,3. Actualmente, se sabe que un estricto control de las hiperglicemias reduce significativamente el riesgo de las complicaciones vasculares tanto en diabéticos tipo 1 como tipo 2. En este sentido la determinación de hemoglobina glicosilada cumple un rol importante en el control clínico de la enfermedad. Implementar la técnica recomendada por el NGSP en un laboratorio asistencial requiere de un equipamiento costoso, situación poco favorable para laboratorios pequeños o de ingresos reducidos los que buscan obtener técnicas simples, de bajo costo y confiables. El método colorimétrico de Gabbay es una buena alternativa para esos laboratorios.

Determinación del índice de resistencia insulínica mediante HOMA en una población de la Región Metropolitana de Chile / Measurement of insulin resistance using the homeostasis model

Background: Insulin resistance is defined as an inappropriate high level of plasma insulin required to maintain metabolic homeostasis. It is associated with type 2 diabetes and cardiovascular diseases. The glucose clamp technique is the standard method for the measurement of insulin resistance. However, this method is laborious, expensive and impractical to perform in epidemiological investigations. The homeostasis model assessment (HOMA) has been proposed to assess insulin resistance and secretion, using fasting glucose and insulin concentrations. Aim: To measure insulin resistance using HOMA (HOMAir) in a population sample from the Metropolitan Region in Chile. Material and Methods: One hundred twenty subjects (59 female) with a normal body mass index and fasting blood glucose were studied. Fasting plasma glucose was measured by a glucose oxidase method and serum insulin was measured by radio immunoassay. Results: Fasting blood glucose was 81.6ñ9.4 mg/dl and serum insulin was 9.7ñ2.4 µU/ml. Mean HOMA insulin resistance was 1.96ñ0.57 (range 0.5 and 3.0). Conclusions: These HOMA values can be used as reference for Chilean non obese individuals

A gastroesophageal electrode for electrophysiological studies.

A novel gastroesophageal electrode has been developed capable of atrial and ventricular pacing. We performed electrophysiological studies using the gastroesophageal electrode (Esothoracic) and compared the results with the standard endocardial approach. The flexible polythene gastroesophageal electrode was passed into the stomach under light sedation. Five ring electrodes, now positioned in the lower esophagus were used for bipolar atrial pacing and recording. Ventricular pacing was performed using a cathodic point source on the gastroesophageal electrode tip; the indifferent electrode (anode) was a high impedance chest pad. Parameters of sinus and AV nodal function were obtained by atrial pacing. Programmed ventricular stimulation was performed using a standard protocol. These electrophysiological parameters were subsequently determined using the endocardial approach. There was close correlation between measurements of sinus and AV node function using the two approaches in 48 subjects: sinus node recovery time (SNRT) r2 = 0.70, corrected sinus node recovery time (CSNRT) r2 = 0.87, AV Wenckebach cycle length (AVWCL) r2 = 0.97. The degree of agreement between the two approaches was estimated by the mean difference delta and standard deviation of the difference sigma (SNRT delta = 40 ms, sigma = 257 ms; CSNRT sigma = 14 ms, delta = 164 ms; AVWCL sigma = 7 ms, delta = 16 ms). Programmed ventricular stimulation was performed in 15 of 48 subjects with known or suspected ventricular tachyarrhythmias. Seven had ventricular tachycardia induced using both esothoracic and endocardial programmed ventricular stimulation. One subject was noninducible using esothoracic programmed ventricular stimulation, but inducible at endocardial electrophysiological studies. Another subject was inducible at esothoracic electrophysiological studies, but noninducible using endocardial programmed ventricular stimulation. Six subjects were noninducible using both endocardial and esothoracic programmed ventricular stimulation. The gastroesophageal electrode permits reliable atrial and ventricular pacing without transvenous catheterization or fluoroscopy. Electrophysiological parameters determined using this electrode are similar to those obtained using endocardial stimulation.

Neuropatía diabética: sensibilidad térmica y control metabólico en diabéticos no insulinodependientes / Diabetic neuropathy: thermal sensation and metabolic control in non insulin dependent diabetics

Background: The early detection of peripheral neuropathy in diabetics is important since it is the main riskfactor for lower limb trophic lesions in diabetics. Aim: To assess the relationship between feet thermal sensation threshold and metabolic control in ambulatory non-insulin-dependent diabetics. Pattients and methods: A random sample of 34 non-insulin-dependent diabetic followed for more than five years in a special clinic, out of 368 patients, was selected. Warmth sensation thresbolds were measured in the dorsum of booth feet using a MSTP-III thermostimulator The average value of all glycosylated hemoglobins obtained during the 9.7 ñ 5.3 years of follow up for each patient was calculated. A multiple stepwise regression analysis was performed between thermal sensation as the dependent variable and glycosylated hemoglobin, fasting blood glucose, age and diabetes duration. Results: The regression model disclosed glycosylated hemoglobin as the only independent predictor of warmth sensation threshold (partial r= 0.385; p= 0.043). Fifteen diabetic patients with metabolic control, defined as those with a mean glycosylated hemoglobin of less than 9.5 percent, had a warmth sensation threhold of 35.6 ñ 3.7 ºC, whereas 19 diabetics with a bad control (glycosylated hemoglobin 9.5 percent) had a threshold of 39 ñ 3.8 ºC(p= 0.017). Conclusions: In this group of diabetics there is a relationship between the severity of distal polyneuropathy and the metabolic contrl, assessed with glycosylated hemoglobin levels