Impaired Reverse Cholesterol Transport is Associated with Changes in Fatty Acid Profile in Children and Adolescents with Abdominal Obesity.

BACKGROUND: Abdominal obesity is an important cardiovascular disease risk factor. Plasma fatty acids display a complex network of both pro and antiatherogenic effects. High density lipoproteins (HDL) carry out the antiatherogenic pathway called reverse cholesterol transport (RCT), which involves cellular cholesterol efflux (CCE), and lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) activities. OBJECTIVES: Our aim was to characterize RCT and its relation to fatty acids present in plasma in pediatric abdominal obesity. METHODS: Seventeen children and adolescents with abdominal obesity and 17 healthy controls were studied. Anthropometric parameters were registered. Glucose, insulin, lipid levels, CCE employing THP-1 cells, LCAT and CETP activities, plus fatty acids in apo B-depleted plasma were measured. RESULTS: The obese group showed a more atherogenic lipid profile, plus lower CCE (Mean±Standard Deviation) (6 ± 2 vs. 7 ± 2%; P < 0.05) and LCAT activity (11 ± 3 vs. 15 ±5 umol/dL.h; P < 0.05). With respect to fatty acids, the obese group showed higher myristic (1.1 ± 0.3 vs. 0.7 ± 0.3; P < 0.01) and palmitic acids (21.5 ± 2.8 vs. 19.6 ± 1.9; P < 0.05) in addition to lower linoleic acid (26.4 ± 3.3 vs. 29.9 ± 2.6; P < 0.01). Arachidonic acid correlated with CCE (r = 0.37; P < 0.05), myristic acid with LCAT (r = -0.37; P < 0.05), palmitioleic acid with CCE (r = -0.35; P < 0.05), linoleic acid with CCE (r = 0.37; P < 0.05), lauric acid with LCAT (r = 0.49; P < 0.05), myristic acid with LCAT (r = -0.37; P < 0.05) ecoisatrienoic acid with CCE (r = 0.40; P < 0.05) and lignoseric acid with LCAT (r = -0.5; P < 0.01). CONCLUSIONS: Children and adolescents with abdominal obesity presented impaired RCT, which was associated with modifications in proinflammatory fatty acids, such as palmitoleic and myristic, thus contributing to increased cardiovascular disease risk.

Characterization of zinc transporter 8 (ZnT8) antibodies in autoimmune diabetic patients from Argentinian population using monomeric, homodimeric, and heterodimeric ZnT8 antigen variants.

OBJECTIVE: In order to gain further knowledge of the structure of zinc transporter 8 (ZnT8) epitopes, we studied the role of the amino acid at position 325 in the antigen and its dimeric conformation for autoantibodies to ZnT8 (ZnT8A) recognition. METHODS: For this purpose, several ZnT8 C-terminal domain variants were designed: monomer carrying Arg325 or Trp325, homo-dimers ZnT8-Arg-Arg325 and ZnT8-Trp-Trp325, and hetero-dimer ZnT8-Arg-Trp325. Two groups of Argentinian diabetic patients were subjected to analysis using [(35)S]-ZnT8 variants by radioligand binding assay (RBA): i) 100 new-onset, insulin-dependent, type 1 diabetic patients and ii) 282 slowly progressing to insulin requirement, non-obese adult-onset diabetic patients. In addition, 50 type 1 diabetic patients and 100 normal control sera provided by the American Diabetes Association (ADA) were evaluated in order to calculate the sensitivity and specificity of ZnT8A assays for each antigenic variant. Other routine ß-cell autoantibodies were also tested by RBA. RESULTS: Of the 100 Argentinian type 1 diabetic patients, 65 were ZnT8A+. Out of them, 8 patients recognized all recombinant forms of ZnT8 and most patients (56) reacted against the heterodimer. Additionally, out of 282 non-obese adult-onset diabetic patients 46 were ZnT8A+, whereas 29 patients recognized only dimers. Besides, exclusive reactivity against ZnT8A was found in 9.0% for type 1 diabetes mellitus and 10.3% for non-obese adult-onset diabetic patients. CONCLUSIONS: Significantly higher signal values in RBA were obtained with the heterodimeric variant. An increased detection of humoral autoimmunity was found in both groups when ZnT8A was employed in combination with the other ß-cell autoantibodies. The inclusion of homodimeric immunoreactive peptides revealed the existence of quaternary structure-defined epitopes probably resembling the actual state of the autoantigen in vivo. Finally, the differential profiles of ZnT8A exhibited by type 1 and non-obese adult-onset diabetic patients suggest the different nature of autoimmune processes underlying both pathologies.

Monitoreo continuo de glucosa: indicaciones, interpretación de datos y toma de decisiones terapéuticas. Recomendaciones de expertos / Continuous glucose monitoring: indications, data interpretation and making therapeutic decisions. Expert recommendations

Las herramientas para evaluar el grado de control glucémico se modificaron últimamente. La emoglobina glicosilada (HbA1c), parámetro de referencia (gold standard), refleja el control glucémico de los últimos tres meses de manera retrospectiva, sin expresar la variabilidad glucémica. El automonitoreo glucémico capilar (AGC) brinda información inmediata y prospectiva, pero dispone de pocos datos glucémicos para generar promedios y desviaciones estándares representativas. No detecta tendencias y tiene limitaciones para obtener datos nocturnos o durante la actividad física. Es invasivo y muchas veces rechazado. Contrariamente, el monitoreo continuo de glucosa (MCG) mide la glucosa instantáneamente, y muestra sus tendencias y su variabilidad en forma continua, incorporando nuevas métricas de control. Mediante el perfil ambulatorio de glucosa (PAG) se analizan los patrones del control glucémico durante el sueño, los ayunos prolongados, la actividad física y las intercurrencias, expresándolos como curvas con sus desviaciones estándar durante períodos de horas (8 a 24 horas) o días (7, 14, 30 y 90 días). El PAG contiene las siguientes métricas: porcentaje de tiempo en rango TIR (del inglés, time in range), porcentaje de tiempo por encima del rango TAR (del inglés, time above range), porcentaje de tiempo por debajo del rango o hipoglucemia TBR (del inglés, time below range) y coeficiente de variabilidad (%CV). La información continua permite tomar decisiones inmediatas, ya sea con la ingesta de carbohidratos o con la aplicación de insulina. El MCG con terapéuticas insulínicas inyectables (TII) o bomba portable de insulina (BPI) es una herramienta muy útil y complementaria para el tratamiento de la diabetes mellitus tipo 1 (DM1) y la DM2 en la insulinoterapia. Su utilización se asoció con descensos significativos en la HbA1c, disminución de la variabilidad glucémica, reducción de las hipoglucemias totales y nocturnas, y mejoría de la calidad de vida en estos pacientes. Nuestro propósito como grupo de expertos es generar una guía práctica para regular la implementación del MCG.

The tools to assess the degree of glycemic control were modified lately. Glycosylated hemoglobin (HbA1c), the gold standard, reflects the glycemic control of the last 3 months retrospectively, without expressing glycemic variability. Selfblood glucose monitoring (SBGM) provides immediate and prospective information, but has little glycemic data to generate representative averages and standard deviations. It does not detect trends and has limitations to obtain nocturnal data or during physical activity. It is invasive and often rejected. On the contrary, continuous glucose monitoring (CGM), allows to measure glucose instantly, shows your trends and variability continuously, incorporating new control metrics. The ambulatory glucose profile (AGP) analyzes the patterns of glycemic control during sleep, prolonged fasting, physical activity and intercurrences, expressing them as curves with their standard deviations during periods of hours (8 to 24 hours) or days (7, 14, 30 and 90 days). The AGP contains the following metrics: percentage time in range (TIR), percentage time above range mg/dl (TAR), percentage time below range or hypoglycemia (TBR) and coefficient of variation (%CV). CGM with IIT or continuous subcutaneous insulin infusion (CSII), is a very useful and complementary tool for the treatment of DM1 and DM2 in insulin therapy. Its use was associated with significant decreases in HbA1c, decreased glycemic variability, reduction of total and nocturnal hypoglycemia and improvement of the quality of life in these patients. Our aim as a group of experts is to generate a practical guide to regulate the implementation of the CGM.

Detección del envejecimiento vascular acelerado por ecografía carotídea en niños y adolescentes con alto riesgo vascular / Detection of early vascular aging by carotid ul-trasound in children and adolescents with high vascular risk

Introducción. El envejecimiento vascular acelerado (EVA) puede ser detectado por ecografía vascular midiendo el espesor miointimal carotídeo (EMC) y/o la rigidez arterial (RA). El objetivo fue estimar la presencia de EVA en niños y adolescentes con alto riesgo vascular. Material y método. Se incluyeron pacientes Diabéticos tipo 1 (DM1), dislipidémicos familiares (DLP) y obesos. Se evaluaron el EMC y determinantes de la RA, y se compararon los resultados con tablas de percentilos para niños y adolescentes sanos ya publicadas. Cuando el EMC y/o los índices de RA superaron el percentilo 95, se informó como EVA. El análisis estadístico se realizó con SPSS 20., Los datos discretos fueron presentados como frecuencia en porcentaje. Se utilizó el chi cuadrado para comparar las variables dicotómicas. Se consideró estadísticamente significativo un valor de p < 0,05. Resultados. De un total de 199 pacientes, 54,8% eran mujeres (109), edad media de 12,6 años ± 3,4 años. Con DM1: el 41,7%; DLP: 32,2%; y obesos: 25,6%. Presentaron EMC anormal el 34,7% (69 pacientes). Los obesos tuvieron menor alteración del EMC (p=0,002), siendo los varones los más afectados: el 43,3%, p= 0,02. A 141 pacientes se les realizaron mediciones de RA, que fueron anormales en el 46,1% (65 pacientes), sin diferencias por sexo o diagnóstico. La presencia de EVA medida por ambos métodos alcanzó al 58% de la muestra. Conclusiones. Presentó EVA el 58% de los pacientes. Un tercio tuvo EMC anormal, que fue más frecuente en los varones, en los pacientes con diabetes y en los dislipidé- micos. La mitad de las mediciones de la rigidez arterial fueron anormales, independientemente del diagnóstico o del sexo. Futuros estudios serán necesarios para determinar la utilidad clínica de estos hallazgos.

Introduction. Early vascular aging can be detected by vascular ultrasound measuring the carotid intima media thickness and/or the arterial stiffness. The objective was to estimate the presence of early vascular aging in children and adolescents with high vascular risk. Material and method. Type 1 diabetic patients, patients with familial dyslipidemia and obese patients were included. The carotid intima media thickness and determinants of arterial stiffness were evaluated, and the results were compared to already published percentile tables of healthy children and adolescents. When the carotid intima media thickness and/or the arterial stiffness indexes exceeded 95th percentile, it was informed as early vascular aging. The statistical analysis was performed using SPSS 20. Data are shown as mean ±SD, median or percentage. Comparisons of dichotomous variables (percentage) were made using χ2 test. P values <0.05 were considered significant. Results. Out of a total of 199 patients, 54.8% were females (109 patients), with mean age of 12.6 years ± 3.4 years. With type 1 diabetes: 41.7%; familial dyslipidemia: 32.2%; obesity: 25.6%. 34.7% (69 patients) presented with abnormal carotid intima media thickness. Obese patients had minor alteration of the carotid intima media thickness (p = 0,002), and males were the most affected ones: 43.3%, p = 0.02. Arterial stiffness was measured in 141 patients, which was abnormal in 46.1% (65 patients), with no age or diagnosis difference. The presence of early vascular aging measured by both methods reached 58% of the sample. Conclusions. Early vascular aging occurred in 58% of the patients. One third had abnormal carotid intima media thickness, which was more frequent in males, in diabetic patients and patients with dyslipidemia. Half of the arterial stiffness measurements were abnormal, independent of diagnosis or sex. Further studies will be required to determine the clinical utility of these findings.

[Prebiotics in infant health]. / Prebióticos en salud infantil.

The composition of human milk is the main base for the development of infant formulas concerning its macronutrients and micronutrients contents and bioactive compounds. Technological advances in the composition of human milk have identified a great number of bioactive compounds such as prebiotics which are responsible for immunological protection and the prevention of different pathologies. In order to achieve similar benefits, they are part of the contents of infant formulas.

Detección y caracterización de autoanticuerpos anti-ZnT8 en pacientes argentinos con diabetes mellitus tipo 1 / Detection and characterisation of zinc transporter 8 autoantibody in Argentinian patients with type 1 diabetes mellitus

Introducción y objetivos: El transportador de Zn8 (ZnT8), identificado como el cuarto autoantígeno inmunodominante en la diabetes mellitus (DM) tipo 1, presenta un polimorfismo en el residuo 325 (Arg/Trp). Sin embargo, aún no se encuentra suficientemente definido el papel de este residuo en la inmunorreactividad de los autoanticuerpos anti-ZnT8 (ZnT8A). En este contexto, el objetivo del presente trabajo involucró la detección y caracterización inmuno-química de los ZnT8A en DM tipo 1 empleando diferentes variantes antigénicas de ZnT8 con Arg o Trp en la posición 325, o bien construcciones quiméricas con ambos aminoácidos en dicha posición. Materiales y métodos: Se evaluaron 100 sueros de pacientes argentinos con reciente diagnóstico de DM tipo 1. La determinación de ZnT8A se realizó mediante el ensayo de unión de radioligando, utilizando distintas variantes antigénicas: ZnT8-Arg325, ZnT8-Trp325, ZnT8- Arg-Trp325, ZnT8-Arg-Arg325 y ZnT8-Trp-Trp325. Paralelamente se determinó la presencia de los otros marcadores de autoinmunidad para DM por ensayo de unión de radioligando. Resultados: De los 100 pacientes estudiados, 65 fueron ZnT8A+ para al menos alguna de las variantes antigénicas empleadas. Ocho reconocieron todas las formas recombinantes de ZnT8. La mayoría (56) resultaron positivos para el heterodímero (ZnT8-Arg-Trp325), 25 de los cuales reconocieron además el homodímero ZnT8-Arg-Arg325 y el monómero ZnT8-Arg325. Nueve pacientes presentaron únicamente ZnT8A como marcador de autoinmunidad. Por otro lado, los niveles de señales obtenidos con el heterodímero fueron significativamente mayores a los niveles alcanzados empleando cualquiera de las otras variantes antigénicas (mediana 17,99 vs. 10,71; 6,32; 5,66 y 4,44 SD scores para ZnT8-Arg325, ZnT8-Trp325, ZnT8-Arg-Arg325 y ZnT8-Trp-Trp325, respectivamente; p < 0,05, test t de Mann-Whitney). Conclusiones: Se logró caracterizar inmunoquímicamente los ZnT8A presentes en pacientes argentinos con DM tipo 1 empleando diferentes variantes antigénicas de ZnT8. Se observó que la incorporación de ZnT8A, en combinación con los marcadores clásicos, incrementa la sensibilidad diagnóstica de autoinmunidad. La reactividad exclusiva de ZnT8A por las variantes antigénicas que contienen arginina en el residuo 325 evidencia la existencia de epítopes dependientes del aminoácido presente en dicho residuo. Además, la aplicación de variantes diméricas reveló la existencia de epítopes definidos por la estructura cuaternaria de ZnT8. La construcción heterodimérica fue la que mostró la mejor combinación de sensibilidad y especificidad a los fines del screening rutinario de ZnT8A.

Introduction and objectives: The aim of this study involved the detection and immunochemical characterisation of ZnT8 autoantibodies (ZnT8A) in new-onset type 1 Argentinian diabetic patients. Material and methods: One hundred sera from type 1 diabetic patients were tested for ZnT8A. The antigens employed were obtained using cDNA plasmids encoding the C-terminal domains of ZnT8 carrying 325Arg, 325Trp and 3 dimeric constructs (ZnT8-Arg-Trp325, ZnT8- Arg-Arg325 and ZnT8-Trp-Trp325). ZnT8A were assessed by radioligand binding assay (RBA). Other islet-autoantibodies were also tested by RBA. Results: Among the 100 type 1 diabetic patients, the prevalence of ZnT8A was 65.0%, 8 recognized all recombinant forms of ZnT8. Most patients (56) were positive for the heterodimer (ZnT8-Arg-Trp325), being 25 of them also positive for the homodimer ZnT8-Arg-Arg325 and monomer ZnT8-Arg325. Single reactivity against ZnT8A was found in 9.0% of the group. Besides, the highest signal values were obtained with the heterodimeric variant (median 17.99 vs. 10.71, 6.32, 5.66 and 4.44 SD scores for ZnT8-Arg325, ZnT8-Trp325, ZnT8-Arg-Arg325 y ZnT8-Trp-Trp325, respectively; p < 0.05, Mann-Whitney t test). Conclusion: Immunochemical characterisation of ZnT8A present in type 1 Argentinian diabetic patients was accomplished, employing different variants of ZnT8. An increased detection of autoimmunity was found when ZnT8A was employed in combination with the other islet-autoantibodies. The presence of autoantibodies that recognized only constructions containing Arg reveals the existence of epitopes dependent of the amino acid present at residue 325. Furthermore, application of dimeric constructions revealed the existence of quaternary structure-defined epitopes which were recognized by type 1 diabetic patients. Finally, the highest combined sensitivity and specificity for routine screening of ZnT8A was accomplished with the heterodimeric construction.

Short allele of serotonin transporter gene promoter is a risk factor for obesity in adolescents.

Obesity and hypertension are increasing medical problems in adolescents. Serotonin transporter (5-HTT) is involved in mood and eating disturbances. Encoded by the gene SLC6A4, the promoter shows functional insertion/deletion alleles: long (L) and short (S). Because individuals who are carriers for the short version are known to be at risk for higher levels of anxiety, we hypothesized that this variant may be associated with overweight. Data and blood samples were collected from 172 adolescents out of a cross-sectional, population-based study of 934 high school students. To replicate the findings, we also included 119 outpatients from the Nutrition and Diabetes Section of the Children's County Hospital. We found that the S allele was associated with overweight (BMI > 85th percentile), being a risk factor for overweight independently of sex, age, and hypertension [odds ratio (OR): 1.85; 95% confidence interval (CI): 1.13, 3.05; p < 0.02]. Additionally, in the outpatient study, compared with the homozygous LL subjects, S allele carriers showed a higher BMI z-score (1.47 +/- 1.09 vs. 0.51 +/- 1.4; p < 0.002) and were more frequent in overweight children. In conclusion, the S allele of the SLC6A4 promoter variant is associated with overweight being an independent genetic risk factor for obesity.

Prebióticos en salud infantil / Prebiotics in infant health

La composición de la leche materna es la base principal para el desarrollo de fórmulas infantiles en cuanto a su contenido de macronutrientes, micronutrientes y compuestos bioactivos. Los avances tecnológicos en el conocimiento de la composición de la leche materna han permitido identificar un gran número de componentes bioactivos, como los prebióticos, responsables de la protección inmunológica y de la prevención de diferentes patologías, lo cual ha llevado a su incorporación en las fórmulas infantiles para lograr beneficios similares.

Prebióticos en salud infantil / Prebiotics in infant health

La composición de la leche materna es la base principal para el desarrollo de fórmulas infantiles en cuanto a su contenido de macronutrientes, micronutrientes y compuestos bioactivos. Los avances tecnológicos en el conocimiento de la composición de la leche materna han permitido identificar un gran número de componentes bioactivos, como los prebióticos, responsables de la protección inmunológica y de la prevención de diferentes patologías, lo cual ha llevado a su incorporación en las fórmulas infantiles para lograr beneficios similares.(AU)