A bout of aerobic exercise in the heat increases carbohydrate use but does not enhance the disposal of an oral glucose load, in healthy active individuals.

We investigated if a bout of exercise in a hot environment (HEAT) would reduce the postprandial hyperglycemia induced by glucose ingestion. The hypothesis was that HEAT stimulating carbohydrate oxidation and glycogen use would increase the disposal of an ingested glucose load [i.e., oral glucose tolerance test (OGTT); 75 g of glucose]. Separated by at least 1 wk, nine young healthy individuals underwent three trials after an overnight fast in a randomized order. Two trials included 50 min of pedaling at 58 ± 5% V̇o2max either in a thermoneutral (21 ± 1°C; NEUTRAL) or in a hot environment (33 ± 1°C; HEAT) eliciting similar energy expenditure (503 ± 101 kcal). These two trials were compared with a no-exercise trial (NO EXER). Twenty minutes after exercise (or rest), subjects underwent an OGTT, while carbohydrate oxidation (CHOxid, using indirect calorimetry) plasma blood glucose, insulin concentrations (i.e., [glucose], [insulin]), and double tracer glucose kinetics ([U-13C] glucose ingestion and [6,6-2H2] glucose infusion) were monitored for 120 min. At rest, [glucose], [insulin], and rates of appearance/disappearance of glucose in plasma (glucose Ra/Rd) were similar among trials. During exercise, heart rate, tympanic temperature, [glucose], glycogen oxidation, and total CHOxid were higher during HEAT than NEUTRAL (i.e., 149 ± 35 vs. 124 ± 31 µmol·kg-1·min-1, P = 0.010). However, during the following OGTT, glucose Rd was similar in HEAT and NEUTRAL trials (i.e., 25.1 ± 3.6 vs. 25.2 ± 5.3 µmol·kg-1·min-1, P = 0.981). Insulin sensitivity (i.e., ISIndexMATSUDA) only improved in NEUTRAL compared with NO EXER (10.1 ± 4.6 vs. 8.8 ± 3.7 au; P = 0.044). In summary, stimulating carbohydrate use with exercise in a hot environment does not improve postprandial plasma glucose disposal or insulin sensitivity in a subsequent OGTT.NEW & NOTEWORTHY Exercise in the heat increases estimated muscle glycogen use. Reduced muscle glycogen after exercise in the heat could increase insulin-mediated glucose uptake during a subsequent oral glucose tolerance test (OGTT). However, plasma glucose kinetics are not improved during the OGTT in response to a bout of exercise in the heat, and insulin sensitivity worsens. Heat stress activates glucose counterregulatory hormones whose actions may linger during the OGTT, preventing increased glucose uptake.

Beta-Blocker Type Effect on Substrate Oxidation during HIIE in Heart Failure Patients: Pilot Data / Efeito do Tipo Betabloqueador na Oxidação de Substratos durante HIIE em Pacientes com Insuficiência Cardíaca: Dados Piloto

Abstract The effect of third and second-generation type of beta-blocker on substrate oxidation especially during high-intensity exercises are scarce. The objective of the study is to explore differences of beta-blocker regimens (vasodilating vs. non-vasodilating beta-blockers) for substrate oxidation during in high-intensity intermittent exercise (HIIE) in chronic heart failure and reduced ejection fraction (HFrEF). Eighteen CHF males (58.8 ± 9 years), 8 under use of β1 specific beta-blockers+alfa 1-blocker and 10 using β1 non-specific beta-blockers, were randomly assigned to 4 different HIIE, in a cross-over design. The 4 protocols were: 30 seconds (A and B) or 90 seconds (C and D) at 100% peak power output, with passive (A and C) or active recovery (50% of PPO; B and D). Energy expenditure (EE; kcal/min), quantitative carbohydrate (CHO) and lipid oxidation (g/min) and qualitative (%) contribution were calculated. Two-way ANOVA and Bonferroni post-hoc test were used (p-value ≤ 0.05) to compare CHO and lipid oxidation at rest and at 10min. Total exercise time or EE did not show differences for beta-blocker use. The type of beta-blocker use showed impact in CHO (%) and lipid (g/min and %) for rest and 10 min, but absolute contribution of CHO (g/min) was different just at 10min (Interaction p = 0.029). Higher CHO oxidation was found in vasodilating beta-blockers when comparing to non-vasodilating. According to our pilot data, there is an effect of beta-blocker type on substrate oxidation during HIIE, but no influence on EE or exercise total time in HFrEF patients.

Resumo Os dados sobre efeito do tipo de betabloqueador de terceira e segunda geração na oxidação do substrato, especialmente durante exercícios de alta intensidade, são escassos. O objetivo do estudo é explorar as diferenças de tratamentos com betabloqueadores (betabloqueadores vasodilatadores vs. não-vasodilatadores) na oxidação de substratos durante exercícios intermitentes de alta intensidade (HIIE) na insuficiência cardíaca crônica e fração de ejeção do ventrículo esquerdo reduzida (ICFEr). Dezoito pacientes do sexo masculino com ICC (58,8 ± 9 anos), 8 em uso de betabloqueadores β1 específicos + bloqueador α-1 e 10 utilizando betabloqueadores β1 não-específicos, foram aleatoriamente designados para 4 diferentes HIIE, em um desenho cruzado. Os 4 protocolos foram: 30 segundos (A e B) ou 90 segundos (C e D) a 100% da potência de pico de saída (PPO), com recuperação passiva (A e C) ou ativa (50% de PPO; B e D). O gasto energético (GE; kcal/min), a ingestão de carboidratos quantitativos (CHO) e oxidação lipídica (g/min) e qualitativa (%) foram calculados. Anova de dois fatores e teste post-hoc de Bonferroni foram usados (p-valor ≤ 0,05) para comparar a oxidação de CHO e lipídios em repouso e aos 10 minutos. O tempo total de exercício ou GE não mostraram diferenças de acordo com o uso de betabloqueadores. O tipo de betabloqueador mostrou impacto em CHO (%) e lípides (g/min e %) para repouso e aos 10 min, mas a contribuição absoluta de CHO (g/min) foi diferente apenas aos 10 minutos (Interação p = 0,029). Foram encontradas maiores oxidações de CHO com betabloqueadores vasodilatadores quando comparados com os não-vasodilatadores. De acordo com nossos dados piloto, há um efeito do tipo do betabloqueador na oxidação do substrato durante o HIIE, mas nenhuma influência no GE ou no tempo total de exercício nos pacientes com ICFEr.

Efecto de los compuestos fenólicos en el metabolismo de los carbohidratos / Effect of phenolic compounds on carbohydrate metabolism

Fundamentos: Una dieta basada en alimentos y bebidas con alto contenido en azúcar y almidón digestible se considera un factor de riesgo de padecer enfermedades crónicas no trasmisibles tales como obesidad y diabetes tipo 2. El objetivo es resumir las evidencias disponibles sobre la efectividad de los compuestos fenólicos en el metabolismo de carbohidratos y en la reducción del riesgo y el tratamiento de estas patologías. Métodos: Revisión bibliográfica mediante los sistemas de búsqueda PubMed y WOS para la identificación de compuestos fenólicos con efecto en el metabolismo de carbohidratos y las patologías metabólicas relacionadas. Resultados: Los compuestos fenólicos actúan a diferentes niveles: vía formación de complejos compuesto fenólico-carbohidrato, vía inhibición enzimática, modulación del transporte y regulación de la liberación de hormonas relacionadas con el metabolismo de los carbohidratos. Su efectividad puede ser igual o superior a la de fármacos utilizados comúnmente en el tratamiento de la diabetes, sin los efectos secundarios que se asocian a estos últimos. Conclusiones: Los flavonoides son los compuestos fenólicos de la dieta que podrían ser más efectivos en la regulación del metabolismo de carbohidratos. Estos pueden inhibir enzimas, modular transportadores; así como, estimular la secreción de hormonas de saciedad

Background: A diet based on foods and beverages with high sugar content and digestible starch is considered a risk factor of non-communicable chronic diseases such as obesity and type 2 diabetes. The aim is to summarize the evidence available on the effect of phenolic compounds in the metabolism of carbohydrates and in the reduction of risk and treatment of these pathologies. Methods: Literature search using PubMed and WOS as search systems for the identification of phenolic compounds with an effect on carbohydrate metabolism and related metabolic pathologies. Results: Phenolic compounds act at different levels: via complex formation of phenolic-carbohydrate compounds, via enzymatic inhibition, modulation of transporters and regulation of the release of hormones related to carbohydrate metabolism. Their effectiveness may be equal or superior to that of drugs commonly used in the treatment of diabetes, but without the side effects that are associated with the latter. Conclusions: Flavonoids are the phenolic compounds found in diet that are effective in regulating carbohydrate metabolism. They can inhibit enzymes, modulate transporters; as well as, stimulate the secretion of satiety hormones

Effect of pre-exercise carbohydrate availability on fat oxidation and energy expenditure after a high-intensity exercise

The aim of this study was to test the hypothesis that reduced pre-exercise carbohydrate (CHO) availability potentiates fat oxidation after an exhaustive high-intensity exercise bout. Eight physically active men underwent a high-intensity exercise (∼95% V̇O2max) until exhaustion under low or high pre-exercise CHO availability. The protocol to manipulate pre-exercise CHO availability consisted of a 90-min cycling bout at ∼70% V̇O2max + 6 × 1-min at 125% V̇O2max with 1-min rest, followed by 48 h under a low- (10% CHO, low-CHO availability) or high-CHO diet (80% CHO, high-CHO availability). Time to exhaustion was shorter and energy expenditure (EE) lower during the high-intensity exercise in low- compared to high-CHO availability (8.6±0.8 and 11.4±1.6 min, and 499±209 and 677±343 kJ, respectively, P<0.05). Post-exercise EE was similar between low- and high-CHO availability (425±147 and 348±54 kJ, respectively, P>0.05), but post-exercise fat oxidation was significantly higher (P<0.05) in low- (7,830±1,864 mg) than in high-CHO availability (6,264±1,763 mg). The total EE (i.e., exercise EE plus post-exercise EE) was similar between low- and high-CHO availability (924±264 and 1,026±340 kJ, respectively, P>0.05). These results suggest that a single bout of high-intensity exercise performed under low-CHO availability increased post-exercise fat oxidation, and even with shorter exercise duration, both post-exercise EE and total EE were not impaired.

Soluble carbohydrate content variation in Sanionia uncinata and Polytrichastrum alpinum, two Antarctic mosses with contrasting desiccation capacities

BACKGROUND: Cryptogamic vegetation dominates the ice-free areas along the Antarctic Peninsula. The two mosses Sanionia uncinata and Polytrichastrum alpinum inhabit soils with contrasting water availability. Sanionia uncinata grows in soil with continuous water supply, while P. alpinum grows in sandy, non-flooded soils. Desiccation and rehydration experiments were carried out to test for differences in the rate of water loss and uptake, with non-structural carbohydrates analysed to test their role in these processes. RESULTS: Individual plants of S. uncinata lost water 60 % faster than P. alpinum; however, clumps of S. uncinata took longer to dry than those of P. alpinum (11 vs. 5 h, respectively). In contrast, rehydration took less than 10 min for both mosses. Total non-structural carbohydrate content was higher in P. alpinum than in S. uncinata, but sugar levels changed more in P. alpinum during desiccation and rehydration (60-50 %) when compared to S. uncinata. We report the presence of galactinol (a precursor of the raffinose family) for the first time in P. alpinum. Galactinol was present at higher amounts than all other non-structural sugars. CONCLUSIONS: Individual plants of S. uncinata were not able to retain water for long periods but by growing and forming carpets, this species can retain water the longest. In contrast individual P. alpinum plants required more time to lose water than S. uncinata, but as moss cushions they suffered desiccation faster than the later. On the other hand, both species rehydrated very quickly. We found that when both mosses lost 50 % of their water, carbohydrates content remained stable and the plants did not accumulate non-structural carbohydrates during the desiccation prosses as usually occurs in vascular plants. The raffinose family oligosaccarides decreased during desiccation, and increased during rehydration, suggesting they function as osmoprotectors.

Executive summary of the consensus document on metabolic disorders and cardiovascular risk in patients with HIV infection

La importancia de las alteraciones metabólicas y su repercusión en los pacientes con VIH requiere un estudio particularizado y actualización continua. A los factores de riesgo presentes en población general se añaden los propios de la infección y/o del tratamiento antirretroviral que obligan a la adecuación de las pautas terapéuticas con fármacos antirretrovirales actualmente disponibles, con un mejor perfil metabólico. Actualmente, las alteraciones metabólicas más comunes de los pacientes con el VIH (resistencia a la insulina, diabetes, hiperlipidemias u osteopenia), así como otros factores de riesgo vascular como la hipertensión arterial, deben tratarse según directrices similares a las de la población general, debiendo insistir en medidas encaminadas a estilos de vida más saludables. El objetivo del presente documento es proporcionar una herramienta de consulta para todos los profesionales que atienden a pacientes con infección por el VIH y que pueden presentar o presentan alguna de las alteraciones metabólicas recogidas en este documento

The importance of the metabolic disorders and their impact on patients with HIV infection requires an individualized study and continuous updating. HIV patients have the same cardiovascular risk factors as the general population. The HIV infection per se increases the cardiovascular risk, and metabolic disorders caused by some antiretroviral drugs are added risk factors. For this reason, the choice of drugs with a good metabolic profile is essential. The most common metabolic disorders of HIV infected-patients (insulin resistance, diabetes, hyperlipidemia or osteopenia), as well as other factors of cardiovascular risk, such as hypertension, should also be dealt with according to guidelines similar to the general population, as well as insisting on steps to healthier lifestyles. The aim of this document is to provide a query tool for all professionals who treat HIV-patients and who may present or display any metabolic disorders listed in this document

Alterations in carbohydrate determinants in rat adrenal gland following experimental hypothyroidism

Thyroid disorders are currently among the most widespread endocrine pathologies, affecting about 3% of the world’s population. Although the thyroid gland interacts with other endocrine organs, including the pituitary and adrenals, the many details of these feedback mechanisms remain obscure. In the relevant literature, no data concerning hypothyroidism-induced remodelling of adrenal gland glycoconjugates were found. Therefore, the aim of the present investigation was to study the effects of experimental hypothyroidism on exposure of glycoepitopes in rat adrenal glands by means of lectin histochemistry. Hypothyroidism was induced by daily diet supplementation of experimental animals with 5 mg/kg mercazolil (1-methyl-2-mercapto-imidazole) for 30 days. Formalin-fixed, paraffin-embedded adrenal glands were labelled by lectin-peroxidase conjugates, with subsequent visualization by diaminobenzidine-tetrahydrochloride. The lectin panel included 12 lectins with different carbohydrate affinities (Con A, PSA, LCA, GNA, PFA, LABA, SNA, RCA, WGA, PNA, SBA, HPA).The most significant effects of hypothyroidism were detected in blood vessels. They included dilation of the adrenal medulla vascular bed, perivascular oedema, and increased LABA reactivity of the vascular endothelium of both the cortex and medulla. Hypothyroidism induced decreased exposure of αDMan/αLFuc with simultaneous accumulation of βDGal/ DGalNAc sugar determinants within the cells of the adrenal parenchyma; this phenomenon apparently was dependent on incomplete glycosylation patterns - i.e. impairments in the processing of oligomannosidic type N-glycans and of fucose-containing glycoconjugates. There was also an increased count of spider-like cells with strongly lectin-reactive cytoplasmic granularity in the cortical region of the adrenal glands, presumably due to hypothyroidism-induced uncoupling of biosynthesis and secretion, with subsequent retention of bioactive compounds within these cells. It can be concluded that hypothyroidism has significant effects on adrenal gland glycoconjugates, inducing decreased αDMan/αLFuc and enhanced βDGal/ DGalNAc determinant exposure, accompanied by an imbalance in the synthesis and secretion of physiologically active substances

No disponible

Marcadores para la detección precoz de las alteraciones del metabolismo hidrocarbonado tras un infarto agudo de miocardio / Markers for early detection of alterations in carbohydrate metabolism after acute myocardial infarction

OBJETIVO: Las alteraciones del metabolismo hidrocarbonado no conocidas son frecuentes en los pacientes con infarto agudo de miocardio, sin que exista un consenso en que pacientes estudiar para su identificación precoz. Nuestro objetivo es evaluar qué variables al ingreso se asocian al diagnóstico posterior de una alteración de dicho metabolismo. DISEÑO: Estudio de cohortes prospectivo. Ámbito: Servicio de Medicina Intensiva del Hospital Universitario Virgen de la Arrixaca (Murcia), España. PACIENTES: Un total de 138 pacientes ingresados en la UCI con infarto agudo de miocardio sin diabetes conocida ni de novo fueron, transcurrido un año, estudiados mediante un test de sobrecarga oral de glucosa. Variables principales: Se recogieron variables clínicas y parámetros analíticos al ingreso y trascurrido un año. Además, al año, se realizó una sobrecarga oral de glucosa y se estudió la capacidad diagnóstica para la diabetes de las variables al ingreso mediante las curvas ROC y análisis multivariable. RESULTADOS: Entre 138 pacientes estudiados, 112 (72,5%) presentaron una alteración del metabolismo hidrocarbonado, incluido un 16,7% de diabetes. La HbA1c se asoció independientemente con el diagnóstico de diabetes (RR: 7,28, IC 95%: 1,65-32,05, p = 0,009) y presentó la mejor área bajo la curva ROC para diabetes (0,81, IC 95%: 0,69-0,92, p < 0,001). CONCLUSIONES: En los pacientes con infarto agudo de miocardio, la HbA1c ayuda a identificar aquellos con alteración del metabolismo hidrocarbonado transcurrido un año. De esta forma, su determinación en este grupo de pacientes puede ser utilizada para identificar a aquellos que precisan un estudio mas detallado para establecer un diagnóstico precoz

OBJECTIVES: Undiagnosed abnormal glucose metabolism is often seen in patients admitted with acute myocardial infarction, although there is no consensus on which patients should be studied with a view to establishing an early diagnosis. The present study examines the potential of certain variables obtained upon admission to diagnose abnormal glucose metabolism. DESIGN: A prospective cohort study was carried out. SETTING: The Intensive Care Unit of Arrixaca University Hospital (Murcia), Spain. PATIENTS: A total of 138 patients admitted to the Intensive Care Unit with acute myocardial infarction and without known or de novo diabetes mellitus. After one year, oral glucose tolerance testing was performed. Main outcomes: Clinical and laboratory test parameters were recorded upon admission and one year after discharge. Additionally, after one year, oral glucose tolerance tests were made, and a study was made of the capacity of the variables obtained at admission to diagnose diabetes, based on the ROC curves and multivariate analysis. RESULTS: Of the 138 patients, 112 (72.5%) had glucose metabolic alteration, including 16.7% with diabetes. HbA1c was independently associated with a diagnosis of diabetes (RR: 7.28, 95% CI 1.65 to 32.05, P = .009), and showed the largest area under the ROC curve for diabetes (0.81, 95% CI 0.69 to 0.92, P = .001). CONCLUSIONS: In patients with acute myocardial infarction, HbA1c helps identify those individuals with abnormal glucose metabolism after one year. Thus, its determination in this group of patients could be used to identify those subjects requiring a more exhaustive study in order to establish an early diagnosis

Proteomic analysis of the regenerating liver following 2/3 partial hepatectomy in rats

BACKGROUND: Liver regeneration (LR) after 2/3 partial hepatectomy (PH) is one of the most studied models of cell, organ, and tissue regeneration. Although the transcriptional profile analysis of regenerating liver has been carried out by many reserachers, the dynamic protein expression profile during LR has been rarely reported up to date. Therefore, this study aims to detect the global proteomic profile of the regenerating rat liver following 2/3 hepatectomy, thereby gaining some insights into hepatic regeneration mechanism. RESULTS: Protein samples extracted from the sham-operated and the regenerating rat livers at 6, 12, 24, 72, 120 and 168 h after PH were separated by IEF/SDS-PAGE and then analyzed by MALDI-TOF/TOF mass spectrometry. Compared to sham-operated groups, there were totally 220 differentially expressed proteins (including 156 up-regulated, 62 down-regulated, and 2 up/down-regulated ones) identified in the regenerating rat livers, and most of them have not been previously related to liver regeneration. According to the expression pattern analysis combined with gene functional analysis, it showed that lipid and carbohydrate metabolism were enhanced at the early phase of LR and continue throughout the regeneration process. Ingenuity Pathway Analysis indicated that YWHAE protein (one of members of the 14-3-3 protein family) was located at the center of pathway networks at all the timepoints after 2/3 hepatectomy under our experimental conditions, maybe suggesting a central role of this protein in regulating liver regeneration. Additionally, we also revealed the role of Cdc42 (cell division cycle 42) in the termination of LR. CONCLUSIONS: For the first time, our proteomic analysis suggested an important role of YWHAE and pathway mediated by this protein in liver regeneration, which might be helpful in expanding our understanding of LR amd unraveling the mechanisms of LR.

Prediabetes y diabetes gestacional / Prediabetes and gestational diabetes

Se debe considerar a la diabetes gestacional (DG) como toda intolerancia a los carbohidratos que aparece o se reconoce durante el embarazo, independientemente del momento de la gestación al diagnóstico del trastorno metabólico, si se administra o no insulina, o si desaparece o no después del parto. Por ello, resulta un grupo heterogéneo de situaciones con diferentes expectativas y pronósticos, en dependencia del momento de su presentación y del grado de afectación metabólica que manifieste...(AU)

Aspectos epidemiológicos de la prediabetes, diagnóstico y clasificación / Epidemiological characteristics of prediabetes, diagnosis and classification

La creciente prevalencia y progresión de la prediabetes a la diabetes (DM) ha convertido a la morbilidad y la mortalidad relacionadas con ella en un problema importante de salud pública. Los diabéticos son vulnerables a complicaciones múltiples y complejas (cardiopatía, accidente cerebrovascular, arteriopatía periférica y microangiopatía entre otras). Las evidencias epidemiológicas indican que esas complicaciones comienzan ya antes de que los pacientes hayan llegado al estadio de diabetes manifiesta. La intervención en los cambios en el estilo de vida sobre las personas en etapas de prediabetes, tiene el potencial de reducir la incidencia de diabetes y la enfermedad cardiovascular y microvascular relacionadas. el término prediabetes se aplica a aquellos casos en los que los niveles de glucemia se encuentran por encima de los valores para individuos normales, pero por debajo de los niveles considerados para DM. Dada su alta frecuencia resulta conveniente considerar la prediabetes como un estado de riesgo importante para la predicción de diabetes y de complicaciones vasculares, así como una manifestación subclínica de un trastorno del metabolismo de los carbohidratos(AU)

Body composition alterarions, energy expenditure and fat oxidation in elderly males suffering from prostate cancer, pre and post orchiectomy

INTRODUCTION: Testosterone is needed for normal male development, muscle strength, bone mineralization, hematopoietic function, and sexual and reproductive functions. The main purpose of androgen deprivation therapy in prostate cancer is to reduce tumor progression, but therapy is often accompanied by significant adverse effects. OBJECTIVE: This study aimed to determine the effects of androgen deprivation therapy on body composition and resting metabolic rate in patients with prostate cancer. PATIENTS AND METHODS: A prospective study was performed to evaluate the body composition of 16 elderly males (aged 63-96; median age 71) with prostate cancer scheduled for orchiectomy, one year before and after surgery. Body composition was measured by DEXA, and energy expenditure, fat and carbohydrate oxidation were measured by indirect calorimetry. RESULTS: Body weight (p=0.01), lean mass (p=0.004), and lipid oxidation (p=0.001) decreased significantly. Carbohydrate oxidation (p=0.02), FSH (p=0.0001) and LH (p=0.0001) levels increased significantly. Changes in fat mass (p=0.06) and bone mineral density (p=0.48) were not significant. CONCLUSIONS: After 12 months of androgen deprivation therapy, elderly men with metastatic prostate cancer exhibit a decline in lean body mass and lipid oxidation, together with increased carbohydrate oxidation.

Effect of carbohydrate availability on time to exhaustion in exercise performed at two different intensities

This study examined the effects of pre-exercise carbohydrate availability on the time to exhaustion for moderate and heavy exercise. Seven men participated in a randomized order in two diet and exercise regimens each lasting 3 days with a 1-week interval for washout. The tests were performed at 50 percent of the difference between the first (LT1) and second (LT2) lactate breakpoint for moderate exercise (below LT2) and at 25 percent of the difference between the maximal load and LT2 for heavy exercise (above LT2) until exhaustion. Forty-eight hours before each experimental session, subjects performed a 90-min cycling exercise followed by 5-min rest periods and a subsequent 1-min cycling bout at 125 percent VO2max/1-min rest periods until exhaustion to deplete muscle glycogen. A diet providing 10 percent (CHOlow) or 65 percent (CHOmod) energy as carbohydrates was consumed for 2 days until the day of the experimental test. In the exercise below LT2, time to exhaustion did not differ between the CHOmod and the CHOlow diets (57.22 ± 24.24 vs 57.16 ± 25.24 min). In the exercise above LT2, time to exhaustion decreased significantly from 23.16 ± 8.76 min on the CHOmod diet to 18.30 ± 5.86 min on the CHOlow diet (P < 0.05). The rate of carbohydrate oxidation, respiratory exchange ratio and blood lactate concentration were reduced for CHOlow only during exercise above LT2. These results suggest that muscle glycogen depletion followed by a period of a low carbohydrate diet impairs high-intensity exercise performance.

Perfil metabólico y estado nutricional en adolescentes de una comunidad del norte de México / Metabolic profile and nutritional status in adolescents in a community in northern Mexico

Introducción: Desde la infancia y la adolescencia pueden aparecer alteraciones en el metabolismo de los lípidos e hidratos de carbono junto con alteraciones en la nutrición, y servir como marcadores cuya identificación en etapas tempranas de la vida puede menguar el desarrollo de episodios patológicos (diabetes mellitus tipo 2, cardiopatías, nefropatías). Sonora (México) es uno de los Estados con mayor prevalencia nacional de obesidad en edades tempranas y de enfermedades crónico-degenerativas y sus complicaciones. Por tal motivo nos propusimos determinar el perfil metabólico y el estado de nutrición en adolescentes de 15-18 años de una comunidad de Sonora. Pacientes y métodos: Estudio transversal analítico, de 56 adolescentes de 15-18 años de edad, en quienes se determinó el peso, la talla, el índice de masa corporal, la glucemia, el perfil lipídico, los valores de insulina y el índice de resistencia a la insulina (HOMA-IR), tomando como punto de corte 3,16 para considerar resistencia a la insulina (RI). Resultados: De los 56 adolescentes, 25 (44,6%) eran de sexo masculino y 31 (55,4%) de sexo femenino. La prevalencia de sobrepeso-obesidad era del 32,1%. Un 17,9% presentaba RI, un 33,3% un índice cintura de cadera elevado, un 8,9% colesterol elevado, un 16,1% triglicéridos elevados, un 25% una disminución de HDL, un 12,3% insulina elevada y solamente el 1,6% glucosa elevada. El 44,4% de los pacientes con sobrepeso-obesidad presentó RI. Conclusión: Uno de cada 4 adolescentes presenta, por lo menos, alguna alteración en el perfil metabólico, y 1 de cada 3 en el estado de nutrición (AU)

Introduction: Alterations in lipid and carbohydrate metabolism coupled with changes in nutrition, may appear in childhood and adolescence and which serve as markers to identify early in life may reduce the development of pathological events (type 2 diabetes, heart disease, nephropathy). Sonora, Mexico, is one of the states with the highest national prevalence of obesity at an early age, and chronic degenerative diseases and their complications. Therefore we decided to determine the metabolic profile and nutritional status in adolescents 15 to 18 years in a community of Sonora, Mexico. Patients and methods: A cross-sectional survey of 56 adolescents aged 15 to 18 years who were weight, height, body mass index, glycemia, lipid profile, insulin, HOMA-IR (resistance index insulin) taking as cutoff consider 3.16 for IR (insulin resistance). Results: Of the 56 teenagers got 25 (44.6%) males and 31 (55.4%) female; prevalence of overweight-obesity 32.1%, 17.9% had IR; 33.3% waist hip ratio high, 8.9% high cholesterol, 16.1% triglycerides, 25% decrease in HDL, high insulin 12.3% and only 1.6% high glucose. The 44.4% of patients with overweight-obesity presents IR. Conclusion: 1 in 4 teens has at least some alteration in the metabolic profile and 1 in 3 in the state of nutrition (AU)

Osteocalcina: nexo de unión entre homeostasis ósea y metabolismo energético / Osteocalcin: A link between bone homeostasis and energy metabolism

La investigación en modelos animales ha demostrado el papel de la osteocalcina, marcador de formación ósea, en la regulación del metabolismo energético. Estos trabajos han dado lugar a un nuevo concepto del hueso como órgano endocrino mediante la secreción de osteocalcina, que actúa incrementando la secreción de insulina, disminuyendo la glucosa plasmática, así como aumentando la sensibilidad a la insulina y el gasto energético. Los resultados en humanos han sido diversos y en ocasiones contradictorios. Por otro lado, los fármacos antirresortivos frente a la osteoporosis disminuyen los niveles de osteocalcina mientras que los osteoanabólicos la incrementan. No obstante, no se han investigado los efectos de estas terapias sobre el metabolismo energético (AU)

Research in animal models has demonstrated the role of osteocalcin, a bone formation marker, in regulation of energy metabolism. Those studies have led to a new concept of the bone acting as an endocrine organ by secreting osteocalcin, which acts by increasing insulin secretion, lowering plasma glucose, and increasing insulin sensitivity and energy expenditure. Results in humans have been conflicting. On the other hand, antiresorptive drugs used against osteoporosis decrease osteocalcin levels, while anabolic drugs increase osteocalcin levels. However, the effects of these therapies on energy metabolism have not been investigated (AU)

Insulinemia, ingesta alimentaria y metabolismo energético / Insulinemia, food intake and energy metabolism

Insulin is an anabolic hormone involved in the control of food intake and energy metabolism. Its secretion is mainly stimulated after the rise of glycemia in response to carbohydrate intake. However, this hormone is also secreted after the ingestion of protein and fat. High-fat diets results in lesser insulin levels, with consequent increase in hunger and prospective desire for food ingestion, favoring weight gain. Moreover, the ingestion of such diets results in an increase of fat oxidation, favoring the reduction of energy metabolism and consequently weight gain. Protein ingestion, separately, seems not to exert significant changes in the glycemic response. To understand the metabolic answers unchained by the ingestion of the different macronutrients is important to elucidate corporal weight modifications and the insulin resistance mechanism.

La insulina es una hormona de carácter anabólico relacionada con el control de la ingesta alimentaria y del metabolismo energético. Su secreción es estimulada, especialmente por la elevación de la glicemia en respuesta a la ingesta de carbohidratos. Sin embargo, esta hormona también es secretada tras la ingesta de proteínas y de lípidos. Dietas ricas en lípidos se traducen en menores niveles séricos de insulina, con un consecuente aumento en la puntuación de la sensación de hambre y del deseo prospectivo de ingerir de alimentos, favoreciendo la ganancia de peso. Además, la ingesta de tales dietas dan como resultado el aumento de la oxidación de lípidos, favoreciendo la reducción del metabolismo energético y consecuentemente de la ganancia de peso. La ingesta de proteínas, aisladamente, parece no ejercer cambios significativos en la respuesta glicémica. Comprender las respuestas metabólicas desencadenadas por la ingesta de los diferentes macronutrientes es de fundamental importancia para aclarar las modificaciones del peso corporal y del mecanismo de resistencia insulínica.

Regulation of adiponectin gene expression in adipose tissue by thyroid hormones

Available experimental data suggest that adiponectin and thyroid hormones have biological interaction in vivo. However, the effects of thyroid hormones on adipose adiponectin gene expression in thyroid dysfunction are unclear. We induced hyper- (HYPER) and hypothyroidism (HYPO) by daily administration of a 12 mg/l of levothyroxine and 250 mg/l of methimazole in drinking water of rats, respectively, for 42 days. The white adipose tissues and serum sample were taken on days 15, 28, 42 and also 2 weeks after treatment cessation. Analysis of adiponectin gene expression was performed by real-time PCR and 2−ÄÄct method. The levels of adipose tissue adiponectin mRNA in the HYPO rats were decreased during the 6-week treatment when compared to control rats (<0.05) and were increased significantly 2 weeks after HYPO cessation (P < 0.05). This decline in adiponectin gene expression occurred in parallel with a decrease in T3, T4, fT3 and fT4 concentrations (P < 0.05). In opposite to HYPO rats, adipose adiponectin gene expression was increased in HYPER rats during the 6-week treatment in parallel with an increase the thyroid hormones concentrations (P < 0.05), and its expression was decreased 2 weeks after HYPER cessation (P < 0.05). Adiponectin gene expression levels showed significant negative correlations with concentrations of LDL (HYPO; r = −0.806, P = 0.001 and HYPER; r = −0.749, P = 0.002), triglyceride (HYPO; r = −0.825, P = 0.001 and HYPER; r = −0.824, P = 0.001) and significant positive correlations with concentrations of glucose (HYPO; r = 0.674, P = 0.004 and HYPER; r = 0.866, P = 0.001) and HDL (HYPO; r = 0.755, P = 0.001 and HYPER; r = 0.839, P = 0.001). The current study provides evidence that adiponectin gene expression in adipose tissue is regulated by thyroid hormones at the translation level and that lipid and carbohydrate disturbances in a patient with thyroid dysfunction may be, in part, due to adiponectin gene expression changes (AU)

Rat liver carbohydrate alterations in streptozotocin-induced diabetic rats

Diabetes mellitus (DM) currently belongs to the most widespread human pathologies, affecting about 4% of the world adult population. Despite the pivotal role of the liver in the development of metabolic disorders, the influence of DM on hepatic glycoconjugates remains obscure. The aim of the present investigation was to use a set of lectins with different carbohydrate affinities to investigate impairment in rat liver glycoconjugates influenced by streptozotocin-induced diabetes mellitus. The lectin panel included 7 conventional lectins - Con A, SNA, RCA, WGA, PNA, SBA, and HPA, supplemented with the original fucose-specific lectin preparation from Laburnum anagyroides bark (LABA). Tissue samples were fixed in 4% neutral formalin, embedded in paraffin, and subjected to lectin-peroxidase-diaminobenzidine staining. In control rats a strong reactivity against Con A, LABA, SBA and SNA with cytoplasmic granularities of hepatocytes was detected, while RCA, WGA and HPA showed a strong reactivity with vascular endothelium, and WGA and HPA with bile capillaries. Experimental diabetes was associated with a redistribution of Con A and LABA receptor sites from centrolobular hepatocytes to hepatocytes with peripheral localization. Among the most remarkable observations was DMinduced exposure of lectin reactivity with hepatocyte and endothelial cell nuclei. The endothelial lining of sinusoidal hemocapillaries, of central veins, and portal tract vessels also displayed a significant and differential rearrangement of carbohydrate determinants when influenced by DM. Diabetes-induced activation of Kupffer cells was accompanied by the expression of SNA, PNA and SBA receptor sites within the cytoplasm of these cells, which was lectin-negative in control specimens. The results reported provide a new insight into the pathogenesis of DM-induced impairment of hepatic carbohydrates, and demonstrate the applicability of the original fucose-specific lectin preparation to experimental histopathology (AU)

No disponible

Composição corporal: influência na ação da insulina, leptina, lipase lipoprotéica e lipase hormônio-sensível / Body composition: influence on insulin action, leptin, lipoproteic-and hormone-sensitive lipase

The balance between food intake and energy expenditure is of major importance for weight control and prevention of non-transmissible diseases. Within this context body composition profile is a determining factor for the adequate functioning of neuroendocrine mechanisms; body fat, especially that localized around the abdomen, plays a major role in these mechanisms. Fat tissue may be considered an endocrine organ since hormones such as insulin and leptin, are directly linked to its storage acting in the control of food intake, energy expenditure and nutrient metabolism. In addition, enzymes such as lipoproteic- and hormone-sensitive lipase, which are directly related to lipid metabolism, are regulated by several hormones, including insulin, which in turn are influenced by fat storages. Usually, alteration of these enzymes trigger important metabolic changes, such as elevated serum tryglicerides, which is involved with onset of diabetes and dislipidemia. Considering the influence of body composition on the body's functioning itis essential to stimulate the practice of regular physical activity and incorporation of adequate feeding habits and life style, since these could contribute to a better body composition profile. Moreover, with relatively simple and inexpensive anthropometric measurements it is possible to detect high percentage of body fat, and by means of appropriate interventions, prevent and control many non-transmissible diseases

El equilibrio entre la ingestión alimentar y elgasto de energía es de importancia fundamental para el control del peso y prevención de las enfermedades crónico-degenerativas. En esse contexto, la composición corpórea es un fator determinante en el funcionamiento correcto delos mecanismos neuroendocrinos, y la grasa corpórea, principalmente aquella localizada enel área abdominal, ejerce gran influencia en esos mecanismos.El tejido adiposo puede ser considerado un órganoendocrino, porque se relacionan hormonas, como insulina y leptina, directamente al tamaño de su depósito y ellos actúan en el control de la ingesta alimentar, en el gasto de energía y en el metabolismo de los nutrientes. Además, enzimas como las lipoprotéica, lipasa y lipasa sensible a hormona que participan directamente en el metabolismo de lípidos tiene su actividad controlada por varias hormonas, como la insulina que es fuertemente influenciada por los depósitos de grasa corpórea existentes. Normalmente, la alteración de esas enzimas desencadena alteraciones metabólicas importantes como la elevación de los niveles séricos de triglicéridos,involucrados principalmente en el aparecimiento de diabetes y dislipidemias.Considerando que la influencia de la composición corpórea en el funcionamiento del organismo semanifiesta la importancia del incentivo de la práctica de actividad física de una manera regulary la adopción de hábitos alimentarios y de estilo devida adecuados. Esto contribuiría a un mejor perfil de la composición corpórea. Además, por médio de medidas antropométricas relativamente simples y de bajo costo es posible descubrir los porcentajes elevados de grasa corpórea y a través de las intervenciones prevenir y controlar muchas de las enfermedades crónico-degenerativas.

O equilíbrio entre a ingestão alimentar e o gasto energético é de fundamental importância para o controle do peso e prevenção de doenças não transmissíveis. Nesse contexto, o padrão de composição corporal é fator determinante no funcionamento adequado dos mecanismos neuro-endócrinos, sendo que a gordura corporal, principalmente a localizada na região abdominal, exerce grande influência nesses mecanismos. O tecido adiposo pode ser considerado um órgão endócrino, visto que hormônios, como insulina e leptina, estão diretamente ligados ao tamanho do seu estoque e atuam no controle da ingestão alimentar, gasto energético e metabolismo dos nutrientes. Além disso, enzimas como lipase lipoprotéica e lipase hormônio sensível, as quais estão envolvidas diretamente no metabolismo de lipídios, têm sua atividade controlada por diversos hormônios, como a insulina, que por sua vez sofrem grande influência dos estoques de gordura corporal. Normalmente, a alteração dessas enzimas desencadeia alterações metabólicas importantes como a elevação dos níveis séricos de triglicerídeos, envolvidos principalmente no aparecimento de diabetes e dislipidemias. Considerando essa influência da composição corporal sobre o funcionamento do organismo torna-se importante o incentivo à prática da atividade física, de forma regular, e a adoção de hábitos alimentares e de estilo de vida adequados, já que isto contribuiria para um melhor perfil da composição corporal. Além disso, por meio de medidas antropométricas ,relativamente simples e de baixo custo, é possível detectar elevados percentuais de gordura corporal e por meio de intervenções, prevenir e controlar muitas das doenças não transmissíveis

Metabolic effects of growth hormone

Human growth hormone (hGH) is a key ‘player’ in the regulation of growth and metabolism. Several disease conditions, mostly involving growth retardation or GH deficiency, have been approved for recombinant hGH replacement therapy. The focus of this review centers on the metabolic effects of GH on carbohydrates, lipids and proteins. Current knowledge of GH signaling pathways and metabolic attributes of GH deficient and GH excess (acromegaly) states are described. Mouse models commonly used for the study of GH action also are compared to further illustrate the metabolic role of GH. Finally, the metabolic effects of a GH receptor antagonist (Pegvisomant) used for the treatment of acromegaly are mentioned (AU)

No disponible