Tempo de jejum e alterações metabólicas em cirurgias eletivas: revisão integrativa / Fasting time and metabolic changes in elective surgeries: an integrative review / Tiempo de ayuno y cambios metabólicos en cirugías electivas: revisión integradora

OBJETIVO: Identificar na produção científica a ocorrência de alterações metabólicas no pós-operatório de cirurgias eletivas e sua relação com o tempo de jejum no pré-operatório. MÉTODO: Revisão integrativa, realizada de junho a julho de 2020 nas bases de dados LILACS, MEDLINE, CINAHL, COCHRANE, SCOPUS e EMBASE. Foram selecionados artigos de 2015 a 2020. Para a análise dos níveis de evidência seguiu-se a categorização de Oxford Centre for Evidence-Based Medicine. RESULTADOS: Foram selecionados 10 artigos científicos. As alterações metabólicas encontradas foram hiperglicemia, elevação dos níveis séricos de IL-6, cortisol e valina, aumento da resistência insulínica, queda dos níveis plasmáticos de ácido glutâmico e elevação dos níveis de IGF-1 com a redução de IGFBP-3. A abreviação do tempo de jejum minimiza o estresse orgânico ao paciente, com a redução das alterações metabólicas, tempo de internação e morbidade. CONCLUSÃO: O tempo de jejum pré-operatório superior a oito horas está relacionado a ocorrência de alterações metabólicas no pós-operatório. As cirurgias de grande porte apresentam as maiores alterações metabólicas.

OBJECTIVE: To identify in the scientific production the occurrence of metabolic changes in the postoperative period of elective surgeries and their relation with preoperative fasting time. METHOD: An integrative review carried out from June to July 2020 in the LILACS, MEDLINE, CINAHL, COCHRANE, SCOPUS, and EMBASE databases. Articles from 2015 to 2020 were selected. For the analysis of the evidence levels, the Oxford Centre for Evidence-Based Medicine categorization was followed. RESULTS: A total of 10 scientific articles were selected. The metabolic changes found were hyperglycemia, elevated serum levels of IL-6, cortisol, and valine, increased insulin resistance, decreased glutamic acid plasma levels, and increased IGF-1 levels with a reduction of IGFBP-3. Shortening the fasting time minimizes the patient's organic stress, with a reduction of metabolic changes, hospitalization time and morbidity. CONCLUSION: Preoperative fasting time longer than eight hours is related to metabolic changes in the postoperative period. Major surgeries present the greatest metabolic changes.

OBJETIVO: Identificar en la producción científica la existencia de cambios metabólicos en el postoperatorio de cirugías electivas y su relación con el tiempo de ayuno en el período preoperatorio. MÉTODO: Revisión integradora, realizada de junio a julio de 2020 de las bases de datos LILACS, MEDLINE, CINAHL, COCHRANE, SCOPUS y EMBASE. Se seleccionaron artículos de 2015 a 2020. Para el análisis de los niveles de evidencia se siguió la categorización del Oxford Center for Evidence-Based Medicine. RESULTADOS: Se seleccionaron 10 artículos científicos. Las alteraciones metabólicas encontradas fueron hiperglucemia, niveles séricos elevados de IL-6, cortisol y valina, aumento de la resistencia a la insulina, reducción de los niveles plasmáticos de ácido glutámico y aumento de los niveles de IGF-1 con disminución de IGFBP-3. La disminución del tiempo de ayuno minimiza el estrés orgánico del paciente, con una reducción de los cambios metabólicos, la duración de la estancia hospitalaria y la morbilidad. CONCLUSIÓN: Existe una relación entre un tiempo de ayuno preoperatorio mayor a ocho horas y la presencia de cambios metabólicos en el postoperatorio. Las cirugías mayores muestran los mayores cambios metabólicos.

Duración del ayuno preoperatorio en pacientes con cirugía programada / Duration of preoperative fasting in patients with scheduled surgery

Antecedentes y objetivo: el ayuno preoperatorio disminuye el riesgo de aspiración del contenido gástrico y sus complicaciones. Sin embargo, si es excesivo, favorece la regurgitación y el riesgo de broncoaspiración tras la inducción anestésica, así como alteraciones metabólicas e hidroelectrolíticas. Analizamos su duración, en pacientes con cirugías programadas en un hospital público de agudos. Material y métodos: se encuestó a todos los pacientes mayores de 18 años con cirugías programadas. Se recolectaron datos sobre la prescripción médica de ayuno, la hora de inducción anestésica y personales. El ayuno prescripto se comparó con las recomendaciones de las guías de la AAARBA (Asociación de Anestesia, Analgesia y Reanimación de Buenos Aires). Resultados: se reclutaron 139 pacientes, con una mediana de edad de 48 años (30; 64), 53% femeninos. La mediana del ayuno prescripto fue de 12,5 horas tanto para sólidos como para líquidos. El ayuno para sólidos que realizaron los pacientes tuvo una mediana de 14 horas, la cual resultó significativamente mayor que la prescripción (p < 0,001). En cambio, el ayuno para líquidos tuvo una mediana de 12 horas, no hallándose una diferencia significativa (p = 0,452) con lo prescripto. En comparación con la guía de la AAARBA, el ayuno prescripto excedió la recomendación para sólidos (4,5 h) y para líquidos (10,5 h). El ayuno realizado por el paciente excedió lo prescripto para sólidos (1,5 h), mientras que para líquidos fue inferior (0,5 h). Conclusión: el ayuno preoperatorio prescripto no se adecuó a las recomendaciones actuales. Las horas de ayuno realizadas por el paciente resultaron excesivas. (AU)

Background and objective: preoperative fasting reduces the risk of aspiration of gastric contents and its complications. However, if fasting is excessive, it favours regurgitation and the risk of pulmonary aspiration in patients undergoing general anaesthetic, such as metabolic and electrolyte disorders. We analysed its duration in patients with elective surgeries in public acute care hospital. Material and methodologies: patients over 18 years old with elective surgeries were surveyed. Data about medical fasting indication, time of induction of anaesthesia and personal information was collected. The prescribed fast was compared with the recommendations of the AAARBA (Association of Anaesthesia, Analgesia and Reanimation of Buenos Aires) guidelines. Results: 139 patients were gathered with a median of 48 years old (30; 64), 53% of them were female. Fasting indication median was of 12.5 h for solids and liquids. The fasting made by the patient for solids had a median of 14 h which resulted to be significantly higher to the indication (p < 0.001). By contrast, the fasting for liquids had a median of 12 h which it did not show a significant difference (p = 0.452) with the indication. In comparison with the AAARBA guideline, the fasting indication exceeded the recommendation for solids (4.5 h) and for liquids (10.5 h). The fasting made by the patient exceeded to what was indicated for solids (1.5 h) while for liquids, it was inferior (0.5 h). Conclusion: the indicated preoperative fasting was not adequate to the current recommendations. The hours of fasting made by patient were excessive. (AU)

Protein and lipid metabolism adjustments in silver catfish (Rhamdia quelen) during different periods of fasting and refeeding / Ajustes no metabolismo de proteínas e lipídios no jundiá (Rhamdia quelen) durante diferentes períodos de jejum e realimentação

Abstract The fish may experience periods of food deprivation or starvation which produce metabolic changes. In this study, adult Rhamdia quelen males were subjected to fasting periods of 1, 7, 14, and 21 days and of refeeding 2, 4, 6, and 12 days. The results demonstrated that liver protein was depleted after 1 day of fasting, but recovered after 6 days of refeeding. After 14 days of fasting, mobilization in the lipids of the muscular tissue took place, and these reserves began to re-establish themselves after 4 days of refeeding. Plasmatic triglycerides increased after 1 day of fasting, and decreased following 2 days of refeeding. The glycerol in the plasma oscillated constantly during the different periods of fasting and refeeding. Changes in the metabolism of both protein and lipids during these periods can be considered as survival strategies used by R. quelen. The difference in the metabolic profile of the tissues, the influence of the period of fasting, and the type of reserves mobilized were all in evidence.

Resumo Os peixes podem sofrer períodos de privação de alimentos ou de fome, que produzem mudanças metabólicas. Neste estudo, jundiás machos adultos foram submetidos a jejum períodos de 1, 7, 14 e 21 dias e realimentação 2, 4, 6, e 12 dias. Os resultados demonstraram que a proteína do fígado foi esgotada depois de um dia de jejum, mas restabeleceu após 6 dias de realimentação. Após 14 dias de jejum, ocorreu a mobilização dos lípidos no tecido muscular sendo que estas reservas começaram a re-estabelecer-se após 4 dias de realimentação. Os triglicérides plasmáticos aumentam após um dia de jejum, e diminuiram após 2 dias de realimentação. O glicerol no plasma oscilou constantemente durante os diferentes períodos de jejum e realimentação. As alterações no metabolismo de proteína e lipídios durante estes períodos podem ser consideradas uma estratégias de sobrevivência utilizada pelo Rhamdia quelen. Sendo que a diferença no perfil metabólico tecidual bem como a influência do período de jejum e o tipo de reserva a ser mobilizada foram observadas neste estudo.

Efectos del ayuno en sujetos que realizan el ramadan sobre la calidad de vida y su relación con la diabetes y la hipertensión / Fasting's effects on people in ramadan about their quality of life and the relationship with diabetes and hypertension

El precepto islámico del Ramadán (R), impone a las personas que lo practican importantes modificaciones fisiológicas debido a las restricciones hídricas y dietéticas a lo largo del día y durante un mes, lo que tiene una especial repercusión física e intelectual de los musulmanes. El objetivo del presente estudio es describir los efectos del ayuno del Ramadán en la calidad de vida, así como, su repercusión en la Diabetes e Hipertensión. Participaron un total de 44 sujetos, 22 hombres y 22 mujeres. Con edades comprendidas entre los 14-80 años residentes en Tetuán y Ceuta. En un diseño de grupo único, creando subgrupos en función del sexo o patología. Las mediciones principales son las 8 escalas que miden los 36 items del cuestionario SF-36. Durante el R se evidencia en hombres y mujeres un mayor deterioro de la función física, siendo también significativa una disminución de la percepción de salud mental en el sexo masculino. En las personas diabéticas la percepción de disminución de la calidad de vida es mayor en relación a los parámetros físicos, así como en la salud mental y salud en general. Los sujetos hipertensos presentaron de forma significativa peores valores en los ítems de salud física y mental. El mes de R, en el conjunto de la población, provoca una menor percepción de la calidad de vida, más pronunciada en el caso de las mujeres. En concreto, los diabéticos y los hipertensos, estudiados, perciben una menor calidad de vida que en condiciones normales en cuanto a función física y rol físico se refiere(AU)

The Islamic precept of Ramadan (R) imposes on individuals who practice it important physiological modifications due to the hydric and dietetic restrictions along a whole month plus a day, all of which have a crucial repercussion over the physical and intellectual performance of Muslim. The objective of this study was todescribe the effects of fasting during R in quality of life and its relationship with pathologies such as diabetes and hypertension. It took part 44 individuals, 22 men and 22 women with an age among 14 and 80 year old, from Tetuan and Ceuta. A model in only one group, making sub-models according to sex and pathology. The main measuring are the eight scales that measure 36 items in the SF-36 survey. During R we can see worst results in both men and women in relation with physical function. We can also observe a decrease in the perception of mental health in male sex the perception is even higher in diabetic people in relation to physical parameters, as in mental health in general. Worst values show individuals suffering of hypertension in their perception of physical and mental health.This month of R in the population as a whole causes a less perception in quality of life which is even worst in the case of women. Being concrete, diabetic and hypertension people receive a less quality of life than in normal conditions talking about physical role and function(AU)

The hepatic ectonucleotide pyrophosphatase/phosphodiesterase 1 gene mRNA abundance is reduced by insulin and induced by dexamethasone

Hormones regulate hepatic gene expressions to maintain metabolic homeostasis. Ectonucleotide pyrophosphatase/phosphodiesterase 1 has been thought to interfere with insulin signaling. To determine its potential role in the regulation of metabolism, we analyzed its gene (Enpp1) expression in the liver of rats experiencing fasting and refeeding cycles, and in primary rat hepatocytes and human hepatoma HepG2 cells treated with insulin and dexamethasone using northern blot and real-time PCR techniques. Hepatic Enpp1 expression was induced by fasting and reduced by refeeding in the rat liver. In primary rat hepatocytes and HepG2 hepatoma cells, insulin reduced Enpp1 mRNA abundance, whereas dexamethasone induced it. Dexamethasone disrupted the insulin-reduced Enpp1 expression in primary hepatocytes. This is in contrast to the responses of the expression of the cytosolic form of phosphoenolpyruvate carboxykinase gene to the same hormones, where insulin reduced it significantly in the process. In addition, the dexamethasone-induced Enpp1 gene expression was attenuated in the presence of 8-Br-cAMP. In conclusion, we demonstrated for the first time that hepatic Enpp1 is regulated in the cycle of fasting and refeeding, a process that might be attributed to insulin-reduced Enpp1 expression. This insulin-reduced Enpp1 expression might play a role in the development of complications in diabetic patients.

Water temperature, body mass and fasting heat production of pacu (Piaractus mesopotamicus)

ABSTRACT Knowledge on fasting heat production (HEf) of fish is key to develop bioenergetics models thus improving feeding management of farmed species. The core of knowledge on HEf of farmed, neotropical fish is scarce. This study assessed the effect of body mass and water temperature on standard metabolism and fasting heat production of pacu, Piaractus mesopotamicus, an omnivore, Neotropical fresh water characin important for farming and fisheries industries all through South American continent. An automated, intermittent flow respirometry system was used to measure standard metabolic rate (SMR) of pacu (17 - 1,050 g) at five water temperatures: 19, 23, 26, 29 and 33 °C. Mass specific SMR increased with increasing water temperature but decreased as function of body mass. The allometric exponent for scaling HEf was 0.788, and lied in the range recorded for all studied warm-water fish. The recorded van't Hoff factor (Q10) for pacu (2.06) shows the species low response to temperature increases. The model HEf = 0.04643×W0.7882×T1.837 allows to predict HEf (kJ d-1) from body mass (W, kg) and water temperature (T, °C), and can be used in bioenergetical models for the species.

Starvation and refeeding in rats: effect on some parameters of energy metabolism and electrolytes and changes of hepatic tissue

Regarding the importance of starvation and refeeding and the occurrence of refeeding syndrome in various conditions, the present study was conducted to investigate the effects of refeeding on some parameters of energy metabolism and electrolytes and changes of hepatic tissue in male Wistar rats. Fifty-seven rats were divided into six groups, having 6 to 11 rats. Food was provided ad-libitum until three months and then the first group was considered without starvation (day 0). Other rats were fasted for two weeks. Group 2 was applied to a group immediately after starvation (day 14). Groups 3 to 6 were refed in days 16 till 22, respectively. At the end of each period, blood and tissue samples were taken and histopathological and serum analysis, including serum electrolytes (calcium, phosphorus, sodium, potassium), the energy parameters (glucose, insulin, cortisol) and the liver enzymes (ALT, AST, ALP) were determined. Insulin decreased by starvation and then showed an increasing trend compared to starvation period, which the highest amount of this parameter was observed eight days post-refeeding. Serum glucose level showed the opposite pattern of insulin. Histopathological examination of the tissue sections revealed clear vacuoles after starvation and refeeding, in which the severity of lesions gradually decreased during refeeding. The cortisol level decreased by starvation and then increased during refeeding. Also, potassium and phosphorus concentrations declined by refeeding and the serum sodium and potassium levels were changed in the relatively opposite manner. The calcium level decreased by starvation and then increased during refeeding. These results could help recognize and remedy the refeeding syndrome.(AU)

A digital volumetric tomography (DVT) study in the mandibular molar region for miniscrew placement during mixed dentition

OBJECTIVE: To assess bone thickness for miniscrew placement in the mandible during mixed dentition by using digital volumetric tomograph (DVT). MATERIAL AND METHODS: A total of 15 healthy patients aged 8-10 years old, with early exfoliated mandibular second deciduous molar, were included. DVT images of one quadrant of the mandible were obtained using Kodak extraoral imaging systems and analyzed by Kodak dental imaging software. The error of the method (EM) was calculated using Dahlberg's formula. Mean and standard deviation were calculated at 6 and 8 mm from the cementoenamel junction (CEJ).Paired t-test was used to analyze the measurements. RESULTS: Buccal cortical bone thickness, mesiodistal width and buccolingual bone depth at 6 mm were found to be 1.73 + 0.41, 2.15 + 0.49 and 13.18 + 1.22 mm, respectively; while at 8 mm measurements were 2.42 + 0.34, 2.48 + 0.33 and 13.65 + 1.25 mm, respectively. EM for buccal cortical bone thickness, mesiodistal width and buccolingual bone depth was 0.58, 0.40 and 0.48, respectively. The difference in measurement at 6 and 8 mm for buccal cortical plate thickness (P < 0.05) and buccolingual bone thickness (P < 0.05) was found to be significant, whereas for mesiodistal width it was insignificant (P > 0.05). CONCLUSION: Bone thickness measurement has shown promising evidence for safe placement of miniscrews in the mandible during mixed dentition. The use of miniscrew is the best alternative, even in younger patients. .

OBJETIVO: avaliar, por meio de tomografia volumétrica digital (TVD), a espessura óssea necessária para a instalação de mini-implante na arcada inferior durante a fase de dentição mista. MÉTODOS: um total de 15 pacientes saudáveis, com idades entre 8 e 10 anos, com segundo molar inferior decíduo irrompido recentemente, foram incluídos no presente estudo. Imagens de TVD da hemiarcada inferior foram obtidas utilizando sistemas de imagens extrabucais Kodak. As imagens foram analisadas por meio do programa de imagens Kodak. O erro do método (EM) foi calculado utilizando a fórmula de Dahlberg. Médias e desvios-padrão foram calculados de 6 a 8mm aquém da junção amelocementária. O teste t foi utilizado para a análise das medidas. RESULTADOS: a espessura do osso cortical vestibular, largura mesiodistal e profundidade óssea vestibulolingual, a 6mm, foram de 1,73 + 0,41; 2,15 + 0,49; e 13,18 + 1,22 mm, respectivamente. Já a 8mm, os valores foram de 2,42 + 0,34; 2,48 + 0,33; e 13,65 + 1,25mm. O EM para a espessura do osso cortical vestibular, largura mesiodistal e profundidade óssea vestibulolingual foi de 0,58, 0,40 e 0,48mm, respectivamente. A diferença entre as medidas a 6 e 8mm para a espessura do osso cortical vestibular (p < 0,05) e a espessura óssea vestibulolingual (p < 0,05) foi significativa, embora não tenha sido significativa para a largura mesiodistal (p < 0,05). CONCLUSÃO: a mensuração da espessura óssea demonstra evidências promissoras para a segura instalação de mini-implantes na arcada inferior e na fase de dentição mista. O uso de mini-implantes tem se mostrado a melhor alternativa, mesmo nos casos de pacientes mais jovens. .

Effect of maternal vitamin A supplementation on retinol concentration in colostrum / Efeito da suplementação materna com vitamina A sobre a concentração de retinol no colostro

OBJECTIVE: To investigate the effect of vitamin A supplementation on the retinol concentration in colostrum under fasting and postprandial conditions. METHODS: This was a quasi-experimental study, with before and after assessments, conducted with 33 patients treated at a public maternity hospital. Blood and colostrum samples were collected under fasting conditions in the immediate postpartum period. A second colostrum collection occurred two hours after the first meal of the day, at which time a mega dose of 200,000 IU of retinyl palmitate was administered. On the following day, the colostrum was collected again under fasting and postprandial conditions. Serum and colostrum retinol concentrations were determined by high performance liquid chromatography. RESULTS: The serum retinol concentration was 37.3 (16.8-62.2) µg/dL, indicating adequate nutritional status. The colostrum retinol concentration before supplementation was 46.8 (29.7-158.9) µg/dL in fasting and 67.3 (31.1-148.7) µg/dL in postprandial condition (p < 0.05), showing an increase of 43.8%. After supplementation, the values were 89.5 (32.9-264.2) µg/dL and 102.7 (37.3-378.3) µg/dL in fasting and postprandial conditions, respectively (p < 0.05), representing an increase of 14.7%. CONCLUSIONS: This study demonstrated that maternal supplementation with high doses of vitamin A in postpartum resulted in a significant increase of the retinol concentration in colostrum under fasting conditions, with an even greater increase after a meal. .

OBJETIVO: Investigar o efeito da suplementação com vitamina A sobre a concentração de retinol no leite colostro em condições de jejum e pós-prandial. MÉTODOS: Estudo quase-experimental, do tipo antes e depois, realizado com 33 parturientes atendidas em uma maternidade pública, das quais foram coletadas, em jejum, amostras de sangue e leite colostro, no pós-parto imediato. Uma segunda coleta de colostro ocorreu duas horas após a primeira refeição do dia, momento em que uma megadose de 200.000 UI de palmitato de retinila foi administrada. No dia seguinte, uma nova coleta de colostro foi realizada em condições de jejum e pós-prandial. As concentrações de retinol no soro e no colostro foram determinadas por cromatografia líquida de alta eficiência. RESULTADOS: A concentração de retinol sérico foi de 37,3 (16,8-62,2) µg/dL, evidenciando um estado nutricional adequado. No colostro, a concentração de retinol antes da suplementação foi de 46,8 (29,7-158,9) µg/dL em jejum e 67,3 (31,1-148,7) µg/dL em condições pós-prandiais (p < 0,05), mostrando um aumento de 43,8%. Após a suplementação, os valores foram de 89,5 (32,9-264,2) µg/dL e 102,7 (37,3-378,3) µg/dL em jejum e pós-prandial, respectivamente (p < 0,05), representando um aumento de 14,7%. CONCLUSÕES: Este trabalho demonstrou que a suplementação materna com altas doses de vitamina A no pós-parto resultou em um aumento significativo da concentração de retinol no colostro em condições de jejum, sendo este valor ainda maior após a refeição. .

Effect of treatment with sitagliptin on somatosensory-evoked potentials and metabolic control in patients with type 2 diabetes mellitus / Efeito do tratamento com sitagliptina sobre os potenciais evocados somatossensoriais e controle metabólico de pacientes com diabetes melito tipo 2

Objective: To evaluate the effect of sitagliptin on somatosensory-evoked potentials (SEPs) and metabolic control in patients with type 2 diabetes mellitus without clinical diabetic neuropathy. Materials and methods: Interventional, prospective, and open study. Patients with less than six months from the diagnosis were included. Examinations of SEPs and laboratory tests at fasting and after food stimulation were performed before and after three months of treatment with sitagliptin (100 mg/day). Results: There was a reduction in the mean levels of HbA1c (P < 0.0001), fasting glucose (P = 0.001), total cholesterol (P = 0.019), and ALT (P = 0.022). An increase in active GLP-1 was found at the end of the study (P = 0.0025). Several SEPs showed statistically significant differences when analyzed before and after treatment with sitagliptin. Conclusion: The results give a glimpse of the possible use of sitagliptin in the treatment of some neurodegenerative conditions of the peripheral nervous system, in addition to its already established role in glycemic control. .

Objetivo: Avaliar o efeito da sitagliptina nos potenciais evocados somatossensoriais (PESS) e controle metabólico de pacientes com diabetes melito tipo 2, sem neuropatia diabética. Materiais e métodos: Estudo de intervenção, prospectivo e aberto. Os pacientes com menos de seis meses de diagnóstico foram incluídos. Exames dos PESS e testes laboratoriais em jejum e após a estimulação com alimentos foram realizados antes e depois de três meses de tratamento com sitagliptina (100 mg/dia). Resultados: Houve redução nos níveis médios de HbA1c (P < 0,0001), glicemia de jejum (P = 0,001), colesterol total (P = 0,019) e ALT (P = 0,022). Verificou-se aumento de GLP-1 ativo (P = 0,0025). Vários PESS mostraram diferenças estatisticamente significativas quando os valores foram analisados antes e após o tratamento com sitagliptina. Conclusão: Os resultados vislumbram a possível utilização de sitagliptina no tratamento de algumas condições neurodegenerativas do sistema nervoso periférico, em adição ao seu papel no controle glicêmico. .

Fasting ghrelin but not PYY(3-36) is associated with insulin-resistance independently of body weight in Wistar rats / A grelina, mas não PYY(3-36), está associada com a resistência à insulina independente do peso corporal em ratos Wistar

Objective: The objective of this study was to evaluate the association between insulin-resistance and fasting levels of ghrelin and PYY in Wistar rats. Materials and methods: A total of 25 male Wistar rats, weighing 200-300 g, was included in this study. The animals were maintained in cages with a 12/12h light-dark cycle and fed standard chow and water ad libitum. After 12-h overnight fasting, ghrelin, PYY, insulin and glucose values were determined. Insulin resistance was assessed by means of the HOMA-IR, which was ranked and the median was used as a cut-off value to categorize insulin-resistance. HOMA-IR values equal and above 2.62 were considered insulin-resistant (IR) while values below 2.62 were considered insulin sensitive (IS). Differences between means were determined using the Student t-test. Multiple regression and Pearson’s correlation test were used to evaluate the association between variables. Results: HOMA-IR median IQ range values for IS and IR groups were, respectively, 1.56 (0.89 – 2.16) vs. [4.06 (3.50 – 4.61); p < 0.001]. The IR group presented increased levels of fasting ghrelin, PYY and insulin respectively: [50.35 (25.99 – 74.71) pg/mL vs. 12.33 (8.77 – 15.89) pg/mL; p = 0.001]; [54.38 (37.50 – 71.26) pg/mL vs. 33.17 (22.34 – 43.99) pg/mL; p = 0.016]; [18.04 (14.48 – 21.60) uU/mL vs. 7.09 (4.83 – 9.35) uU/mL; p = 0.001]. Ghrelin, but not PYY, correlated linearly and positively with HOMA-IR: ghrelin vs. HOMA-IR (r = 0.52; p = 0.008), and PYY vs. HOMA-IR (r = 0.22; p = 0.200). This correlation was independent of body weight. Conclusion: Fasting ghrelin and PYY serum levels are increased in lean, relatively insulin resistant Wistar rats, and this increase is independent of weight. .

Objetivo: O objetivo deste estudo foi avaliar a associação entre a resistência à insulina e os níveis de grelina e PYY em jejum em ratos Wistar. Materiais e métodos: Um total de 25 ratos Wistar machos, pesando 200-300 g, foi usado neste estudo. Os animais foram mantidos em gaiolas com um ciclo de luz escuro de 12/12h e alimentados com ração padrão e água ad libitum. Depois de um jejum de 12h, os valores de grelina, PYY, insulina e glicose foram determinados. A resistência à insulina foi avaliada pelo HOMA-IR que foi ordenado e a mediana utilizada como valor de corte para categorizar a resistência à insulina. Os valores de HOMA-IR iguais ou acima de 2,62 foram considerados resistentes à insulina (RI), enquanto valores abaixo de 2,62 foram considerados sensíveis (SI). As diferenças entre as médias foram determinadas usando-se o teste t de Student. A análise de regressões múltiplas e o teste de correlação de Pearson foram usados para se avaliar a associação entre as variáveis. Resultados: A mediana e a variação IQ do HOMA-IR para os grupos RI e SI foram, respectivamente, 1,56 (0,89 – 2,16) contra [4,06 (3,50 – 4,61); p < 0,001]. O grupo RI apresentou níveis aumentados de grelina, PYY e insulina em jejum, respectivamente, [50,35 (25,99 – 74,71) pg/mL contra 12,33 (8,77 – 15,89) pg/mL; p = 0,001]; [54,38 (37,50 – 71,26) pg/mL contra 33,17 (22,34 – 43,99) pg/mL; p = 0,016]; [18,04 (14,48 – 21,60) uU/mL contra 7,09 (4,83 – 9,35) uU/mL; p = 0.001]. A grelina, mas não PYY, se correlacionou de forma linear e positiva com o HOMA-IR: a grelina contra HOMA-IR (r = 0,52; p = 0,008), e PYY contra HOMA-IR (r = 0,22; p = 0,200). Essa correlação foi independente do peso corporal. Conclusão: Os níveis séricos de jejum de grelina ...

Effects of fasting and refeeding on the metabolic functions of the turtle Kinosternon scorpioides (Linnaeus, 1766) raised in captivity / Efeitos do jejum e da realimentação sobre as funções metabólicas da tartaruga Kinosternon scorpioides (Linnaeus, 1766) criada em cativeiro

The metabolic responses of adult and young freshwater Kinosternon scorpioides turtles raised in captivity were evaluated. Two experiments were performed: a) blood metabolite changes caused by food deprivation, and b) liver and muscle glycogen and total lipid differences after fasting and refeeding. Blood glucose concentration of young animals was susceptible to food deprivation. In both groups this metabolite decreased after 30 days of fasting. Feeding for 15 days did not recover blood glucose. Total seric proteins were not affected by food deprivation. Fasting decreased blood urea nitrogen and the highest difference was found around 30 days. Uric acid increased in young animals after 60 days of fasting. Triacylglicerol decreased after 15 days of fasting and refeeding for 15 days recovered the pre-fasting levels. Free fatty acid plasma tended to increase around 15 days of fasting. Liver glycogen decreased at day 15 of fasting, being stable thereafter while muscle glycogen decreased at a slower rate. Total liver lipid stabilized after 30 days and then decreased 70% after 60 days of fasting. Muscle lipids remained stable throughout fasting. It could be concluded that fasting of Kinosternon scorpioides led to metabolic adaptations similar to the one reported from reptiles and fish.

Neste trabalho foi avaliada as respostas metabólicas da tartaruga Kinosternon scorpioides criada em cativeiro, nas fases, adultos e jovens nos estados: alimentado, jejuado e realimentado. O estudo compreendeu dois experimentos: (a) mudanças metabólicas no sangue causadas por privação alimentar e realimentação e (b) diferenças nas concentrações de glicogênio e lipídeos totais no fígado e no músculo após jejum e realimentação. No experimento dos animais jovens a concentração de glicose no sangue apresentou mudanças significativas. Entretanto, nos dois experimentos esse metabólito reduziu significativamente aos 30 dias de jejum. Realimentados por um período de 15 dias foi observado que a concentração de glicose não recuperou os níveis de pré-jejum. Concentração de glicose no sangue de animais jovens foi mais suscetível à privação de alimentos. Em ambos os grupos os metabólitos analisados decresceu após 30 dias de jejum. Retomando a alimentação por 15 dias foi observado que a concentração de glicose não recuperou. As concentrações de proteínas séricas totais não foram afetadas pela privação alimentar. O jejum decresceu a concentração de uréia no sangue e a maior diferença ocorreu aos 30 dias. O ácido úrico decresceu nos animais jovens após 60 dias de jejum. O triacilglicerol diminuiu após 15 dias de jejum e a realimentação por 15 dias recuperou os níveis de pré-jejum. O glicogênio hepático diminuiu aos 15 dias de jejum, e estabilizou a partir daí, enquanto o glicogênio muscular diminuiu a um ritmo mais lento. O lipídio total hepático total se manteve estável até os 30 dias de jejum, diminuindo até 70% aos 60 dias de jejum. E, em seguida, diminuiu 70% após 60 dias de jejum. Os lipídeos musculares permaneceram estáveis durante o jejum. Conclui-se que o jejum na espécie Kinosternon scorpioides apresentou adaptações metabólicas semelhantes aos relatados para outros répteis e peixes.

Modificación de la glucemia en ayuno en adultos con diabetes mellitus tipo 2 después de la ingesta de refrescos de cola y de dieta en el Estado de Querétaro, México / Modification of fasting blood glucose in adults with diabetes mellitus type 2 after regular soda and diet soda intake in the State of Querétaro, México

El objetivo del presente estudio fue comparar la modificación de la glucemia en ayuno en adultos con diabetes mellitus tipo 2 después de la ingesta de refrescos de cola y de dieta. Se realizó un ensayo clínico aleatorizado, en unidades clínicas del Instituto Mexicano del Seguro Social en Querétaro, México. Se incluyeron 80 pacientes con diabetes (media de peso 74.2±13.66, IMC 30.5±4.305, cintura 98.2±12.9 y tiempo de evolución 3.8±3.009) a los que se les pidió asistir con ayuno de 8 horas y sin tomar medicamentos antes de la prueba. Se dividieron en dos grupos de 40 sujetos, a los cuales se le midió glucosa capilar en ayuno y después de la ingesta de 200 ml de refresco light (con aspartame y acesulfame potásico) o normal (sin edulcorantes) se volvió a medir glucosa a los 10, 15 y 30 minutos. Para el análisis estadístico se utilizó la prueba t de Student para grupos dependientes e independientes, X² y t pareada. Los niveles de glucosa capilar tuvieron a los 10 minutos -34.52 y -25.41%, a los 15 minutos -48.8 y -36.2% y a los 30 minutos 57.75 y 43.6% de diferencia absoluta y relativa respectivamente, con una p=0.000. En conclusión de acuerdo a lo observado, el refresco light con edulcorantes no aumenta la glucosa capilar, teniendo una diferencia significativa en su disminución del ayuno a los 30 minutos.

The objective of the study was to compare the modification of fasting blood glucose in adults with diabetes mellitus type 2 after intake of regular soda and diet soda. We conducted a randomized clinical trial in clinics of Instituto Mexicano del Seguro Social in Querétaro, México. We included 80 patients with diabetes (mean weight 74.2 ± 13.66, BMI 30.5 ± 4.305, waist 98.2 ± 12.9 and time evolution of diabetes 3.8 ± 3.009) who were asked to come with fasting for 8 hours and without taking any medicine before testing. They were divided into two groups of 40 subjects, to whom was measured fasting blood glucose after the ingestion of 200 ml of diet soda (with aspartame and acesulfame potassium) or regular soda (without sweetener) we measure glucose at 10, 15 and 30 minutes. For statistical analysis performed we used Student’s t-test for dependent and independent samples, and paired t-test, and chi square test (X²). Capillary glucose levels at 10 minutes were -34.52 and -25.41%, at 15 minutes -48.8 and -36.2% and at 30 minutes 57.75 and 43.6% of absolute and relative differences, with p=0.000. In conclusion, according to the observations, diet soda doesn’t increased blood glucose levels, with a significant difference in fasting decreased at 30 minutes.

Ajustes endocrino-metabólicos durante el ayuno de Ramadán en jóvenes deportistas / Endocrine-metabolic adjustments during Ramadan fasting in young athletes

El precepto islámico del Ramadán (R), implica importantes modificaciones fisiológicas debido a las restricciones hídricas y dietéticas a lo largo del día y durante un mes, lo que tiene una especial repercusión física e intelectual de los musulmanes, particularmente en sociedades occidentales, en las que no se producen reajustes horarios para las actividades cotidianas. Entre las modificaciones impuestas por el R, el ayuno intermitente día/noche, desencadena mecanismos de adaptación para rentabilizar el consumo energético. El objetivo del presente estudio ha sido valorar algunos cambios endocrinometabólicos que acontecen a lo largo de la jornada, durante el mes de ayuno, en jóvenes que tienen que continuar con su actividad y entrenamiento deportivo habitual. Diez jóvenes musulmanes, varones, sanos, sometidos a entrenamiento deportivo, con edades entre 18 y 25 años que realizaron el R. Se analizaron parámetros bioquímicos y hormonales en plasma, una semana previa al R, primera y cuarta del periodo de ayuno (mañana y tarde) y semana posterior. Durante el R, se observa un descenso de los parámetros bioquímicos a lo largo del día, especialmente de la glucemia, siendo estos cambios más evidentes en la primera semana. La concentración de cortisol se encuentran significativamente elevada durante todo el mes, como consecuencia del cambio de ritmo circadiano de secreción. El R obliga al organismo a un ajuste endocrino-metabólico con el fin de preservar la eficiencia energética durante la jornada. Este control se vuelve más eficaz conforme avanza el mes de ayuno y la consecuente adaptación fisiológica.

The Islamic precept of R implies important physiological modifications due to the hydric and dietetic restrictions along a whole month plus a day, all of which have a crucial repercussion over the physical and intellectual performance of Muslims, particularly in occidental societies, in which there is no hour readjustments for daily activities. Among the imposed modifications by Ramadan in daily habits, intermittent fasting along day and night causes adaptation mechanisms to optimize the energy consumption. The objective of this study was to analyze the metabolic-endocrine changes that happen during daily working hours, along the month of fasting in young subjects who have to continue their usual activities and sport training. Ten young muslim subjects, male, healthy, set to sport training, ages in between 18 and 25 who completed Ramadan. Plasma biochemical and hormonal parameters were analyzed in plasma, a week before Ramadan, in the first and fourth of the fasting month and a week after conclusion. During Ramadan, have been observed a drop of biochemical parameters along daytime, especially those related to glycemia, being these changes stronger in the first week. The concentration of cortisol found to be significantly high during the whole month as a consequence of adaptation to the change of circadian secretion rhythms. Ramadan obliges subject´s organisms to readjust their endocrine and metabolic system in order to preserve the energetic efficiency during daytime. This auto control becomes more efficient as long as the month advances due to physiological adaptations.

Desenvolvimento biométrico e desempenho de frangos de corte submetidos a diferentes períodos de jejum pós-eclosão / Biometric development and performance of broilers submitted to different periods of post-hatching fasting

Foram avaliados os efeitos do tempo de jejum pós-eclosao sobre a biometria dos orgãos do trato digestório e o desempenho zootecnico de frangos de corte. Foram utilizadas 640 aves.sexadas, distribuidas em delineamento experimental inteiramente casualizado com quatro períodos de jejum pós-eclosão (0, 12, 24, 36 horas) e quatro repetições de 40 aves cada (20 fêmeas e 20 machos). A avaliação do peso vivo e da biometria dos órgãos no alojamento das aves revelou perda de peso relativo do saco vitelino e a redução no paso vivo nesta fase foi tanto maior quanto maior o tempo decorrido entre nascimento e alokamento. O jejum influenciou o peso relativo de todos os órgãos do trato digestório exceto para esôfago + papo que permaneceram inalterados. Com o aumento do tempo de jejum houve aumento do peso relativo de proventriculo + moela, intestino delgado + pancreas, intestino grosso e fígado + visícula biliar. O peso vivo aos 7 e 21 dias de idade foi maior nas aves que permaneceram em restrição de 24 a 36 horas de jejum, Todavia, as demais variáveis de desempenho não foram influenciadas pelo jejum. Portanto, o uso de até 36 horas de jejum p´´os-eclusão afetou o desenvolvimento biométrico do trato digestório, no entento, o desempenho zootecnico dos frangos de corte aos 42 dias de idade não foi influenciado pelas restrição alimentar.

The objective of this study was to evaluate the effects of fasting time on biometrics organ digestive tract and performance of broilers. A total of 640 sexed birds were, distributed according to a completely randomized design with four periods of fasting after hatching (0, 12, 24 and 36 hours) and four replicates of 40 birds each (20 females and 20 males). The evaluation of body weight and biometrics of the organs during the housing of the birds showed that there was loss of relative weight of the yolk sac and reduction in weight as they increased the time between birth and accommodation. Fasting influenced the relative weight of all of the digestive tract, except for esophagus + craw that remained unchanged. With the increasing fasting time there was an increase in relative weight of the proventriculus + gizzard, small intestine + pancreas, large intestine, liver + gallbladder. The live weight at 7 and 21 days of age was higher in birds that remained in restriction of 24 and 36 hours of fasting. However, the other performance variables were not affected by fasting compared with birds with no fasting. Therefore, the use of up to 36 hours post-hatching fasting affects the development biometric digestive tract, however the production performance of broiler at 42 days of age is not affected by food restriction.

Risk factors for nonalcoholic steatohepatitis in cryptogenic cirrhosis / Fatores de risco para esteatohepatite não-alcoólica na cirrose criptogênica

CONTEXT: In about 10% of patients with chronic liver disease, it is not possible to identify an etiologic factor. These cases are called cryptogenic cirrhosis. Currently, nonalcoholic steatohepatitis (NASH) is being considered as a possible etiologic factor for a significant segment of patients that presents with cryptogenic cirrhosis. OBJECTIVE: To estimate the prevalence of risk factors for NASH in patients with cryptogenic cirrhosis, in order to verify if there is a causal relationship between them. METHOD: Cross-sectional study, with evaluation of the demographic and laboratorial data of patients with cryptogenic cirrhosis. They were compared with data obtained from a group with NASH and a group with alcoholic and/or hepatitis C (HCV) cirrhosis. RESULTS: Forty seven patients with cryptogenic cirrhosis were evaluated, 47 with NASH and 196 with HCV and/or alcoholic cirrhosis. The mean age of patients with cryptogenic cirrhosis was 52 years, while in those with NASH it was 46.4 years (P = 0,041). The group with cryptogenic cirrhosis had 23 female and 24 male patients. Of the patients who presented with NASH, 68.1% were female. Of the patients who presented with alcoholic/HCV cirrhosis, 64.8% were male. There were no statistically significant differences between the groups. In cryptogenic cirrhosis patients, the following prevalences could be observed: impaired fasting glycemia - 68.2%; obesity - 27.5%; total hypercholesterolemia - 27.9%; low HDL levels - 58.1% (women - 81%; men - 36.4%); hypertriglyceridemia - 16.3%. The results seen in cryptogenic cirrhosis patients showed statistical similarity with the results of the NASH group regarding fasting glycemia (62.8%) and male HDL levels (53.8%). The comparison with the alcoholic/HCV cirrhosis group showed statistical differences regarding fasting glycemia (45.2%), hypercholesterolemia (13.3%) and female HDL levels (50.8%). CONCLUSIONS: It is not possible to establish a causal relationship between cryptogenic cirrhosis and NASH. Only data related to fasting glycemia and HDL levels in male patients showed statistical similarities between both groups of patients.

CONTEXTO: Em aproximadamente 10% dos pacientes com doença hepática crônica não é possível identificar um fator etiológico, sendo então rotulados como tendo cirrose criptogênica. Atualmente a esteatohepatite não-alcoólica (EHNA) tem sido considerada como provável etiologia em parcela significativa desses pacientes. OBJETIVO: Estimar a prevalência de fatores de risco para EHNA em pacientes com cirrose criptogênica com o intuito de verificar uma possível relação causal entre as duas doenças. MÉTODOS: Estudo transversal em que foi avaliado o registro de dados demográficos e laboratoriais de pacientes com cirrose criptogênica com a finalidade de compará-los com aqueles obtidos de um grupo de pacientes com EHNA e de um grupo controle composto de cirróticos por hepatite C (HCV) e/ou álcool. RESULTADOS: Foram avaliados 47 pacientes com cirrose criptogênica, 47 com EHNA e 196 com cirrose por HCV e/ou álcool. A média de idade dos pacientes com cirrose criptogênica foi 52 anos, enquanto a daqueles com EHNA foi 46,4 anos (P = 0,041). No grupo com cirosse criptogênica havia 23 mulheres e 24 homens. Naqueles com EHNA predominou o gênero feminino (68,1%) e nos cirróticos por HCV e/ou álcool predominou o gênero masculino (64,8%), sem diferença estatística entre os grupos. Naqueles com cirrose criptogênica, a prevalência de glicemia de jejum alterada foi 68,2%; obesidade, 27,5%; hipercolesterolemia total, 27,9%; baixos níveis de HDL, 58,1% (81% nas mulheres e 36,4% nos homens); e hipertrigliceridemia, 16,3%. A comparação com dados observados nos pacientes com EHNA mostra semelhança estatística entre o perfil glicêmico (62,8%) e níveis de HDL nos homens (53,8%). A comparação com os cirróticos relacionados ao HCV e/ou álcool mostra diferença estatística no perfil glicêmico (45,2%), colesterol total (13,3%) e HDL nas mulheres (50,8%). CONCLUSÃO: Não foi possível estabelecer uma relação causal entre a EHNA e a cirrose criptogênica. Apenas o perfil glicêmico e os níveis de HDL colesterol nos pacientes masculinos apresentaram semelhanças estatísticas entre os dois grupos de doentes.

Respuesta metabólica a la injuria grave / Metabolic response to severe injury

Si bien es cierto, los procesos de adaptación que afrontan los tejidos durante el ayuno y la injuria severa son los mismos, existen varias diferencias importantes entre una y otra respuesta. La velocidad y la magnitud en que se desarrollan, es considerablemente mayor durante la injuria severa. Después de unos días de ayuno, el catabolismo proteico disminuye como una forma de protección frente al compromiso vital que significaría agotar por completo las reservas de proteínas; en la injuria severa, por el contrario, el catabolismo proteico tan solo disminuye cuando los mediadores de la respuesta inflamatoria han sido controlados. Durante el ayuno, la introducción progresiva de nutrientes cesa los procesos catabólicos. En la injuria, estos no cesan si el foco inflamatorio, no lo ha hecho.

Análise de fatores que se associam a alterações no teste de tolerância oral à glicose, independentemente dos valores da glicemia de jejum / Analysis of factors associated with changes in the oral glucose tolerance test, regardless of the values of fasting glucose

OBJETIVO: Identificar fatores associados a alterações do teste oral de tolerância à glicose (TOTG), independentemente da glicemia de jejum (GJ). SUJEITOS E MÉTODOS: 377 pacientes (53,8 ± 15,2 anos; 77,7 por cento mulheres e IMC = 31,4 ± 5,9 kg/m²), sem história de diabetes melito (DM), foram submetidos ao TOTG e comparados de acordo com o resultado: normal (NGT), intolerantes (IGT) e DM. RESULTADOS: 202 pacientes (53,6 por cento) apresentaram TOTG alterado, sendo identificados 69 com DM (18,3 por cento) e 133 com IGT (35,3 por cento). Na análise multivariada, os fatores, além da GJ, que se associaram (P < 0,05) ao TOTG alterado foram: idade (DM = 58,7 ± 12,9; IGT = 56,7 ± 14,3; NGT = 49,6 ± 15,6 anos), hipertensão arterial (DM = 69,6 por cento; IGT = 63,9 por cento; NGT = 43,4 por cento), GJ (DM = 111,9 ± 9,2; IGT = 103,5 ± 10,3; NGT = 96,6 ± 11,1 mg/dL), HbA1C (DM = 6,1 ± 0,7 por cento; IGT = 6,1 ± 0,5 por cento; NGT = 5,8 ± 0,4 por cento), triglicérides (DM = 179,3 ± 169,9; IGT = 154,2 ± 84,1; NGT = 129,1 ± 71,9 mg/dL), HDL-c (DM = 44,7 ± 9,2; IGT = 47,5 ± 12,3; NGT = 50,6 ± 13,4 mg/dL) e ácido úrico em mulheres (DM = 5,3 ± 1,5; IGT = 5,3 ± 1,3; NGT = 4,7 ± 1,3 mg/dL). CONCLUSÃO: Idade, hipertensão arterial, níveis elevados de triglicérides, de HbA1C e de ácido úrico (em mulheres) e baixos níveis de HDL-c se associam a alterações do TOTG em pacientes com sobrepeso/obesidade, independentemente da GJ.

OBJECTIVE: To identify factors associated with changes in oral glucose tolerance test (OGTT), regardless of fasting glucose (FG). SUBJECTS AND METHODS: 377 patients (53.8 ± 15.2 years, 77.7 percent women and BMI = 31.4 ± 5.9 kg/m²) with no history of diabetes mellitus(DM), underwent OGTT and compared according to the results: normal (NGT), impaired (IGT) and DM. RESULTS: 202 patients (53.6 percent) had altered glucose tolerance: 69 with DM (18.3 percent) and 133 with IGT (35.3 percent). In multivariate analysis, factors regardless of FG that were associated (P < 0.05) with changes in the OGTT were age (DM = 58.7 ± 12.9; IGT = 56.7 ± 14.3; NGT = 49.6 ± 15.6 years), hypertension (DM = 69.6 percent; IGT = 63.9 percent; NGT = 43.4 percent), FG (DM = 111.9 ± 9.2; IGT = 103.5 ± 10.3; NGT = 96.6 ± 11.1 mg/dL), HbA1C (DM = 6.1 ± 0.7 percent; IGT = 6.1 ± 0.5 percent; NGT = 5.8 ± 0.4 percent), triglycerides (DM = 179.3 ± 169.9; IGT = 154.2 ± 84.1; NGT = 129.1 ± 71.9 mg/dL), HDL-c (DM =44.7 ± 9.2; IGT = 47.5 ± 12.3; NGT = 50.6 ± 13.4 mg/dL) and uric acid in women (DM = 5.3 ± 1.5; IGT = 5.3 ± 1.3; NGT = 4.7 ± 1.3 mg/dL). CONCLUSION: Age, hypertension, elevated triglycerides, HbA1C, uric acid (in women) and low HDL-C are associated with changes in the OGTT patients with overweight / obesity, irrespective of FG.

Respuesta metabólica al ayuno / Metabolic response to fasting

La glucosa es el combustible más importante para el organismo. En condiciones de ayuno, las células orgánicas deben adaptarse para obtener energía de otros combustibles naturales como son las grasas y las proteínas. Durante las primeras horas de ayuno, la pérdida neta de proteínas es significativamente alta, evento que no puede ser sostenido por mucho tiempo, puesto que las proteínas realizan diversas funciones vitales, que sin ellas no se podrías realizar. Conforme el ayuno avanza, cesa progresivamente el volumen de proteína utilizada como fuente de energía y la grasa se convierte en el principal sustrato empleado. Todos estos procesos generan respuestas diferentes a nivel del músculo esquelético y el tejido adiposo que son importantes revisar, además de los procesos relacionados con la eliminación del nitrógeno de desecho.

Suplemento múltiplo com ionóforos para novilhos em pasto: desempenho / Multiple supplement with ionophores for grazing steers: performance

Avaliou-se o desempenho de 25 novilhos Holandês x Zebu, castrados, com média de peso vivo inicial de 265±50 kg, sob pastejo emBrachiaria decumbens, distribuídos em cinco grupos e em cinco piquetes, segundo os tratamentos: controle - suplementação múltipla sem ionóforos (CONT); suplementação múltipla com 100mg/cab/dia de monensina (M100); suplementação múltipla com 200mg/cab/dia de monensina (M200); suplementação múltipla com 100mg/cab/dia de lasalocida (L100); suplementação múltipla com 200mg/cab/dia de lasalocida (L200). O período experimental foi de 105 dias, com rotação dos grupos nos piquetes a cada 21 dias. A suplementação foi fornecida ad libitum. A avaliação de desempenho ocorreu mediante a pesagem dos animais, em jejum de alimento e água de 14 horas, no início de cada período e término do experimento. Os animais alimentados com suplementos com ionóforos apresentaram maior ganho de peso em relação aos do controle (0,357 vs. 0,268; P = 0,0068). Entre os ionóforos, os animais alimentados com lasalocida ganharam mais peso (0,398 vs. 0,333; P=0,0175). O melhor desempenho pode ser explicado pelo maior consumo dos suplementos pelos animais alimentados com lasalocida (0,53 vs. 0,42; P<0,0001).

The performance of 25 castrated Holstein x Zebu crossbred steers averaging 265±50kgBW, grazing on Brachiaria decumbens, during dry season was evaluated. The experiment was carried out in a completed randomized design and the animals were grouped in five different paddocks with the following treatments: control - multiple supplement without ionophores (CONT); multiple supplement with 100mg of monensin/animal/day (M100); multiple supplement with 200mg of monensin/animal/day (M200); multiple supplement with 100mg of lasalocid/animal/day (L100); and multiple supplement with 200mg of lasalocid/animal/day (L200). The experimental period was 105 days, with changing groups on paddocks every 21 days. The multiple supplement was offered ad libitum. Body weight was evaluated after 14 hours of fasting. Animals fed multiple supplement with ionophores showed higher average daily weight gain than control (0.357 vs 0.268; P= 0.0068), as well as steers fed lasalocid in comparision to monensin (0.398 vs. 0.333; P= 0.0175). Animals suplemented with lasalocid had higher intakes and higher average daily gain (0.53 vs. 0.42; P<0.0001).