Identificação de limiares metabólicos durante testes de exercício em esteira rolante de ratos geneticamente obesos
Nenhuma Miniatura disponível
Data
2014-09-30
Autores
Rosa, Thiago dos Santos [UNIFESP]
Orientadores
Silva, Bruno Moreira [UNIFESP]
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Atualmente não é claro se os métodos tradicionais de avaliação da capacidade aeróbia são adequados para animais obesos, nem qual é o efeito do treinamento aeróbio sobre os diferentes índices de medida da capacidade aeróbia, assim como em parâmetros metabólicos (e.g. colesterol e frações, triacilglicerol, glicemia e balanço redox) associados à obesidade. Assim, verificou-se 1) em qual percentagem de velocidade máxima (Vmax) ocorre a máxima fase estável de lactato (MLSS) em ratos Zucker, machos de 12 semanas de idade; 2) o efeito do treinamento sobre a MLSS e sobre os limiares de lactato (LT) e glicêmico (GT); 3) a associação entre a MLSS e os limiares; 4) o efeito do treinamento sobre parâmetros metabólicos. Dez ratos Zucker obesos e dez magros realizaram testes contínuos em esteira para determinar a MLSS e testes incrementais para determinar o LT e o GT. O treinamento consistiu em 8 semanas de treinamento em carga constante (intensidade relativa a MLSS), 5 vezes por semana, 60 minutos por dia. Os limiares foram identificados por meio de inspeção visual (LTv e GTv), ajuste polinomial (LTp e GTp) e outros modelos matemáticos (LTs. Dmax e Log- log LTs). A MLSS correspondeu a 78% e 68% da Vmax no pré-treinamento para grupos obesos e magros, respectivamente. O treinamento aumentou a MLSS, LT e GT de modo semelhante entre os grupos. O LTv, GTv, LTs e o Log- log LTs apresentaram maior concordância com à MLSS em comparações intra-grupos, em análise por Bland-Altman plot, além de apresentarem maiores valores nas análises de coeficiente de correlação intraclasse. O treinamento aeróbio promoveu melhora de fatores que podem indicar risco à saúde, como o colesterol total, triacilglicerol, HDLc, balanço entre marcadores anti- e pró-oxidantes (razão GSH/TBARS) e glicemia em obesos, demosntrando que a intensidade relativa à MLSS é eficiente no controle da resistência à insulina, dislipidemias e estresse oxidativo que caracterizam a síndrome metabólica em obesos. Além disso, a razão GSH/TBARS (pré- e pós-treinamento) apresentou maior associação com a MLSS do que com a glicemia, peso corporal ou variáveis lipídicas (pré e pós-treinamento). Portanto, a identificação da MLSS e / ou LT e GT pode ser usada para definir com precisão os protocolos de treinamento e quantificar o efeito do treinamento em ratos Zucker, assim como o treinamento baseado na MLSS pode melhorar a condição de saúde metabólica de maneira independente do peso corporal.
It is currently unclear whether traditional methods for aerobic capacity assessment are suitable for obese animals and what is the effect of aerobic training on the different indices measure of aerobic capacity, as well as metabolic parameters (e.g. cholesterol and lipoproteins, triacylglycerol, glycemia and redox balance) associated with obesity. Thus, we verified 1) at what percentage of the maximum velocity (Vmax) the maximal lactate steady state (MLSS) occurs in Zucker rats; 2) the effect of training on the MLSS and the lactate (LT) and glycemic (GT) thresholds; 3) the association between the MLSS and the thresholds; 4) determine the effect of training on metabolic parameters. Ten obese and ten lean Zucker rats performed constant treadmill bouts to determine the MLSS and an incremental treadmill test to determine the LT and GT. The training consisted of eight weeks of training at constant load (relative MLSS intensity), 5 times a week, 60 minutes per day. Thresholds were identified via visual inspection (LTv and GTv), polynomial adjustment (LTp and GTp) and other mathematical models (LTs, Loglog LTs and Dmax). The MLSS corresponded to 78% and 68% of the Vmax at pretraining for obese and lean groups, respectively. Training increased Vmax, MLSS, LT and GT similarly between groups. The LTv, GTv, Log-log LTs and LTs corresponded to the MLSS on most within group comparisons, showed greater agreement in analysis by Bland-Altman plot, and showed the highest intraclass correlations. Aerobic training promoted improvement of health risk factors such as total cholesterol, triglyceride, HDLC, markers of anti- and pro-oxidant balance (ratio GSH / TBARS) and glucose in the obese group, demonstrating that the MLSS intensity is effective to control insulin resistance, dyslipidemia and oxidative stress that characterize the metabolic syndrome in obese patients. In addition, GSH/TBARS showed greater association with MLSS than glucose, body weight or lipid variables. Therefore, the identification of the MLSS and/or LT and GT can be used to precisely define training protocols and quantify the training effect in Zucker rats, as well as training at the MLSS can improve the condition of metabolic health independently of body weight.
It is currently unclear whether traditional methods for aerobic capacity assessment are suitable for obese animals and what is the effect of aerobic training on the different indices measure of aerobic capacity, as well as metabolic parameters (e.g. cholesterol and lipoproteins, triacylglycerol, glycemia and redox balance) associated with obesity. Thus, we verified 1) at what percentage of the maximum velocity (Vmax) the maximal lactate steady state (MLSS) occurs in Zucker rats; 2) the effect of training on the MLSS and the lactate (LT) and glycemic (GT) thresholds; 3) the association between the MLSS and the thresholds; 4) determine the effect of training on metabolic parameters. Ten obese and ten lean Zucker rats performed constant treadmill bouts to determine the MLSS and an incremental treadmill test to determine the LT and GT. The training consisted of eight weeks of training at constant load (relative MLSS intensity), 5 times a week, 60 minutes per day. Thresholds were identified via visual inspection (LTv and GTv), polynomial adjustment (LTp and GTp) and other mathematical models (LTs, Loglog LTs and Dmax). The MLSS corresponded to 78% and 68% of the Vmax at pretraining for obese and lean groups, respectively. Training increased Vmax, MLSS, LT and GT similarly between groups. The LTv, GTv, Log-log LTs and LTs corresponded to the MLSS on most within group comparisons, showed greater agreement in analysis by Bland-Altman plot, and showed the highest intraclass correlations. Aerobic training promoted improvement of health risk factors such as total cholesterol, triglyceride, HDLC, markers of anti- and pro-oxidant balance (ratio GSH / TBARS) and glucose in the obese group, demonstrating that the MLSS intensity is effective to control insulin resistance, dyslipidemia and oxidative stress that characterize the metabolic syndrome in obese patients. In addition, GSH/TBARS showed greater association with MLSS than glucose, body weight or lipid variables. Therefore, the identification of the MLSS and/or LT and GT can be used to precisely define training protocols and quantify the training effect in Zucker rats, as well as training at the MLSS can improve the condition of metabolic health independently of body weight.
Descrição
Citação
ROSA, Thiago dos Santos. Identificação de limiares metabólicos durante testes de exercício em esteira rolante de ratos geneticamente obesos. 2014. Tese (Doutorado) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2014.