Background: The excess body fat characteristic of obesity is related to various metabolic alterations, which includes insulin resistance (IR). Among the non-pharmacological measures used to improve insulin sensitivity are aerobic physical training, such as high-intensity interval training (HIIT). This study investigated the effects of 8 weeks of HIIT on blood and skeletal muscle markers related to IR and oxidative metabolism in physically inactive individuals with obesity and compared the changes between insulin resistant and non-insulin resistant phenotypes.Methods: Initially to investigate the effect of obesity and IR in the analyzed parameters, insulin-sensitive eutrophic volunteers (CON; n = 9) and obese non-insulin (OB; n = 9) and insulin-resistant (OBR; n = 8) were enrolled. Volunteers with obesity completed 8 weeks of HIIT in a cycle ergometer. Venous blood and vastus lateralis muscle samples were obtained before and after the HIIT. Body composition and peak oxygen consumption (VO2peak) were estimated before and after HIIT.Results: HIIT reduced IR assessed by the homeostatic model assessment of insulin resistance (HOMA-IR) in OBR (4.4 ± 1.4 versus 4.1 ± 2.2 μU L−2), but not in OB (HOMA-IR 1.8 ± 0.5 versus 2.3 ± 1.0 μU L−2) volunteers. HIIT increased VO2peak with no change in body fat in both groups. In skeletal muscle, HIIT increased the phosphorylation of IRS (Tyr612), Akt (Ser473), and increased protein content of β-HAD and COX-IV in both groups. There was a reduction in ERK1/2 phosphorylation in OBR after HIIT.Conclusion: Eight weeks of HIIT increased the content of proteins related to oxidative metabolism in skeletal muscle of individuals with obesity, independent of changes total body fat.

Resumo: Este estudo caracterizou indivíduos adultos obesos que participaram de um programa de atividades de extensão composto por orientações nutricionais no município de Diamantina-MG. Foram recrutados 42 indivíduos obesos (7 homens e 35 mulheres, índice de massa corporal [IMC] de 36,5 ± 4,3 kg m-2) com idade entre 19 e 56 anos. Todos os voluntários foram submetidos à avaliação do IMC, circunferência da cintura (CC) e percentual de gordura, glicemia e insulinemia de jejum, teste de tolerância oral à glicose (TTOG) triglicérides, colesterol total e frações e aptidão cardiorrespiratória. Dos 42 participantes, onze indivíduos apresentaram resistência à insulina, onze aumento na insulina de jejum (26%) e sete (17%) apresentaram aumento na glicemia de jejum e/ou alteração no TTOG. Vinte e quatro porcento dos participantes apresentaram concentração de triglicerídeos elevada, 48% apresentaram HDL-colesterol reduzido e noventa e quatro por cento dos participantes apresentaram CC acima do valor recomendado pela Organização Mundial de Saúde. Os participantes do estudo apresentaram um consumo máximo de oxigênio médio menor que 21 ml kg-1 min-1, indicando um baixo condicionamento cardiorrespiratório. Parte dos participantes do estudo (n=10, 23%) participaram de uma oficina de orientação nutricional que possibilitou uma ampla discussão sobre a obesidade, seus impactos na saúde, e a necessidade de se adotar hábitos de vida saudáveis. Palavras-chave: Extensão Universitária, Excesso de Peso, Resistência à Insulina, Sedentarismo. Obesity in the adult population of Diamantina city: health guidelines, anthropometric, biochemical and cardiorespiratory fitness characterization Abstract: This study characterized obese adults who participated in an outreach program activity on nutrition education in the city of Diamantina, Minas Gerais State, Brazil. 42 obese subjects, aged between 19 and 56 years old, were recruited (7 men and 35 women, body mass index [BMI] of 36.5 ± 4.3 kg m-2). All subjects underwent assessment of BMI, waist circumference (WC), body fat percentage, blood glucose, fasting insulin, oral glucose tolerance test (OGTT), triglycerides, total cholesterol and its fractions, and cardiorespiratory fitness. Of the 42 participants, eleven had insulin resistance, eleven had high fasting insulin (26%), and seven (17%) showed high fasting glucose and/or altered OGTT. Twenty-four percent of the participants showed high concentration of triglycerides, 48% had low HDL-cholesterol and ninety-four percent of the participants had WC greater than what is recommended by the World Health Organization. The participants had a maximum oxygen consumption rate average less than ml kg-1 min-1, which indicates a low cardiorespiratory conditioning. Part of the subjects of the study (n = 10, 23%) attended to a nutritional orientation workshop that allowed a wide discussion on obesity, its impact on health, and the need of having healthy lifestyle habits. Keywords: Continuing Education, Overweight, Insulin Resistance, Inactivity.   La obesidad en la población adulta en la ciudad de Diamantina: directrices de salud, caracterización antropométrica, bioquímica y de la capacidad cardiorrespiratoria Resumen: En este estudio se caracterizaron adultos obesos que participaron de un programa de actividades de extensión que tuvo el objetivo de ofrecer orientaciones nutricionales en el municipio de Diamantina, Minas Gerais, Brasil. Fueron analizados 42 individuos obesos (7 hombres y 35 mujeres, índice de masa corporal [ICM] de 36,5 ± 4,3 kg m-2) con edades entre los 19 y 56 años. Todos los voluntarios fueron sometidos a una evaluación de ICM, circunferencia de la cintura (CC), y porcentaje de grasa, glucemia e insulinemia en ayunas, test de tolerancia oral a la glucosa (TTOG), triglicéridos, colesterol total y fracciones, de aptitud cardiorrespiratoria. De los cuarenta y dos participantes, once sujetos presentaron resistencia a la insulina, once presentaron aumento en la insulina en ayunas (el 26%) y siete (el 17%) presentaron aumento de glucemia en ayunas y/o alteración en TTOG. El Veinticuatro por ciento de los participantes presentaron concentración  elevada de triglicéridos, el 48% presentaron HDL-colesterol reducido y el noventa y cuatro por ciento de los participantes presentaron CC demasiado alto y no recomendable por la Organización Mundial de la Salud. Los participantes de este estudio presentaron un consumo máximo de oxígeno medio menor que 21 ml kg-1 min-1, indicando un bajo acondicionamiento cardiorrespiratorio. Parte de los participantes del estudio (n=10, 23%) participaron de un taller de orientación nutricional que facilitó una amplia discusión sobre la obesidad, sus impactos en la salud, y la necesidad de adoptar hábitos de vida saludable. Palabras-clave: Extensión Universitaria, Sobre Peso, Resistencia a La Insulina, Sedentarismo.

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