Nivel de actividad física en estudiantes de la Universidad de Colima

El propósito de este trabajo fue estimar la prevalencia del nivel de actividad física en estudiantes de la Facultad de Ciencias de la Educación de la Universidad de Colima. Fueron evaluados 138 estudiantes de licenciatura (48 de educación física y deportes, 42 de educación media superior en matemáticas y 48 educación especial). Para apreciar el nivel de actividad física se aplicó la versión en español del cuestionario internacional de actividad física (IPAQ), en el formato corto, resultando en el género masculino un nivel de actividad física alta en 52.1%, moderada en 41.7% y baja en 6.3%, mientras en el género femenino un nivel de actividad física alta en 28.9%, moderada en 55.6% y baja en 15.6%. Al comparar el nivel de actividad física por género de la licenciara en educación física y deportes y las demás carreras, solo se encontraron diferencias significativas entre mujeres. Concluimos que en la población estudiada el sedentarismo se presenta en menor medida que en población de adolescentes mexicanos según la Encuesta Nacional de Salud y Nutrición 2006.The purpose of this work was to estimate the prevalence of physical activity level in students of the Faculty of Educational Sciences of the University of Colima. A total of 138 undergraduate students were evaluated (48 for physical education and sports, 42 for high school in mathematics and 48 for special education). To assess the level of physical activity, the Spanish version of the International Physical Activity Questionnaire (IPAQ) was applied in the short format, resulting in a high physical activity level of 52.1% in men, moderate in 41.7% and low in physical activity. 6.3%, while in the female gender a level of physical activity is high at 28.9%, moderate at 55.6% and low at 15.6%. When comparing the level of physical activity by gender of the licensee in physical education and sports and other careers, only significant differences were found among women. We conclude that sedentary lifestyle in the population studied is less than in Mexican adolescents according to the 2006 National Health and Nutrition Survey

Chronic exercise increases plasma brain-derived neurotrophic factor levels, pancreatic islet size, and insulin tolerance in a TrkB-dependent manner.

BACKGROUND: Physical exercise improves glucose metabolism and insulin sensitivity. Brain-derived neurotrophic factor (BDNF) enhances insulin activity in diabetic rodents. Because physical exercise modifies BDNF production, this study aimed to investigate the effects of chronic exercise on plasma BDNF levels and the possible effects on insulin tolerance modification in healthy rats. METHODS: Wistar rats were divided into five groups: control (sedentary, C); moderate- intensity training (MIT); MIT plus K252A TrkB blocker (MITK); high-intensity training (HIT); and HIT plus K252a (HITK). Training comprised 8 weeks of treadmill running. Plasma BDNF levels (ELISA assay), glucose tolerance, insulin tolerance, and immunohistochemistry for insulin and the pancreatic islet area were evaluated in all groups. In addition, Bdnf mRNA expression in the skeletal muscle was measured. PRINCIPAL FINDINGS: Chronic treadmill exercise significantly increased plasma BDNF levels and insulin tolerance, and both effects were attenuated by TrkB blocking. In the MIT and HIT groups, a significant TrkB-dependent pancreatic islet enlargement was observed. MIT rats exhibited increased liver glycogen levels following insulin administration in a TrkB-independent manner. CONCLUSIONS/SIGNIFICANCE: Chronic physical exercise exerted remarkable effects on insulin regulation by inducing significant increases in the pancreatic islet size and insulin sensitivity in a TrkB-dependent manner. A threshold for the induction of BNDF in response to physical exercise exists in certain muscle groups. To the best of our knowledge, these are the first results to reveal a role for TrkB in the chronic exercise-mediated insulin regulation in healthy rats

Pancreatic immunohistochemistry, effects of an 8-week treadmill exercise regimen in studied rats.

<p>(A) Insulin distribution and (B) pancreatic islet size. Light micrographs reveal the staining patterns of the pancreatic islets; the pancreatic islet areas (mm²) were evaluated in 209 islets. C, control sedentary group; CK sedentary rats that received K252a as in MITK and HITK groups; MIT, medium-intensity training rats; MITK, as MIT with a TrkB inhibitor (K252a) injection; HIT, high-intensity training rats; HITK, as HIT with a TrkB inhibitor injection; data are shown as means ± S.E. *<i>p</i><0.05 <i>vs</i>. C; ^§<i>p</i><0.05 <i>vs.</i> HITK; ANOVA and Tukey' tests.</p

Glucose tolerance test in all experimental groups.

<p>All rats received i.p. injections of D-glucose (200 mg/100 g body weight) at the 0 time point. A) Glucose concentrations in mmol/L. B) Glucose concentrations from (A), expressed as area under the curve (AUC) in % basal during a 2.25-h period. Values are means ± S.E. from 6 independent samples; *<i>p</i><0.05, ANOVA and Tukey's tests.</p

Hepatic glycogen levels in studied rats after insulin injection into the portal veins (0.2 mL 10⁻⁶M), effects of an 8-week treadmill exercise regimen.

<p>Liver fragments were stained according to the PAS method (n = 6 per group). Six representative fields from at least 4 different liver fragments per rat (80 and 90 µm²) were analyzed. Data are shown as means ± SEM. *<i>p</i><0.05 <i>vs</i>. the C group, #<i>p</i><0.05 <i>vs</i>. the MIT group, and §<i>p</i><0.05 <i>vs</i>. the HITK group; ANOVA and Tukey's tests.</p

Carnitine Palmitoyltransferase 1B 531K Allele Carriers Sustain a Higher Respiratory Quotient after Aerobic Exercise, but β3-Adrenoceptor 64R Allele Does Not Affect Lipolysis: A Human Model

<div><p>Carnitine palmitoyltransferase IB (CPT1B) and adrenoceptor beta-3 (ADRB3) are critical regulators of fat metabolism. CPT1B transports free acyl groups into mitochondria for oxidation, and ADRB3 triggers lipolysis in adipocytes, and their respective polymorphisms <i>E531K</i> and <i>W64R</i> have been identified as indicators of obesity in population studies. It is therefore important to understand the effects of these mutations on ADRB3 and CPT1B function in adipose and skeletal muscle tissue, respectively. This study aimed to analyze the rate of lipolysis of plasma indicators (glycerol, free fatty acids, and beta hydroxybutyrate) and fat oxidation (through the non-protein respiratory quotient). These parameters were measured in 37 participants during 30 min of aerobic exercise at approximately 62% of maximal oxygen uptake, followed by 30 min of recovery. During recovery, mean respiratory quotient values were higher in K allele carriers than in non-carriers, indicating low post-exercise fatty acid oxidation rates. No significant differences in lipolysis or lipid oxidation were observed between R and W allele carriers of <i>ADRB3</i> at any time during the aerobic load. The substitution of glutamic acid at position 531 by lysine in the CPT1B protein decreases the mitochondrial beta-oxidation pathway, which increases the non-protein respiratory quotient value during recovery from exercise. This may contribute to weight gain or reduced weight-loss following exercise.</p></div

Mean macronutrient proportions and dietary fatty acid amounts adjusted to body weight in each of the genetic classifications.

<p><b><i>SD</i></b><i>:</i> Standard deviation. <b><i>A</i></b>: One-way analysis of variance (ANOVA): significance, p<0.05. <b><i>U</i></b>: Mann–Whitney test: significance, p<0.05. <b><i>K–W</i></b>: Kruskal–Wallis H test: significance, p<0.05.</p><p><b>C–H</b>: Carbohydrates. <b>SFA/kg</b>: Saturated fatty acids per kg of body weight. <b>MUFA/kg</b>: Mono unsaturated fatty acids per kg of body weight. <b>PUFA/kg</b>: Poly unsaturated fatty acids per kg of body weight. <b>K+</b>: K allele carriers. <b>K−</b>: K allele non-carriers. <b>R+</b>: R allele carriers. <b>R−</b>: R allele non-carriers. <b>K+/R+</b>: K and R allele carriers. <b>K+/R−</b>: K allele only carriers. <b>R+/K−</b>: R allele only carriers.</p

Free fatty acid (FFA) levels before and after the aerobic load.

<p>(<b>A</b>) R allele carriers (12 K and 8 E carriers) versus R allele non-carriers (15 K and 2 E carriers). (<b>B</b>) K allele carriers (12 R and 15 W allele carriers) versus K allele non-carriers (2 R and 8 W carriers). The asterisk indicates significant difference. (<b>C</b>) Interaction (<i>CPT1B–ADRB3</i>), carriers of both K and R alleles versus only K and only R allele carriers. Venous blood was sampled at rest and at 2, 15, and 30 min into the recovery period.</p

Mean non-protein respiratory quotients during and after the aerobic load for each of the genetic classifications.

<p>SD: Standard deviation. One-way analysis of variance (ANOVA), significance p<0.05. <b><i>U</i></b>: Mann–Whitney test, significance p<0.05. Asterisk (<b>*</b>) indicates the values that significantly differ in the same stage.</p><p><b>K+</b>: K allele carriers. <b>K−</b>: K allele non-carriers. <b>R+</b>: R allele carriers. <b>R−</b>: R allele non-carriers. <b>K+/R+</b>: K and R allele carriers. <b>K+/R−</b>: K allele only carriers. <b>R+/K−</b>: R allele only carriers.</p