El polimorfismo del promotor del gen de la leptina en la posición -2549 disminuye la leptina plasmática y aumenta el apetito de los voluntarios con peso normal

Introduction: Investigate whether polymorphism in the promoter region encoding leptin and leptin receptor gene, in normal weight individuals, affects hormonal and appetite responses to peanuts.Materials and methods: Appetite, anthropometric indices, body composition, physical activity, dietary intake and leptin, ghrelin and insulin levels were monitored. Polymorphism analyses were also carried out.Results: None of the treatments led to statistical differences in the analyzed hormones. No polymorphism was found for leptin receptor gene, while for leptin gene, 50% of the volunteers presented one polymorphic allele and 13% presented both polymorphic alleles. These last ones presented lower body fat mass, leptin and ghrelin plasma concentrations, and fullness rates. They also presented higher hunger, desire to eat, and desire to eat sweet and salty foods.Conclusions: Peanut did not affect appetite and presented no different hormonal responses, compared to other foods studied. Polymorphic allele carriers in both alleles presented higher probability to develop obesity. However, the magnitude of this probability could not be measured.Introducción: Identificar polimorfismos en la región promotora del gen del receptor de la leptina en los individuos con peso normal e investigar si este polimorfi smo afecta a las respuestas hormonales y el apetito tras la ingesta de cacahuetes o una mezcla de ingredientes con un aporte de macronutrientes semejante.Material y método: Se controló el apetito, los índices antropométricos, la composición corporal, la actividad física, la ingesta dietética y las concentraciones de leptina, grelina e insulina de todos los sujetos. Además, se llevaron a cabo los análisis de polimorfi smo.Resultados: Ninguno de los tratamientos dio lugar a una diferencia estadísticamente signifi cativa en las hormonas analizadas. No se encontró polimorfi smo del gen del receptor de leptina, pero para el gen de la leptina, el 50% de los voluntarios tenían un alelo polimórfi co y el 13%, dos. Estos presentaron menores índices de masa grasa corporal, concentraciones plasmáticas de leptina y grelina y tasas de plenitud gástrica. Asimismo, tenían más hambre, deseo de comer y deseo de comer algo dulce y salado.Conclusiones: Ingerir cacahuetes no afecta al apetito y no produce respuestas hormonales diferentes que con otros alimentos estudiados. Los portadores de alelos polimórficos en los dos alelos tuvieron mayor probabilidad de sufrir obesidad, aunque no ha sido posible evaluar su magnitud

The effects of a high dosage of creatine and caffeine supplementation on the lean body mass composition of rats submitted to vertical jumping training

<p>Abstract</p> <p>Background</p> <p>The influences of creatine and caffeine supplementation associated with power exercise on lean body mass (LBM) composition are not clear. The purpose of this research was to determine whether supplementation with high doses of creatine and caffeine, either solely or combined, affects the LBM composition of rats submitted to vertical jumping training.</p> <p>Methods</p> <p>Male Wistar rats were randomly divided into 8 groups: Sedentary (S) or Exercised (E) [placebo (Pl), creatine (Cr), caffeine (Caf) or creatine plus caffeine (CrCaf)]. The supplemented groups received creatine [load: 0.430 g/kg of body weight (BW) for 7 days; and maintenance: 0.143 g/kg of BW for 35 days], caffeine (15 mg/kg of BW for 42 days) or creatine plus caffeine. The exercised groups underwent a vertical jump training regime (load: 20 - 50% of BW, 4 sets of 10 jumps interspersed with 1 min resting intervals), 5 days/wk, for 6 weeks. LBM composition was evaluated by portions of water, protein and fat in the rat carcass. Data were submitted to ANOVA followed by the Tukey post hoc test and Student's <it>t </it>test.</p> <p>Results</p> <p>Exercised animals presented a lower carcass weight (10.9%; <it>P </it>= 0.01), as compared to sedentary animals. However, no effect of supplementation was observed on carcass weight (P > 0.05). There were no significant differences among the groups (P > 0.05) for percentage of water in the carcass. The percentage of fat in the group SCr was higher than in the groups SCaf and ECr (P < 0.05). A higher percentage of protein was observed in the groups EPl and ECaf when compared to the groups SPl and SCaf (P < 0.001). The percentage of fat in the carcass decreased (P < 0.001), while those of water and protein increased (P < 0.05) in exercised animals, compared to sedentary animals. Caffeine groups presented reduced percentage of fat when compared to creatine supplemented groups (P < 0.05).</p> <p>Conclusions</p> <p>High combined doses of creatine and caffeine does not affect the LBM composition of either sedentary or exercised rats, however, caffeine supplementation alone reduces the percentage of fat. Vertical jumping training increases the percentages of water and protein and reduces the fat percentage in rats.</p