Serum leptin and insulin levels in lactating protein-restricted rats: implications for energy balance

The present study analysed the effect of protein restriction on serum insulin and leptin levels and their relationship with energy balance during lactation. Four groups of rats received isocaloric diets containing 170 g protein/kg or 60 g protein/kg from pregnancy until the 14th day of lactation: control non-lactating, control lactating (both fed a control diet), low-protein non-lactating and low-protein lactating. Energy intake, body composition, energy balance. serum insulin and leptin concentrations and the relationship between these hormones and several factors related to obesity were analysed. Low-protein-intake lactating rats exhibited hypoinsulinaemia, hyperleptinaemia, hypophagia and decreased energy expenditure compared with control lactating rats. The protein level in the carcasses was lower in the low-protein lactating group than in the control lactating group, resulting in a higher fat content in the first group compared with the latter. Body fat correlated inversely with serum insulin and positively with serum leptin level. There was a significant negative correlation between serum leptin and energy intake, and a positive relationship between energy intake and serum insulin level in lactating rats and in the combined data from both groups. Energy expenditure was correlated positively with serum insulin and negatively with serum leptin in lactating rats and when data from control non-lactating and lactating rats were pooled. Lactating rats submitted to protein restriction, compared with lactating control rats, showed that maternal reserves were preserved owing to less severe negative energy balance. This metabolic adaptation was obtained, at least in part, by the hypoinsulinaemia that resulted in increased insulin sensitivity favouring enhanced fat deposition, hyperleptinaemia and hypophagia.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.971273

Exercise training improves sleep pattern and metabolic profile in elderly people in a time-dependent manner

Aging and physical inactivity are two factors that favors the development of cardiovascular disease, metabolic syndrome, obesity, diabetes, and sleep dysfunction. In contrast, the adoption a habitual of moderate exercise may present a non-pharmacological treatment alternative for sleep and metabolic disorders. We aimed to assess the effects of moderate exercise training on sleep quality and on the metabolic profile of elderly people with a sedentary lifestyle. Fourteen male sedentary, healthy, elderly volunteers performed moderate training for 60 minutes/day, 3 days/week for 24 wk at a work rate equivalent to the ventilatory aerobic threshold. The environment was kept at a temperature of 23 +/- 2 degrees C, with an air humidity 60 +/- 5%. Blood and polysomnographs analysis were collected 3 times: at baseline (1 week before training began), 3 and 6 months (after 3 and 6 months of training). Training promoted increasing aerobic capacity (relative VO2, time and velocity to VO(2)max; p < 0.05), and reduced serum NEFA, and insulin concentrations as well as improved HOMA index (p < 0.05), and increased adiponectin levels (p < 0.05), after 3 months of training when compared with baseline data. The sleep parameters, awake time and REM sleep latency were decreased after 6 months exercise training (p < 0.05) in relation baseline values. Our results demonstrate that the moderate exercise training protocol improves the sleep profile in older people, but the metabolism adaptation does not persist. Suggesting that this population requires training strategy modifications as to ensure consistent alterations regarding metabolism.1

Green Tea Extract Supplementation Induces the Lipolytic Pathway, Attenuates Obesity, and Reduces Low-Grade Inflammation in Mice Fed a High-Fat Diet

The aim of this study was to evaluate the effects of green tea Camellia sinensis extract on proinflammatory molecules and lipolytic protein levels in adipose tissue of diet-induced obese mice. Animals were randomized into four groups: CW (chow diet and water); CG (chow diet and water + green tea extract); HW (high-fat diet and water); HG (high-fat diet and water + green tea extract). The mice were fed ad libitum with chow or high-fat diet and concomitantly supplemented (oral gavage) with 400 mg/kg bodyweight/day of green tea extract (CG and HG, resp.). The treatments were performed for eight weeks. UPLC showed that in 10 mg/mL green tea extract, there were 15 mu g/mg epigallocatechin, 95 mu g/mg epigallocatechin gallate, 20.8 mu g/mg epicatechin gallate, and 4.9 mu g/mg gallocatechin gallate. Green tea administered concomitantly with a high-fat diet increased HSL, ABHD5, and perilipin in mesenteric adipose tissue, and this was associated with reduced body weight and adipose tissue gain. Further, we observed that green tea supplementation reduced inflammatory cytokine TNF alpha levels, as well as TLR4, MYD88, and TRAF6 proinflammatory signalling. Our results show that green tea increases the lipolytic pathway and reduces adipose tissue, and this may explain the attenuation of low-grade inflammation in obese mice