New Findings r What is the central question of this study?Sleep curtailment in infancy and adolescence may lead to long-term risk for obesity, but the mechanisms involved have not yet been determined. This study examined the immediate and long-term metabolic effects produced by sleep restriction in young rats. r What is the main finding and its importance?Prolonged sleep restriction reduced weight gain (body fat stores) in young animals. After prolonged recovery, sleep-restricted rats tended to save more energy and to store more fat, possibly owing to increased gross food efficiency. This could be the first step to understand this association.Sleep curtailment is associated with obesity and metabolic changes in adults and children. The aim of the present study was to evaluate the immediate and long-term metabolic alterations produced by sleep restriction in pubertal male rats. Male Wistar rats (28 days old) were allocated to a control (CTL) group or a sleep-restricted (SR) group. This was accomplished by the single platform technique for 18 h per day for 21 days. These groups were subdivided into the following four time points for assessment: sleep restriction and 1, 2 and 4 months of recovery. Body weight and food intake were monitored throughout the experiment. At the end of each time period, blood was collected for metabolic profiling, and the carcasses were processed for measurement of body composition and energy balance. During the period of sleep restriction, SR animals consumed less food in the home cages. This group also displayed lower body weight, body fat, triglycerides and glucose levels than CTL rats. At the end of the first month of recovery, despite eating as much as CTL rats, SR animals showed greater energy and body weight gain, increased gross food efficiency and decreased energy expenditure. At the end of the second and fourth months of recovery, the groups were no longer different, except for energy gain and gross food efficiency, which remained higher in SR animals. In conclusion, sleep restriction affected weight gain of young animals, owing to reduction of fat stores. Two months were sufficient to recover this deficit and to reveal that SR rats tended to save more energy and to store more fat.

Objective: The aim of this study was to evaluate the late effects of maternal obesity induced by lesion of the ventromedial hypothalamus on offspring metabolism. Materials and methods: Thirty days after the bilateral lesion of the ventromedial hypothalamus, female rats were mated and divided into 2 groups of pregnant animals: Control (C) -false lesion (sham) and Obese (OB) -lesion. Three months after that, with the groups of mothers, offspring were divided into control and obese animals that received a normocaloric diet (C-N and OB-N), and control and obese animals that received a hypercaloric diet (C-H and OB-H). At 120 days of age, the animals were euthanized and their carcasses, feces and food were submitted to calorimetric analysis to determine energy balance and body composition. Results: During the growth period, offspring from obese mothers showed higher values of body weight and food intake than controls. Obese animals showed higher body weight gain and gross food efficiency than control animals in adulthood. The hypercaloric diet led to increased metabolizable energy intake, percentage of absorbed energy and energy expenditure in both groups. Body composition was only affected by the association of hypercaloric diet and maternal obesity that led to increased body fat. Conclusions: Maternal obesity has led to the development of later overweight in offspring, suggesting fetal programming. According to the trend presented, it is believed that the prolonged intake of hypercaloric diets in adult animals may, as an additional effect, induce worsening of the overweight induced by maternal obesity. Arq Bras Endocrinol Metab. 2014;58(3):301-7 Keywords Fetal programming; obesity; energy metabolism; body composition; hypercaloric diet RESUMO Objetivo: Avaliar os efeitos tardios da obesidade materna induzida por lesão do núcleo ventromedial do hipotálamo sobre o metabolismo da prole. Materiais e métodos: Trinta dias após a lesão bilateral do hipotálamo ventromedial, ratos fêmeas foram colocadas para acasalar e divididas em dois grupos de animais gestantes: Controle (C) -falsa lesão e Obeso (OB) -lesionados. Três meses após o nascimento, de acordo com os grupos das mães, os filhotes foram divididos em animais controle e obesos que recebiam dieta normocalórica (C-N and OB-N) e animais controle e obesos que recebiam dieta hipercalórica (C-H and OB-H). Aos 120 dias de idade, os animais foram eutanasiados e as carcaças, fezes e ração foram submetidas à análise calorimétrica para determinação do balanço energético e composição corporal. Resultados: Durante o período de crescimento, os filhos de mães obesas mostraram maiores valores de peso corporal e ingestão alimentar que animais controle. Os animais obesos apresentaram maiores valores de ganho de peso corporal e eficiência metabólica que os animais controle quando adultos. A dieta hipercalórica levou ao aumento da energia metabolizável, percentagem de energia absorvida e gasto energético para ambos os grupos. A composição corporal foi somente afetada pela assoc...

Reduced sleep is associated with metabolic alterations, not only in adults, but also in children and adolescents. Several studies have shown that sleep restricted (SR) adult rats exhibit metabolic changes, followed by increased food intake, but few have evaluated these functions in young animals. The aim of the present study was to establish the metabolic parameters of young rats subjected to different periods of REM sleep restriction and to propose a correction factor for the correct measurement of food intake. Young male Wistar rats were distributed in control and SR groups for 7, 14 or 21 days. Sleep restriction was performed by the single platform method for 18 h. Regardless of the length of sleep restriction, all SR rats had a negative energy balance, evidenced by reduction in body weight gain, body energy gain and gross food efficiency, accompanied by increased energy expenditure. In addition, sleep restriction reduced body fat content throughout the entire period. Discounting food spillage, there was no increase in food intake by SR rats. In conclusion, the present study revealed metabolic changes in SR young rats after different lengths of REM sleep restriction and that weight loss and increased energy expenditure were not compensated by increased dietary intake as occurs in adult rats, indicating that young rats use other mechanisms to cope with the negative energy balance caused by sleep restriction. In addition, we propose a correction factor for food intake, to prevent overestimation of this parameter, due to food spillage in the water containers.

OBJECTIVE: The effects of maternal obesity on fetal development are controversial. Our aim was to evaluate the effects of energy intake equalization during pregnancy on the maternal energy balance and fetal development. METHODS: Female rats were mated 30 days following the bilateral lesion of ventromedial hypothalamus (VMH) divided into three groups: CONTROL (C) – false lesionated (sham) fed ad libitum; OBESE (OB) - lesionated fed ad libitum; OBESE PAIR-FED (OBP) - lesionated fed on the equalized C ingestion. Cesarean was made on the 20th day of pregnancy. Maternal and pups carcass, feces and food were submitted to calorimetric measurement for energy balance determination. Body composition and plasmatic levels of hormones and lipids were determined. Body weight, food intake and fat content were increased in obese animals following experimental lesion of the VMH. RESULTS: During pregnancy, obese animals showed higher metabolizable energy intake and energy expenditure compared to the control and pair-fed animals, in which food-equalization reduced net body weight gain, metabolizable energy intake, energy gain, and gross food efficiency, compared to control and obese animals. Maternal obesity did not alter hormone and lipid profiles, body weight, energy content and body composition of the offspring, except for a reduction of lipid content in OBP newborns. CONCLUSION: The results suggest that at birth the fetuses were preserved of deleterious effects of maternal obesity. Hence, unlike the expected, caloric equalization imposed during the gestational period to previously obese pregnant seems to exert negative effects on the offspring.

No abstract