HIGH-FIBER DIET PROMOTES METABOLIC, HORMONAL, AND SATIETY EFFECTS IN OBESE WOMEN ON A SHORT-TERM CALORIC RESTRICTION.

•Body weight and BMI decrease in both the EG and CG groups during the period of caloric restriction. •For both the EG and CG groups, fat-free mass decreases during food restriction. •Subjects on a high-fiber diet have reduced fasting glucose and basal insulin as well as improved insulin resistance, as attested by the lower HOMA-IR index. •Obese women on a high-fiber diet have suppressed postprandial (after 60 min) acylated ghrelin, confirming that the diet composition influences ghrelin levels from the first day. •In the present study, it was possible to verify that fasting leptin concentration diminishes in obese women on a high-fiber diet. Background - Several mechanisms, including excessive hunger, account for patients' difficulties in maintaining weight loss and dietary changes after caloric restriction. Objective - To evaluate the effect of short-term high-fiber calorie-restricted diet in appetite-regulating hormones, and hunger and satiety sensations in women with obesity. In a randomized controlled trial study, thirty women with body mass index (BMI) higher than 30 kg/m2, and aged from 20 to 50 years were hospitalized following a calorie-restricted diet (1000 kcal/day) for three days. The experimental group (n=15) received high-fiber diet and the control group (n=15), conventional diet. Results - Body weight, BMI, resting energy expenditure (REE), acylated and total ghrelin, leptin, insulin and glucose, and hunger and satiety sensations were evaluated. Linear regression models with mixed effects (fixed and random effects) helped to assess the variables between the two groups and within the groups. Body weight and BMI decreased in both the experimental and control groups (P<0.001). After the high-fiber diet, postprandial acylated ghrelin (P=0.04), glucose (P<0.001), insulin (P=0.04), and leptin (P=0.03) levels as well as the HOMA-IR index (P=0.01) decreased, whereas satiety improved (P=0.02). Obese women that followed the conventional diet had increased body fat percentage (P=0.04) and lower REE (P=0.02). The two diets did not differ in terms of hunger sensation. Conclusion - A short-term high-fiber diet improves satiety sensations and metabolic parameters while suppressing postprandial acylated ghrelin (60 minutes) and maintaining the resting energy expenditure.

Dieta rica em fibra promove efeitos metabólicos, hormonais e de saciedade em mulheres obesas com restrição calórica de curto prazo / High-fiber diet promotes metabolic, hormonal, and satiety effects in obese women on a short-term caloric restriction

ABSTRACT Background: Several mechanisms, including excessive hunger, account for patients' difficulties in maintaining weight loss and dietary changes after caloric restriction. Objective: To evaluate the effect of short-term high-fiber calorie-restricted diet in appetite-regulating hormones, and hunger and satiety sensations in women with obesity. Methds: In a randomized controlled trial study, thirty women with body mass index (BMI) higher than 30 kg/m2, and aged from 20 to 50 years were hospitalized following a calorie-restricted diet (1000 kcal/day) for three days. The experimental group (n=15) received high-fiber diet and the control group (n=15), conventional diet. Body weight, BMI, resting energy expenditure (REE), acylated and total ghrelin, leptin, insulin and glucose, and hunger and satiety sensations were evaluated. Linear regression models with mixed effects (fixed and random effects) helped to assess the variables between the two groups and within the groups. Results: Body weight and BMI decreased in both the experimental and control groups (P<0.001). After the high-fiber diet, postprandial acylated ghrelin (P=0.04), glucose (P<0.001), insulin (P=0.04), and leptin (P=0.03) levels as well as the HOMA-IR index (P=0.01) decreased, whereas satiety improved (P=0.02). Obese women that followed the conventional diet had increased body fat percentage (P=0.04) and lower REE (P=0.02). The two diets did not differ in terms of hunger sensation. Conclusion: A short-term high-fiber diet improves satiety sensations and metabolic parameters while suppressing postprandial acylated ghrelin (60 minutes) and maintaining the resting energy expenditure.

RESUMO Contexto: Vários mecanismos, incluindo a fome excessiva, são responsáveis pelas dificuldades dos pacientes em manter a perda de peso e mudanças na dieta após a restrição calórica. Objetivo: Avaliar o efeito da dieta de curta duração rica em fibras e com restrição calórica nos hormônios reguladores do apetite e nas sensações de fome e saciedade em mulheres com obesidade. Métodos: Em um estudo randomizado controlado, 30 mulheres com índice de massa corporal (IMC) superior a 30 kg/m2 e com idade entre 20 e 50 anos foram hospitalizadas seguindo dieta com restrição calórica (1000 kcal/dia) por 3 dias. O grupo experimental (n=15) recebeu dieta rica em fibras e o grupo controle (n=15), dieta convencional. Foram avaliados peso corporal, IMC, gasto energético de repouso (GER), grelina acilada e total, leptina, insulina e glicose e sensações de fome e saciedade. Modelos de regressão linear com efeitos mistos (efeitos fixos e aleatórios) ajudaram a avaliar as variáveis entre os dois grupos e dentro dos grupos. Resultados: O peso corporal e o IMC diminuíram tanto no grupo experimental quanto no controle (P<0,001). Após a dieta rica em fibras, os níveis de grelina acilada pós-prandial (P=0,04), glicose (P<0,001), insulina (P=0,04) e leptina (P=0,03), bem como o índice HOMA-IR (P=0,01) diminuiu, enquanto a saciedade melhorou (P=0,02). Mulheres obesas que seguiram a dieta convencional apresentaram aumento do percentual de gordura corporal (P=0,04) e menor GER (P=0,02). As duas dietas não diferiram em termos de sensação de fome. Conclusão: Uma dieta rica em fibras de curto prazo melhora as sensações de saciedade e os parâmetros metabólicos, suprimindo a grelina acilada pós-prandial (60 minutos) e mantendo o gasto energético de repouso.

Hepatic Osteodystrophy: The Mechanism of Bone Loss in Hepatocellular Disease and the Effects of Pamidronate Treatment.

OBJECTIVES:: The present study was designed to evaluate the bone phenotypes and mechanisms involved in bone disorders associated with hepatic osteodystrophy. Hepatocellular disease was induced by carbon tetrachloride (CCl4). In addition, the effects of disodium pamidronate on bone tissue were evaluated. METHODS:: The study included 4 groups of 15 mice: a) C = mice subjected to vehicle injections; b) C+P = mice subjected to vehicle and pamidronate injections; c) CCl4+V = mice subjected to CCl4 and vehicle injections; and d) CCl4+P = mice subjected to CCl4 and pamidronate injections. CCl4 or vehicle was administered for 8 weeks, while pamidronate or vehicle was injected at the end of the fourth week. Bone histomorphometry and biomechanical analysis were performed in tibiae, while femora were used for micro-computed tomography and gene expression. RESULTS:: CCl4 mice exhibited decreased bone volume/trabecular volume and trabecular numbers, as well as increased trabecular separation, as determined by bone histomorphometry and micro-computed tomography, but these changes were not detected in the group treated with pamidronate. CCl4 mice showed increased numbers of osteoclasts and resorption surface. High serum levels of receptor activator of nuclear factor-κB ligand and the increased expression of tartrate-resistant acid phosphatase in the bones of CCl4 mice supported the enhancement of bone resorption in these mice. CONCLUSION:: Taken together, these results suggest that bone resorption is the main mechanism of bone loss in chronic hepatocellular disease in mice.

Hepatic Osteodystrophy: The Mechanism of Bone Loss in Hepatocellular Disease and the Effects of Pamidronate Treatment

OBJECTIVES: The present study was designed to evaluate the bone phenotypes and mechanisms involved in bone disorders associated with hepatic osteodystrophy. Hepatocellular disease was induced by carbon tetrachloride (CCl4). In addition, the effects of disodium pamidronate on bone tissue were evaluated. METHODS: The study included 4 groups of 15 mice: a) C = mice subjected to vehicle injections; b) C+P = mice subjected to vehicle and pamidronate injections; c) CCl4+V = mice subjected to CCl4 and vehicle injections; and d) CCl4+P = mice subjected to CCl4 and pamidronate injections. CCl4 or vehicle was administered for 8 weeks, while pamidronate or vehicle was injected at the end of the fourth week. Bone histomorphometry and biomechanical analysis were performed in tibiae, while femora were used for micro-computed tomography and gene expression. RESULTS: CCl4 mice exhibited decreased bone volume/trabecular volume and trabecular numbers, as well as increased trabecular separation, as determined by bone histomorphometry and micro-computed tomography, but these changes were not detected in the group treated with pamidronate. CCl4 mice showed increased numbers of osteoclasts and resorption surface. High serum levels of receptor activator of nuclear factor-κB ligand and the increased expression of tartrate-resistant acid phosphatase in the bones of CCl4 mice supported the enhancement of bone resorption in these mice. CONCLUSION: Taken together, these results suggest that bone resorption is the main mechanism of bone loss in chronic hepatocellular disease in mice.

Trabecular bone loss after administration of the second-generation antipsychotic risperidone is independent of weight gain.

Second generation antipsychotics (SGAs) have been linked to metabolic and bone disorders in clinical studies, but the mechanisms of these side effects remain unclear. Additionally, no studies have examined whether SGAs cause bone loss in mice. Using in vivo and in vitro modeling we examined the effects of risperidone, the most commonly prescribed SGA, on bone in C57BL6/J (B6) mice. Mice were treated with risperidone orally by food supplementation at a dose of 1.25 mg/kg daily for 5 and 8 weeks, starting at 3.5 weeks of age. Risperidone reduced trabecular BV/TV, trabecular number and percent cortical area. Trabecular histomorphometry demonstrated increased resorption parameters, with no change in osteoblast number or function. Risperidone also altered adipose tissue distribution such that white adipose tissue mass was reduced and liver had significantly higher lipid infiltration. Next, in order to tightly control risperidone exposure, we administered risperidone by chronic subcutaneous infusion with osmotic minipumps (0.5 mg/kg daily for 4 weeks) in 7 week old female B6 mice. Similar trabecular and cortical bone differences were observed compared to the orally treated groups (reduced trabecular BV/TV, and connectivity density, and reduced percent cortical area) with no change in body mass, percent body fat, glucose tolerance or insulin sensitivity. Unlike in orally treated mice, risperidone infusion reduced bone formation parameters (serum P1NP, MAR and BFR/BV). Resorption parameters were elevated, but this increase did not reach statistical significance. To determine if risperidone could directly affect bone cells, primary bone marrow cells were cultured with osteoclast or osteoblast differentiation media. Risperidone was added to culture medium in clinically relevant doses of 0, 2.5 or 25 ng/ml. The number of osteoclasts was significantly increased by addition in vitro of risperidone while osteoblast differentiation was not altered. These studies indicate that risperidone treatment can have negative skeletal consequences by direct activation of osteoclast activity and by indirect non-cell autonomous mechanisms. Our findings further support the tenet that the negative side effects of SGAs on bone mass should be considered when weighing potential risks and benefits, especially in children and adolescents who have not yet reached peak bone mass.

VDR haploinsufficiency impacts body composition and skeletal acquisition in a gender-specific manner.

The vitamin D receptor (VDR) is crucial for virtually all of vitamin D's actions and is thought to be ubiquitously expressed. We hypothesized that disruption of one allele of the VDR gene would impact bone development and would have metabolic consequences. Body composition and bone mass (BMD) in VDR heterozygous (VDR HET) mice were compared to those obtained in male and female VDR KO and WT mice at 8 weeks of age. Male mice were also evaluated at 16 weeks, and bone marrow mesenchymal stem cell (MSC) differentiation was evaluated in VDR female mice. Additionally, female VDR HET and WT mice received intermittent PTH treatment or vehicle (VH) for 4 weeks. BMD was determined at baseline and after treatment. MRI was done in vivo at the end of treatment; µCT and bone histomorphometry were performed after killing the animals. VDR HET male mice had normal skeletal development until 16 weeks of age but showed significantly less gain in fat mass than WT mice. In contrast, female VDR HET mice showed decreased total-body BMD at age 8 weeks but had a normal skeletal response to PTH. MSC differentiation was also impaired in VDR HET female mice. Thus, female VDR HET mice show early impairment in bone acquisition, while male VDR HET mice exhibit a lean phenotype. Our results indicate that the VDR HET mouse is a useful model for studying the metabolic and skeletal impact of decreased vitamin D sensitivity.

Short-term carbohydrate-restricted diet for weight loss in severely obese women.

BACKGROUND: Weight loss in bariatric pre-surgery period reduces surgical complications, surgery time, blood loss, and length of hospital stay. Carbohydrate-restricted diets have been used as an alternative for weight loss. We tested the efficacy of a low-calorie carbohydrate-restricted diet (RD) for short-term weight loss in women with severe obesity and evaluate its metabolic effects in relation to a conventional low-calorie diet (CD). METHODS: The subjects received a 1,200-kcal diet with or without carbohydrate restriction for a period of 1 week in the hospital. Nineteen obesity class III women were distributed into two groups: experimental (n = 10) and control (n = 9). The following variables were assessed at the beginning and end of the study: anthropometric measurements, body composition, resting energy expenditure, substrate oxidation, and biochemical tests. RESULTS: Compared with CD, RD led to larger weight loss (2.6 and 4.4 kg, respectively; p = 0.01) and waist circumference reduction (p < 0.01). Among the assessed biochemical indicators, only plasma and urine acetone levels were different (p < 0.01); higher values were found in the experimental group with no symptoms and other diet-related complaints. There was also a significant decrease in triglycerides and carbohydrate oxidation, as well as a significant enhancement in lipid oxidation in the RD group. CONCLUSION: Short-term RD was more efficient than CD regarding quick weight loss and waist circumference reduction, which may favor gastroplasty. Also, RD did not lead adverse metabolic effects.