RESUMO
Online experiments are an alternative for researchers interested in conducting behavioral research outside the laboratory. However, an online assessment might become a challenge when long and complex experiments need to be conducted in a specific order or with supervision from a researcher. The aim of this study was to test the computational validity and the feasibility of a remote and synchronous reinforcement learning (RL) experiment conducted during the social-distancing measures imposed by the pandemic. An additional feature of this study was to describe how a behavioral experiment originally created to be conducted in-person was transformed into an online supervised remote experiment. Open-source software was used to collect data, conduct statistical analysis, and do computational modeling. Python codes were created to replicate computational models that simulate the effect of working memory (WM) load over RL performance. Our behavioral results indicated that we were able to replicate remotely and with a modified behavioral task the effects of working memory (WM) load over RL performance observed in previous studies with in-person assessments. Our computational analyses using Python code also captured the effects of WM load over RL as expected, which suggests that the algorithms and optimization methods were reliable in their ability to reproduce behavior. The behavioral and computational validation shown in this study and the detailed description of the supervised remote testing may be useful for researchers interested in conducting long and complex experiments online.
Assuntos
Aprendizagem , Reforço Psicológico , Humanos , Memória de Curto Prazo , Simulação por Computador , SoftwareRESUMO
Objective: The current cross-sectional study aimed to examine the association between childhood trauma, impulsivity, binge eating symptoms, and body mass index (BMI) in a sample of males and females. We also aimed to investigate the indirect association of childhood trauma with binge eating through impulsivity while controlling for BMI.Method: Participants were 410 young adults (mean age = 20.9 years, range 18-24; female = 73.9%) who completed online measures of childhood trauma, impulsivity, binge eating symptoms, and self-reported height and weight. Mediation models were tested using multi-group structural equation modelling.Results: Childhood trauma and impulsivity were associated with an increased risk of binge eating symptoms in females but not males, corroborating previous studies. There was a significant difference in the binge eating symptoms index between sexes, but not regarding the index of childhood trauma and impulsivity. Additionally, adverse childhood experiences were associated with impulsivity and the association of childhood trauma with binge eating was mediated by impulsivity in the female sample.Conclusions: Our results suggest sex-dependent patterns and risk factors that may impact binge eating symptoms. The implications of our results suggest that impulsivity might be a vulnerability factor for binge eating, especially for females.
RESUMO
AIMS: We hypothesized that critically ill patients with SARS-CoV-2 infection and insulin resistance would present a reduced Heat Shock Response (HSR), which is a pathway involved in proteostasis and anti-inflammation, subsequently leading to worse outcomes and higher inflammation. In this work we aimed: (i) to measure the concentration of extracellular HSP72 (eHSP72) in patients with severe COVID-19 and in comparison with noninfected patients; (ii) to compare the HSR between critically ill patients with COVID-19 (with and without diabetes); and (iii) to compare the HSR in these patients with noninfected individuals. METHODS: Sixty critically ill adults with acute respiratory failure with SARS-CoV-2, with or without diabetes, were selected. Noninfected subjects were included for comparison (healthy, n = 19 and patients with diabetes, n = 22). Blood samples were collected to measure metabolism (glucose and HbA1c); oxidative stress (lypoperoxidation and carbonyls); cytokine profile (IL-10 and TNF); eHSP72; and the HSR (in vitro). RESULTS: Patients with severe COVID-19 presented higher plasma eHSP72 compared with healthy individuals and noninfected patients with diabetes. Despite the high level of plasma cytokines, no differences were found between critically ill patients with COVID-19 with or without diabetes. Critically ill patients, when compared to noninfected, presented a blunted HSR. Oxidative stress markers followed the same pattern. No differences in the HSR (extracellular/intracellular level) were found between critically ill patients, with or without diabetes. CONCLUSIONS: We demonstrated that patients with severe COVID-19 have elevated plasma eHSP72 and that their HSR is blunted, regardless of the presence of diabetes. These results might explain the uncontrolled inflammation and also provide insights on the increased risk in developing type 2 diabetes after SARS-CoV-2 infection.
Assuntos
COVID-19 , Diabetes Mellitus Tipo 2 , Adulto , Humanos , Interleucina-10 , SARS-CoV-2 , Estado Terminal , Proteínas de Choque Térmico HSP72/metabolismo , Hemoglobinas Glicadas , Resposta ao Choque Térmico , Citocinas , Inflamação , Chaperonas Moleculares , GlucoseRESUMO
Introduction and objectives: Obesity represents a major global public health problem. Its etiology is multifactorial and includes poor dietary habits, such as hypercaloric and hyperlipidic diets (HFDs), physical inactivity, and genetic factors. Regular exercise is, per se, a tool for the treatment and prevention of obesity, and recent studies suggest that the beneficial effects of exercise can be potentiated by the fasting state, thus potentially promoting additional effects. Despite the significant number of studies showing results that corroborate such hypothesis, very few have evaluated the effects of fasted-state exercise in overweight/obese populations. Therefore, the aim of this study was to evaluate the subacute effects (12 h after conclusion) of a single moderate-intensity exercise bout, performed in either a fed or an 8 h fasted state, on serum profile, substrate-content and heat shock pathway-related muscle protein immunocontent in obese male rats. Methods: Male Wistar rats received a modified high-fat diet for 12 weeks to induce obesity and insulin resistance. The animals were allocated to four groups: fed rest (FER), fed exercise (FEE), fasted rest (FAR) and fasted exercise (FAE). The exercise protocol was a 30 min session on a treadmill, with an intensity of 60% of VO2max. The duration of the fasting period was 8 h prior to the exercise session. After a 12 h recovery, the animals were killed and metabolic parameters of blood, liver, heart, gastrocnemius and soleus muscles were evaluated, as well as SIRT1 and HSP70 immunocontent in the muscles. Results: HFD induced obesity and insulin resistance. Soleus glycogen concentration decreased in the fasted groups and hepatic glycogen decreased in the fed exercise group. The combination of exercise and fasting promoted a decreased concentration of serum total cholesterol and triglycerides. In the heart, combination fasting plus exercise was able to decrease triglycerides to control levels. In the soleus muscle, both fasting and fasting plus exercise were able to decrease triglyceride concentrations. In addition, heat shock protein 70 and sirtuin 1 immunocontent increased after exercise in the gastrocnemius and soleus muscles. Conclusions: An acute bout of moderate intensity aerobic exercise, when realized in fasting, may induce, in obese rats with metabolic dysfunctions, beneficial adaptations to their health, such as better biochemical and molecular adaptations that last for at least 12 h. Considering the fact that overweight/obese populations present an increased risk of cardiovascular events/diseases, significant reductions in such plasma markers of lipid metabolism are an important achievement for these populations.
Assuntos
Jejum , Resistência à Insulina , Animais , Glicemia , Insulina , Masculino , Obesidade , Ratos , Ratos Wistar , TriglicerídeosRESUMO
BACKGROUND: Uncoupling protein 2 (UCP2) plays an important role in energy expenditure regulation. Previous studies have associated the common -866G/A (rs659366) and Ins/Del polymorphisms in the UCP2 gene with metabolic and obesity-related phenotypes. However, it is still unclear whether these polymorphisms influence weight loss after bariatric surgery. OBJECTIVES: To investigate whether UCP2 -866G/A and Ins/Del polymorphisms are associated with weight loss outcomes after bariatric surgery. SETTING: Longitudinal study in a university hospital. METHODS: We retrospectively evaluated 186 patients who underwent Roux-en-Y gastric bypass (RYGB) surgery for clinical and laboratory characteristics in the preoperative period, 6, 12, and 18 months after RYGB. The -866G/A (rs659366) polymorphism was genotyped using real-time PCR, while the Ins/Del polymorphism was genotyped by direct separation of PCR products in 2.5% agarose gels. RESULTS: Patients with the -866A/A genotype showed higher body mass index (BMI) after 6, 12, and 18 months of surgery and excess body weight after 6 and 12 months compared with G/G patients. They also showed lower excess weight loss (EWL%) after 6 and 12 months of surgery. Ins allele carriers (Ins/Ins + Ins/Del) had lower delta (Δ) BMI 12 months after surgery compared with Del/Del patients. Accordingly, patients carrying haplotypes with ≥2 risk alleles of these polymorphisms had higher BMI and excess weight and lower EWL% during follow-up. CONCLUSION: UCP2 -866A/A genotype is associated with higher BMI and excess weight and lower EWL% during an 18-month follow-up of patients who underwent RYGB, while the Ins allele seems to be associated with lower ΔBMI 12 months after surgery. Further studies are needed to confirm the associations of the -866G/A and Ins/Del polymorphisms with weight loss after bariatric surgery.
Assuntos
Derivação Gástrica , Obesidade Mórbida , Índice de Massa Corporal , Humanos , Canais Iônicos/genética , Estudos Longitudinais , Proteínas Mitocondriais/genética , Obesidade Mórbida/genética , Obesidade Mórbida/cirurgia , Estudos Retrospectivos , Proteína Desacopladora 2/genética , Redução de Peso/genéticaRESUMO
INTRODUCTION: Persistent episodes of postprandial hyperlipemia (PPL) and hyperglycemia (PPG) are considered risk factors for coronary heart disease (CHD) and premature death; whereas physical exercise improves lipid profile and glucose tolerance thus decreasing cardiovascular risks. OBJECTIVE: To investigate the effects of low-intensity fasted aerobic exercise on the magnitude of the PPL and PPG responses to meals with different energy content, in normal and obese subjects. METHODS: The study used a randomized crossover design. Twenty-one male (Lean: n = 9, BMI: 24.3 ± 2.2; and obese: n = 12, BMI 32.31 ± 2.1) volunteers aged 20-30 years, performed three interventions, separated by 7 days each: (i) 45 min at rest and isocaloric high-fat meal (60% lipids, 30% carbohydrates and 10% protein); (ii) fasted low-intensity aerobic exercise (50% VO2max) for 45 min followed by an isocaloric or (iii) calorie deficit high-fat meal. Subjects were serially assessed for blood triglycerides, and glucose levels. RESULTS AND CONCLUSIONS: Low-intensity fasted aerobic exercise had no acute effect on PPL in lean and obese subjects. Glucose concentrations were reduced only in lean subjects. There is a significant difference in PPL values when comparing lean to obese subjects, implying that the nutritional status influences lipid and carbohydrate after fasted low-intensity aerobic exercise. Registered under ClinicalTrials.gov Identifier no. NCT00929890.
Assuntos
Glicemia , Hiperlipidemias , Estudos Cross-Over , Exercício Físico , Humanos , Masculino , Refeições , ObesidadeRESUMO
BACKGROUND: Several studies have investigated if bariatric surgery candidates with binge eating disorder (BED) are at risk for suboptimal postoperative weight loss. The aim of this systematic review with meta-analysis was to evaluate the association between binge eating diagnosed preoperatively and weight loss after bariatric surgery. METHODS: MEDLINE, EMBASE, CENTRAL, LILACS, and other specialized databases were searched on August 2020. Clinical trials and observational studies including individuals who had undergone any type of bariatric surgical treatment with preoperative evaluation of BED and at least one postoperative measure of weight were initially selected. Four reviewers independently screened for eligibility. The mean difference was calculated using the random-effects model. RESULTS: Nineteen studies, comprising 3223 participants (80.25% women; median age 41 years), met the inclusion criteria for meta-analysis. At 6 months postoperative, the percentage of total weight loss (%TWL) was not significantly different between BED and non-BED groups [6 studies, 914 participants: - 0.75% (95% CI, - 2.79 to 1.29; I2 = 0%)], even when analyzing only those three studies that included gold standard assessment tools. No significant differences were found at 12, 24, 36, or 60 months. CONCLUSIONS: Pre-bariatric BED seems to have little or no influence on weight loss after surgery. However, many questions remain unanswered because of the use of different measures across studies. The heterogeneity among studies emphasizes the importance of investigators using the same assessment measures.
Assuntos
Cirurgia Bariátrica , Transtorno da Compulsão Alimentar , Bulimia , Obesidade Mórbida , Adulto , Feminino , Humanos , Masculino , Obesidade Mórbida/cirurgia , Redução de PesoRESUMO
ABSTRACT Objective A large number of studies have used abdominal computed tomography (CT) to quantify body composition, and different software programmes have been used to perform these analyses. Thus, this comparison is important to enable researchers to know the performance of more accessible software. Subjects and methods Fifty-four abdominal CT scans of obese (BMI 30 to 39.9 kg/m2), sedentary adults (24-41 years) patients from a Brazilian single center were selected. Two software programs were compared: Slice-O-Matic (Tomovision, Canada) version 5.0 and OsiriX version 5.8.5. The body composition analysis were segmented using standard Hounsfield unit (HU) (adipose tissue: -190 to +30 and skeletal muscle: -29 to +150) and measured at the mid third lumbar vertebra (L3) level on a slice showing both transversal processes. Bland-Altman limits of agreement analyses were used to assess the level of agreement between Slice-O-Matic and OsiriX. Results A total of fifty-four participants were evaluated, with majority women (69%), mean of age 31.3 (SD 6.5) years and obesity grade I most prevalent (74.1%). The agreement, in Bland-Altman analysis, between Slice-O-Matic and OsiriX analisys for the muscle mass tissue, visceral adipose tissue and subcutaneous adipose tissue were excellent (≥ 0.954) with P-values < 0.001. Conclusion These findings show that Slice-O-Matic and OsiriX softwares agreement in measurements of skeletal muscle and adipose tissue and sarcopenia diagnosis in obese patients, suggesting good applicability in studies with body composition in this population and clinical practice.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Composição Corporal , Gordura Intra-Abdominal/diagnóstico por imagem , Gordura Subcutânea/diagnóstico por imagem , Obesidade/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Comportamento SedentárioRESUMO
Objective A large number of studies have used abdominal computed tomography (CT) to quantify body composition, and different software programmes have been used to perform these analyses. Thus, this comparison is important to enable researchers to know the performance of more accessible software. Subjects and methods Fifty-four abdominal CT scans of obese (BMI 30 to 39.9 kg/m2), sedentary adults (24-41 years) patients from a Brazilian single center were selected. Two software programs were compared: Slice-O-Matic (Tomovision, Canada) version 5.0 and OsiriX version 5.8.5. The body composition analysis were segmented using standard Hounsfield unit (HU) (adipose tissue: -190 to +30 and skeletal muscle: -29 to +150) and measured at the mid third lumbar vertebra (L3) level on a slice showing both transversal processes. Bland-Altman limits of agreement analyses were used to assess the level of agreement between Slice-O-Matic and OsiriX. Results A total of fifty-four participants were evaluated, with majority women (69%), mean of age 31.3 (SD 6.5) years and obesity grade I most prevalent (74.1%). The agreement, in Bland-Altman analysis, between Slice-O-Matic and OsiriX analisys for the muscle mass tissue, visceral adipose tissue and subcutaneous adipose tissue were excellent (≥ 0.954) with P-values < 0.001. Conclusion These findings show that Slice-O-Matic and OsiriX softwares agreement in measurements of skeletal muscle and adipose tissue and sarcopenia diagnosis in obese patients, suggesting good applicability in studies with body composition in this population and clinical practice.
Assuntos
Composição Corporal , Gordura Intra-Abdominal/diagnóstico por imagem , Obesidade/diagnóstico por imagem , Gordura Subcutânea/diagnóstico por imagem , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Comportamento Sedentário , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
BACKGROUND: Hypovitaminosis D is common, before and after gastric bypass surgery. The prevalence of hypovitaminosis D in a large group of candidates for bariatric surgery in Brazil and South America has not been studied. OBJECTIVE: To evaluate the prevalence of hypovitaminosis D and associated factors in patients undergoing bariatric surgery in Southern Brazil. MATERIALS AND METHODS: Cross-sectional study involving all patients presenting for bariatric surgery at Hospital de Clínicas de Porto Alegre, from January 2013 to June 2018. Data were extracted from the patients' electronic medical records. Patients who were taking multivitamin supplements or vitamin D supplements, who had renal insufficiency, or had missing data for 25(OH) vitamin D [25(OH)D] levels were excluded. RESULTS: A total of 291 patients were included. Mean subjects' age was 44.9 (SD 10.7) years, and BMI 49.3 (SD 8.3) kg/m2; 76.6% of the study patients were women, and 87.3% were white. More than half the patients (55.3%) were vitamin D deficient (serum 25(OH)D ≤ 19.9 ng/ml), and 37.1% had insufficient levels (20-29.9 ng/mL). Mean vitamin D level was 19.2 ng/mL (SD 7.6). An inverse correlation was found between 25(OH)D levels and BMI. Vitamin D deficiency was more prevalent in patients with higher BMI [PR 1.02; CI 95% (1.00-1.03)], higher fasting glucose [PR 1.01; CI 95% (1.00-1.01)], in nonwhite patients [PR 1.58; CI 95% (1.30-1.92)] and during autumn/winter season [PR 1.41; CI 95% (1.14-1.75)]. CONCLUSIONS: Prevalence of vitamin D insufficiency and deficiency is very high among patients presenting for bariatric surgery in Southern Brazil, and the known associated factors are confirmed in this population.
Assuntos
Cirurgia Bariátrica , Obesidade Mórbida/epidemiologia , Deficiência de Vitamina D/epidemiologia , Adulto , Brasil/epidemiologia , Estudos Transversais , Suplementos Nutricionais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Prevalência , Estações do Ano , Vitamina D/uso terapêutico , Deficiência de Vitamina D/complicaçõesRESUMO
PURPOSE: Differences in weight loss outcomes after bariatric surgery may be related to individual preoperative characteristics. The aim of this study was to evaluate the potential effect of fatty acid binding protein-2 (rs1799883), leptin receptor (LEP223, rs1137101 and LEP656, rs1805094), and fat mass and obesity-related (rs9939609) genotypes on weight loss 2 years after bariatric surgery in Brazilian patients. MATERIALS AND METHODS: Prospective observational study involving 105 patients (lost to follow-up, 25.7%). In the preoperative period, patients were clinically evaluated and a fasting blood sample for genetic analysis (by real-time DNA amplification technique) was collected. From the patient's medical records, follow-up weight loss (3, 6, 12, 24 months) was obtained. Percentage of excess weight loss (%EWL) was examined by pairwise comparison across the polymorphisms. RESULTS: At baseline, the mean weight was 127.5 (23.3) kg and age 43.1 (10.9) years old. The %EWL was significant over time (p < 0.01). Only the LEP223 genotype showed association (p < 0.01). Up to 6 months after surgery, no differences were observed. At 12 months, a significant difference (p = 0.03) between AA (n = 19) and GG (n = 34) groups was observed, with 76.5% EWL versus 52.0%, respectively. This difference remained at 24 months. Other genotypes did not present any significant association. CONCLUSIONS: There is a different evolution of weight loss in carriers of the LEP223 after bariatric surgery. The AA genotype seems to be associated with a higher weight loss. However, this pattern was evident only at 12 months after surgery.
Assuntos
Cirurgia Bariátrica/estatística & dados numéricos , Obesidade Mórbida , Redução de Peso/genética , Adulto , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Brasil , Proteínas de Ligação a Ácido Graxo , Genótipo , Humanos , Pessoa de Meia-Idade , Obesidade Mórbida/epidemiologia , Obesidade Mórbida/genética , Obesidade Mórbida/cirurgia , Estudos Prospectivos , Receptores para LeptinaRESUMO
BACKGROUND: Diabetes remission is not observed in all obese patients with type 2 diabetes submitted to bariatric surgery. Relapses occur in patients in whom remission is achieved. We investigated the factors associated with long-term (≥3 years) remission and relapse of type 2 diabetes after Roux-en-Y gastric bypass (RYGB) in these patients. METHODS: By a retrospective review, we analyzed data from 254 patients with type 2 diabetes who had undergone RYGB from May 2000 to November 2011 and had at least 3 years of follow-up. The criteria for remission and relapse of type 2 diabetes followed the current American Diabetes Association recommendations. RESULTS: Remission was achieved in almost 82% of participants (69.7% complete, and 12.2% partial remission). Of these, 12% relapsed within a mean follow-up of 5.1 ± 2.0 years after surgery. Predictors of complete remission were younger age, better preoperative glycemic control, and shorter diabetes duration. Preoperative insulin use was associated with a ninefold increase in the relapse hazard (HR = 9.1 (95% CI: 3.3-25.4)). Use of two or more oral anti-diabetic agents increased the relapse hazard sixfold (HR = 6.1 (95% CI: 1.8-20.6)). Eighteen point one percent of patients did not achieve any remission during follow-up. However, they exhibited significant improvements in glycemic control. CONCLUSIONS: These data indicate that RYGB should not be delayed when remission of type 2 diabetes is a therapeutic goal, and also suggest that the best possible metabolic control should be sought in obese patients who may eventually be candidates for RYGB.
Assuntos
Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/cirurgia , Derivação Gástrica , Obesidade Mórbida/diagnóstico , Obesidade Mórbida/cirurgia , Adulto , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Feminino , Seguimentos , Derivação Gástrica/métodos , Derivação Gástrica/reabilitação , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/sangue , Obesidade Mórbida/complicações , Prognóstico , Indução de Remissão , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
Attentional bias is an implicit cognition relevant to development and maintenance of obesity, but little is known of how binge eating modulates attentional bias in severe obesity. This study investigated attentional bias towards unhealthy foods at different stages of attentional processing in a clinical sample, comparing obese patients (Body Mass Index, BMI>35 kg/m2) with and without binge eating behaviors. Participants were separated into two groups according to their score on the Binge Eating Scale (BES): no binge eating (NB; score ≤17; n = 23) and binge eating (BE; score > 17; n = 19). Participants performed a computerized visual probe task designed to evaluate attentional bias in different stages of attentional process; matching pairs of unhealthy food and matching non-food pictures concealed a target for 100, 500 or 2000 ms. Reduced reaction times to targets following food-related images are indicative of attentional bias towards food images. BE group exhibited a greater bias towards food than NB. Both groups showed positive attentional bias to food in the initial orientation stage (100 ms), whereas bias was close to zero in the maintenance of attention stage (2000 ms), suggesting ambivalent approach-avoidance responses to food stimuli. Only the BE group showed a bias towards food images when displayed for 500 ms, indicating disengaging from food-related stimuli was faster in NB group. Although both groups were ambivalent about attending to food cues, slower attentional disengagement from unhealthy food might be a cognitive marker of binge eating behavior in severe obesity.
Assuntos
Viés de Atenção/fisiologia , Transtorno da Compulsão Alimentar/psicologia , Bulimia/psicologia , Dieta , Obesidade Mórbida/psicologia , Adulto , Idoso , Índice de Massa Corporal , Brasil , Cognição/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
ABSTRACT Body weight is regulated by the ability of hypothalamic neurons to orchestrate behavioral, endocrine and autonomic responses via afferent and efferent pathways to the brainstem and the periphery. Weight maintenance requires a balance between energy intake and energy expenditure. Although several components that participate in energy homeostasis have been identified, there is a need to know in more detail their actions as well as their interactions with environmental and psychosocial factors in the development of human obesity. In this review, we examine the role of systemic mediators such as leptin, ghrelin and insulin, which act in the central nervous system by activating or inhibiting neuropeptide Y, Agouti-related peptide protein, melanocortin, transcript related to cocaine and amphetamine, and others. As a result, modifications in energy homeostasis occur through regulation of appetite and energy expenditure. We also examine compensatory changes in the circulating levels of several peripheral hormones after diet-induced weight loss.
Assuntos
Humanos , Peso Corporal/fisiologia , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Tecido Adiposo/metabolismo , Ilustração Médica , Obesidade/etiologia , Obesidade/metabolismoRESUMO
Body weight is regulated by the ability of hypothalamic neurons to orchestrate behavioral, endocrine and autonomic responses via afferent and efferent pathways to the brainstem and the periphery. Weight maintenance requires a balance between energy intake and energy expenditure. Although several components that participate in energy homeostasis have been identified, there is a need to know in more detail their actions as well as their interactions with environmental and psychosocial factors in the development of human obesity. In this review, we examine the role of systemic mediators such as leptin, ghrelin and insulin, which act in the central nervous system by activating or inhibiting neuropeptide Y, Agouti-related peptide protein, melanocortin, transcript related to cocaine and amphetamine, and others. As a result, modifications in energy homeostasis occur through regulation of appetite and energy expenditure. We also examine compensatory changes in the circulating levels of several peripheral hormones after diet-induced weight loss.
Assuntos
Peso Corporal/fisiologia , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Tecido Adiposo/metabolismo , Humanos , Ilustração Médica , Obesidade/etiologia , Obesidade/metabolismoRESUMO
O polimorfismo p.Ala54Thr (rs1799883) do gene fatty acid-binding protein-2 (FABP2) tem associação com resistência insulínica, síndrome metabólica e obesidade. A hipótese é de que o alelo mutante aumente a absorção de ácidos graxos intestinais, a concentração lipídica plasmática e a oxidação de gordura. Assim, o objetivo deste trabalho foi revisar o papel do polimorfismo p.Ala54Thr do gene FABP-2 na obesidade. A busca da literatura foi realizada na base de dados MEDLINE, através do PubMed e no Portal de Periódicos de Aperfeiçoamento de Pessoal de Nível Superior (Capes) com termos relacionados com o polimorfismo e obesidade. Parece não haver uma associação significativa da presença do alelo Thr54 com obesidade, apesar de ser uma doença complexa e que possivelmente não tenha sido captada por estudos de associação; diferente do colesterol total e lipoproteína de baixa densidade (low density level cholesterol, LDL-c), maior nos portadores do alelo Thr54. Alterações de adipocitocinas devem estar associadas a estas diferenças de perfil lipídico.
The p.Ala54Thr polymorphism (rs1799883) of the fatty acid-binding Protein-2 (FABP-2) gene has been associated with insulin resistance, metabolic syndrome and obesity. The hypothesis that the mutant allele increases the absorption of fatty acid by the bowel, plasma lipid concentration, and fat oxidation. Thus, the aim of this study was to review the role of FABP-2 Ala54Thr polymorphism in obesity. A literature search was conducted in MEDLINE database, using PubMed and Capes Portal with terms related to polymorphism and obesity. It does not seem to be a significant association between Thr54 allele and obesity, although being a complex disease and that possibly has not been captured by association studies; unlike total cholesterol and low density level cholesterol (LDL-c), which were higher in Thr54 allele carriers. Adipocytokines changes should be associated with these differences in lipid profile.