Natália Yumi Noronha

UCP1 and UCP3 Expression Is Associated with Lipid and Carbohydrate Oxidation and Body Composition

Background/Objective Uncoupling proteins (UCPs) are located in the inner membrane of mitochondria. These proteins participate in thermogenesis and energy expenditure. This study aimed to evaluate how UCP1 and UCP3 expression influences substrate oxidation and elicits possible changes in body composition in patients submitted to bariatric surgery. Subjects/Methods This is a longitudinal study comprising 13 women with obesity grade III that underwent bariatric surgery and 10 healthy weight individuals (control group). Body composition was assessed by bioelectrical impedance. Carbohydrate and fat oxidation was determined by indirect calorimetry. Subcutaneous adipose tissue was collected for gene expression analysis. QPCR was used to evaluate UCP1 and UCP3 expression. Results Obese patients and the control group differed significantly in terms of lipid and carbohydrate oxidation. Six months after bariatric surgery, the differences disappeared. Lipid oxidation correlated with the percentage of fat mass in the postoperative period. Multiple linear regression analysis showed that the UCP1 and UCP3 genes contributed to lipid and carbohydrate oxidation. Additionally, UCP3 expression was associated with BMI, percentage of lean body mass, and percentage of mass in the postoperative period. Conclusions UCP1 and UCP3 expression is associated with lipid and carbohydrate oxidation in patients submitted to bariatric surgery. In addition, UCP3 participates in body composition modulation six months postoperatively.

UCP2 expression is associated with weight loss after hypocaloric diet intervention

Background/Objectives:Although energy restriction contributes to weight loss, it may also reduce energy expenditure, limiting the success of weight loss in the long term. Studies have described how genetics contributes to the development of obesity, and uncoupling proteins 1 and 2 (UCP1 and UCP2) and beta-3-adrenoceptor (ADRB3) have been implicated in the metabolic pathways that culminate in this condition. This study aimed to evaluate how the UCP1, UCP2 and ADRB3 genes influence weight loss in severely obese women submitted to hypocaloric dietary intervention.Subjects/Methods:This longitudinal study included 21 women divided into two groups: Group 1 (Dietary intervention (G1)) consisted of 11 individuals with severe obesity (body mass index (BMI) ⩾40 kg/m2), selected for dietary intervention and Group 2 (Control (G2)) consisted of 10 normal-weight women (BMI between 18.5 and 24.9 kg/m2). Evaluation included weight (kg), height (m), waist circumference (cm), body composition, resting metabolic rate (RMR, kcal) and abdominal subcutaneous adipose tissue collection. The dietary intervention required that G1 patients remained hospitalized in the university hospital for 6 weeks receiving a hypocaloric diet (1200 kcal per day). The statistical analyses included t-test for paired samples, Spearman correlation and multivariate linear regressions, with the level of significance set at P<0.05.Results:Weight (155.0±31.4–146.5±27.8 kg), BMI (58.5±10.5–55.3±9.2 kg/m2), fat-free mass (65.4±8.6–63.1±7.1 kg), fat mass (89.5±23.0–83.4±21.0 kg) and RMR (2511.6±386.1–2324.0±416.4 kcal per day) decreased significantly after dietary intervention. Multiple regression analyses showed that UCP2 expression contributed to weight loss after dietary intervention (P=0.05).Conclusions:UCP2 expression is associated with weight loss after hypocaloric diet intervention.

A new resting metabolic rate equation for women with class III obesity

OBJECTIVE Resting metabolic rate (RMR) is an important parameter to guide the nutritional therapy of class III obese patients. The aims of the present study were to develop a predictive equation for RMR estimation in class III obese women using anthropometric indicators and to compare indirect calorimetry with other predictive equations. METHODS This was a cross-sectional study on women with class III obesity (body mass index >40 kg/m2). Weight, height, fat-free mass, fat mass, and RMR of all individuals were measured. Multiple linear regression was used to determine the new RMR equation and the Bland-Altman plot was used to analyze the agreement between indirect calorimetry and the results of predictive equations. RESULTS We evaluated 101 women with obesity class III and a mean age of 36.3 ± 10 y. The anthropometric and body composition variables used in the new equation had a coefficient of determination of 0.80, and a significant influence on RMR (P = 0.01). Harris-Benedict and World Health Organization equations showed similar bias and limits (181.6, +2 SD = 765.5, -2 SD = -402.2; 156.4, +2 SD = 799.4, -2 SD = -486.6, respectively). The Mifflin-St Jeor and Owen equations showed large clinical bias (mean, 239.2 and 463.9, respectively), and a tendency to overestimate RMR. CONCLUSION The prediction equations tested in the study had low accuracy in estimating RMR of women with class III obesity. However, our equation was developed specifically for this population, using variables known to influence their energy expenditure.

Mammalian target of rapamycin complex 2 signaling in obese women changes after bariatric surgery

OBJECTIVES After bariatric surgery, modifications to signaling pathway networks including those of the metabolic regulator called mammalian or mechanistic target of rapamycin (mTOR) may lead to molecular alterations related to energy source availability, systemic nutrients, and catabolic and anabolic cellular processes. This study aimed to identify gene expression changes with regard to the mTOR complex 2 subunit signaling pathway in obese patients before and after bariatric surgery. METHODS The experimental group included 13 obese women who were examined before (preoperative) and 6 mo after (postoperative) Roux-en-Y gastric bypass (RYGB) surgery. The control group included nine apparently eutrophic women matched by age and without any other metabolic diseases (i.e., no diabetes and no liver or kidney diseases). Peripheral blood mononuclear cell samples were collected for RNA extraction and subsequent microarray analysis. RESULTS After this methodological procedure, we identified 47 000 differentially expressed genes. A subsequent bioinformatic analysis showed that three diferentially expressed genes (rapamycin-insensitive companion of mTOR [RICTOR], phosphoinositide-3-kinase regulatory subunit 1 [PIK3 R1], and hypoxia inducible factor 1 alpha subunit 1A [HIF1 A]) participated in the mTOR signaling pathway. Real-time quantitative polymerase chain reaction revealed that RICTOR, PIK3 R1, and HIF1 A were upregulated 6 mo after RYGB surgery (P <0.05). In addition, patients in the experimental group lost weight significantly and presented significant improvement in biochemical/metabolic variables. CONCLUSIONS The weight loss that was induced by RYGB surgery alters the mTOR signaling pathway and specifically the mTOR complex 2 subunit. The increased expression of genes that act in this pathway such as RICTOR, PIK3 R1, and HIF1 A reflects the induced weight loss and improved metabolic indicators (e.g., insulin resistance and lipolysis) that are evidenced in this study.

Green tea supplementation promotes leukocyte telomere length elongation in obese women

INTRODUCTION inflammation and oxidative stress are factors that may play a substantial role in telomere attrition. In line of this, obesity is associated with telomere shortening. Green tea had anti-inflammatory and antioxidant effects and may alter telomere length (TL). OBJECTIVES we evaluated the effect of decaffeinated green tea supplementation in obese women on TL. METHODS we conducted a cross-sectional interventional study with ten obese (body mass index [BMI] > 40 kg/m²) and eight normal weight (BMI > 18.5 and < 24.9 kg/m²) women (age between 27 and 48 years). The supplementation was carried out with capsules (each contained 450.7 mg of epigallocatechin-3-gallate) during eight weeks. Anthropometric and dietary intake assessment, and blood collection (for biochemical and TL analysis by quantitative PCR) were performed before and after supplementation. Normal weight patients were evaluated at a single moment. RESULTS we observed a significant increase on TL after supplementation (1.57 ± 1.1 to 3.2 ± 2.1 T/Sratio; p < 0.05). Moreover, we found shorter TL in obese patients (day 0) when compared to normal weight individuals (3.2 ± 1.9 T/Sratio; p < 0.05) and an inverse association between TL and BMI, even after age adjustment (beta = -0.527; r² = 0.286; IC = -0.129, -0.009). CONCLUSION obesity is related to shorter telomeres. Green tea supplementation during eight weeks promotes telomere elongation in obese women.

Green tea supplementation upregulates uncoupling protein 3 expression in severe obese women adipose tissue but does not promote weight loss

Abstract This study aims (i) to verify expression of the UCPs, PLIN1, PPARG2, and ADRB3 genes in the abdominal subcutaneous adipose tissue of obese women at baseline and after 8 weeks of supplementation with decaffeinated green tea extract, and (ii) to associate findings with clinical parameters. This is a longitudinal study during which 11 women with obesity grade III were submitted to supplementation with 450 mg of (–)-epigallocatechin gallate (EGCG) (intervention group); the control group consisted of 10 eutrophic women. Anthropometric parameters [weight, height, and body mass index (BMI)], resting metabolic rate (RMR, measured by indirect calorimetry), and gene expression (measured by real-time PCR, RT-qPCR) were determined before and after supplementation. After 8 weeks, clinical parameters and UCP1, PLIN1, PPARG2, and ADRB3 expression remained unaltered in the intervention group (p > .05). Genetic analysis also showed that the UCP3 gene was upregulated (p = .026), but its upregulation did not promote weight loss.