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Background: Bariatric surgery (BS) is currently the most effective long-term treatment of severe obesity. However, the interindividual variability observed in surgical outcomes suggests a moderating effect of several factors, including individual genetic background. This study aimed to investigate the contribution of the genetic architecture of body mass index (BMI) to the variability in weight loss outcomes after BS., Methods: A total of 106 patients with severe obesity who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy were followed up for 5 years. Changes in BMI (BMIchange) and percentage of total weight loss (%TWL) were evaluated during the postoperative period. Polygenic risk scores (PRSs), including 50 genetic variants, were calculated for each participant to determine their genetic risk of high BMI based on a previous genome-wide association study. Generalized estimating equation models were used to study the role of the individual's polygenic score and other factors on BMIchange and %TWL in the long term after surgery., Results: This study found an effect of the polygenic score on %TWL and BMIchange, in which patients with lower scores had better outcomes after surgery than those with higher scores. Furthermore, when analyzing only patients who underwent RYGB, the results were replicated, showing greater weight loss after surgery for patients with lower polygenic scores., Discussion: Our results indicate that genetic background assessed with PRSs, along with other individual factors, such as biological sex, age, and preoperative BMI, has an effect on BS outcomes and could represent a useful tool for estimating surgical outcomes in advance., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Obesity is a polygenic multifactorial disease. Recent genome-wide association studies have identified several common loci associated with obesity-related phenotypes. Bariatric surgery (BS) is the most effective long-term treatment for patients with severe obesity. The huge variability in BS outcomes between patients suggests a moderating effect of several factors, including the genetic architecture of the patients., Objective: To examine the role of a genetic risk score (GRS) based on 7 polymorphisms in 5 obesity-candidate genes (FTO, MC4R, SIRT1, LEP, and LEPR) on weight loss after BS., Setting: University hospital in Spain., Methods: We evaluated a cohort of 104 patients with severe obesity submitted to BS (Roux-en-Y gastric bypass or sleeve gastrectomy) followed up for >60 months (lost to follow-up, 19.23%). A GRS was calculated for each patient, considering the number of carried risk alleles for the analyzed genes. During the postoperative period, the percentage of excess weight loss total weight loss and changes in body mass index were evaluated. Generalized estimating equation models were used for the prospective analysis of the variation of these variables in relation to the GRS., Results: The longitudinal model showed a significant effect of the GRS on the percentage of excess weight loss (P = 1.5 × 10 -5 ), percentage of total weight loss (P = 3.1 × 10 -8 ), and change in body mass index (P = 7.8 × 10 -16 ) over time. Individuals with a low GRS seemed to experience better outcomes at 24 and 60 months after surgery than those with a higher GRS., Conclusion: The use of the GRS in considering the polygenic nature of obesity seems to be a useful tool to better understand the outcome of patients with obesity after BS., (Copyright © 2024 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Background: There is little information about the effect of single nucleotide polymorphisms (SNP) and nutritional status and weight loss after bariatric surgery. This study investigated the interactive effect of eight obesity-related SNPs and nutritional status on weight loss after Roux-en-Y gastric bypass (RYGB)., Method: This is a case-control study. After 1-year follow-up, the patients who underwent RYGB were dividing into two groups. The case group consisted of patients who lost more than 50% of their excess body weight (EBW%) 1 year after the surgery. The control group included patients who lost < 50% of EBW at same time frame. Then, the relationship between eight SNPs related to UCP2, FTO, LEPR, GHRL, and NPY genes with weight loss were checked., Results: In this study, 160 patients were recruited. The median of age for case and control group were 43 and 42 respectively. The presence of mutant variant NPYrs16147 had a significant relationship in terms of weight loss between the two groups (P > 0.05). In dominant model, two SNPs, UCP2 rs659366 and UCP2 rs660339, showed protective effect of the vitamin D deficiency., Conclusion: In conclusion, the presence mutant variant of NPYrs16147 is directly related to the incidence of weight loss greater than 50% of EBW. However, it is apparent individual behavioral, dietary, and other factors may have more influence on weight loss among patients underwent RYGB., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Metabolic and bariatric surgery (MBS) effectively treats obesity and related comorbidities, though individual responses vary. This systematic review examines how genetic variants influence MBS outcomes in morbidly obese patients. A comprehensive search in PubMed, Embase, Medline, and the Cochrane Library identified 1572 studies, with 52 meeting the inclusion criteria. Two reviewers independently filtered and selected studies, including relevant cross-references. Research focused on polymorphisms in genes such as UCP2, UCP3, 5-HT2C, MC4R, FKBP5, FTO, CAT haplotypes, LYPAL-1, PTEN, FABP-2, CNR1, LEP656, LEP223, GLP-1R, APOA-1, APOE, ADIPOQ, IL-6, PGC1a, TM6SF2, MBOAT7, PNPLA3, TCF7L2, ESR1, GHSR, GHRL, CD40L, DIO2, ACSL5, CG, TAS2R38, CD36, OBPIIa, NPY, BDNF, CLOCK, and CAMKK2. Most studies explored associations with post-surgery weight loss, while some examined metabolic, cardiovascular, taste, and eating behavior effects as well. Understanding the role of genetic factors in weight loss and metabolic outcomes post-MBS can help tailor personalized treatment plans for improved efficacy and long-term success. Further research with larger sample sizes and extended follow-up is needed to clarify the effects of many genetic variants on MBS outcomes in morbidly obese patients.

Purpose: Obesity is a risk factor for many chronic diseases. This study aimed to investigate the effect of bariatric surgery on the gut microbiota from patients with obesity., Materials and Methods: The microbiota composition from stool samples before and after bariatric surgery were identified using bacterial 16S rRNA gene sequencing. Based on the speed of weight loss, patients were classified as the slow-loss group and fast-loss group. The ɑ- and β-diversity analysis was done to compare the species richness, evenness, and overall structure of the microbiota between different groups. Next, linear discriminant analysis effect size (LEfSe) and receiver operating characteristic (ROC) analysis were implemented to identify high-dimensional biomarkers and significantly different species of microbial taxa between different groups. Finally, the pathway analysis was inferred using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) to predict the functional profiling of microbial communities., Results: β-diversity analysis suggested that species diversity of preoperative samples of slow-loss group was significantly higher than the fast-loss group. High levels of Oscillospira and Abiotrophia in the preoperative gut microbiota may lead to poor postoperative weight loss. For patients with poor postoperative weight loss due to changes in gut microbiota, the gut microbiota is mainly composed of Lactobacillus. For patients with good postoperative results, the gut microbiota is mainly composed of Escherichia, Robinsonella, and Dialister. In addition, multiple metabolic-related pathways were significantly different between the four groups., Conclusion: This comparative study revealed biomarker species based on microfloral composition in patients with obesity before and after bariatric surgery., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose of Review: To conduct a systematic review to summarize the results of studies on this subject and to identify whether single nucleotide polymorphisms (SNPs) are good prognostic markers for body weight trajectory after bariatric surgery., Recent Findings: A considerable number of events can influence the body weight trajectory after bariatric surgery, and in the post-genomic era, genetic factors have been explored. This study is registered with PROSPERO (CRD42021240903). SNPs positively associated with poor weight loss after bariatric surgery were rs17702901, rs9939609, rs1360780, rs1126535, rs1137101, rs17782313, rs490683, and rs659366. Alternatively, SNPs rs2229616, rs5282087, rs490683, rs9819506, rs4771122, rs9939609, rs4846567, rs9930506, rs3813929, rs738409, rs696217, rs660339, rs659366, rs6265, rs1801260, and rs2419621 predicted a higher weight loss after bariatric surgery. Six studies performed with a genetic risk score (GRS) model presented significant associations between GRS and outcomes following bariatric surgery. This systematic review shows that, different SNPs and genetic models could be good predictors for body weight trajectory after bariatric surgery. Based on the results of the selected studies for this Systematic Review is possible to select SNPs and metabolic pathways of interest for the GRS construction to predict the outcome of bariatric surgery to be applied in future studies., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Mutations in MC4R are the most common genetic cause of obesity. In the reported Chinese morbid obesity cohort, 10 out of 59 harbor six MC4R variants, including Y35C, T53I, V103I, R165W, G233S, and C277X, among which V103I has a relatively high frequency, while other five variants are rare in the population. The prevalence of MC4R carriers in Chinese morbid obese patients (body mass index ≥ 45 kg m -2 ) is detected as 16.9% in this study. R165W and C277X are loss-of-function variants. The patient with R165W achieves excess weight loss (%EWL) as high as 20.6% and 50.3% at 1 and 8 months after surgery, respectively. G233S is reported for the first time in Asia obese population. The patient harboring G233S has a %EWL as 23.3% one month postsurgery. It is concluded that morbid obese patients with rare MC4R variants can benefit from metabolic surgery. More importantly, the choice of surgery procedure and MC4R variant should be taken into consideration for personalized treatment. In the future, a larger size cohort, accompanied with regular and longer follow-up, would be helpful., (© 2023 Wiley-VCH GmbH.)

Background: Transoral outlet reduction (TORe) is a safe and effective technique for management of weight regain (WR) after Roux-en-Y Gastric Bypass (RYGB). Carriers of a heterozygous variant in the leptin melanocortin pathway (LMP) have been shown to be at high risk for WR in the mid- and long-term after RYGB. Our case series includes four patients with heterozygous LMP variants and presents novel data on their weight loss after TORe., Methods: We performed a retrospective study of the Mayo Clinic Biobank and identified adult participants who had been genotyped and found to have or do not have a heterozygous variant in the LMP ("carriers" vs "non-carriers", respectively) and had undergone a TORe procedure. TBWL% at 1, 3, 6, 9, and 12 months ± 15 days were calculated based on baseline weight at TORe procedure., Results: A total of 14 patients were included in the analysis: four patients (mean age 51.0 [5.2] years, 100% females, body mass index [BMI] 40.5 [8.7] kg/m 2 ) with LMP variant and 10 non-carriers (age 55.4 [15.3] years, 90% females, BMI 37.3 [7.7] kg/m 2 ). There were no baseline differences between carriers and non-carriers at time of TORe procedure. After TORE, carriers lost less weight when compared to non-carriers at 3, 6, 9, and 12 months. The difference at 12 months was statistically significant (1.6 vs 12.3%; p = 0.03)., Conclusions: Patients with a LMP variant and that underwent RYGB showed decreased weight loss after undergoing TORe. Further and larger studies are needed to comprehend the effect of TORe on patients with LMP variants., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Obesity is a multifactorial and chronic condition of growing universal concern. It has recently been reported that bariatric surgery is a more successful treatment for severe obesity than other noninvasive interventions, resulting in rapid significant weight loss and associated chronic disease remission. The identification of distinct epigenetic patterns in patients who are obese or have metabolic imbalances has suggested a potential role for epigenetic alterations in causal or mediating pathways in the development of obesity-related pathologies. Specific changes in the epigenome (DNA methylome), associated with metabolic disorders, can be detected in the blood. We investigated whether such epigenetic changes are reversible after weight loss using genome-wide DNA methylome analysis of blood samples from individuals with severe obesity (mean BMI ~ 45) undergoing bariatric surgery., Results: Our analysis revealed 41 significant (Bonferroni p < 0.05) and 1169 (false discovery rate p < 0.05) suggestive differentially methylated positions (DMPs) associated with weight loss due to bariatric surgery. Among the 41 significant DMPs, 5 CpGs were replicated in an independent cohort of BMI-discordant monozygotic twins (the heavier twin underwent diet-induced weight loss). The effect sizes of these 5 CpGs were consistent across discovery and replication sets (p < 0.05). We also identified 192 differentially methylated regions (DMRs) among which SMAD6 and PFKFB3 genes were the top hypermethylated and hypomethylated regions, respectively. Pathway enrichment analysis of the DMR-associated genes showed that functional pathways related to immune function and type 1 diabetes were significant. Weight loss due to bariatric surgery also significantly decelerated epigenetic age 12 months after the intervention (mean =  - 4.29; p = 0.02)., Conclusions: We identified weight loss-associated DNA-methylation alterations targeting immune and inflammatory gene pathways in blood samples from bariatric-surgery patients. The top hits were replicated in samples from an independent cohort of BMI-discordant monozygotic twins following a hypocaloric diet. Energy restriction and bariatric surgery thus share CpGs that may represent early indicators of response to the metabolic effects of weight loss. The analysis of bariatric surgery-associated DMRs suggests that epigenetic regulation of genes involved in endothelial and adipose tissue function is key in the pathophysiology of obesity., (© 2022. The Author(s).)

Background: Single-nucleotide polymorphisms (SNPs) associated with obesity predict laparoscopic Roux-en-Y gastric bypass (LRYGB) and biliopancreatic diversion with duodenal switch (BPD/DS) for weight loss with good efficiency. However, prediction of weight loss after laparoscopic sleeve gastrectomy using SNPs has not been well investigated., Objectives: To predict weight loss after laparoscopic sleeve gastrectomy using obesity-related SNPs and clinical variants in Chinese patients with body mass index (BMI) ≥ 32.5 kg/m 2 ., Methods: We detected 29 SNPs. Binary logistic regression was used to screen SNPs and clinical variables with predictive value. Receiver operating characteristic (ROC) curves were plotted for clinical variables, SNPs, and their combination, and areas under the ROC curve (AUC) were compared. Internal and external validation tests were performed., Results: rs12535708, rs651821, and rs5082 were constructed as the genetic risk score (GRS). Preoperative BMI was constructed as the clinical risk score (CRS). Preoperative BMI and SNPs were constructed as the cumulative genetic risk score (CGRS). ROC curves of GRS, CRS, and CGRS showed that the optimal cutoffs were 0.831 (AUC = 0.840; sensitivity, 92.96%; specificity, 64.29%), 43.46 kg/m 2 (AUC = 0.830; sensitivity, 76.06%; specificity, 85.71%), and 0.921 (AUC = 0.931; sensitivity, 77.46%; specificity, 92.86%), respectively. The AUC of CGRS was significantly greater than that of CRS (P < 0.05) and greater than GRS without statistical significance., Conclusion: In Chinese patients with BMI ≥ 32.5 kg/m 2 , GRS and CRS could predict weight loss success. However, CGRS was superior to GRS or CRS alone., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The present study aimed to investigate the influence of food intake on body weight loss (WL) and the association of gene polymorphisms, 1 year after Roux-en-Y gastric bypass (RYGB) surgery., Methods: In total, 95 obese women (age ranged 20-50 years) in a Brazilian cohort underwent RYGB surgery and completed the study. Anthropometric measurements and food intake were assessed before and 1 year after surgery. Twelve gene polymorphisms (GHRL rs26802; GHSR rs572169; LEP rs7799039; LEPR rs1137101; 5-HT2C rs3813929; UCP2 rs659366; UCP2 rs660339; UCP3 rs1800849; SH2B1 rs7498665; TAS1R2 rs35874116; TAS1R2 rs9701796; and FTO rs9939609) were determined using a real-time polymerase chain reaction and a TaqMan assay. The subjects were divided into quartiles regarding percentage of excess weight loss (%EWL). The effect of genetic variants on energy and macronutrient intake was evaluated by simple logistic regression, followed by multiple logistic regression., Results: Subjects in the first and second quartiles showed a higher initial body mass index. Energy and macronutrient intake before and 1 year after RYGB surgery did not differ between the %EWL quartiles. None of gene polymorphisms investigated showed an association with the estimated energy intake 1 year after surgery., Conclusions: In conclusion, the estimate energy and food intake did not predict a greater body WL 1 year after RYGB surgery. In addition, the 12 gene polymorphism investigated did not affect the energy intake among female patients., (© 2021 The British Dietetic Association Ltd.)

Background: Although effective, the impact of bariatric surgery on weight loss is variable, and little is known about the influence of single-nucleotide polymorphisms (SNPs). The present study investigated the association of eleven SNPs related to obesity with weight loss 1 year after Roux-Y gastric bypass (RYGB) surgery in female patients., Methods: This prospective study included 351 women with obesity. The genotypes for eleven SNPs (GHRL-rs26802; GHSR-rs572169; LEP-rs7799039; LEPR-rs1137101; 5HT2C-rs3813929; UCP2-rs659366; UCP3-rs1800849; SH2B1-rs7498665; TAS1R2-rs35874116; TAS1R2-rs9701796; FTO-rs9939609) were determined using a real-time polymerase chain reaction and TaqMan assays. Anthropometric measurements were performed before and 1 year after RYGB surgery. To evaluate the factors that influenced the proportion of weight loss 1 year after surgery, beta regression analysis was used. The models were estimated using the GLIMMIX procedure in SAS statistical software. p < 0.05 was considered statistically significant., Results: The mean ± SD percentage of total body weight loss in 1 year was 64.4 ± 5.8% and the median was 65.0%. When assessing the proportion of weight loss in 1 year after surgery, using univariate analysis (beta regression), no SNPs influenced weight loss. Furthermore, in the multiple analysis, with stepwise process of variable selection, no variable was significant to compose the multiple model., Conclusions: The 11 SNPs investigated did not influence weight loss 1 year after RYGB surgery in female patients. This result indicates that individual behaviours and other factors might better contribute to the magnitude of loss weight loss in a short period after bariatric surgery., (© 2022 The British Dietetic Association Ltd.)

Introduction: Heterozygous variants in the leptin-melanocortin pathway are associated with obesity. However, their effect on the long-term outcomes after Roux-en-Y gastric bypass (RYGB) is still unknown., Methods: In this matched case-control study, 701 participants from the Mayo Clinic Biobank with a history of RYGB were genotyped. Sixty-three patients had a heterozygous variant in the leptin-melanocortin pathway. After excluding patients with potential confounders, carriers were randomly matched (on sex, age, body mass index [BMI], and years since surgery) with two non-carrier controls. The electronic medical record of carriers and matched non-carriers was reviewed for up to 15 years after RYGB., Results: A total of 50 carriers and 100 matched non-carriers with a history of RYGB were included in the study. Seven different genes (LEPR, PCSK1, POMC, SH2B1, SRC1, MC4R, and SIM1) in the leptin-melanocortin pathway were identified. At the time of surgery, the mean age was 50.8 ± 10.6 years, BMI 45.6 ± 7.3 kg/m 2 , and 79% women. There were no differences in postoperative years of follow-up, Roux limb length, or gastric pouch size between groups. Fifteen years after RYGB, the percentage of total body weight loss (%TBWL) in carriers was - 16.6 ± 10.7 compared with - 28.7 ± 12.9 in non-carriers (diff = 12.1%; 95% CI, 4.8 to 19.3) and the percentage of weight regain after maximum weight loss was 52.7 ± 29.7 in carriers compared with 29.8 ± 20.7 in non-carriers (diff = 22.9%; 95% CI, 5.3 to 40.5). The nadir %TBWL was lower - 32.1 ± 8.1 in carriers compared with - 36.8 ± 10.4 in non-carriers (diff = 4.8%; 95% CI 1.8 to 7.8)., Conclusions: Carriers of a heterozygous variant in the leptin-melanocortin pathway have a progressive and significant weight regain in the mid- and long-term after RYGB. Genotyping patients experiencing significant weight regain after RYGB could help implement multidisciplinary and individualized weight loss interventions to improve weight maintenance after surgery., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

A single nucleotide polymorphism in the Type 2 deiodinase (DIO2) gene (p.Thr92Ala) was found to be associated with hypertension, type 2 diabetes mellitus (T2DM), insulin resistance, and body mass index (BMI). We retrospectively evaluated 182 patients to assess whether the DIO2 p.Thr92Ala was associated with severe obesity and response to bariatric surgery. Genomic DNA was extracted from peripheral blood leukocytes before surgery. Glycemic control parameters, cardiometabolic risk biomarkers (waist circumference, lipid assessment and blood pressure) and hormonal parameters were assessed at baseline and after surgery. Based on genotype evaluation, 78/182 (42.9%) patients were homozygous wild-type (Thr/Thr), 83/182 (45.6%) heterozygous (Thr/Ala), and 21/182 (11.5%) rare homozygous (Ala/Ala). Age at the time of the first evaluation in our Unit was significantly lower in patients with DIO2 p.Thr92Ala. No significant association was observed between DIO2 p.Thr92Ala and BMI, excess weight, waist circumference, Homa Index. The prevalence of comorbidities was not associated with allele distribution except for hypertension that was more frequent in wild-type patients (p = 0.03). After bariatric surgery, excess weight loss (EWL) % and remission from comorbidities occurred without differences according to genotypes. DIO2 p.Thr92Ala does not affect the severity of obesity and its complications, but it seems to determine an earlier onset of morbid obesity. The presence of polymorphism seems not to impact on the response to bariatric surgery, both in terms of weight loss and remission of comorbidities., (© 2022. The Author(s).)

Background: Bariatric surgery is an effective therapy for individuals with severe obesity to achieve sustainable weight loss and to reduce comorbidities. Examining the molecular signature of subcutaneous adipose tissue (SAT) following different types of bariatric surgery may help in gaining further insight into their distinct metabolic impact., Results: Subjects undergoing biliopancreatic diversion with duodenal switch (BPD-DS) showed a significantly higher percentage of total weight loss than those undergoing gastric bypass or sleeve gastrectomy (RYGB + SG) (41.7 ± 4.6 vs 28.2 ± 6.8%; p = 0.00005). Individuals losing more weight were also significantly more prone to achieve both type 2 diabetes and dyslipidemia remission (OR = 0.75; 95%CI = 0.51-0.91; p = 0.03). Whole transcriptome and methylome profiling showed that bariatric surgery induced a profound molecular remodeling of SAT at 12 months postoperative, mainly through gene down-regulation and hypermethylation. The extent of changes observed was greater following BPD-DS, with 61.1% and 49.8% of up- and down-regulated genes, as well as 85.7% and 70.4% of hyper- and hypomethylated genes being exclusive to this procedure, and mostly associated with a marked decrease of immune and inflammatory responses. Weight loss was strongly associated with genes being simultaneously differentially expressed and methylated in BPD-DS, with the strongest association being observed for GPD1L (r 2  = 0.83; p = 1.4 × 10 -6 )., Conclusions: Present findings point to the greater SAT molecular remodeling following BPD-DS as potentially linked with higher metabolic remission rates. These results will contribute to a better understanding of the metabolic pathways involved in the response to bariatric surgery and will eventually lead to the development of gene targets for the treatment of obesity. Trial registration ClinicalTrials.gov NCT02390973., (© 2022. The Author(s).)

Introduction: Pathogenic heterozygous MC4R variants are associated with hyperphagia and variable degrees of obesity. Several research groups have reported short-term weight loss outcomes after bariatric surgery in a few patients with MC4R variants, but lack of longer-term data prevents evidence-based clinical decision-making., Materials and Methods: Bariatric surgery patients with heterozygous (likely) pathogenic MC4R variants, from three collaborating centers in the Netherlands, France, and the UK, were compared to matched controls (matched 2:1 for age, sex, preoperative BMI, surgical procedure, and diabetes mellitus, but without MC4R mutations). Weight loss and regain outcomes up to 6 years of follow-up were compared., Results: At 60 months of follow-up after RYGB, cases with MC4R variants showed weight regain with a mean of 12.8% (± 10.4 SD) total weight loss (TWL) from nadir, compared to 7.9% (± 10.5 SD) in the controls (p = 0.062). Among patients receiving SG, the cases with MC4R variants experienced inferior weight loss (22.6% TWL) during the first year of follow-up compared to the controls (29.9% TWL) (p = 0.010)., Conclusions: This multicenter study reveals inferior mid-term weight outcomes of cases with MC4R variants after SG, compared to RYGB. Since adequate weight loss outcomes were observed after RYGB, this procedure would appear to be an appropriate surgical approach for this group. However, the pattern of weight regain seen in cases with MC4R variants after both RYGB and SG highlights the need for pro-active lifelong management to prevent relapse, as well as careful expectation management., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

This systematic review synthesized research evaluating the relationship between genetic predictors and weight loss after bariatric surgery. Fifty-seven studies were identified that examined single genes or genetic risk scores. Uncoupling protein (UCP) rs660339 was associated with excess weight loss after surgery in 4 of 6 studies. The most commonly assessed genes were fat mass and obesity-associated (FTO) gene (n = 10) and melanocortin-4 receptor (MC4R) (n = 14). Both were inconsistently related to weight loss. Genetic risk scores predicted weight loss in 6 of 7 studies. This evidence suggests the potential of using genetic variants and genetic risk scores to predict the amount of weight loss anticipated after bariatric surgery and identify patients who may be at risk for suboptimal weight reduction., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

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., (Copyright © 2021 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Laparoscopic Roux-en-Y gastric bypass (RYGB) modulates the low-grade inflammatory state associated with severe obesity. This study sought to investigate whether weight loss is causally implicated with changes in serum levels of inflammatory molecules., Methods: Using the largest genome-wide association study (n = 1,020 individuals), this study curated five genetic variants associated with weight loss following RYGB. Phenome-wide association studies (PheWAS) were performed to identify other phenotypes associated with these variants. Subsequently, two-sample Mendelian randomization was used to study the causal effects of weight loss on the serum levels of 382 inflammatory proteins (measured in 3,033 individuals). This is the first systematic quasi-experimental investigation of weight loss following RYGB and serum markers of inflammation., Results: The PheWAS analysis revealed that four of the five variants are associated with phenotypes relating to metabolism and inflammation, including insulin response and levels of C-reactive protein. Two-sample Mendelian randomization of the 382 serum inflammatory markers revealed that weight loss following RYGB increases serum levels of interleukin 22 (IL-22) (beta = 0.021, P < 10 -3 ; 95% CI: 0.010-0.031). Sensitivity analyses further supported the results and the causal direction., Conclusions: Weight loss following RYGB may cause an increase in IL-22 serum levels, suggesting that weight loss directly contributes to immune modulation following bypass. These results demonstrate the utility of genetic studies to disentangling molecular cause and effect following bariatric surgery., (© 2021 The Obesity Society.)

Vertical sleeve gastrectomy (VSG) is one of the most effective and durable therapies for morbid obesity and its related complications. Although bile acids (BAs) have been implicated as downstream mediators of VSG, the specific mechanisms through which BA changes contribute to the metabolic effects of VSG remain poorly understood. Here, we confirm that high fat diet-fed global farnesoid X receptor ( Fxr ) knockout mice are resistant to the beneficial metabolic effects of VSG. However, the beneficial effects of VSG were retained in high fat diet-fed intestine- or liver-specific Fxr knockouts, and VSG did not result in Fxr activation in the liver or intestine of control mice. Instead, VSG decreased expression of positive hepatic Fxr target genes, including the bile salt export pump ( Bsep ) that delivers BAs to the biliary pathway. This reduced small intestine BA levels in mice, leading to lower intestinal fat absorption. These findings were verified in sterol 27-hydroxylase ( Cyp27a1 ) knockout mice, which exhibited low intestinal BAs and fat absorption and did not show metabolic improvements following VSG. In addition, restoring small intestinal BA levels by dietary supplementation with taurocholic acid (TCA) partially blocked the beneficial effects of VSG. Altogether, these findings suggest that reductions in intestinal BAs and lipid absorption contribute to the metabolic benefits of VSG., Competing Interests: The authors declare no competing interest.

Roux-en-Y gastric bypass (RYGB) is the most effective treatment for morbid obesity and results in rapid remission of type 2 diabetes (T2D), before significant weight loss occurs. The underlying mechanisms for T2D remission are not fully understood. To gain insight into these mechanisms we used RYGB-operated diabetic GK-rats and Wistar control rats. Twelve adult male Wistar- and twelve adult male GK-rats were subjected to RYGB- or sham-operation. Oral glucose tolerance tests (OGTT) were performed six weeks after surgery. RYGB normalized fasting glucose levels in GK-rats, without affecting fasting insulin levels. In both rat strains, RYGB caused increased postprandial responses in glucose, GLP-1, and GIP. RYGB caused elevated postprandial insulin secretion in Wistar-rats, but had no effect on insulin secretion in GK-rats. In agreement with this, RYGB improved HOMA-IR in GK-rats, but had no effect on HOMA-β. RYGB-operated GK-rats had an increased number of GIP receptor and GLP-1 receptor immunoreactive islet cells, but RYGB had no major effect on beta or alpha cell mass. Furthermore, in RYGB-operated GK-rats, increased Slc5a1, Pck2 and Pfkfb1 and reduced Fasn hepatic mRNA expression was observed. In summary, our data shows that RYGB induces T2D remission and enhanced postprandial incretin hormone secretion in GK-rats, without affecting insulin secretion or beta cell mass. Thus our data question the dogmatic view of how T2D remission is achieved and instead point at improved insulin sensitivity as the main mechanism of remission., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Roux-en-Y gastric bypass (RYGB) is the most efficient intervention in morbid obesity and promotes metabolic improvements in several peripheral tissues. However, the underlying molecular mechanisms are still poorly understood. To further understand the effects of RYGB on peripheral tissues transcriptomes, we determined transcriptome signatures in pancreatic islets, adipose and liver tissue from diet-induced obese (DIO) rats model following RYGB. Whereas RYGB led to discrete gene expression changes in pancreatic islets, substantial transcriptome changes were observed in metabolic and immune signaling pathways in adipose tissue and the liver, indicating major gene adaptive responses in fat-storing tissues. Compared to RYGB DIO rats, peripheral tissue transcriptome signatures were markedly different in caloric restricted weight matching DIO rats, implying that caloric restriction paradigms do not reflect transcriptomic regulations of RYGB induced weight loss. The present gene expression study may serve as a basis for further investigations into molecular regulatory effects in peripheral tissues following RYGB-induced weight loss., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Bariatric surgery is currently the most effective long-term treatment for severe obesity. However, interindividual variation in surgery outcome has been observed, and research suggests a moderating effect of several factors including baseline co-morbidities (e.g., type 2 diabetes [T2D] and genetic factors). No data are currently available on the interaction between T2D and variants in brain derived neurotrophic factor (BDNF) and its effect on weight loss after surgery., Objectives: To examine the role of the BDNF Val66Met polymorphism (rs6265) and the influence of T2D and their interaction on weight loss after bariatric surgery in a cohort of patients with severe obesity., Setting: University hospital in Spain., Methods: The present study evaluated a cohort of 158 patients with obesity submitted to bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy) followed up for 24 months (loss to follow-up: 0%). During the postoperative period, percentage of excess body mass index loss (%EBMIL), percentage of excess weight loss (%EWL), and total weight loss (%TWL) were evaluated., Results: Longitudinal analyses showed a suggestive effect of BDNF genotype on the %EWL (P = .056) and indicated that individuals carrying the methionine (Met) allele may experience a better outcome after bariatric surgery than those with the valine/valine (Val/Val) genotype. We found a negative effect of a T2D diagnosis at baseline on %EBMIL (P = .004). Additionally, we found an interaction between BDNF genotype and T2D on %EWL and %EBMIL (P = .027 and P = .0004, respectively), whereby individuals with the Met allele without T2D displayed a greater %EWL and greater %EBMIL at 12 months and 24 months than their counterparts with T2D or patients with the Val/Val genotype with or without T2D., Conclusion: Our data showed an association between the Met variant and greater weight loss after bariatric surgery in patients without T2D. The presence of T2D seems to counteract this positive effect., (Copyright © 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Morbid obesity (BMI>40 kg/m2) is a challenging health condition with an increasing incidence in the last decades. Conventional therapy which consists in diet and lifestyle interventions, along with pharmaceutical therapy, has a limited effect on morbidly obese patients. In this context, bariatric surgery is the most effective approach, leading to significant weight loss, along with other beneficial effects like type 2 diabetes resolution or improvement of cardiovascular status. The bariatric surgery outcomes can widely vary among individuals, with a significant percentage of patients having small benefits from the operation. These variations may be partially explained by the genetic background of each individual. During the last years, several studies have been conducted in order to determine the genetic and epigenetic factors involved in bariatric surgery outcomes. Many genes involved in different molecular pathways were found to be associated with weight loss after bariatric surgery. Epigenetic studies revealed that genes methylation may be influenced by weight loss interventions. All these findings suggest that there is an intimate connection between genetic and epigenetic factors and the bariatric surgery outcomes. Further studies are required in order to better understand if genetics can be used in order to predict the operation results. KEY WORDS: Bariatric surgery, Body-mass index, Epigenetic, Genetic.

Background: There is significant variability in weight loss after bariatric surgery. We hypothesize that part of this variability may be predetermined by genetic differences associated with metabolic homeostasis. MicroRNA (miRNA) are short pieces of RNA that regulate gene expression and are readily detectable in serum. They are implicated in numerous metabolic processes, including weight homeostasis. In this pilot study, we briefly review the role of miRNA, and assess the feasibility of using them in the clinical setting of obesity treatment., Objectives: To evaluate the feasibility of using miRNA to predict weight loss after bariatric surgery., Setting: Academic medical center., Methods: Serum was collected from patients at the initial bariatric surgery consultation. Weight loss data were collected 6 to 12 months postoperatively. Individuals experiencing the least and the greatest amount of percentage of excess weight lost at 6 months were analyzed to assess for genetic differences in miRNA expression., Results: The median percentage of excess weight lost was 51% (range, 34%-63%) for those who lost the least and 87% (range, 82%-111%) for those who lost the most weight. Groups were similar in age, sex, diabetic status, and type of surgery. In total, of the 119 miRNA detected in the serum of the patients, 6 demonstrated potential for discriminating between the high and low weight loss groups. These miRNA have previously been implicated in regulation of fatty acid biosynthesis, adipocyte proliferation, type 2 diabetes, and obesity., Conclusions: In this pilot study, we demonstrated the feasibility of identifying genetic differences between high and low weight loss groups by identifying distinct serum miRNA. In the near future, these biomarkers could facilitate informed decisions about surgery. In addition, these miRNA could open new genetic pathways that describe the pathophysiology of obesity, and provide targets for future treatment., (Copyright © 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Background/objectives: We aimed to investigate the effects of short-term hypocaloric diet-induced weight loss on DNA methylation profile in leukocytes from women with severe obesity., Methods: Eleven women with morbid obesity (age: 36.9 ± 10.3 years; BMI: 58.5 ± 10.5 kg/m 2 ) were assessed before and after 6 weeks of a hypocaloric dietary intervention. The participants were compared with women of average weight and the same age (age: 36.9 ± 11.8 years; BMI: 22.5 ± 1.6 kg/m 2 ). Genome-wide DNA methylation analysis was performed in DNA extracted from peripheral blood leukocytes using the Infinium Human Methylation 450 BeadChip assay. Changes (Δβ) in the methylation level of each CpGs were calculated. A threshold with a minimum value of 10%, p < 0.001, for the significant CpG sites based on Δβ and a false discovery rate of <0.05 was set., Results: Dietary intervention changed the methylation levels at 16,064 CpG sites. These CpGs sites were related to cancer, cell cycle-related, MAPK, Rap1, and Ras signaling pathways. However, regardless of hypocaloric intervention, a group of 878 CpGs (related to 649 genes) remained significantly altered in obese women when compared with normal-weight women. Pathway enrichment analysis identified genes related to the cadherin and Wnt pathway, angiogenesis signaling, and p53 pathways by glucose deprivation., Conclusion: A short-term hypocaloric intervention in patients with severe obesity partially restored the obesity-related DNA methylation pattern. Thus, the full change of obesity-related DNA methylation patterns could be proportional to the weight-loss rate in these patients after dietary interventions.

Background: The FUT2 gene (Se gene) encoding the enzyme α-1,2-L-fucosyltransferase 2 seems to have a significant effect on the number and type of bacteria colonizing the intestines., Methods: In a group of 19 patients after bariatric surgery, the polymorphism (rs601338) of FUT2 gene was analyzed in combination with body mass reduction, intestinal microbiome (16S RNA sequencing), and short chain fatty acids (SCFA) measurements in stools., Results: Among the secretors (Se/Se polymorphism of the FUT2 gene rs601338, carriers of GG variant), correlations between waist-hip ratio (WHR) and propionate content and an increase in Prevotella , Escherichia , Shigella , and Bacteroides were observed. On the other hand-in non-secretors (carriers of GA and AA variants)-higher abundance of Enterobacteriaceae , Ruminococcaceae , Enterobacteriaceae , Clostridiales was recorded., Conclusions: The increased concentrations of propionate observed among the GG variants of FUT 2 may be used as an additional source of energy for the patient and may have a higher risk of increasing the WHR than carriers of the other variants (GA and AA).

Background: The FTO (fat mass- and obesity-associated) gene variant is an established obesity-susceptibility locus. FTO protein is a nucleic acid demethylase and FTO genetic variants form long-range functional connections with IRX3, which regulates fat mass and metabolism in humans. From our previous results, we found FTO regulates the metabolism of triglyceride in adipocytes through demethylating Angptl4 (angiopoietin-like protein 4) mRNA in mice. We hypothesized that the FTO genetic variants regulate ANGPTL4 abundances in human adipose tissues and affect the outcome after bariatric surgery., Methods and Results: We recruited 188 obesity subjects with body mass indices (BMI)>35kg/m 2 and 102 non-obese subjects with BMI<30kg/m 2 from the OCEAN registry between 2011 and 2014. The distribution of FTO variants rs9939609 among participates was 73.79% TT, 23.79% AT, and 2.41% AA. The subjects with FTO variants AA or AT were correlated with higher BMI than those with FTO variants TT. The serum ANGPTL4 levels were significantly higher in obese subjects and positively correlated with the presence of FTO AA or AT haplotype. Of these participates, 84 obese subjects underwent bariatric surgery and adipose Angptl4 expressions were analyzed. The adipose Angptl4 mRNA levels and protein abundances were correlated with FTO AA or AT haplotype. The magnitude of excess body weight reduction 2 years after bariatric surgery was correlated with the adipose ANGPTL4 protein levels., Conclusion: Adipose ANGPTL4 abundances were affected by the presence of FTO obesity risk haplotype and correlated with excess weight loss percentage after bariatric surgery. These data signify the critical role of FTO variants and adipose ANGPTL4 in fatty acid metabolism and bariatric outcomes in humans., (Copyright © 2020 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.)

Background: Emerging evidence suggests that the FK506 binding protein 51 (FKBP5/FKBP51), encoded by the FKBP5 gene, influences weight and metabolic regulation. The T allele of a functional polymorphism in FKBP5 (rs1360780), has been associated with the expression of FKBP51 and weight loss after bariatric surgery., Objective: To examine the role of the FKBP5 rs1360780 polymorphism in relation to age, sex, and type of surgery in weight loss after bariatric surgery in patients with severe obesity., Setting: University Hospital in Spain METHODS: A cohort of 151 obese patients submitted to Roux-en-Y gastric bypass (62.3%) and sleeve gastrectomy (37.7%) were followed-up during 24-months (t 24m ; loss to follow-up: 0%). During the postoperative period body mass index (BMI) and percentage of excess and total weight loss were evaluated., Results: The BMI analysis showed an effect of the interaction FKBP5 genotype by sex (P = .0004) and a tendency to the interaction genotype by surgery (P = .048), so that men carrying the T allele had higher BMI at t 24m than those without the T allele, and T-allele carriers that underwent sleeve gastrectomy had higher BMI at t 24m than the noncarriers. Additionally, we found an interaction between FKBP5 and age for the percentage of excess weight loss and BMI (P = .0005 and P = 1.5e-7, respectively), whereby individuals >48 years with the T allele displayed significant differences for the analyzed variables at t 24m compared with the homozygotes for the alternate C allele showing lower weight loss., Conclusion: FKBP5 rs1360780 genotype has specific effects on weight loss outcomes after bariatric surgery depending on sex, age, and type of surgery, suggesting worse results in older males carrying the T allele who have undergone sleeve gastrectomy., Competing Interests: Disclosures The authors have no commercial associations that might be a conflict of interest in relation to this article., (Copyright © 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Interleukin (IL)-1β is involved in obesity-associated inflammation and in the pathogenesis of type 2 diabetes (T2D) mellitus. Our aim was to correlate serum IL-1β and caspase-1 levels with weight loss, glucose metabolism, and insulin resistance (IR) after bariatric surgery., Methods: A total of 32 patients with morbid obesity and T2D (Ob-T2D) and 29 patients with morbid obesity and normal glucose tolerance (Ob-NGT), treated by Roux-en-Y gastric bypass, were studied before and 1 year after surgery. Sixteen healthy individuals served as a control (HC) group. IR was assessed by the oral glucose insulin sensitivity method. Plasma IL-1β levels and caspase-1 were measured., Results: Presurgery BMI was similar in Ob-NGT and Ob-T2D. IR was progressively impaired in Ob-NGT and Ob-T2D (P < 0.0001). Fasting plasma IL-1β and caspase-1 levels were lower in HCs than in patients with Ob-NGT or Ob-T2D (P < 0.02; P = 0.05), and both were inversely correlated with IR (P = 0.01; P = 0.02). After surgery, BMI decreased and IR improved to a similar extent in Ob-NGT and Ob-T2D (P < 0.0001). Plasma caspase-1 concentrations normalized in both groups (P < 0.0001), whereas plasma IL-1β levels normalized only in Ob-NGT., Conclusions: Plasma IL-1β and caspase-1 levels were inversely correlated with IR. Caspase-1 levels normalized after weight loss, whereas IL-1β normalized only in people without T2D, suggesting the persistence of a systemic inflammatory condition in people with T2D., (© 2020 The Obesity Society.)

Background: Morbid obesity could last for a long period of life and increase the risk of morbidity as well as premature mortality. Although bariatric surgery benefits patients by quick weight loss, not all bariatric patients lose the same percentage of weight after a long time from surgery, which may be the result of diet, physical activity, and genetic components., Objectives: In this study, we evaluated the association between the MC4R gene and both excess weight loss percentage (EWL%) and excess BMI loss percentage (EBMIL%) in a cohort of bariatric surgery patients after 6 and 12 months from surgery., Methods: A total of 424 bariatric surgery patients who had participated in the Tehran Obesity Treatment Study and had weight measurements after 6 and 12 months from surgery were included in the study. Four SNPs in the MC4R gene were selected for evaluating the associations., Results: We found that rs17773430 had a significant effect on both EWL% and EBMIL%, especially after 12 months of bariatric surgery. Furthermore, three other SNPs, rs17782313, rs476828, and rs11152213, did not show any significant association with EWL% and EBMIL%., Conclusion: This study was the first to report on the association of rs17773430 with both EWL% and EBMIL% in a cohort of patients after bariatric surgery. We found that weight loss after surgery is influenced by genetic factors, and there were significant differences between the distribution of EWL% and EBMIL% in morbid obese bariatric patients who have two minor alleles of the rs17773430 and other SNPs.

Adiponectin exerts positive effects on metabolic and inflammatory processes. Adiponectin levels and some single-nucleotide polymorphisms (SNPs) seem to be associated with obesity. Here, we investigated the effects of a 4-week Hypocaloric diet and Physical exercise Program (HPP) on 268 young people with severe obesity. We evaluated the relationship between adiponectin levels and anthropometric and biochemical parameters, at baseline and after a 4-week HPP. Finally, we investigated some adiponectin gene variants and their correlation to biochemical parameters. Adiponectin levels were statistically lower in people with severe obesity than in controls. At the end of the HPP, all the people with severe obesity showed a Body Mass Index (BMI) reduction with a statistically significant increase in adiponectin levels. Genotyping, the adiponectin gene demonstrated a significant difference in 3 polymorphisms within the people with severe obesity. Besides, c.11377C>G and c.11391G>A homozygous subjects experienced more advantages by HPP. Furthermore, c.268G>A heterozygous subjects showed an enhancement in lipid profile as well in adiponectin levels. The best predictor of the changes in adiponectin levels was represented by the c.268G>A WT allele. Our study confirmed that a 4-weeks HPP in people with severe obesity results in metabolic amelioration associated with a significant increase of adiponectin levels. Importantly, we found that a specific genetic background in the ADIPOQ gene can predispose toward a more significant weight loss.

Bariatric surgery (BS) is a highly effective therapy for morbid obesity, yet with a wide inter-individual variability on weight-loss responses. To determine genetic influence on weight loss after BS we compared the within-pairs difference in maximum percentage excess weight loss (%EWL) and the within-pairs %EWL differences over a mean follow-up of 53.6 ± 36.4 months between 47 pairs of first-degree relatives and 47 genetically unrelated control pairs. Within-pairs maximum %EWL difference was similar between first-degree related pairs and control pairs (p = 0.100). Within-pairs %EWL difference increased through follow-up (p < 0.001). However, effect of time was different depending on genetic background (p time*group  = 0.001). Increased variability in mid-term weight response was present in unrelated pairs but not in first-degree pairs (p < 0.001 and p = 0.535, respectively). To assess shared environment influence, 16 married couples were identified and 16 unrelated and non-cohabiting matched pairs were also analyzed. In these analysis within-pairs difference in %EWL also increase over time (p = 0.025) but no group by time effect was observed (p time×group  = 0.177). In conclusion first-degree related participants showed closer weight trajectories after BS time than genetically unrelated subjects. Genetic background might partially explain the variability in mid-term weight-loss after BS.

Background: The weight loss after bariatric surgery shows considerable individual variation. Twin studies of response to dietary interventions and studies of bariatric surgery patients suggest that genetic differences may play a role. This study aimed to examine the effect of three genetic risk scores on the inter-individual variation in excess body mass index loss (EBMIL) after Roux-en-Y gastric bypass. Furthermore, we searched among known adiposity-related single nucleotide polymorphisms (SNPs) for genetic determinants of the inter-individual variation in EBMIL., Methods: Patients with morbid obesity underwent Roux-en-Y gastric bypass and were genotyped (n = 577). Two genetic risk scores for weight loss after bariatric surgery and a genetic risk score for body mass index were calculated. Associations between the genetic risk scores and EBMIL were evaluated. Lasso regression was performed on 126 SNPs known to be associated with adiposity., Results: The average EBMIL was 76.9% (range 21.7-149.2%). EBMIL was 81.1% (SD 20.6) and 73.9% (SD 21.7) in the high and low tertile groups of a genetic risk score for weight loss. Patients with a low genetic risk score for body mass index (in the lowest 5% percentile) had an EBMIL of 68.8% (SD 20.6, p = 0.018). Thirteen adiposity-related SNPs were identified to associate with EBMIL through lasso regression., Discussion: A genetic risk score was associated with EBMIL after bariatric surgery, but may not yet be applicable to clinical practice. Patients genetically predisposed to low body mass index had lower weight loss after bariatric surgery.

We aimed to explore the relationship between GLP-1 receptor (GLP-1R) expression in adipose tissue (AT) and incretin secretion, glucose homeostasis and weight loss, in patients with morbid obesity and type 2 diabetes undergoing bariatric surgery. RNA was extracted from subcutaneous (SAT) and visceral (VAT) AT biopsies from 40 patients randomized to metabolic gastric bypass, sleeve gastrectomy or greater curvature plication. Biochemical parameters, fasting plasma insulin, glucagon and area under the curve (AUC) of GLP-1 following a standard meal test were determined before and 1 year after bariatric surgery. GLP-1R expression was higher in VAT than in SAT. GLP-1R expression in VAT correlated with weight (r = -0.453, p = 0.008), waist circumference (r = -0.494, p = 0.004), plasma insulin (r = -0.466, p = 0.007), and systolic blood pressure (BP) (r = -0.410, p = 0.018). At 1 year, GLP-1R expression in VAT was negatively associated with diastolic BP (r = -0.361, p = 0.039) and, following metabolic gastric bypass, with the increase of GLP-1 AUC, (R 2  = 0.46, p = 0.038). Finally, GLP-1R in AT was similar independently of diabetes outcomes and was not associated with weight loss after surgery. Thus, GLP-1R expression in AT is of limited value to predict incretin response and does not play a role in metabolic outcomes after bariatric surgery.

Objective: A common G-to-A transition (rs670) of the Apoprotein subtype 1 APOA1 gene has been evaluated. The presence of the A allele has been related with increased activity. We investigated the role of this genetic variant (rs670) on lipoprotein levels and anthropometric parameters after biliopancreatic diversion (BPD) surgery in morbid obese patients., Patients and Methods: Sixty-three patients with morbid obesity without diabetes mellitus type 2 were enrolled. Biochemical and anthropometric evaluation were registered before and after one, two and three years follow-up., Results: Genotype distribution was 73% (n=46) GG, 25.6% (n=16) GA and 1.4% (n=1) AA for the rs670 polymorphism. Percent excess weight loss, anthropometric and biochemical parameters improved in both groups (GG vs. GA±AA). The decrease of fasting insulin levels at 1 years (delta: -3.7±1.4 mUI/L vs. -2.9±1.2 mUI/L; p=0.02), 2 years (delta: -4.8±0.3 mUI/L vs. -4.0±0.2 mUI/L; p=0.01) and 3 years (delta: -6.7±3.1 mUI/L vs. -3.9±2.1 mUI/L; p=0.03) was higher in A allele carriers than in non carriers. The improvement of HOMA-IR levels at 1 years (delta: -3.7±1.4 mUI/L vs. -2.9±1.2 mUI/L; p=0.02), 2 years (delta: -4.8±0.3 mUI/L vs. -4.0±0.2 mUI/L; p=0.01) and 3 years (delta: -6.7±3.1 mUI/L vs. -3.9±2.1 mUI/L; p=0.03) was also higher in A allele carriers than non-carriers. Finally, the increase of HDL-cholesterol levels at 1 years (delta: 2.2±0.6 mg/dl vs. -1.2±0.2 mg/dl; p=0.001), 2 years (delta: 2.5±0.4 mg/dl vs. 0.3±0.1 mg/dl; p=0.01) and 3 years (delta: 2.4±0.6 mg/dl vs. 0.4±2.3 mg/dl; p=0.02) was higher in A allele carriers than non-carriers., Conclusions: This variant of the APOA1 gene showed important effects on HDL-cholesterol, HOMA-IR and insulin resistance after DBP for 3 years.

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.

Background: Differential gene expression in peripheral blood mononuclear cells (PBMCs) after Roux-en-Y gastric bypass (RYGB) is poorly characterized. Markers of these processes may provide a deeper understanding of the mechanisms that underlie these events. The main goal of this study was to identify changes in PBMC gene expression in women with obesity before and 6 months after RYGB-induced weight loss., Methods: The ribonucleic acid (RNA) of PBMCs from 13 obese women was analyzed before and 6 months after RYGB; the RNA of PBMCs from nine healthy women served as control. The gene expression levels were determined by microarray analysis. Significant differences in gene expression were validated by real-time quantitative polymerase chain reaction (RT-qPCR)., Results: Microarray analysis for comparison of the pre- and postoperative periods showed that 1366 genes were differentially expressed genes (DEGs). The main pathways were related to gene transcription; lipid, energy, and glycide metabolism; inflammatory and immunological response; cell differentiation; oxidative stress regulation; response to endogenous and exogenous stimuli; substrate oxidation; mTOR signaling pathway; interferon signaling; mitogen-activated protein kinases (MAPK), cAMP response element binding protein (CREB1), heat shock factor 1 (HSF1), and sterol regulatory element binding protein 1c (SREBP-1c) gene expression; adipocyte differentiation; and methylation., Conclusions: Six months after bariatric surgery and significant weight loss, many molecular pathways involved in obesity and metabolic diseases change. These findings are an important tool to identify potential targets for therapeutic intervention and clinical practice of nutritional genomics in obesity.

Background: The effects of rs1501299 variant of ADIPO gene on weight loss after bariatric surgery have not been evaluated. We decided to investigate the role of this genetic variant on anthropometric and biochemical outcomes such as serum adiponectin levels after biliopancreatic diversion (BPD) surgery in morbidly obese patients during 3 years., Material and Methods: A sample of 64 patients with morbid obesity without diabetes mellitus was operated. Biochemical and anthropometric evaluation were realized at basal visit and at each visit during 3 years (1, 2, and 3 years)., Results: Percent excess weight loss, body mass index, weight, waist circumference, fat mass, blood pressure, fasting glucose, LDL cholesterol, total cholesterol, and triglycerides levels improved in both genotype groups. Fasting insulin levels and HOMA-IR decreased significantly only in non-T allele carriers. The decrease of fasting insulin levels at 3 years (delta -9.2 ± 3.4 vs -2.9 ± 2.2 mUI/L; p = 0.01) and HOMA-IR (delta -1.3 ± 0.3 vs -0.8 ± 0.4 units; p = 0.03) were higher in non-T allele carriers than T carriers. Adiponectin levels increased in all times after surgery in non-T allele carriers, too. The increase of adiponectin levels at 3 years (delta 12.2 ± 3.6 vs 1.8 ± 1.2 ng/mL; p = 0.01) was higher in non-T allele carriers than T carriers., Conclusion: Non-T allele of ADIPOQ gene variant (rs1501299) is associated with increases in adiponectin levels and better improvements of insulin and HOMA-IR after BPD massive weight loss. These parameters remained unchanged in T allele carriers.

Background/objectives: Roux-en-Y gastric bypass (RYGB) surgery improves insulin sensitivity (S I ) and β-cell function in obese non-diabetic subjects. Exercise also improves S I and may be an effective adjunct therapy to RYGB surgery. However, the mechanisms by which exercise or weight loss improve peripheral S I after RYGB surgery are unclear. We hypothesized that microRNAs (miRNAs) mediate at least some of the regulatory processes driving such mechanisms. Consequently, this work aimed at profiling plasma miRNAs in participants of the Physical Activity Following Surgery Induced Weight Loss study (clinicaltrials.gov identifier: NCT00692367), to assess whether miRNA levels track with improvements in S I and cardiometabolic risk factors., Subjects/methods: Ninety-four miRNAs implicated in metabolism were profiled in plasma samples from 22 severely obese subjects who were recruited 1-3 months after RYGB surgery and followed for 6 months of RYGB surgery-induced weight loss, with (exercise program (EX), N=11) or without (CON, N=11) an exercise training intervention. The subjects were selected, considering a priori sample size calculations, among the participants in the parent study. Mixed-effect modeling for repeated measures and partial correlation analysis was implemented in the R environment for statistical analysis., Results: Mirroring results in the parent trial, both groups experienced significant weight loss and improvements in cardiometabolic risk. In the CON group, weight loss significantly altered the pattern of circulating miR-7, miR-15a, miR-34a, miR-106a, miR-122 and miR-221. In the EX group, a distinct miRNA signature was altered: miR-15a, miR-34a, miR-122, miR-135b, miR-144, miR-149 and miR-206. Several miRNAs were significantly associated with improvements in acute insulin response, S I , and other cardiometabolic risk factors., Conclusions: These findings present novel insights into the RYGB surgery-induced molecular changes and the effects of mild exercise to facilitate and/or maintain the benefits of a 'comprehensive' weight-loss intervention with concomitant improvements in cardiometabolic functions. Notably, we show a predictive value for miR-7, miR-15a, miR-106b and miR-135b.

Introduction: Obesity is the result of a complex interaction between multiple genetic traits and psychological, behavioral, nutritional and environmental factors., Objectives: The aims of the study were (a) to comparatively evaluate the presence of 20 candidate gene single nucleotide polymorphisms (SNPs) in morbidly obese patients, (2) their association to comorbid conditions and (3) their impact on weight loss after a Roux-en-Y gastric bypass (RYGB)., Patients and Methods: Two hundred forty-nine patients were eligible for this study. Clinical, anthropometric, biochemical and demographic variables were analyzed. Body mass index (BMI) and composition were assessed by bioelectrical impedance. Twenty SNPs were included for analysis., Results: There were 168 Mexican mestizos (67.5 %) and 81 (32.5 %) patients with other ancestral origin. One hundred fifty-nine (64.1 %) were females. Mean ± SD age of the general cohort was 41.1 ± 11.3 years (17-71). Preoperative mean ± SD BMI was 42.5 ± 6.5 kg/m 2 . There were no significant differences between mestizo and non-mestizo for most SNPs except for IFI, LIPC, and ST8SIA2. FTO (OR = 1.71; CI 95 %  = 1.14-2.57; p = 0.008) and APOB (OR = 0.31; CI 95 %  = 0.14-0.72; p = 0.004) result is statistically associated to high blood pressure and FTO (OR = 2.0; CI 95 %  = 1.3-3.1; p = 0.001), GNB3 (OR = 2.69; CI 95 %  = 1.0-7.2; p = 0.04), IFI30 (OR = 2.0; CI 95 %  = 1.16-3.6; p = 0.01), and MC4R (OR = 1.81; CI 95 %  = 1.13-2.9; p = 0.01) to type 2 diabetes (T2D). Based on ANOVA analysis, POMC (rs1042571) was the SNP most significantly associated to a higher weight loss after RYGB., Conclusions: Obese patients have similar SNP frequencies. Several SNP results are statistically associated to high blood pressure and T2D. POMC was significantly associated to a higher surgically induced weight loss.

Background: Several patients encompass a scarce weight loss after Roux-en-Y gastric bypass (RYGB). As such event is not related to surgical complications, finding markers able to identify "well responders" and to predict weight loss outcome is clinically relevant. Ghrelin regulates appetite and energy balance. Common single nucleotide polymorphisms (SNPs) in its encoding genes have been associated with body weight regulation. Other peptides involved in satiety modulation, like the CD40/CD40L complex, are less explored., Methods: One hundred, otherwise healthy, obese subjects (aged 45 ± 11 years, 65 females, BMI 48.0 ± 0.7 kg/m 2 ) were sequentially enrolled in years 2014-2015. SNPs rs2241766 for adiponectin gene, rs490683 for ghrelin receptor, rs696217 and rs27647 for the preproghrelin/ghrelin gene, and rs1126535 for the CD40L gene were determined on DNA extracted from circulating lymphomonocytes. Patients were reevaluated at 6 (n = 100), 26 (n = 91), and 52 weeks (n = 79) after RYGB., Results: Subjects carrying the rs696217 T allele encompassed a significantly greater reduction in BMI 52 weeks after surgery (GG vs GT 30.5 ± 1.1 vs 38.1 ± 2.1 %; p < 0.001). Carrying the rs1126535 C allele in the CD40L gene was associated with a significantly lower BMI reduction at week 52 (TT vs CT 33.2 ± 1.1 vs 28.1 ± 2.3 %, p = 0.049). rs490683 and rs27647 SNPs of ghrelin and rs2241766 for adiponectin gene did not show any difference between carriers and non-carriers of the mutant allele., Conclusion: Carrying a G to T substitution in rs696217 (preproghrelin gene) seems to mark a successful weight loss outcome; we also report for the first time that the rs1126535 C allele (CD40L gene) may predict a worse response to bariatric surgery.

Background: Analysis of the expression of genes related to the energy metabolism can elucidate the understanding of physiological and genetic factors that contribute to obesity. This study aimed to evaluate the expression of genes and its influence on resting metabolic rate and weight loss in obese patients before and after bariatric surgery., Methods: This study was conducted on 23 women, who were divided into two groups: bariatric surgery (preoperative and 6 months after surgery) and control. Abdominal subcutaneous adipose tissue samples were collected to analyze the gene expression, and the resting metabolic rate (RMR) was measured by indirect calorimetry., Results: Significant differences were observed in weight reduction (22 %, p = 0.01), BMI (22.5 %, p = 0.01), and RMR values (10.5 %, p = 0.01) after the bariatric surgery, while the weight-adjusted RMR increased (15.8 %, p = 0.01). Increased UCP2 expression after 6 months of Roux-en-Y gastric bypass (RYGB) as compared to preoperative period (0.764 to 1.268, p = 0.01) was observed. Analysis with weight-adjusted RMR as dependent variable revealed that UCP2 (r 2  = 0.517, p = 0.01) and PLIN1 (r 2  = 0.420, p = 0.04) expression determine the RMR values in preoperative period. Moreover, UCP2 and PLIN1 expression in preoperative period influenced the percentage of weight loss, even when adjusted for age and BMI., Conclusions: We have demonstrated that after 6 months of bariatric surgery, there is significant increase in the UCP2 expression. Additionally, the expression of UCP2 and PLIN1 genes influences the resting metabolic rate in obese individuals and could predict the weight loss after bariatric surgery.

Background: Weight loss success is determined by genetic factors, which may differ according to treatment strategy., Methods: From a multidisciplinary obesity treatment program involving dietary advice, psychological counseling, and increased physical activity, 587 subjects (68% female; 46.1 ± 12.4 years; BMI 39.9 ± 6.3) were recruited. At baseline, a blood sample was drawn for DNA isolation. Genotypes were determined for 30 polymorphisms in 25 candidate genes. The association between genotypes and weight loss was assessed after 3 months (short-term) and after 12 months of treatment (long-term). Weight loss was categorized as ≥5% or <5% of initial weight., Results: The G/G genotype of PLIN1 (rs2289487) and PLIN1 (rs2304795), the T/T genotype of PLIN1 (rs1052700), and the C/C genotype of MMP2 predicted ≥5% weight loss in the first 3 months. The C/G-G/G genotype of PPARγ (rs1801282) and the T/C genotype of TIMP4 (rs3755724) predicted ≥5% weight loss after 12 months. Subjects with the combination of PPARγ (rs1801282) C/G-G/G and TIMP4 (rs3755724) T/C lost even more weight., Conclusion: Polymorphisms in genes related to regulation of fat storage and structural adaptation of the adipocytes are predictors for weight loss success with different genes being relevant for short-term and long-term weight loss success., (© 2017 The Author(s) Published by S. Karger AG, Basel.)

This study aimed to investigate the association between twelve gene polymorphisms and body weight loss, 12 months after Roux-en-Y gastric bypass (RYGB) surgery. Three hundred and fifty-one obese women participated in this study. The statistical software WEKA was used to identify which gene polymorphisms were potential predictors of postoperative percentage of excess weight loss (%EWL). Our results indicate that the only gene polymorphism that predicted %EWL was rs3813929, which is related to the serotonin receptor gene (5-HT2C). Therefore, the 5-HT2C gene polymorphism rs3813929 (more specifically, the TT genotype) predicted greater %EWL 12 months after RYGB surgery among female patients., (Copyright © 2016 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.)

Background: Chronotype has been related to obesity and metabolic disturbances. However, little is known about the relationship between circadian preferences and genetic background in CLOCK genes with obesity and weight loss among severely obese patients after bariatric surgery., Objectives: The research goals were (1) to examine whether evening chronotype is related to obesity and weight loss evolution in severely obese followed during 6 years after bariatric surgery and (2) to examine potential interactions between circadian preferences and CLOCK 3111T/C for obesity in this population., Subjects/methods: Participants (n=252, 79% female; age (mean±s.d.): 52±11 years; body mass index (BMI): 46.4±6.0 kg m -2 ) were grouped into evening and morning types. Obesity and weight loss parameters, energy and macronutrients intake, energy expenditure, chronotype, meal timing, sleep duration and CLOCK genotype were studied., Results: Evening-type subjects showed significantly higher initial body weight (P=0.015) and BMI (P=0.014) than morning types. Moreover, evening-type, when compared with morning types, lost less weight (percentage of excess weight loss) after bariatric surgery (P=0.015). Weight-loss progression between the two chronotype groups differed significantly from the fourth year after the bariatric surgery toward a higher weight regain among evening types (P<0.05). We also detected a significant interaction between CLOCK 3111T/C SNP and chronotype for body weight at baseline (P<0.001). Specifically, among carriers of the risk allele C, evening types showed higher body weight than morning types (P=0.012). In addition, CLOCK 3111T/C SNP significantly associated with obesity and sleep duration in the older subjects., Conclusions: Evening chronotype is associated with higher obesity in severely obese subjects and with lower weight loss effectiveness after bariatric surgery. In addition, circadian preferences interact with CLOCK 3111T/C for obesity. The circadian and genetic assessment could provide tailored weight loss recommendations in subjects who underwent bariatric surgery.

Objective: Bariatric surgery is the most efficient treatment of severe obesity. We investigated to what extent BMI- or waist-hip ratio (WHR)-related genetic variants are associated with excess BMI loss (EBMIL) two years after Roux-en-Y gastric bypass (RYGB) surgery, and elucidated the affected biological pathways., Methods: Two-hundred fifty-one obese patients (age: 43 ± 10.7, preoperative BMI: 45.1 ± 6.1 kg/m(2), 186 women) underwent RYGB surgery and were followed up after two years with regard to BMI. Patients were genotyped for 32 single-nucleotide polymorphisms (SNPs) that were investigated with regard to their impact on response to RYGB and preoperatively measured Three Factor Eating Questionnaire (TFEQ) scores., Results: Homozygous T carriers of the SNP rs4846567 in proximity to the Lysophospholipase-like 1 (LYPLAL1) gene showed a 7% higher EBMIL compared to wild-type and heterozygous carriers (p = 0.031). TT-allele carriers showed furthermore lower scores for Hunger (74%, p < 0.001), lower Disinhibition (53%, p < 0.001), and higher Cognitive restraint (21%, p = 0.017) than GG/GT carriers in the TFEQ. Patients within the lowest quartile of Hunger scores had a 32% greater EBMIL compared to patients in the highest quartile (p < 0.001)., Conclusion: The LYPLAL1 genotype is associated with differences in eating behavior and loss of extensive body weight following RYGB surgery. Genotyping and the use of eating behavior-related questionnaires may help to estimate the RYGB-associated therapy success.