Impact of Bariatric Surgery on Circulating Metabolites and Cognitive Performance.

INTRODUCTION: Bariatric surgery is an effective intervention to reduce obesity and improve associated comorbidities. However, its effects on cognitive function are still the subject of debate. Given that the bioavailability of circulating metabolites can influence brain metabolism and cognitive performance, we aimed to assess the effects of bariatric surgery on plasma metabolic profiles and cognitive performance. METHODS: We recruited 26 women undergoing gastric bypass surgery. We conducted anthropometric assessments and collected plasma samples for metabolomic analysis. A set of 4 cognitive tests were used to evaluate cognitive performance. Participants were reevaluated 1 year post-surgery. RESULTS: After surgery, attention capacity and executive function were improved, while immediate memory had deteriorated. Regarding metabolic profile, reduction of beta-tocopherol and increase of serine, glutamic acid, butanoic acid, and glycolic acid were observed. To better understand the relationship between cognitive function and metabolites, a cluster analysis was conducted to identify more homogeneous subgroups based on the cognitive performance. We identified cluster 1, which did not show changes in cognitive performance after surgery, and cluster 2, which showed improved attention and executive function, but reduced performance in the immediate memory test. Thus, cluster 2 was more homogeneous group that replicated the results of non-clustered subjects. Analysis of the metabolic profile of cluster 2 confirmed serine, glutamic acid, and glycolic acid as potential metabolites associated with cognitive performance. CONCLUSIONS: Metabolites identified in this study have potential for biomarkers and alternative therapeutic target to prevent obesity-related cognitive decline. KEY POINTS: • Attention capacity and executive function were improved 12 months post bariatric surgery. • Immediate memory was worsened 12 months post bariatric surgery. • Serine, glutamic acid, and glycolic acid are potential metabolites linked to the alteration of cognitive performance.

Severe Obesity in Women Can Lead to Worse Memory Function and Iron Dyshomeostasis Compared to Lower Grade Obesity.

Objective: Obesity is one of the modifiable risk factors for dementia. Insulin resistance, the abundance of advanced glycated end-products, and inflammation are some of the mechanisms associated with the lower cognitive performance observed in obesity. This study aims to evaluate the cognitive function of subjects with distinct degrees of obesity, comparing class I and II obesity (OBI/II) to class III obesity (OBIII), and to investigate metabolic markers that can distinguish OBIII from OBI/II. Study Design. This is a cross-sectional study, in which 45 females with BMI varying from 32.8 to 51.9 kg/m2 completed a set of 4 cognitive tests (verbal paired-associate test, stroop color, digit span, and Toulouse-Pieron cancellation test) and their plasma metabolites, enzymes, and hormones related to glycemia, dyslipidemia, and liver function, as well as the biomarkers of iron status, were concomitantly analyzed. Results: OBIII showed lower scores in the verbal paired-associate test compared to OBI/II. In other cognitive tests, both groups showed similar performance. OBIII presented a lower iron status compared to OBI/II based on total iron binding capacity, degree of transferrin saturation, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin. The levels of indicators for glycemia, liver function, and lipid metabolism were similar in both groups. Analysis of plasma metabolites showed that OBIII had lower levels of pyroglutamic acid, myoinositol, and aspartic acid and higher levels of D-ribose than OBI/II. Conclusion: Iron is an essential micronutrient for several metabolic pathways. Thus, iron dyshomeostasis observed in severe obesity may aggravate the cognitive impairment by altering metabolic homeostasis and enhancing oxidative stress. These findings can contribute to searching for biomarkers that indicate cognitive performance in the population with obesity.

Extreme bariatric endoscopy: stenting to reconnect the pouch to the gastrojejunostomy after a Roux-en-Y gastric bypass.

BACKGROUND: Among the possible complications of bariatric surgery, fistula and partial dehiscence of the gastric suture are well known. Reoperation often is required but results in significant morbidity. Endoscopic treatment of some bariatric complications is feasible and efficient. METHODS: A modified metallic stent was placed between the gastroaesophageal junction and the alimentary jejunal limb, allowing the passage of a nasoenteric feeding tube into the jejunal limb. RESULTS: Endoscopy showed disruption of nearly the entire staple line at the gastric pouch. The modified stent was placed and allowed wound healing. After 31 days, the stent had migrated and was removed endoscopically. Total closure of the fistula was reported 30 days afterward. CONCLUSIONS: Endoscopic treatment of some bariatric surgery complications is feasible and has been reported previously. This report presents a case of a serious leakage treated by placement of a self-expandable metal stent to bridge the fistula.