Effects Of Weight Loss Surgery Research Articles

O024 Weight loss surgery in obese patients with obstructive sleep apnoea is associated with increased inter-hemispheric electroencephalographic coherence

Abstract Introduction Electroencephalogram (EEG) analysis of obstructive sleep apnoea (OSA) patients has shown reductions in both delta band frequency power and interhemispheric coherence. Weight loss surgery is increasing in popularity and is often effective in reducing the symptoms and severity of OSA. No study has examined the effects of weight loss surgery on the sleep EEG of OSA patients. Methods Twenty patients underwent diagnostic polysomnography (PSG) prior to- and twelve months after weight loss surgery. Quantitative EEG analysis was conducted to calculate spectral power (fast fourier transform with four second overlapping windows) as well as amplitude and phase coherence between the two hemispheres (C3/C4 electrodes). Results Weight loss surgery was successful in reducing weight (137±17 kg vs 102±17kg P<0.001 for pre- and post-surgery, respectively), and OSA severity (Apnoea-Hypopnoea Index: 26±15 events/hour vs 10±12 events/hour P<0.001 for pre- and post-surgery, respectively). Stage N1 proportions were slightly decreased (12±7% vs 9±8%; P=0.039 for pre- and post-surgery, respectively) but all other stages were unchanged. Increases in interhemispheric phase coherence was observed following weight loss surgery, with significant changes observed in theta (-0.07±0.09 degrees vs -0.03±0.03 degrees P=0.035), alpha (-0.12±0.13 degrees vs -0.03±0.06 degrees P=0.008), sigma (-0.19±0.18 degrees vs -0.07±0.07 degrees P=0.011) and beta (-0.29±0.25 degrees vs -0.11±0.09 degrees P=0.004) band frequencies. There were no differences in EEG spectral power or interhemispheric amplitude coherence. Discussion Sleep EEG coherence, a putative marker of neurocognitive susceptibility in OSA, improves following weight loss surgery. Further studies are needed to determine the functional consequences of these EEG changes.

S1255 Effect of Weight Loss Surgery and Weight Loss Medications on the Risk of Colorectal Cancer: A Nationwide Population-Based Cohort Study

S1255 Effect of Weight Loss Surgery and Weight Loss Medications on the Risk of Colorectal Cancer: A Nationwide Population-Based Cohort Study

Effect of Weight Loss Surgery on Biomarkers of Angiogenesis in Obese Patients

BackgroundThe present study aims to clarify the effects of weight loss on biomarkers associated with angiogenesis in patients who underwent laparoscopic sleeve gastrectomy (SG) or adjustable gastric banding (LAGB) in the 12-month follow-up study.Materials and MethodsWe studied 24 obese patients who underwent laparoscopic weight loss surgery, 13 of whom underwent SG and 11 of whom underwent LAGB. We evaluated the circulating level of angiogenesis biomarkers preoperatively and 12 months after surgery.ResultsBefore surgery, the following angiogenic circulating factors were significantly higher than those of healthy subjects: angiopoietin 2 (ANG-2) (p < .05), granulocyte colony-stimulating factor (G-CSF) (p < .05), hepatocyte growth factor (HGF) (p < .01), platelet endothelial cell adhesion molecule (PECAM-1) (p < .01), and vascular endothelial growth factor (VEGF) (p < .05). The following angiogenesis biomarkers decreased significantly after weight loss compared with their baseline values: ANG-2 (p < .05), follistatin (p < .05), HGF (p < .01), PECAM-1 (p < .01), and VEGF (p < .05). There were no significant differences in the circulating levels of angiogenesis biomarkers between individuals who underwent SG and those who underwent LAGB; however, HGF, PECAM-1, and VEGF tended to be lower after SG. %BMI correlated negatively with HGF, PECAM-1, and VEGF. A similar significant negative correlation was found for %WL and %EWL. WHR correlated with PDGF-B and VEGF.ConclusionsWe concluded that weight loss surgery induces the changes of circulating levels of angiogenesis biomarkers in obese patients. The changes in angiogenesis status in obese patients who lost weight after bariatric surgery depended on the amount of weight loss.

Bariatric surgery and kidney disease outcomes in severely obese youth

Bariatric surgery, an emerging treatment for severely obese youth with and without T2D, provides marked improvement in insulin resistance, beta-cell function, and central adiposity. Further, preliminary data suggest that bariatric surgery also results in significant improvement in markers of obesity-related nephropathy and DKD, beyond that which can be achieved with current medical interventions. Yet, the mechanisms whereby bariatric surgery attenuates kidney disease remain unclear. This review summarizes the data on the effects of bariatric surgery on obesity-related nephropathy and DKD in youth with and without T2D, in addition to potential mechanisms underlying the nephroprotective effects of weight loss surgery and how these may differ in Roux-en-Y gastric bypass vs. vertical sleeve gastrectomy. Finally, we discuss potential future non-surgical therapies to mitigate kidney disease.

Effect of Weight Loss Surgery on Stem Cells.

Effect of Weight Loss Surgery on Stem Cells.

A580 Sagittal Abdominal Diameter in Adolescents: Association with Metabolic Syndrome Severity and Effects of Weight Loss Surgery

A580 Sagittal Abdominal Diameter in Adolescents: Association with Metabolic Syndrome Severity and Effects of Weight Loss Surgery

Metabolic Surgery for Hypertension in Patients With Obesity.

The global prevalence of overweight and obesity has risen substantially over the past 4 decades and is accompanied by an increasing burden of cardiovascular risk factors such as hypertension. Metabolic surgery is the most effective method to treat obesity and may further improve associated conditions. Although most research has been directed toward the glycemic effects of weight loss surgery, there has been a growing interest in exploring its potential blood pressure-reducing properties. Systematic reviews and meta-analyses based primarily on observational data have suggested that metabolic surgery may aid in controlling hypertension. Only one randomized controlled trial specifically addressing this concept has been conducted, though supportive of the findings from observational studies. We review contemporary procedures for weight loss and their effects on cardiometabolic risk, particularly hypertension. In addition, we describe potential pathophysiological mechanisms and the effects of metabolic surgery on cardiovascular events and mortality.

Changes in gastrointestinal symptoms and food tolerance 6\xa0months following weight loss surgery: associations with dietary changes, weight loss and the surgical procedure

BackgroundGastrointestinal (GI) co-morbidity is common in obese patients, but the effect of weight loss surgery on GI symptoms is incompletely elucidated. The aims of the present study were to explore changes in GI symptoms and food tolerance following weight loss surgery and to study whether such changes were associated with dietary modifications and/or the type of surgical procedure [Roux-en-Y Gastric Bypass (RYGB) versus Vertical Sleeve Gastrectomy (VSG)].MethodsParticipants: Patients with morbid obesity scheduled for weight loss surgery.The patients filled in paper-based questionnaires addressing diet, GI symptoms (bloating, pain, satiety, constipation and diarrhea) and food tolerance/quality of alimentation (satisfaction about current food intake, tolerance to specific foods and frequency of vomiting/regurgitation/reflux) 6 months prior to and 6 months after the surgery. Patients with pre-existing major GI co-morbidity or previous major GI surgery were excluded.ResultsFifty-four patients (RYGB/VSG: 43/11) were included. Constipation and satiety increased and food tolerance decreased significantly after the surgery (all p-values < 0.05). The increase in satiety was significantly more notable after VSG than after RYGB (p < 0.05).The increase in satiety also correlated with an overall reduction in food tolerance (rho: -0.488, p < 0.01). Divergent changes were seen in the frequency of vomiting/regurgitation/reflux, with a decline after RYGB (p = 0.01) and an increase after VSG (p = 0.06). Intakes of energy, macronutrients, fiber and fluid decreased significantly after the surgery (all p-values < 0.05), but did not correlate with the changes in constipation, satiety or food tolerance (all p-values > 0.05). Pre-operatively, total energy intake correlated with bloating and abdominal pain (rho = 0.343 and 0.310 respectively, p < 0.05 for both), but these correlations did not persist 6 months after the surgery (rho = 0.065 and 0.054 respectively, p > 0.05 for both).ConclusionA high caloric intake may explain some of the GI symptoms experienced by non-operated obese patients. The worsening or new-onset of symptoms post-surgery is likely due to anatomical or physiological alterations following surgery. The increase in satiety and the decrease in food tolerance are likely explained by the restrictive nature of the surgeries, as satiety increased more after VSG than after RYGB and correlated with an overall reduction in food tolerance.

Efficacy of oral glucose tolerance testing of pregnant women post bariatric surgery

Worldwide, a large proportion of childbearing women are overweight or obese, and it is becoming increasingly common for pregnant women to have undergone bariatric surgery before conceiving. Women with a history of sleeve gastrectomy may not be able to undertake the oral glucose tolerance test, due to the risk of dumping syndrome. There is limited research on the effects of weight loss surgery on the pregnancy oral glucose tolerance test and conducting this test on a woman who has had bariatric surgery may be an inadequate form of diagnosing gestational diabetes mellitus. A cost-effective alternative to an oral glucose tolerance test is to monitor pre-and post-meal blood glucose levels.

Gastric Bypass and Influence on Improvement of NAFLD.

Obesity is recognized as a chronic and recurring disease, often accompanied by other weight-related comorbid conditions such as obstructive sleep apnea, hypertension, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD). This chapter will seek to focus on the effect of weight loss surgery (WLS), in particular Roux-en-Y gastric bypass (RYGB), on NAFLD. Among several modalities available to treat NAFLD, the one most likely to achieve rapid, significant, and sustained improvement of liver disease is WLS. The most commonly studied WLS procedure at this time is RYGB, and there is significant evidence that this is a safe and effective procedure both for weight loss and to bring about improvement of multiple associated comorbid conditions, including NAFLD. Further research focusing on non-surgical approaches that might mimic the effect of WLS on liver pathology is needed.

Estimated GFR Before and After Bariatric Surgery in CKD

Several reviews have recently detailed the beneficial effects of weight loss surgery for kidney function. However, these studies have a number of limitations, including small sample size, few done in chronic kidney disease (CKD) stages 3 and 4, and many not including the main bariatric surgery procedures used in the United States today. This was an observational retrospective cohort study comparing propensity score-matched bariatric surgery patients and nonsurgery control patients who were referred for, but did not have, surgery. Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy were also compared using propensity matching. Patients (714 surgery patients; 714 controls) were from a large integrated health care system, a mean of 58±8 (SD) years old, and mostly women (77%) and non-Hispanic whites (56%) and had diabetes mellitus (66%) and/or hypertension (91%). Predictors at the time of surgery or referral to surgery were age, sex, race/ethnicity, weight, and presence of diabetes and/or hypertension. The primary outcome for this study was change in estimated glomerular filtration rate (eGFR) from serum creatinine level over a median 3-year follow-up period. Serum creatinine was used to calculate eGFR using the CKD-EPI (CKD Epidemiology Collaboration) creatinine equation. Surgery patients had 9.84 (95% CI, 8.05-11.62) mL/min/1.73m2 greater eGFRs than controls at a median 3 years' follow-up and RYGB patients had 6.60 (95% CI, 3.42-9.78) mL/min/1.73m2 greater eGFRs than sleeve gastrectomy patients during the same period. This study is limited by its nonrandomized observational study design, estimation of GFR, and large changes in muscle mass, which may affect serum creatinine level independent of changes in kidney function. Bariatric surgery, especially the RYGB procedure, results in significant improvements for up to 3 years in eGFRs for patients with CKD stages 3 and4.

The Short-Term Effect of Weight Loss Surgery on Volumetric Breast Density and Fibroglandular Volume

PurposeObesity and breast density are both associated with an increased risk of breast cancer and are potentially modifiable. Weight loss surgery (WLS) causes a significant reduction in the amount of body fat and a decrease in breast cancer risk. The effect of WLS on breast density and its components has not been documented. Here, we analyze the impact of WLS on volumetric breast density (VBD) and on each of its components (fibroglandular volume and breast volume) by using three-dimensional methods.Materials and MethodsFibroglandular volume, breast volume, and their ratio, the VBD, were calculated from mammograms before and after WLS by using Volpara™ automated software.ResultsFor the 80 women included, average body mass index decreased from 46.0 ± 7.22 to 33.7 ± 7.06 kg/m2. Mammograms were performed on average 11.6 ± 9.4 months before and 10.1 ± 7 months after WLS. There was a significant reduction in average breast volume (39.4 % decrease) and average fibroglandular volume (15.5 % decrease), and thus, the average VBD increased from 5.15 to 7.87 % (p < 1 × 10−9) after WLS. When stratified by menopausal status and diabetic status, VBD increased significantly in all groups but only perimenopausal and postmenopausal women and non-diabetics experienced a significant reduction in fibroglandular volume.ConclusionsBreast volume and fibroglandular volume decreased, and VBD increased following WLS, with the most significant change observed in postmenopausal women and non-diabetics. Further studies are warranted to determine how physical and biological alterations in breast density components after WLS may impact breast cancer risk.

Effect of weight loss surgery on cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke in overweight and obese post-menopausal women (P1.071)

Effect of weight loss surgery on cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke in overweight and obese post-menopausal women (P1.071)

Effect of weight loss surgery on cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke in overweight and obese post-menopausal women (I12-5C)

Effect of weight loss surgery on cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke in overweight and obese post-menopausal women (I12-5C)

The effects of weight loss surgery on blood rheology in severely obese patients

BackgroundThe effects of dieting on blood rheology in obese individuals suggest that improving the rheologic profiles depends on the amount of weight lost and its long-term maintenance. The aim of this study was to evaluate the effects of weight loss after surgery on blood rheology at 12-month follow-up. MethodsWe studied 38 obese patients who underwent laparoscopic weight loss surgery, 22 of whom had sleeve gastrectomy (SG) and 16 of whom had gastric banding (LAGB). We evaluated rheologic parameters such as blood viscosity, plasma viscosity, and erythrocyte deformability (as measured by elongation index [EI]) preoperatively and 12 months after surgery. ResultsWhole blood viscosity at 150 s-1 shear rate (P<.01) and 300 s-1 shear rate (P<.05), blood viscosity corrected to a standard hematocrit at both shear rates (P<.0005 and P<.005, respectively), and plasma viscosity (P<.005) were significantly reduced after surgery. EI evaluated at different shear stresses (18.49–60.03 Pa) decreased (P<.005) 12 months after surgery. There were significantly decreased EI and blood viscosity corrected to a standard hematocrit after SG (P<.005 and P<.05) and LAGB (P = .0621 and P<.05), but plasma viscosity significantly decreased only after SG (P<.005). Blood viscosity at both shear rates correlated with plasma viscosity (r = .51, P<.005 and r = .5, P<.005). Plasma viscosity correlated positively with body mass index (r = .57; P<.0005) and negatively with percentage of excess weight lost (r = –.56; P< .005). ConclusionsThis study found that weight loss after bariatric surgery induced improvement in blood rheology in obese patients at 12 months after surgery. The increased red blood cell rigidity after surgery requires further study because the physiologic importance of this change has not yet been established.

Abstract T P138: Effect Of Weight Loss Surgery On Cardiovascular Death, Nonfatal Myocardial Infarction, Or Nonfatal Stroke In Overweight And Obese Post-menopausal Women

Background: Weight loss surgery has been used for various indications but the effects of such surgery on cardiovascular events remain understudied. Methods: We analyzed the data from Women's Health Initiative (WHI) observational study. The participants in the observational study were 93,676 women aged 50-79 years who were recruited from September 1994 to December 1998, with annual follow-up through August 14, 2009 (an average of 8 years). Cox proportional hazards analysis was used to examine the modifying effect of weight loss surgery (entered as an interaction) on the relationship between baseline body mass index categorized into various obesity groups and the outcome of total cardiovascular disease defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. Results: Weight loss surgery occurred in 42 (0.2%) of the 25406 participants who were overweight, obese or morbidly obese at baseline evaluation. Weight loss surgery was performed over a mean period (month’s ±SD) of 38.0 ±3.2 from baseline assessment. The cumulative endpoint of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke was seen in 3 of 42 and 1191 of 25364 participants who did or did not undergo weight loss surgery, respectively (p=0.5). In the multivariate analysis, weight loss surgery (interaction term p=0.6) modified the relationship between categories of obesity and cardiovascular endpoint (relative risk 1.1, 95% confidence interval 1.0 -1.1, p=0.02), after adjusting for age/gender, hypertension, diabetes mellitus, cigarette smoking, and hyperlipidemia. Conclusions: We did not observe any significant effect of weight loss surgery on reduction of cardiovascular endpoint of death, nonfatal myocardial infarction, or nonfatal stroke.

Updates in weight loss surgery and gastrointestinal peptides.

Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy are referred to as 'metabolic surgery' due to hormonal shifts with impacts on diabetes remission and weight loss. The purpose of this review is to summarize recent findings in mechanisms underlying beneficial effects of weight loss surgery. Importantly, gut hormone secretion is altered after RYGB and sleeve gastrectomy due to accelerated transit of nutrients to distal parts of the small intestine, leading to excessive release of L-cell peptide hormones [e.g. glucagon-like peptide-1 (GLP-1), peptide YY].Improved glucose metabolism after RYGB and sleeve gastrectomy involves several mechanisms: early increased hepatic insulin sensitivity, resulting from reduced liver fat content in response to the postoperative caloric restriction, improved beta-cell function mediated by exaggerated postprandial GLP-1 secretion; as demonstrated by relapse of impaired glucose tolerance in studies blocking the GLP-1 receptor by exendin 9-39, and later after major weight loss increased peripheral insulin sensitivity. Gut hormone secretion changes towards a more anorectic profile and is likely important for less caloric intake and weight loss. Changes in gut hormone secretion after RYGB and sleeve gastrectomy surgery induce the beneficial effects on weight and glycemic control through the influence on appetite regulation and insulin secretion.

Effects of glucagon like peptide-1 to mediate glycemic effects of weight loss surgery.

To date, weight loss surgeries are the most effective treatment for obesity and glycemic control in patients with type 2 diabetes. Roux-en-Y gastric bypass surgery (RYGB) and sleeve gastrectomy (SG), two widely used bariatric procedures for the treatment of obesity, induce diabetes remission independent of weight loss while glucose improvement after adjustable gastric banding (AGB) is proportional to the amount of weight loss. The immediate, weight-loss independent glycemic effect of gastric bypass has been attributed to postprandial hyperinsulinemia and an enhanced incretin effect. The rapid passage of nutrients into the intestine likely accounts for significantly enhanced glucagon like-peptide 1 (GLP-1) secretion, and postprandial hyperinsulinemia after GB is typically attributed to the combined effects of elevated glucose and GLP-1. For this review we focus on the beneficial effects of the three most commonly performed bariatric procedures, RYGB, SG, and AGB, on glucose metabolism and diabetes remission. Central to this discussion will be the extent to which the effects of surgery are mediated by GLP-1. Better understanding of these mechanisms could provide insight to development of novel therapeutic strategies for treatment of diabetes as well as refinement of surgical techniques.

The negative effects of obesity and poor glycemic control on cognitive function: a proposed model for possible mechanisms.

Obesity has reached epidemic proportions and is a contributor to many adverse health outcomes, including increased risk for dementia and adverse structural and functional brain changes. Milder forms of cognitive impairment in multiple domains can also be found in obese individuals of all ages that are believed to stem from brain abnormalities long prior to onset of neurologic conditions such as dementia. However, the mechanisms for adverse brain changes and subsequent cognitive dysfunction in obesity are complex and poorly understood. This paper proposes a possible etiologic model for obesity associated cognitive impairment with emphasis on the role of poor glycemic control and conditions like type 2 diabetes mellitus. Clinical implications associated with treatment of obesity in persons with cognitive deficits in addition to the cognitive promoting effects of weight loss surgery are also discussed.

The effect of bariatric surgery on gout: a comparative study

BackgroundObesity is a risk factor for the development of gout. An increased incidence of early gouty attacks after bariatric surgery has been reported, but the data is sparse. The effect of weight loss surgery on the behavior of gout beyond the immediate postoperative phase remains unclear. The objective of this study was to evaluate the pre- and postoperative frequency and features of gouty attacks in bariatric surgery patients. MethodsCharts were reviewed to identify patients who had gout before bariatric surgery. Demographic and gout-related parameters were recorded. The comparison group consisted of obese individuals with gout who underwent nonbariatric upper abdominal procedures. ResultsNinety-nine morbidly obese patients who underwent bariatric surgery had gout. The comparison group consisted of 56 patients. The incidence of early gouty attack in the first month after surgery was significantly higher in the bariatric group than the nonbariatric group (17.5% versus 1.8%, P = .003). In the bariatric group, 23.8% of patients had at least one gouty attack during the 12-month period before surgery, which dropped to 8.0% during postoperative months 1–13 (P = .005). There was no significant difference in the number of gouty attacks in the comparison group before and after surgery (18.2% versus 11.1%, P = .33). There was a significant reduction in uric acid levels 13-months after bariatric surgery compared with baseline values (9.1±2.0 versus 5.6±2.5 mg/dL, P = .007). ConclusionThe frequency of early postoperative gout attacks after bariatric surgery is significantly higher than that of patients undergoing other procedures. However, the incidence decreases significantly after the first postoperative month up to 1 year.