Physical activity and weight loss following bariatric surgery

Physical activity is a cornerstone in the medical management of obesity and could be important for weight loss following bariatric surgery. This review aims to describe the evolution of physical activity following massive weight loss induced by bariatric surgery, and to identify the relationship between physical activity and amount of weight loss. A literature search identified 20 publications (19 studies) reporting physical activity data in relation to bariatric surgery. All studies were observational. Self‐assessment of physical activity was used in all the studies. Objective measures (pedometry) were used in two studies. The time frame for physical activity assessment varied: before surgery in two publications, after surgery in nine, and longitudinal pre‐ to post‐operative evolution in nine. The latter nine publications found an increase in physical activity after bariatric surgery. In 10/13 studies where it was described, there was a positive relationship between physical activity level and amount of weight loss. In conclusion, observational evidence of self‐reported physical activity suggests that physical activity increases after bariatric surgery and that physical activity is associated with surgically induced weight loss. However, these findings warrant further evaluation using objective measures of physical activity and testing in controlled trials.     

Anorectal malformations: definitive surgery during adulthood

Background

Anorectal malformations (ARMs) are rarely seen in adults, since majority of cases are corrected in infancy or childhood. The aim of this study was to describe the profile of patients who underwent definitive surgery to correct their ARM in adulthood, and to discuss the outcomes of surgery (morbidity, mortality, and function).

Methods

This retrospective study included patients 18 years old and above, managed surgically by the Division of Colorectal Surgery at the Philippine General Hospital, University of the Philippines, Manila, from January 1, 2004, to December 31, 2012. Data from the Integrated Surgical Information System and the patients’ hospital records were used to fill out a Data Collection Form. Frequencies and percentages were then computed.

Results

Eight patients were included in the study. The most common reason for consult was recurrent urinary tract infection (UTI, 25%). One patient had an imperforate anus (IA) without a fistula, and 1 patient had IA with rectal atresia, and the 6 had an IA with a fistula. All but one (87.5%) of the patients had undergone a prior diversion in infancy or childhood. Definitive surgical procedures included posterior sagittal anorectoplasty (PSARP) in 3 patients, anal transposition in 2 patients, laparotomy with colocutaneous anastomosis in two patients, and laparotomy and PSARP in 1 patient. There were 3 cases (37.5%) of postoperative complications. These complications included ureteral injury, enterocutaneous fistula, anal stricture, rectal stricture, rectovesical fistula, and recurrent rectourethral fistula. There was no reported mortality. Five patients already had their stomas reversed at the time of this writing.

Conclusion

Our results showed that the rarity of the disease, limited surgical experience, and a technically challenging anatomy make the management of ARMs that persist into adulthood a formidable undertaking.

     

Plasminogen activator inhibitor 1 and visceral obesity during pronounced weight loss after bariatric surgery

Background and aimsElevated plasminogen activator inhibitor 1 (PAI-1) concentrations are a hallmark of obesity and are considered to contribute to the development of cardiovascular disease. As adipose tissue constitutes a major source for PAI-1 in obesity, we investigated the individual contribution of subcutaneous and intra-abdominal fat on PAI-1 concentrations during pronounced weight loss after bariatric surgery.Methods and resultsThirty-seven obese adults were examined before and 18 months after surgery. Abdominal fat distribution was determined by ultrasound, metabolic parameters and plasma PAI-1 levels by standard methods. BMI was reduced by 9.2 ± 4.9 kg/m², while total fat mass and visceral fat diameter (VFD) decreased by 20.7 ± 11.9 kg and 4.2 ± 2.3 cm, respectively. Concomitantly, PAI-1 levels diminished by 3.2 ± 5.6 ng/ml (all p ≤ 0.015). Change in PAI-1 levels was correlated with change in VFD (r = 0.441, p = 0.008), but not with subcutaneous fat diameter. In stepwise multiple regression analysis change in VFD was an independent predictor of change in PAI-1 concentrations. When adjusted for age and sex or total fat mass associations between PAI-1 and VFD remained significant.ConclusionWe demonstrate that VFD is a major determinant for PAI-1 concentrations during pronounced weight loss after bariatric surgery. Thus, significant reduction of visceral fat mass may contribute to the reduced cardiovascular morbidity and mortality after bariatric surgery by a concomitant decrease in PAI-1 concentrations.     

Mechanisms responsible for excess weight loss after bariatric surgery

Obesity has increased alarmingly in the United States and is increasing in many countries of the world. Because obesity is an important risk factor for type 2 diabetes and other chronic diseases, it is important to develop approaches to counter the rapid increase in adiposity. One approach is bariatric surgery, the most successful clinical intervention known for treating obesity. Surgery can result in impressive weight loss and improvement of obesity-related comorbidities. Yet the mechanisms responsible for this remarkable effect of surgery remain controversial. It is now clear that caloric restriction, per se, does not explain all the reduction in stored fat mass after surgery. A number of gastrointestinal hormones, including glucagon-like peptide (GLP)-1, peptide YY, oxyntomodulin, GLP-2, glucose-dependent insulinotropic polypeptide, ghrelin, and others, can play roles in energy homeostasis and could be involved in bariatric-surgery-related weight loss and weight loss maintenance. Vagal innervation may play a role. In addition, there may be other yet-uncharacterized factors that could participate. This review discusses the possible roles of these hormonal mechanisms in various types of bariatric surgery to help elucidate some of the potential mechanisms at play in short-term and long-term post-bariatric surgery weight loss. Understanding such mechanisms could lead to new and efficacious means to control or even reduce the epidemic of obesity.     

Mechanisms of bariatric surgery for weight loss and diabetes remission

Obesity and type 2 diabetes(T2D) lead to defects in intestinal hormones secretion, abnormalities in the composition of bile acids (BAs), increased systemic and adipose tissue inflammation, defects of branched-chain amino acids (BCAAs) catabolism, and dysbiosis of gut microbiota. Bariatric surgery (BS) has been shown to be highly effective in the treatment of obesity and T2D, which allows us to view BS not simply as weight-loss surgery but as a means of alleviating obesity and its comorbidities, especially T2D. In recent years, accumulating studies have focused on the mechanisms of BS to find out which metabolic parameters are affected by BS through which pathways, such as which hormones and inflammatory processes are altered. The literatures are saturated with the role of intestinal hormones and the gut-brain axis formed by their interaction with neural networks in the remission of obesity and T2D following BS. In addition, BAs, gut microbiota and other factors are also involved in these benefits after BS. The interaction of these factors makes the mechanisms of metabolic improvement induced by BS more complicated. To date, we do not fully understand the exact mechanisms of the metabolic alterations induced by BS and its impact on the disease process of T2D itself. This review summarizes the changes of intestinal hormones, BAs, BCAAs, gut microbiota, signaling proteins, growth differentiation factor 15, exosomes, adipose tissue, brain function, and food preferences after BS, so as to fully understand the actual working mechanisms of BS and provide nonsurgical therapeutic strategies for obesity and T2D.     

Pseudoachalasia secondary to bariatric surgery

Secondary achalasia may result from diseases that either infiltrate or compress the lower esophageal sphincter to create an increased high‐pressure zone and subsequent esophageal body changes. With bariatric surgery, a potential high‐pressure zone is created by a sleeve, band, or bypass just distal to the esophagus. We report four patients who years after a bariatric procedure developed dysphagia followed by esophageal body radiographic and/or manometric features of achalasia. In addition, each of these patients responded symptomatically to endoscopic or surgical therapy either which lowered this high‐pressure zone. Furthermore, review of prior cases in the literature suggests this has occurred before. Physicians should be aware of this association but further study is needed on its true prevalence.     

Aortic atresia: survival to adulthood without surgery

Aortic atresia is a rare congenital cardiac defect. It usually leads to death in the neonatal period. A patient with aortic atresia has survived to the age of 24 years without any surgical procedure. In view of the uncertain results of reconstructive surgery this case may have therapeutic implications.     

Mechanisms for weight gain during blood glucose normalization

Secondary failure to dietary and maximal oral treatment leads to insulin therapy in type 2 diabetic patients. However, weight gain is a frequent side effect of insulin therapy in these patients. Mechanisms for this weight gain are complex. Insulin 1) reduces glycosuria and its caloric expenditure; 2) stimulates the stockage of fatty acids into triglycerides in adipose tissue, thus favoring an increase in adipose mass; 3) yields a positive nitrogen balance through an inhibition of muscle proteolysis, thus favoring an increase in lean mass. Most studies report an average 6 kg weight gain during the first year following the initiation of insulin therapy in type 2 diabetic patients. Analysing body composition variations shows that weight gain results both from an increase in fat mass (mean 63%) and an increase in lean mass (mean 37%). Preexisting obesity does not influence this weight gain. Finally, the 10 year-follow up of UKPDS showed a beneficial effect of insulin therapy on microangiopathy prevention, without increasing cardiovascular mortality as compared with type 2 diabetic patients on oral treatment. Thus, while weight gain seems mandatory, it should not refrain from initiating insulin therapy in poorly controlled type 2 diabetic patients, as its expected beneficial effects on the prevention of microangiopathy seem well established.     

Relationship between dietary macronutrient composition with weight loss after bariatric surgery: A systematic review

This systematic review evaluated the relationship between macronutrient intake and weight loss after bariatric surgery (BS). The MEDLINE/Pubmed, EMBASE, COCHRANE/CENTRAL, and SCOPUS databases were accessed in August 2021 to search for eligible articles: original publications with adults undergoing BS and indicating the relationship between macronutrients and weight loss. Titles that did not meet these criteria were excluded. The review was written according to the PRISMA guide, and the risk of bias was according to the Joanna Briggs manual. Data were extracted by one reviewer and checked by another. Eight articles with 2.378 subjects were included. The studies indicated a positive relationship between weight loss and protein intake after BS. Prioritization of protein followed by carbohydrates with a lower percentage of lipids favors weight loss and increases weight stability after BS. Among the results found, a 1% increase in protein intake raises the probability of obesity remission by 6%, and high-protein diet increase 50% weight loss success. Limitations are the methods of included studies and review process. It is concluded that high-protein intake >60 g a 90 g/day may favor weight loss and maintenance after BS, but it is relevant to balance the other macronutrients.     

Impact of postoperative weight gain on complications after liver surgery

BackgroundRecent data has suggested that excessive perioperative weight gain may be associated with adverse outcomes after abdominal surgery, but this observation remains unexplored following liver surgery. The present study aimed to investigate the predictive value of perioperative weight fluctuation in predicting complications after liver surgery.MethodsRetrospective monocentric analysis of consecutive patients undergoing liver surgery between 2010 and 2016. Patients without available perioperative weight were excluded. Test variable was postoperative weight change (ΔWeight) measured on day 2 (POD2). Primary outcome was postoperative major morbidity according to Clavien classification (grades III–IV). Secondary outcomes were overall complications, Comprehensive Complication Index (CCI) and length of hospital stay (LoS). Area under the receiver operating characteristic curve (AUROC) and logistic regression with multivariable analysis were performed.ResultsA total of 181 patients met the inclusion criteria. Major and overall postoperative complications were reported in 25 (14%) and 87 (48%) patients, respectively. On POD2, median ΔWeight was 2.6 Kg (IQR: 1.1–4.0). Patients with major complications showed increased ΔWeight of 4.2 Kg (IQR: 2.7–5.7), compared to 2.3 Kg (IQR: 0.9–3.7) in patients without major complications (p < 0.001). AUROC of ΔWeight for major complications was 0.74, determining an optimal cut-off of 3.5 Kg, which yielded a negative predictive value of 94%. Multivariable analysis identified ΔWeight ≥3.5 Kg as independent predictor of major complications (OR, 4.73; 95% CI, 1.51–14.80; p = 0.008).ConclusionΔWeight ≥3.5 Kg was independently associated with major complications after liver surgery. Perioperative fluctuation of weight appears as an important predictor of adverse outcomes after liver surgery.     

Nutritional deficiency of selenium secondary to weight loss (bariatric) surgery associated with life-threatening cardiomyopathy

This case report and others demonstrate the importance of selenium awareness in patients with long-term total parenteral nutrition. Assessment of cardiac function in such cases by echocardiography is critical to the detection and management of this potentially life-threatening complication in this patient population.     

Sexual abuse in bariatric surgery candidates – impact on weight loss after surgery: a systematic review

Bariatric surgery is becoming more and more influential as efficient weight loss therapy for the morbidly obese. As many studies propose a relationship between sexual abuse and obesity in general, but especially with regard to weight regain after successful weight loss, sexual abuse might also have a crucial impact on the outcome of the surgical procedures. This review examines the literature comparing weight loss after bariatric surgery in sexually abused and non‐abused individuals. We conducted a systematic electronic literature search covering PubMed/Medline, ScienceDirect, PsychInfo and Web of Science. While 13 studies examined prevalence rates of sexual abuse among bariatric patients, eight studies explicitly investigated the effect of sexual abuse on surgery outcome. We hypothesized that individuals with a history of sexual abuse lose less weight compared to individuals with no such abuse history. At first glance, only three out of eight studies demonstrated significantly reduced weight loss in the sexually abused patients. However, a closer investigation of all studies revealed that patients with abuse experiences may indeed tend to lose less weight initially. Still, this sub‐population apparently benefits from the surgical procedure, as revealed by increased weight loss over time. Reasons for these mixed results are discussed, as well as the clinical implications that can be drawn from these studies.     

Aortic atresia: survival to adulthood without surgery.

Aortic atresia is a rare congenital cardiac defect. It usually leads to death in the neonatal period. A patient with aortic atresia has survived to the age of 24 years without any surgical procedure. In view of the uncertain results of reconstructive surgery this case may have therapeutic implications.     

Effects of weight loss after bariatric surgery on epicardial fat measured using echocardiography

Epicardial fat assessed using echocardiography is associated with abdominal visceral adipose tissue and cardiovascular risk factors. Because of its location, epicardial fat may directly affect the coronary vasculature and myocardium through local secretion of bioactive molecules. This study examines the effects of weight loss after bariatric surgery on epicardial adipose tissue in patients with severe obesity. Clinical data and echocardiograms of 23 patients with severe obesity who had echocardiograms recorded before and 8.3 +/- 3.7 months after undergoing bariatric surgery were retrospectively reviewed. Epicardial fat thickness was measured as the hypoechoic space anterior to the right ventricle in both the parasternal long- and short-axis views, and an average was obtained. At baseline, patients had increased epicardial fat compared with normal-weight controls matched for age, gender, and ethnicity (5.3 +/- 2.4 vs 3.0 +/- 1.1 mm, p <0. 001). Epicardial fat thickness was associated with the patient's initial weight in severely obese patients (r = 0.51, p = 0.011). Patients lost an average of 40 +/- 14 kg after surgery. Epicardial fat thickness decreased from 5.3 +/- 2.4 to 4.0 +/-1.6 mm (p = 0.001). Change in epicardial fat correlated with initial epicardial fat thickness measured using echocardiography (r = 0.71, p <0.001). In conclusion, epicardial fat thickness decreases in severely obese patients who have substantial weight loss after bariatric surgery. Measuring epicardial fat thickness using echocardiography may be useful to monitor visceral fat loss with weight reduction therapies.     

Genetic variants associated with weight loss and metabolic outcomes after bariatric surgery: A systematic review

The extent to which genetic variations contribute to interindividual differences in weight loss and metabolic outcomes after bariatric surgery is unknown. Identifying genetic variants that impact surgery outcomes may contribute to clinical decision making. This review evaluates current evidence addressing the association of genetic variants with weight loss and changes in metabolic parameters after bariatric surgery. A search was conducted using Medline, Embase, Scopus, Web of Science, and Cochrane Library. Fifty-two eligible studies were identified. Single nucleotide polymorphisms (SNPs) at ADIPOQ (rs226729, rs1501299, rs3774261, and rs17300539) showed a positive association with postoperative change in measures of glucose homeostasis and lipid profiles (n = 4), but not with weight loss after surgery (n = 6). SNPs at FTO (rs11075986, rs16952482, rs8050136, rs9939609, rs9930506, and rs16945088) (n = 10) and MC4R (rs11152213, rs476828, rs2229616, rs9947255, rs17773430, rs5282087, and rs17782313) (n = 9) were inconsistently associated with weight loss and metabolic improvement. Four studies examining the UCP2 SNP rs660339 reported associations with postsurgical weight loss. In summary, there is limited evidence supporting a role for specific genetic variants in surgical outcomes after bariatric surgery. Most studies have adopted a candidate gene approach, limiting the scope for discovery, suggesting that the absence of compelling evidence is not evidence of absence.     

Review: long-term impact of bariatric surgery on body weight, comorbidities, and nutritional status

CONTEXT: The number of patients who undergo Roux-en-Y gastric bypass (RYGB) and gastric banding (GB) surgeries has increased dramatically over the past decade, yet the long-term impact of these surgeries on body weight, comorbidities, and nutritional status remains unclear, as do the mechanisms of weight regain. EVIDENCE ACQUISITION: The articles were found via PubMed searches. To review the impact of bariatric surgery on weight maintenance and comorbidities, only articles with a postoperative follow-up of 3 yr or longer were included. The articles on nutritional status had a follow-up of 12 months or longer. CONCLUSIONS: RYGB and GB surgeries lead to substantial weight loss in individuals with morbid obesity. However, significant weight regain occurs over the long term, and according to the only well-designed prospective controlled study, the improvement in comorbidities associated with weight loss mitigates in the long term on weight regain. There is some evidence from a retrospective study that RYGB surgery is associated with a modest decrease in long-term mortality. These results remain to be substantiated by well-designed, long-term, randomized and prospective controlled studies. The mechanisms that lead to weight regain need to be further examined and may include increase in energy intake due to enlargement of stoma and adaptive changes in the levels of gut and adipocyte hormones such as ghrelin and leptin, which regulate energy intake; decrease in physical activity; changes in energy expenditure; and other factors. In addition to weight regain, RYGB surgery is associated with frequent incidence of iron, vitamin B12, folate, calcium, and vitamin D deficiency, which requires regular supplementation and monitoring.