Comparison of changes in lipid profile after bilio-intestinal bypass and gastric banding in patients with morbid obesity

Targeting bile acid metabolism in obesity reduction: A systematic review and meta-analysis

A systematic review and meta-analysis was conducted of studies that address the association of bile acid (BA) with obesity and of studies on the effects of treatment in patients with obesity on BA metabolism, assessed from systemic BA, fibroblast growth factor 19 (FGF19), 7α-hydroxy-4-cholesten-3-one (C4) level, and faecal BA. We searched PubMed, Embase, and the Cochrane Library from inception to 1 August 2019 using the keywords obesity, obese, body mass index, and overweight with bile acid, FGF19, FXR, and TGR5. Two reviewers independently searched, selected, and assessed the quality of studies. Data were analysed using either fixed or random effect models with inverse variance weighting. Of 3771 articles, 33 papers were relevant for the association of BA with obesity of which 22 were included in the meta-analysis, and 50 papers were relevant for the effect of obesity interventions on BA of which 20 were included in the meta-analysis. Circulating fasting total BA was not associated with obesity. FGF19 was inversely and faecal BA excretion was positively associated with obesity. Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) modulated BA metabolism, ie, increased BA and FGF19. Our results indicate that BA metabolism is altered in obesity. Certain bariatric surgeries including RYGB and SG modulate BA, whether these underlie the beneficial effect of the treatment should be investigated.

Lipid profile change after bariatric surgeries: laparoscopic gastric plication versus mini gastric bypass

INTRODUCTION

Bariatric surgeries are known to have profound effects on lipid profile. Laparoscopic gastric plication (LGP) has been shown to have a comparable effect on weight loss rather than Roux-en-Y gastric bypass (RYGB) and mini gastric bypass (MGB). But the post-operative effect on lipid profile is not well-compared. We aimed to compare post-operative lipid profile change after LGP and MGB.

METHODS

In a retrospective analysis, we reviewed 91 patients for at least 12 months. Patients were assigned to undergo either LGP (71 patients) or MGB (20 patients). Preoperative and postoperative visits were accomplished and weight, BMI, fasting blood glucose (FBG) and lipid profile including triglyceride (TG), and total cholesterol (TC) levels were repeatedly measured. Follow up rate for the first year was 100%.

RESULTS

LGP significantly decreased both TG and TC levels in each follow up (all p values < .05). The same trends were observed in BMI reduction, total body weight loss percentage, and FBG. When comparing either TC or TG level between LGP and MGB, there was just one statistically significant result in TG reduction at 6 months (p value = .042) while MGB showed more reduction. All other variables in different follow up visits were not significantly different between two techniques.

CONCLUSIONS

LGP would result in lipid profile improvement lasting at least for one year. Lipid-lowering effect seems to be similar between LGP and MGB. This lipid-lowering property and weight reduction might be indicative that LGP is an alternative for RYGB and MGB in selective patients.

A 9 years comparison of weight loss, disappearance of obesity, and resolution of diabetes mellitus with biliointestinal bypass and with adjustable gastric banding: experience of a collaborative network

AIMS

Long-term comparisons between bariatric surgical techniques have been performed for gastric bypass (RYGB), sleeve gastrectomy (LSG), and biliopancreatic diversion (BPD) vs gastric banding (LAGB), but short-term studies (6 months-4 years) have only compared biliointestinal bypass (BIBP) and LAGB. The participating institutions regularly perform both BIBP and LAGB with a common protocol, and the aim of this retrospective study was to compare long-term effects of the two procedures on body weight, on clinical and metabolic variables, and on resolution of obesity and of diabetes.

METHODS

All procedures performed between 01/01/1998 and 31/12/2005 were considered; 73 out of 91 patients undergoing BIBP, and 154 out of 249 patients undergoing LAGB were evaluable up to 9 years.

RESULTS

BIBP was significantly more effective than LAGB in terms of weight loss and of resolution of obesity (BMI < 30 kg/m²), in terms of decrease of systolic blood pressure and of serum cholesterol, and similar in terms of resolution of diabetes. In addition, the effect of BIBP was stable, while the effect of LAGB decreased with time.

CONCLUSIONS

Both BIBP and LAGB exert long-term effects on body weight, on blood pressure, and on resolution of diabetes mellitus; the effect of BIBP is significantly greater than the effect of LAGB in terms of weight loss, resolution of obesity, of control of systolic blood pressure and of serum cholesterol, but not in terms of resolution of diabetes.

Long-Term Trends in Hematological and Nutritional Status After Gastrectomy for Gastric Cancer

BACKGROUND

This study investigated long-term trends in hematological and nutritional parameters after gastrectomy for gastric cancer and evaluated the influence of the reconstruction type on these trends.

METHODS

The medical records of 558 patients who underwent curative gastrectomy with standard lymph node dissection for stage I gastric cancer between January 2006 and December 2013 were reviewed. The hematological and nutritional parameters evaluated included hemoglobin, ferritin, vitamin B₁₂, total protein, albumin, total cholesterol, triglyceride, and calcium. The patients were followed up for 6 months postoperatively and then annually until death, cancer recurrence, or follow-up loss.

RESULTS

In the long term, ferritin and triglyceride gradually decreased after gastrectomy, while the other parameters decreased slightly or were stable. In the comparisons according to reconstruction type, the Roux-en-Y group had the lowest levels of hemoglobin, ferritin, vitamin B12, total protein, albumin, and total cholesterol beginning 6 months postoperatively compared with the Billroth I and II groups. However, only ferritin and vitamin B₁₂ had significant differences in the 5-year cumulative incidences of deficiency/reduction according to the reconstruction type, whereas albumin, triglyceride, total cholesterol, and calcium did not.

CONCLUSIONS

Although malabsorption and malnutrition are common in patients after a gastrectomy, most nutritional parameters were stable or decreased slightly in the long-term and were not markedly influenced by the reconstruction type or extent of gastrectomy. Therefore, for more accurate nutritional assessment after gastrectomy, multidirectional monitoring should be considered rather than simply measuring biochemical parameters.

Comparison of Effects of Sleeve Gastrectomy and Gastric Bypass on Lipid Profile Parameters in Indian Obese: a Case Matched Analysis

BACKGROUND

Obesity is associated with increased mortality due to higher cardiovascular risk. A proportion of this risk is attributed to impaired lipid profile in the form of high levels of serum total cholesterol, triglycerides, and low levels of HDL cholesterol. Both sleeve gastrectomy (LSG) and gastric bypass (LGB) have been shown to have favourable effects on lipid profile with some variability in improvement. We aimed to study the difference in changes in lipid profile after LSG and LGB.

METHODS

We performed a retrospective case-matched study comparing effects of LSG and LGB on lipid profile of patients who underwent bariatric surgery from September 2014 to September 2015. The matching was done based on criteria of age and body mass index (BMI).

RESULTS

Out of a total of 92 selected patients, 69 patients underwent LSG and 23 patients underwent LGB. There was a significant improvement in serum triglycerides and HDL cholesterol with no significant reduction in serum total cholesterol in both LSG and LGB group. There was a significant reduction in cardiovascular risk calculated as total cholesterol: HDL cholesterol ratio following bariatric surgery (p = 0.002).

CONCLUSION

Both LSG and LGB have similar effects on lipid profile cardiovascular risk attributed to it in Indian obese. Thus, sleeve gastrectomy may be considered as effective as a gastric bypass for dyslipidaemia improvement in Indian patients.

Physiology, pathophysiology and therapeutic implications of enteroendocrine control of food intake

With the increasing prevalence of obesity and its associated comorbidities, strides to improve treatment strategies have enhanced our understanding of the function of the gut in the regulation of food intake. The most successful intervention for obesity to date, bariatric surgery effectively manipulates enteroendocrine physiology to enhance satiety and reduce hunger. Areas covered: In the present article, we provide a detailed overview of the physiology of enteroendocrine control of food intake, and discuss its pathophysiologic correlates and therapeutic implications in both obesity and gastrointestinal disease. Expert commentary: Ongoing research in the field of nutrient sensing by L-cells, as well as understanding the role of the microbiome and bile acid signaling may facilitate the development of novel strategies to combat the rising population health threat associated with obesity. Further refinement of post-prandial satiety gut hormone based therapies, including the development of chimeric peptides exploiting the pleiotropic nature of the gut hormone response, and identification of novel methods of delivery may hold the key to optimization of therapeutic modulation of gut hormone physiology in obesity.

Metabolic profile and psychological variables after bariatric surgery: association with weight outcomes

PURPOSE

This study aims to examine associations between metabolic profile and psychological variables in post-bariatric patients and to investigate if metabolic and psychological variables, namely high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), glycated hemoglobin (HbA 1c), impulsivity, psychological distress, depressive and eating disorder symptoms are independently associated with percentage of excess weight loss (%EWL) after bariatric surgery.

METHODS

One hundred and fifty bariatric patients (BMI = 33.04 ± 5.8 kg/m(2)) who underwent to bariatric surgery for more than 28.63 ± 4.9 months were assessed through a clinical interview, a set of self-report measures and venous blood samples. Pearson's correlations were used to assess correlations between %EWL, metabolic and psychological variables. Multiple linear regression was conducted to investigate which metabolic and psychological variables were independently associated with %EWL, while controlling for type of surgery.

RESULTS

Higher TG blood levels were associated with higher disordered eating, psychological distress and depression scores. HDL-C was associated with higher depression scores. Both metabolic and psychological variables were associated with %EWL. Regression analyses showed that, controlling for type of surgery, higher % EWL is significantly and independently associated with less disordered eating symptoms and lower TG and HbA_1c blood concentrations (R (2) aj = 0.383, F (4, 82) = 14.34, p < 0.000).

CONCLUSION

An association between metabolic and psychological variables, particularly concerning TG blood levels, disordered eating and psychological distress/depression was found. Only higher levels of disordered eating, TG and HbA_1c showed and independent correlation with less weight loss. Targeting maladaptive eating behaviors may be a reasonable strategy to avoid weight regain and optimize health status post-operatively.

The role of bile acids in reducing the metabolic complications of obesity after bariatric surgery: a systematic review

BACKGROUND

Bariatric surgery is currently the most efficacious treatment for obesity and its associated metabolic co-morbidities, such as diabetes. The metabolic improvements occur through both weight-dependent and weight-independent mechanisms. Bile acids (BAs) have emerged as key signalling molecules that have a central role in modulating many of the physiological effects seen after bariatric surgery. This systematic review assesses the evidence from both human and animal studies for the role of BAs in reducing the metabolic complications of obesity following bariatric surgery.

METHODS

We conducted a systematic search of Medline and Embase databases to identify all articles investigating the role of BAs in mediating the metabolic changes observed following bariatric surgery in both animal and human studies. Boolean logic was used with relevant search terms, including the following MeSH terms: 'bile acids and salts', 'bariatric surgery', 'metabolic surgery', 'gastrointestinal tract/surgery' and 'obesity/surgery'.

RESULTS

Following database searches (n=1197), inclusion from bibliography searches (n=2) and de-duplication (n=197), 1002 search results were returned. Of these, 132 articles were selected for full-text review, of which 38 articles were deemed relevant and included in the review. The findings support the effects of BAs on satiety, lipid and cholesterol metabolism, incretins and glucose homoeostasis, energy metabolism, gut microbiota and endoplasmic reticulum stress following bariatric surgery. Many of these metabolic effects are modulated through the BA receptors FXR and TGR5. We also explore a possible link between BAs and carcinogenesis following bariatric surgery.

CONCLUSIONS

Overall there is good evidence to support the role of BAs in the metabolic effects of bariatric surgery through the above mechanisms. BAs could serve as a novel therapeutic pharmacological target for the treatment of obesity and its associated co-morbidities.

Changes of lipid profiles after radical gastrectomy in patients with gastric cancer

BACKGROUND

We investigated the changes of lipid profiles after radical gastrectomy.

METHODS

We analyzed the lipid-profile changes after radical gastrectomy in 144 patients with gastric cancer. Their lipid profiles, including total cholesterol (TC), triglyceride (TG), LDL-cholesterol (LDL), and HDL-cholesterol (HDL), were evaluated preoperatively as well as 6 and 12 months postoperatively. We compared the changes of lipid profile according to the reconstruction type and resection extent.

RESULTS

The TC level had decreased 6 months after surgery, and remained unchanged thereafter. The LDL level also had decreased 6 months after surgery, but had increased again after 12 months after surgery. The HDL level had increased 12 months after surgery, whereas the TG level was unchanged. In a comparison of the lipid levels according to the reconstruction type or resection extent, the HDL level significantly differed by reconstruction type 12 months after surgery: it was markedly higher in the total gastrectomy than in the subtotal gastrectomy group both 6 months and 12 months after surgery. Both the male gender and total gastrectomy were associated with probability of normalization of LDL after surgery.

CONCLUSIONS

The lipid profiles including the TC, LDL and HDL levels were changed after radical gastrectomy; therefore, after this procedure, the lipid profiles of patients with hyperlipidemia should be evaluated.

Haemostatic and fibrinolytic changes in obese subjects undergoing bariatric surgery: the effect of different surgical procedures

BACKGROUND

Little is known about effects of different bariatric surgery procedures on haemostatic and fibrinolytic parameters.

MATERIAL AND METHODS

Consecutive obese subjects undergoing gastric bypass (GBP) or sleeve gastrectomy (SG) were enrolled. In all patients, levels of haemostatic factors (FII, FVII, FVIII, FIX, FX, vWF, fibrinogen), fibrinolytic variables (PAI-1, t-PA and D-dimer) and natural anticoagulants (AT, protein C and protein S) were evaluated before and 2 months after surgery.

RESULTS

A total of 77 GBP and 79 SG subjects completed the study. At baseline no difference in coagulation parameters was found between the two groups. After both GBP and SG, subjects showed significant changes in haemostatic and fibrinolytic variables and in natural anticoagulant levels. The Δ% changes in FVII, FVIII, FIX, vWF, fibrinogen, D-dimer, protein C and protein S levels were significantly higher in subjects who underwent GBP than in those who underwent SG. Multivariate analysis confirmed that GBP was a predictor of higher Δ% changes in FVII (β=0.268, p=0.010), protein C (β=0.274, p=0.003) and protein S (β=0.297, p<0.001), but not in all the other variables. Following coagulation factor reduction, 31 subjects (25.9% of GBP and 13.9% of SG; p=0.044) showed overt FVII deficiency; protein C deficiency was reported by 34 subjects (32.5% of GBP vs 11.4% of SG, p=0.033) and protein S deficiency by 39 (37.6% of GBP vs 12.6% of SG, p=0.009). Multivariate analyses showed that GBP was associated with an increased risk of deficiency of FVII (OR: 3.64; 95% CI: 1.73-7.64, p=0.001), protein C (OR: 4.319; 95% CI: 1.33-13.9, p=0.015) and protein S (OR: 5.50; 95% CI: 1.71-17.7, p=0.004).

DISCUSSION

GBP is associated with an increased risk of post-operative deficiency in some vitamin K-dependent coagulation factors. Whereas such deficiency is too weak to cause bleeding, it is significant enough to increase the risk of thrombosis.

Cholesterol metabolism after bariatric surgery in grade 3 obesity: differences between malabsorptive and restrictive procedures

OBJECTIVE

Malabsorptive bariatric surgery (biliopancreatic diversion and biliointestinal bypass [BIBP]) reduces serum cholesterol levels more than restrictive surgery (adjustable gastric banding [AGB]), and this is thought to be due to greater weight loss. Our aim was to evaluate the changes of cholesterol metabolism induced by malabsorptive and restrictive surgery independent of weight loss.

RESEARCH DESIGN AND METHODS

In a nonrandomized, self-selected, unblinded, active-comparator, bicenter, 6-month study, glucose metabolism (blood glucose and serum insulin levels and homeostasis model assessment of insulin resistance [HOMA-IR] index) and cholesterol metabolism (absorption: serum campesterol and sitosterol levels; synthesis: serum lathosterol levels; catabolism: rate of appearance and serum concentrations of serum 7-α- and serum 27-OH-cholesterol after infusions of deuterated 7-α- and 27-OH-cholesterol in sequence) were assessed in grade 3 obesity subjects undergoing BIBP (n = 10) and AGB (n = 10). Evaluations were performed before and 6 months after surgery.

RESULTS

Subjects had similar values at baseline. Weight loss was similar in the two groups of subjects, and blood glucose, insulin levels, HOMA-IR, and triglycerides decreased in a similar way. In contrast, serum cholesterol, LDL cholesterol, non-HDL cholesterol, serum sitosterol, and campesterol levels decreased and lathosterol levels increased only in BIBP subjects, not in AGB subjects. A significant increase in 7-α-OH-cholesterol occurred only with BIBP; serum 27-OH-cholesterol decreased in both groups.

CONCLUSIONS

Malabsorptive surgery specifically affects cholesterol levels, independent of weight loss and independent of glucose metabolism and insulin resistance. Decreased sterol absorption leads to decreased cholesterol and LDL cholesterol levels, accompanied by enhanced cholesterol synthesis and enhanced cholesterol catabolism. Compared with AGB, BIBP provides greater cholesterol lowering.

ESR1 gene and insulin resistance remission are associated with serum uric acid decline for severely obese patients undergoing bariatric surgery

BACKGROUND

Hyperuricemia is associated with obesity. Few studies have reported the effects of different types of bariatric surgery on uric acid metabolism. The aim of our study was to determine the relationships between serum uric acid reduction and estrogen receptor-α (ESR1) gene polymorphism, as well as the type of bariatric surgery received. The potential physiological pathways involved in postsurgery serum uric acid reduction were also discussed.

METHODS

A total of 508 severely obese Han Chinese patients, aged 20 to 50 years, with a body mass index (BMI)≥35 kg/m(2) were selected. Patients received either laparoscopic adjustable gastric banding (LAGB; n = 164) or laparoscopic mini-gastric bypass (LMGB; n = 344). A 12-month follow-up was performed to explore the effects of the type of bariatric surgery and ESR1 polymorphism on serum uric acid reduction.

RESULTS

The rs712221 polymorphism of ESR1 affects serum uric acid reduction after bariatric surgery. The LMGB group exhibited a greater reduction in serum uric acid level compared with the LAGB counterpart after adjusting for sex, age, and metabolic confounders (-2.3 ± 2.1 mg/dL versus-1.2 ± 1.1 mg/dL; P = .002). Patients with the rs712221 genotype exhibited better glycemic control and a greater serum uric acid reduction at 12 months after surgery. The effects of the rs712221 polymorphism in LMGB patients resulted in the greatest serum uric acid reduction (-2.7 ± 1.4 mg/dL).

CONCLUSIONS

For severely obese Han Chinese patients, bariatric surgery appears to reduce serum uric acid levels, potentially mediated by synergic effects of surgery type, BMI reduction, rs712221 locus, insulin sensitivity, and changed dietary factors via an unknown mechanism.

Endocrine and nutritional management of the post-bariatric surgery patient: an Endocrine Society Clinical Practice Guideline

OBJECTIVE

We sought to provide guidelines for the nutritional and endocrine management of adults after bariatric surgery, including those with diabetes mellitus. The focus is on the immediate postoperative period and long-term management to prevent complications, weight regain, and progression of obesity-associated comorbidities. The treatment of specific disorders is only summarized.

PARTICIPANTS

The Task Force was composed of a chair, five additional experts, a methodologist, and a medical writer. It received no corporate funding or remuneration.

CONCLUSIONS

Bariatric surgery is not a guarantee of successful weight loss and maintenance. Increasingly, patients regain weight, especially those undergoing restrictive surgeries such as laparoscopic banding rather than malabsorptive surgeries such as Roux-en-Y bypass. Active nutritional patient education and clinical management to prevent and detect nutritional deficiencies are recommended for all patients undergoing bariatric surgery. Management of potential nutritional deficiencies is particularly important for patients undergoing malabsorptive procedures, and strategies should be employed to compensate for food intolerance in patients who have had a malabsorptive procedure to reduce the risk for clinically important nutritional deficiencies. To enhance the transition to life after bariatric surgery and to prevent weight regain and nutritional complications, all patients should receive care from a multidisciplinary team including an experienced primary care physician, endocrinologist, or gastroenterologist and consider enrolling postoperatively in a comprehensive program for nutrition and lifestyle management. Future research should address the effectiveness of intensive postoperative nutritional and endocrine care in reducing morbidity and mortality from obesity-associated chronic diseases.

Cholesterol absorption decreases after Roux-en-Y gastric bypass but not after gastric banding

The differences in cholesterol metabolism after the 2 most common forms of obesity surgery, Roux-en-Y gastric bypass (RYGB) and gastric banding (GB), have not been well characterized. In this study, effects of RYGB and GB on cholesterol absorption and synthesis were investigated. To this aim, 1-year follow-up of cholesterol metabolism in 2 nonrandomized cohorts undergoing either RYGB (n = 29; age, 45.2 +/- 7.7 years; body mass index [BMI], 46.0 +/- 6.1 kg/m(2)) or GB (n = 26; age, 45.9 +/- 8.6 years; BMI, 50.1 +/- 7.7 kg/m(2)) was performed in a university hospital center specializing in the treatment of morbid obesity. Serum markers of cholesterol synthesis (cholestenol, desmosterol, and lathosterol) and cholesterol absorption (campesterol, sitosterol, avenasterol, and cholestanol) were measured preoperatively and at follow-up and expressed as ratios to cholesterol. As expected based on observed weight loss (25% after RYGB and 17% after GB, P < .001 between groups), both operations decreased serum levels of cholesterol synthesis markers by 12% to 28% (all Ps < .001). A decrease in cholesterol absorption markers was only observed after RYGB (-26% for sitosterol) and not after GB (+16%, P = 2 x 10(-6) for difference between the groups). The difference in sitosterol ratio between the groups remained significant after adjustment for age, BMI, fasting insulin levels, and nutritional status (P = 2 x 10(-4)), indicating a specific effect related to RYGB. We conclude that decrease in cholesterol absorption is a novel beneficial effect of RYGB. Together with an improved control of blood glucose, this may contribute to a better cardiovascular risk profile after RYGB.

Ileal interposition surgery improves glucose and lipid metabolism and delays diabetes onset in the UCD-T2DM rat

BACKGROUND & AIMS

Bariatric surgery has been shown to reverse type 2 diabetes; however, mechanisms by which this occurs remain undefined. Ileal interposition (IT) is a surgical model that isolates the effects of increasing delivery of unabsorbed nutrients to the lower gastrointestinal tract. In this study we investigated effects of IT surgery on glucose tolerance and diabetes onset in UCD-T2DM (University of California at Davis type 2 diabetes mellitus) rats, a polygenic obese animal model of type 2 diabetes.

METHODS

IT or sham surgery was performed on 4-month-old male UCD-T2DM rats. All animals underwent oral glucose tolerance testing (OGTT). A subset was killed 2 months after surgery for tissue analyses. The remainder was followed until diabetes onset and underwent oral fat tolerance testing (OFTT).

RESULTS

IT surgery delayed diabetes onset by 120 +/- 49 days compared with sham surgery (P < .05) without a difference in body weight. During OGTT, IT-operated animals exhibited lower plasma glucose excursions (P < .05), improved early insulin secretion (P < .01), and 3-fold larger plasma glucagon-like peptide-1(7-36) (GLP-1(7-36)) excursions (P < .001), and no difference in glucose-dependent insulinotropic polypeptide responses compared with sham-operated animals. Total plasma peptide YY (PYY) excursions during OFTT were 3-fold larger in IT-operated animals (P < .01). IT-operated animals exhibited lower adiposity (P < .05), smaller adipocyte size (P < .05), 25% less ectopic lipid deposition, lower circulating lipids, and greater pancreatic insulin content compared with sham-operated animals (P < .05).

CONCLUSIONS

IT surgery delays the onset of diabetes in UCD-T2DM rats which may be related to increased nutrient-stimulated secretion of GLP-1(7-36) and PYY and improvements of insulin sensitivity, beta-cell function, and lipid metabolism.

Metabolic or bariatric surgery? Long-term effects of malabsorptive vs restrictive bariatric techniques on body composition and cardiometabolic risk factors

BACKGROUND

Obesity is an increasing health problem and surgery seems to be the only treatment effective in achieving weight loss without relapse. Among bariatric techniques, many differences exist in terms of weight loss and resolution of comorbidities. Up to now, there are no prospective studies comparing long-term effects of malabsorptive vs restrictive techniques.

OBJECTIVE

In this study, cardiometabolic risk factors and body composition changes after malabsorptive biliointestinal bypass (BIBP) and restrictive laparoscopic adjustable gastric banding (LAGB) were compared during a 4-year follow-up.

DESIGN

Prospective, case-control and cohort study.

PATIENTS

In all, 80 obese subjects, matched for weight and age. Altogether, 40 patients underwent BIBP and 40 underwent LAGB.

MEASUREMENTS

Weight, body composition, fasting and post-loading plasma glucose and insulin, homeostatic model assessment index (HOMA-I), lipid profile, blood pressure (BP), erythrocyte sedimentation rate and fibrinogen were monitored at baseline, 12 and 48 months.

RESULTS

At 12 months after surgery, a significant reduction in body mass index, total fat mass (FM), trunk FM (trFM), trFM/legs FM (lFM) ratio (trFM/lFM), triglycerides, BP and inflammation markers was observed in both groups. BIBP patients showed a significant reduction in total cholesterol (Tot-C), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C), whereas the LAGB group showed a significant increase of HDL-C. A further improvement of all the parameters evaluated was seen in the BIBP group at 48 months after surgery.

CONCLUSIONS

Both bariatric procedures exerted positive effects on cardiometabolic risk factors and on weight loss in the population studied, but on the long-term period, HOMA-I, Tot-C/HDL-C ratio and body composition improvements were more evident after BIBP. We conclude that malabsorptive BIBP seems to be more effective than LAGB in treating visceral obesity and its metabolic complications.

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery medical guidelines for clinical practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice are systematically developed statements to assist health-care professionals in medical decision making for specific clinical conditions. Most of the content herein is based on literature reviews. In areas of uncertainty, professional judgment was applied. These guidelines are a working document that reflects the state of the field at the time of publication. Because rapid changes in this area are expected, periodic revisions are inevitable. We encourage medical professionals to use this information in conjunction with their best clinical judgment. The presented recommendations may not be appropriate in all situations. Any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances. The American Society for Parenteral & Enteral Nutrition fully endorses sections of these guidelines that address the metabolic and nutritional management of the bariatric surgical patient.

Bariatric surgery in obesity: changes of glucose and lipid metabolism correlate with changes of fat mass

BACKGROUND AND AIM

Bariatric surgery induces significant weight loss and improves glucose metabolism in obese patients (BMI>35 kg/m(2)). Our aim was to compare restrictive (LAGB, laparoscopic gastric banding) and malabsorptive approaches (BIBP, biliary-intestinal bypass) on the loss of fat-free mass (FFM), fat mass (FM), and on changes of glucose and lipid metabolism.

METHODS AND RESULTS

Body composition (bio-impedance analysis, BIA), blood glucose (BG), insulin, triglycerides, total- and HDL-cholesterol, liver enzymes (AST and ALT) were measured at baseline and 1 year after surgery in patients undergoing LAGB, BIBP, and in diet-treated control patients. In the main study, with patients matched for initial BMI (43-55 kg/m(2), LAGB=24, BIBP=12, controls=6), decreases of BMI, FM, BG and cholesterol were greater in patients with BIBP than with LAGB (p<0.01), while decreases of FFM, insulin, HOMA-IR and triglycerides were similar. No effects on BMI, FM, FFM, BG, insulin, HOMA-IR or cholesterol were observed in the control patients. Decreases of BG, insulin, HOMA-IR, cholesterol and triglycerides correlated with FM but not with FFM decrease. Similar results were obtained in an additional study in patients with a different initial BMI (LAGB=25, BIBP=6, controls=24) and when considering all subjects together. A decrease of liver enzymes (ALT) was greater with LAGB than with BIBP, and HDL-cholesterol increased with LAGB and decreased with BIBP.

CONCLUSION

BMI, FM, BG and cholesterol decrease more with malabsorptive than with restrictive surgery, while FFM, insulin, HOMA-IR and triglycerides decrease in a similar way. FFM loss is of low entity. Changes of glucose and lipid metabolism are proportional to a decrease of fat mass but not of fat-free mass.

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient

American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical Practice are systematically developed statements to assist healthcare professionals in medical decision making for specific clinical conditions. Most of the content herein is based on literature reviews. In areas of uncertainty, professional judgment was applied. These guidelines are a working document that reflects the state of the field at the time of publication. Because rapid changes in this area are expected, periodic revisions are inevitable. We encourage medical professionals to use this information in conjunction with their best clinical judgment. The presented recommendations may not be appropriate in all situations. Any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances. The American Society for Parenteral & Enteral Nutrition fully endorses sections of these guidelines that address the metabolic and nutritional management of the bariatric surgical patient.

Orlistat and sibutramine beyond weight loss

BACKGROUND AND AIM

To investigate, through a meta-analysis of clinical trials, the effect of two weight-reducing drugs, such as orlistat and sibutramine, on serum lipid profiles in overweight and obese subjects, independently of weight loss.

METHODS

A systematic search strategy, incorporating the terms orlistat, sibutramine, fat, cholesterol, lipid profile, cardiovascular risk, was developed to identify randomized trials in MEDLINE from inception to the end of May 2005. Trial selection was limited by language of publication (English) and duration (6-12 months).

RESULTS

Fifteen and ten randomized, double-blind, placebo-controlled trials on orlistat and sibutramine respectively, were eligible for inclusion. In the 15 trials with orlistat, mean weight loss showed a significant correlation with mean reduction of total cholesterol (r=0.48; p<0.05), which maintained statistical significance after adjustment for mean weight loss (B=-2.81+/-1.28; p<0.05). Conversely, in the ten trials with sibutramine, treatment was not associated with a significant decrease in cholesterol levels after adjustment for weight loss (B=3.25+/-4.13; p not significant).

CONCLUSION

Orlistat or sibutramine, when individually compared to placebo, are effective in promoting significant weight loss. In addition, orlistat determines a significant reduction of total cholesterol, independent of weight loss itself. These observations indicate that orlistat is a useful adjunctive tool for improving cardiovascular risk factor profiles in overweight and obese patients.

The effect of loss of excess weight on the metabolic risk factors after bariatric surgery in morbidly and super-obese patients

BACKGROUND

Changes in metabolic risk factors such as dyslipidemia and hyperinsulinemia as well as levels of sex hormones and leptin were studied in morbidly obese (MO) and super-obese (SO) patients during excess weight loss (EWL), separately in males and females.

METHODS

In this prospective clinical intervention study, 431 patients were included (361 females and 70 males). There were 217 patients with MO (BMI 40-49.9 kg/m2) and 214 patients with SO (BMI > or =50 kg/m2). All patients underwent restrictive bariatric operations. Metabolic parameters (lipids, insulin, leptin, hepatic transaminases, uric acid, and sex hormones) were measured before obesity surgery and at defined postoperative points of EWL (25%, 50%, 75% and 100%).

RESULTS

Successful weight reduction of 25% EWL was achieved by 94% of patients at 2 months. With this moderate EWL, most of the patients already improved their risk profile considerably, including normalization of insulin levels. Additional EWL led to a further amelioration of risk profile in all patients, including normalization of triglyceride levels. Male MO and SO patients had a worse metabolic situation preoperatively and a greater benefit after weight loss. Even though SO patients did not lose as much excess weight as MO patients, they did profit comparably.

CONCLUSION

Bariatric surgery is a valuable tool not only to reduce excess weight in severely obese patients but also to improve the metabolic risk profile within a short time-frame. This benefit is most pronounced in high-risk males.

Effect of Weight Loss following Bariatric Surgery on Myocardial Dispersion of Repolarization in Morbidly Obese Patients

BACKGROUND

Weight-stable obese subjects have an increased risk of arrhythmias and sudden death, even in the absence of cardiac dysfunction, and the risk of sudden cardiac death (SCD) with increasing weight is seen in both genders. The mechanism of unexplained deaths in obese patients is still unclear and may be related to ventricular repolarization abnormalities. The aim of this study is to determine the effect of severe obesity on spatial and transmural ventricular repolarization and to clarify the influence of bariatric surgery with a consequent substantial weight loss on arrhythmogenic substrate in the morbidly obese population.

METHODS

For the study, we enrolled 100 severely obese patients; 50 age-matched non-obese healthy subjects were also recruited as controls. All subjects underwent conventional 12-lead electrocardiography for analysis of spatial and transmural ventricular repolarization assessed by corrected QT dispersion (QTc-d), corrected JT dispersion (JTc-d) and transmural dispersion of repolarization, (TDR). All subjects underwent bariatric surgery and were resubmitted to electrocardiographic, biochemical and anthropometric examination 12 months postoperatively.

RESULTS

Severely obese patients had greater values in QTc-d, JTc-d and TDR than the normal-weight controls. Bariatric surgery reduced significantly the QTc-d value, JTc-d value and TDR value. There was a significant correlation between decrease of heterogeneity of repolarization indexes (QTd, JTd and TDR) and bariatric surgery-induced weight loss.

CONCLUSIONS

In severely obese patients, surgically-induced weight loss is associated with significant decrease in the heterogeneity of ventricular repolarization. The reduction of spatial (QTc-d, JTc-d) and transmural dispersion of repolarization (TDR) may be of clinical significance, by reducing the risk of potentially fatal arrhythmias in morbidly obese subjects.

Vertical gastric resection (sleeve gastrectomy) in a morbidly obese patient with past jejunoileal bypass

Jejunoileal bypass (JIB) is a purely malabsorptive operation, which has been abandoned in the USA and Western Europe due to occasional serious complications. We are still seeing past JIB patients who have become obese again over the years, but are not suffering side-effects of the previous JIB, and are complaining of typical co-morbidities of the obesity. We present a prior JIB patient who underwent a sleeve gastrectomy in 2003 for recurrence of morbid obesity. The patient has been followed for another 4 years with regular laboratory tests, monitoring of weight loss, bone densitometry and possible complications. Selected morbidly obese patients who have undergone past JIB, can be safely treated by a restrictive procedure, sleeve gastrectomy, to accomplish successful weight loss without increasing the risk of possible serious complications.

A rat model of childhood diet-induced obesity: Roux-en-Y gastric bypass induced changes in metabolic parameters and gastric peptide ghrelin

Childhood morbid obesity is reaching epidemic proportions. Roux-en-Y gastric bypass (RYGB) results in many metabolic alterations, including changes in glucose and lipid metabolism, and changes in levels of the gastric hormone, ghrelin. As more children are undergoing RYGB, an animal model would be beneficial to further study RYGB and its subsequent metabolic effects. DIO Sprague Dawley rats underwent RYGB, sham jejunojejunostomy (SH), or no operation (HFC) after 6 weeks of high-fat diet. Non-obese rats fed standard chow (SC) were a final control group. Animals were post-operatively fed standard chow for 7 days before sacrifice. At sacrifice, venous blood and gastric mucosa was collected for metabolic parameters and ghrelin determination. RYGB rats weighed less than SH and HFC (361 +/- 8.8 vs. 437 +/- 9.3 and 443 +/- 6.2 g, P < 0.05). Compared to HFC, RYGB animals had decreased plasma glucose (292 +/- 23 vs. 141 +/- 10 mg/dL), cholesterol (80 +/- 12 vs. 45 +/- 5 mg/dL), triglycerides (138 +/- 37 vs. 52 +/- 7 mg/dL), HDL (43 +/- 5 vs. 20 +/- 3 mg/dL), and free fatty acids (0.72 +/- 0.14 vs. 0.23 +/- 0.02 mEq/L), all P < 0.05. Plasma ghrelin increased in RYGB rats compared to SC and HFC (116.22 +/- 32.27 vs. 31.60 +/- 2.66 and 31.75 +/- 0.75 pg/mL, P < 0.05). In a rat model of RYGB, we demonstrated improved metabolic parameters and increased plasma and gastric mRNA ghrelin levels. The rat model for RYBG appears to be a reasonable model for future study of the cellular and molecular regulatory pathways of obesity and its surgical treatment.

Results of bariatric surgery

Overweight and obesity are rapidly growing to epidemic proportions in the United States and globally. Since sustainable weight loss is only achieved by bariatric surgery, medicine has seen an explosion in the diversity and number of bariatric procedures performed over the past few years. Systematic studies of postoperative outcomes and investigations into the physiology and biology of weight loss provide a more comprehensive understanding of the sequelae of bariatric surgery. Adipose tissue is the predominant site of fat stores. Increasing obesity results in an overload of lipids within the body's natural storage sink (i.e., the adipocyte) followed by the necessary deposition of fat within ectopic sites such as muscle, liver, and pancreas. The resulting metabolic derangements are associated with insulin resistance, central obesity, and chronic inflammation as adipose tissue acts as an endocrine organ, producing and secreting a host of biologic mediators. Whereas there are conflicting data on the cardiovascular effects of peripheral, subcutaneous liposuction, malabsorptive bariatric procedures result almost universally in significant amelioration of insulin resistance, hypertension, dyslipidemia, and hepatic steatosis. Concomitant changes in adipocyte-derived hormones may provide mechanistic explanations to the observed improvements.

Nutritional consequences of bariatric surgery

PURPOSE OF REVIEW

Bariatric surgery is being increasingly used to help treat morbidly obese adults and adolescents. As a greater percentage of this population faces a lifetime of living with surgically altered gastrointestinal anatomy and physiology, increased awareness of the nutritional consequences is critical for all health care practitioners, as many of these patients may be lost to follow-up and can present with significant nutritional complications years after surgery.

RECENT FINDINGS

Nutritional deficiencies can occur after bariatric surgery, although to a lesser degree after restrictive procedures. Risk may increase over time, perhaps due to poor compliance with supplementation, continued inadequate intake and/or ongoing malabsorption. Adolescent patients may be at greater risk due to poor compliance and longer life span. Nutritional monitoring and supplementation among bariatric programs has been widely variable and few prospective studies of outcomes exist.

SUMMARY

Bariatric surgery can carry significant risk of nutritional complications. Compliance with dietary recommendations should be monitored and encouraged, with annual screening for selected deficiencies. Prospective longitudinal research is needed to identify the true prevalence and significance of nutritional deficiency in these patients and to determine optimum dietary recommendations.