DÄ internationalArchive5/2022Obesity Surgery: Weight Loss, Metabolic Changes, Oncological Effects, and Follow-Up

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Obesity Surgery: Weight Loss, Metabolic Changes, Oncological Effects, and Follow-Up

Dtsch Arztebl Int 2022; 119: 70-80. DOI: 10.3238/arztebl.m2021.0359

Fink, J; Seifert, G; Blüher, M; Fichtner-Feigl, S; Marjanovic, G

Background: In 2017, the prevalence of obesity (BMI ≥= 30  kg/m2) in Germany was approximately 16%. Obesity increases an individual’s risk of developing type 2 diabetes (T2DM) and arterial hypertension; it also increases overall mortality. Consequently, effective treatment is a necessity. Approximately 20 000 bariatric operations are performed in Germany each year.

Methods: This review is based on pertinent publications retrieved by a selective search in the PubMed and Cochrane databases and on current German clinical practice guidelines.

Results: The types of obesity surgery most commonly performed in Germany, Roux-en-Y gastric bypass and sleeve gastrectomy, lead to an excess weight loss of 27–69% ≥= 10 years after the procedure. In obese patients with T2DM, the diabetes remission rate ≥= 10 years after these procedures ranges from 25% to 62%. Adjusted regression analyses of data from large registries have shown that the incidence of malignancies is 33% lower in persons who have undergone obesity surgery compared to control subjects with obesity (unadjusted incidence 5.6 versus 9.0 cases per 1000 person-years). The operation can cause vitamin deficiency, surgical complications, gastroesophageal reflux, and dumping syndrome. Therefore, lifelong follow-up is necessary.

Conclusion: In view of an increasing number of patients undergoing bariatric surgery, it will probably not be feasible in the future for lifelong follow-up to be provided exclusively in specialized centers.

LNSLNS

The prevalence of obesity (body-mass index [BMI] ≥ 30kg/m2) has risen in the last 40 years in all countries for which epidemiologic data are available (1). In Germany, 16.3% of the population was obese in 2017 (e1). Obesity has a clear effect on overall mortality, which rises by 29% with every 5 kg/m2 increase in BMI (hazard ratio [HR]: 1.29; 95% confidence interval: [1.27; 1.32]). The life expectancy of persons with a BMI in the range of 40–45 kg/m2 is reduced by eight to ten years. This effect is comparable to that of cigarette smoking (2). 25.6% of persons with BMI ≥ 40 kg/m2 suffer from type 2 diabetes (T2DM), and 50.9% from arterial hypertension. This corresponds to a 7.4-fold increase of the risk of T2DM and a 6.4-fold increase of the risk of arterial hypertension compared to persons of normal weight (e2). Among persons with BMI ≥ 30 kg/m2, 14.9% have T2DM and 40.9% have arterial hypertension (e2). In western Europe, 3.3% [3.0; 3.6] of all cancers in men and 7.8% [7.1; 8.5] of all cancers in women can be attributed to obesity (3). Table 1 contains a description of five tumor entities for which a strong epidemiologic association with obesity has been shown in a global meta-analysis (4). 13% of the overall healthcare costs of obesity associated diseases (such as T2DM) in Germany, amounting to 5.2 billion euros per year, are attributable to obesity (e3). These data highlight the urgency of effective treatment and improved secondary prevention.

Cancer risk in obese persons and reduction of the risk of selected types of cancer after obesity surgery
Table 1
Cancer risk in obese persons and reduction of the risk of selected types of cancer after obesity surgery

Obesity surgery, with appropriate preoperative care and lifelong follow-up, leads to sustained weight loss (45.9–80.9% loss of excess body weight [EWL] at 10–25 years) (e4) as well as to improvement of pre-existing T2DM (5). Moreover, in a meta-analysis of data from 174 772 persons, mortality in the 30 years after obesity surgery was found to be 49.2% [46.3; 51.9] lower than in control patients with obesity (with or without any other specific treatment), with a life expectancy that was 6.1 [5.2; 6.9] years longer (6).

In this CME article, we present the indications, basic principles, and results of obesity surgery. Moreover, typical long-term effects of surgery are discussed, and specific aspects of follow-up care are described, including vitamin supplementation.

Learning objectives

Readers of this article should achieve the following learning objectives:

  • an understanding of the mechanism of action of obesity surgery and a knowledge of its indications;
  • acquaintance with the key results of obesity surgery;
  • the ability to recognize reflux and dumping syndrome as clinically relevant long-term consequences of obesity surgery.

Methods

This article is based on a selective literature review in the PubMed and Cochrane databases for the years 2003–2021, with the following searching terms: bariatric surgery AND type 2 diabetes; vitamin supplementation; dumping syndrome; complication; cancer; oncology. Further searching terms were endoscopy AND dumping syndrome, as well as obesity AND disease risk; cancer. The contents of the current German clinical practice guidelines were considered as well (7, 8).

Baseline treatment for patients desiring obesity surgery

Patients with a potential indication for obesity surgery should be offered preparatory and accompanying conservative treatment options (7). These should include a combination of dietary counseling, exercise, and behavioral therapy and should contain individualized nutritional recommendations. The treatment goal is the loss of at least 10% of initial weight within 6 to 12 months in a patient whose BMI exceeds 35 kg/m2 (7). The data show that efficient, high-intensity interval training combined with dietary counseling in patients with a BMI of 40.4 ± 7.2 kg/m2 resulted in 5.3 [3.3; 7.3] kg of weight loss at 12 weeks and in a significant improvement of cardiovascular risk factors (abdominal girth −7.5 cm [–9.8; –5.1 cm], mean blood pressure −11 mm Hg [–14; –8 mm Hg]) (e5).

Long-term results were investigated in a meta-analysis of 91 studies on patients with obesity (BMI >30 kg/m2) treated with combined nutritional and behavioral therapy. In the subgroup analysis of patients with grade II and III obesity, the overall weight loss at six to 24 months was 5.3% and 6.3%, respectively (9). Accordingly, the German clinical practice guideline summarizes that treatment goals for obesity are “generally not achieved” by conservative treatment (7).

Conservative treatment has thus taken its place as a component of the interdisciplinary preparatory phase and the postoperative care of patients with a BMI ≥ 35 kg/m2 who desire obesity surgery. Baseline treatment need not necessarily be followed by obesity surgery. The efficacy of this strategy has been shown in a meta-analysis of studies on targeted interventions including nutritional counseling, behavioral therapy, and exercise in the 12 months before and after obesity surgery. 12 months after surgery, the patients so treated had lost 4.4 kg [1.69; 7.1] more than the control patients who had undergone obesity surgery without any other targeted intervention (e6).

The surgical treatment of obesity

The indication criteria for obesity surgery are listed in the Box. The patient’s body weight remains the main criterion on which the indication for obesity surgery is based, even though the goals of obesity surgery now extend well beyond weight loss alone (10).

Indications for obesity and metabolic surgery
Box
Indications for obesity and metabolic surgery

Metabolic surgery is indicated in patients with grade II obesity (BMI ≥ 35 to < 40 kg/m2) and T2DM whenever the treatment goals for T2DM as stated in the guidelines cannot be achieved with conservative therapy alone. For patients with T2DM and grade III obesity (BMI >40kg/m2), surgery is indicated independently of glycemic control, as long as potential contraindications have been excluded (Box) (7). As with the primary indication, the documented inefficacy of conservative obesity therapy is not required (7). Data on diabetes remission at least five years after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) reveal that particularly patients with a short history of type 2 diabetes, no insulin use, a treatment regimen with a small number of antidiabetic drugs, and good glycemic control (HbA1c <7%) under conservative treatment stand to benefit from metabolic surgery (11). Moreover, diabetes remission after metabolic surgery is independent of the initial BMI, as shown by a meta-analysis of data from 94 579 patients (12). These findings may prompt a reappraisal of the indications for metabolic surgery in the near future.

The contraindications for obesity surgery and metabolic surgery are clearly presented in the German clinical practice guideline. These include untreated bulimia nervosa, active substance dependence, or untreated endocrine causes of obesity (7).

Mechanisms of action of obesity surgery

The main objective of obesity surgery is to restrict energy intake. This is done by surgically decreasing the stomach volume, so that only small portions of food can be consumed. The surgical procedures often involve gastric reduction combined with bypassing the duodenum and part of the jejunum (Figure). The ones most commonly performed in Germany, SG and RYGB, do not cause any clinically relevant malabsorption of macronutrients (e7). The contribution of malabsorption to weight loss after RYGB has been estimated at 11% in a systematic review (e8). Though they differ in their anatomical details, the various obesity surgery procedures all cause complex intestinal hormonal changes, including increased levels of glucagon-like peptide 1 (GLP-1) and circulating bile acids, as well as lower ghrelin levels; clinically, patients have a reduced appetite, decreased neural stimulability, and lessened food reward compared to their preoperative state (e9). The hormonal changes after surgery are partly opposite to those induced by conservative treatment, which can raise ghrelin and cholecystokinin levels and increase the appetite (e10). If the described entero-endocrine regulation did not occur after obesity surgery, the ensuing sustained weight loss would be unexplained, because dilation of the stomach over the long term would again permit the consumption of large portions of food (e11). The most common surgical procedures are depicted in the Figure.

Surgical procedures in obesity and metabolic surgery
Figure
Surgical procedures in obesity and metabolic surgery

Weight loss

A meta-analysis of eleven randomized controlled trials (RCTs) revealed that obesity surgery leads to a mean amount of weight loss at two years that is 26 kg [31; 21 kg] greater than that resulting from conservative treatment alone (-38.5 to -14.4 kg, versus -7.9 to +1.0 kg) (13). The only Cochrane review to date on weight loss after obesity surgery revealed a similar difference of 21.3 kg [18.9; 23.6 kg] at 12–24 months (14). Long-term data from one of the included studies have become available in the meantime and show a large sustained difference in weight loss between RYGB and conservative treatment at 10 years (RYGB, -37.3 kg; conservative treatment, -6.5 kg; difference, 30.8 kg [16.7; 44.8 kg]) (15). In the prospective Swedish Obese Subjects (SOS) cohort trial, which involved 4047 patients, the overall weight loss at 15 years was 27% after RYGB, versus 0% in the control patients (some of whom received no specific treatment for obesity) (16).

Table 2 contains a detailed overview of weight loss after different obesity surgery procedures. It has been found in multiple RCTs that the two most common surgical procedures, SG and RYGB, lead to similar degrees of weight loss (14). Pooled data from the two largest randomized trials of SG versus RYGB, both of them published in 2021, imply that RYGB leads to significantly more weight loss at five years (EWL 67.7% versus 55.5%) (17). An advantage for RYGB over SG has likewise been found in three more recent meta-analyses, as well as in one RCT with 7-year follow-up data (18, 19, e12, e13). These newer findings remain to be confirmed.

The outcomes of obesity surgery and metabolic surgery
Table 2
The outcomes of obesity surgery and metabolic surgery

A meta-analysis of data from 12 445 patients revealed that weight loss one, two, and five years after one-anastomosis gastric bypass (OAGB) was greater than after RYGB: the difference in EWL at five years was 12.82% [5.37; 20.27%] (20). A disadvantage of OAGB compared to RYGB is a higher rate of malnutritive complications (21% versus 0%), as shown in one randomized controlled trial (e14).

Clinically relevant weight regain (defined as an increase of at least 25% from the nadir) occurs in approximately 20% of patients at a median follow-up of five years and is apparently higher after SG than after RYGB (e15). In such cases, a reoperation may be indicated. In order to minimize weight regain, silicone rings can be implanted around the stomach during the primary procedure. Weight regain three to five years after RYGB or SG has been found to be significantly less if silicone rings are used (21, e16).

The course of diabetes after obesity surgery

In a meta-analysis of data from 1108 patients, metabolic surgery brought about a remission of preexisting T2DM in 59.3% (RYGB) to 91.2% (OAGB) of patients at five years (5). The only RCT to date with 10 years of follow-up revealed a diabetes remission rate of 37.5% after metabolic surgery and 0% after medical management alone. In this trial, the percentage of patients needing insulin rose from 47% to 53.3% in the medical group and fell from 47.5% to 2.5% in the surgical group. The incidence of macrovascular and microvascular complications of T2DM at 10 years was 5.0% in the surgical group and 72.2% in the medical group (relative risk 0.07 [0.01; 0.48] (15). Likewise, a meta-analysis of data from 17 532 patients with T2DM who were treated either medically or surgically revealed lower incidences of diabetic retinopathy (1.9% versus 6.6%; odds ratio [OR] 0.30) and nephropathy (5.9% versus 22.4%; OR 0.19) in the surgical group at 1–15 years (e17). The incidence of diabetes in the prospective SOS cohort at 15 years was 6.8 per 1000 person-years after obesity surgery and 28.4 per 1000 person-years in the control group, corresponding to a relative risk reduction of 78% (22).

Multiple meta-analyses have shown statistically similar antidiabetic effects for SG and RYGB at five years (Table 2) (23, 24). In contrast, in a cohort study from the USA including 9710 patients with SG or RYGB at 34 centers, RYGB resulted in better glycemic control (ΔHbA1c 0.45; [0.27; 0.63]), a 10% higher diabetes remission rate (HR 1.1 [1.04; 1.16], and a lower diabetes recurrence rate (HR 0.75 [0.67; 0.84] than SG (25). In a study of 629 patients followed up for a median of 4.9 years after RYGB, independent predictive factors for diabetes recurrence were the preoperative insulin requirement, lower weight loss at 12 months, and greater regaining of weight after the first year (26).

Cancer prevention

A retrospective observational study of 22 198 patients who underwent obesity surgery, compared to 66 427 controls who were closely matched for sex, age, BMI, and comorbidities, determined that the incidence of cancer in 3.5 years of follow-up was 5.6 per 1000 person-years in the surgical group, compared to 9.0 per 1000 person-years in the nonsurgical group, which corresponded to a 33% relative reduction (27). With regard to individual types of cancer, a meta-analysis of data from more than 7 million patients revealed that endometrial cancer arose within four to 26 years in 0.4% of women who underwent obesity surgery, compared to 0.6% of women in the control group. This meta-analysis showed a 59% (OR 0.41 [0.22; 0.74]) lower risk of endometrial cancer after obesity surgery (e18). As for colorectal cancer (CC), a population-based, multicenter study from France involving 1.05 million persons with obesity followed up for at least 2 years revealed an absolute CC incidence of 0.6% within 10 years after obesity surgery compared to 1.3% in the control group. The risk of CC after obesity surgery was the same as in the normal population (standard incidence ratio [SIR] 1.0; [0.9; 1.09]), but it was 34% higher (SIR 1.34; [1.32; 1.36]) in obese persons who did not undergo obesity surgery (28).

Follow-up

Patients who have undergone obesity surgery benefit from regular follow-ups. In support of this assertion, a register based study including 46 381 patients 12 months after RYGB showed that those who adhered to scheduled postsurgical follow-ups had better remission rates of T2DM (OR 1.27; [1.18; 1.37]) and arterial hypertension (OR 1.25; [1.18; 1.32]), after adjustment for age, sex, BMI, and other factors (e19). In Germany, approximately 20 000 surgical procedures for obesity are performed per year (e20). The rapidly rising numbers of patients and operations will soon make it impossible for lifelong follow-up to be provided in specialized centers alone (29). In the next section, we outline what appropriate follow-up consists of and discuss two potential long-term sequelae, i.e., reflux and dumping syndrome. The necessary laboratory tests and supplementation recommendations are listed in Table 3.

Prevalences of micronutrient deficiency, laboratory tests, recommendations on vitamin supplementation following obesity surgery, and recommended vitamin and micronutrient intake according to the German Nutrition Society (Deutsche Gesellschaft für Ernährung)
Table 3
Prevalences of micronutrient deficiency, laboratory tests, recommendations on vitamin supplementation following obesity surgery, and recommended vitamin and micronutrient intake according to the German Nutrition Society (Deutsche Gesellschaft für Ernährung)

Specific aspects of follow-up

In a large-scale meta-analysis, obesity surgery led to the remission of preexisting arterial hypertension in 24 902 (50%) of 49 844 patients (e21). This implies that the antihypertensive medication must be continually readjusted. The same applies to T2DM: insulin secretagogues should be stopped, and the subcutaneous insulin dose should be adjusted (30). The use of sodium-glucose cotransporter 2 (SGLT2) inhibitors is not recommended for six to twelve months after obesity surgery because of the increased risk of ketoacidosis (7). A meta-analysis on the effect of exercise after obesity surgery revealed that participation in an exercise program was associated with a slightly greater degree of weight loss (–1.8 kg [–3.2; –0.4]) and improved physical performance (VO2max and muscle strength) (e22).

It is recommended in the German clinical practice guideline that self-injurious behavior should be directly asked about if the patient has a relevant preoperative disturbance, and that the history of self-injurious behavior should be appropriately documented (7). A meta-analysis of 29 studies revealed a suicide rate of 2.7 per 1000 patients after obesity surgery. The risk of suicide after obesity surgery was 1.9 times higher [1.23; 2.95] than in the same population preoperatively, and 3.8 times higher than in matched controls [2.91; 6.59] (e23). A comparison of the SOS cohort with persons in two Swedish national registries showed that the additional risk was much higher in men than in women. Moreover, it was found that a history of psychological consultations, psychotropic drug use, and sleep disturbances are risk factors for suicide after obesity surgery (e24). A systematic review of 48 studies on depression, anxiety disorder, and binge eating indicated that these disorders may improve 6–24 months after obesity surgery; some of the included studies showed, however, that these disorders may return to baseline levels beyond 24 months after surgery (31). In light of these findings a psycholocical follow up is desirable, especially for patients at risk.

Data show that 4.6% of patients develop anastomotic ulcers after RYGB. Nonsteroidal anti-inflammatory drugs (NSAID, OR 30.6 [6.4; 146]) and smoking (OR 11.5 [4.8; 28]) markedly increase this risk (e25). Proton-pump inhibitors are protective and are thus recommended for ulcer prophylaxis for one to six months after gastric bypass (7). Short-term NSAID use is, however, possible even after RYGB (30). A meta-analysis of 10 031 patients revealed a 2% incidence of internal hernias after RYGB, despite the initial closure of the mesenteric defects (e26). Because of the risk of incarceration, such hernias should be treated surgically (e27).

Reflux

According to a meta-analysis of data from 460 984 patients, obesity (BMI ≥ 30 kg/m2) is associated with a 1.7-fold [1.46; 2.06] higher prevalence of gastroesophageal reflux disease (GERD; absolute prevalence, 22.1% versus 14.2%), (e28). For patients with reflux who have an indication for obesity surgery, gastric bypass is an optimal operative technique, as it creates an anatomical barrier to reflux by bypassing a large portion of the stomach. SG is a poorer choice for this group of patients (7), as it is associated with de novo reflux symptoms in 20% [14; 27], an overall increase in reflux symptoms in 19% [15; 22], and a 28% rate of reflux esophagitis [–9; 66] in the first two years after surgery (32). A meta-analysis of 680 patients who underwent SG accordingly showed an 11.5% [7.8; 16.7] prevalence of Barrett’s mucosa in three years of follow-up (e29). Although no clear temporal relationship was seen between surgery and the onset of Barrett’s metaplasia, the prevalence of reflux esophagitis was found to increase by 13% per year after SG (e29). As there is no correlation between endoscopic findings and reflux symptoms in more than half of cases, the American Society for Metabolic and Bariatric Surgery recommends endoscopic follow-up of all patients three years after SG, and potentially at five-year intervals thereafter, as long as the findings remain unremarkable (e30). Reflux after SG is often a consequence of scarring or functional sleeve stenosis, both of which can relatively impede gastric outflow. Furthermore, axial hiatal hernias with intrathoracic migration of part of the sleeve have been described, inevitably leading to esophageal shortening and partial dysfunction of the lower esophageal sphincter (e31, 33). As causes of reflux after SG are prevalently anatomical in nature, conservative treatment is often ineffective; the most effective and most common treatment is conversion of the sleeve to a RYGB. In a published series of 10 cases, this also led to the remission of Barrett’s esophagus 80% of the time, after a median follow-up of 33.4 months (e32). Other options include hiatoplasty, possibly combined with augmentation using the round ligament of the liver, or the implantation of a magnetic ring (e33).

Patients who have undergone OAGB may develop both acid and biliary reflux because of retrograde flow of bile into the gastric pouch in the absence of a Roux anastomosis (e34). The logical management of clinically relevant biliary reflux would be the conversion of the OAGB to a RYGB.

Dumping

The prevalence of dumping syndromes after RYGB is 20–40% (e35). There are two types of dumping syndrome. Type 1 dumping (early dumping, less than one hour after food intake) is caused by rapid transport of hyperosmolar chyme into the small intestine, leading to an influx of interstitial fluid into the intestinal lumen. The mechanism of type 2 dumping (late dumping, one to three hours after food intake) is much less well understood; it is probably due to excessive GLP-1 secretion in response to the rapid transport of glucose into the small intestine (e36), which results in disproportionate insulin secretion and ensuing hypoglycemia. The main symptoms of both types of dumping are dizziness, sweating, tachycardia, and hypotension. They often occur in combination, as both are triggered by the rapid passage of food into the small intestine. Specific therapeutic measures are directed against this rapid passage. The mainstay of treatment is nutritional therapy, with the goal of getting the patient to ingest multiple, small portions of food that are low in carbohydrates, instead of a single large portion. Dumping syndrome can be effectively treated endoscopically by narrowing the gastroenterostomy (e37, e38); open surgical reduction of the gastric pouch and implantation of a silicone ring also markedly improves symptoms, although only limited confirmatory data are available to date (e39). The drugs used to treat dumping syndrome slow glucose uptake (acarbose) and gastrointestinal motility (somatostatin analogues, GLP-1 agonists), or else inhibit insulin secretion (diazoxide, somatostatin analogues) (e40). The treatment that would theoretically seem most effective, i.e., reversal of the gastric bypass, often fails to relieve the symptoms completely (e40).

Perspectives

As recommended in the German clinical practice guideline, patients should be followed up 1, 3, 6, 12, 18, and 24 months after obesity surgery, and annually thereafter (7). The appropriate follow-up is most likely to be delivered under real-world conditions if it is comprehensively reimbursed by health insurance carriers. Yet, in Germany at present, full reimbursement is only possible for standard care. The situation is likely to improve markedly in the near future with the adoption of a proposed law mandating the creation of a disease management program for obesity. One result of this may be the reimbursement of pharmacotherapy directed at weight loss, which is currently excluded under §34 of the German Social Code, Book V. This would be of particular benefit to patients with grade I obesity (BMI ≥ 30–35 kg/m2), a group that suffers from increased mortality, yet often cannot achieve sustained weight loss: these patients generally are not candidates for bariatric surgery, and conservative treatment often has no more than a modest effect (34, e41). Moreover, the adjuvant use of weight-reducing drugs after obesity surgery will be increasingly important as better and more comprehensive data are acquired (e42, e43).

Conflict of interest statement
Prof. Fink has received lecture honoraria from KLS Martin GmbH + Co KG and reimbursement of travel expenses from Bariatric Solutions GmbH.

Prof. Marjanovic has received lecture honoraria from KLS Martin GmbH + Co KG and reimbursement of travel expenses from Bariatric Solutions GmbH.

PD Dr.Seifert has received lecture honoraria from KLS Martin GmbH + Co KG and reimbursement of travel expenses from Bariatric Solutions GmbH.

Prof. Blüher has received lecture honoraria from, and has served as a paid advisor for, the following firms: Amgen, AstraZeneca, Bayer, Böhringer Ingelheim, Daiichi-Sankyo, Lilly, MSD, Novartis, Novo Nordisk, Pfizer, and Sanofi.

Prof. Fichtner-Feigl states that he has no conflict of interest.

Manuscript received on 27 March 2021, revised version accepted on
7 October 2021.

Translated from the original German by Ethan Taub, M.D.

Corresponding author
Prof. Dr. Jodok Fink
Klinik für Allgemein- und Viszeralchirurgie
Sektion für Adipositas und Metabolische Chirurgie
Universitätsklinikum Freiburg
Hugstetter Str. 55, D-79106 Freiburg, Germany
jodok.fink@uniklinik-freiburg.de

Cite this as:
Fink J, Seifert G, Blüher M, Fichtner-Feigl S, Marjanovic G: Obesity surgery—weight loss, metabolic changes, oncological effects, and follow-up. Dtsch Arztebl Int 2022; 119: 70–80. DOI: 10.3238/arztebl.m2021.0359

Supplementary material

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Department of General and Visceral Surgery, Center for Obesity and Metabolic Surgery, Medical Center, University of Freiburg: Prof. Dr. Jodok Fink, PD Dr. Gabriel Seifert, Prof. Dr. Stefan Fichtner-Feigl, Prof. Dr. Goran Marjanovic
Helmholtz-Institute for Metabolic, Obesity and Vascular Research, (HI-MAG), Helmholtz Zentrum München at the University of Leipzig and the Medical Faculty of Leipzig AöR: Prof. Dr. Matthias Blüher
Indications for obesity and metabolic surgery
Box
Indications for obesity and metabolic surgery
Surgical procedures in obesity and metabolic surgery
Figure
Surgical procedures in obesity and metabolic surgery
Cancer risk in obese persons and reduction of the risk of selected types of cancer after obesity surgery
Table 1
Cancer risk in obese persons and reduction of the risk of selected types of cancer after obesity surgery
The outcomes of obesity surgery and metabolic surgery
Table 2
The outcomes of obesity surgery and metabolic surgery
Prevalences of micronutrient deficiency, laboratory tests, recommendations on vitamin supplementation following obesity surgery, and recommended vitamin and micronutrient intake according to the German Nutrition Society (Deutsche Gesellschaft für Ernährung)
Table 3
Prevalences of micronutrient deficiency, laboratory tests, recommendations on vitamin supplementation following obesity surgery, and recommended vitamin and micronutrient intake according to the German Nutrition Society (Deutsche Gesellschaft für Ernährung)
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