Long-term Changes in Leptin, Chemerin and Ghrelin Levels Following Different Bariatric Surgery Procedures: Roux-en-Y Gastric Bypass and Sleeve Gastrectomy

Background

Different studies have evaluated changes in adipo/cytokine levels after bariatric surgery and have given conflicting results. The adipo/cytokines, leptin and chemerin, and the orexigenic hormone, ghrelin, have been shown to play a role in the regulation of metabolism and appetite. The aims of our study were to test the levels of these molecules after bariatric surgery and to compare the results between Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy.

Methods

We analysed circulating levels of chemerin, ghrelin and leptin in 30 morbidly obese women (body mass index of >40 kg/m²). Subjects were studied at three time points: baseline (before the surgery started), and after 6 and 12 months.

Results

After surgery, chemerin (baseline, 95.03?±?23.79; after 12 months, 76.80?±?21.51; p?=?0.034) and leptin levels (baseline, 248.17?±?89.16; after 12 months, 63.85?±?33.48; p?<?0.001) were significantly lower than their baseline levels, whereas ghrelin was higher (baseline, 0.87?±?0.38; after 12 months, 1.08?±?0.31; p?=?0.010). Fasting glucose, insulin and homeostasis model assessment of insulin resistance levels were markedly lower postoperatively. High-density lipoprotein levels moderately increased and triglyceride levels sharply decreased. There were no differences between the types of bariatric surgery in terms of weight reduction, general metabolic state or adipo/cytokine levels after surgery.

Conclusions

Our study demonstrates a marked decrease in fasting leptin and chemerin levels, and an increase in ghrelin levels, after bariatric surgery-induced weight loss, independently of the type of surgery performed. Further studies are needed on the interrelation between the changes in the circulating levels of these molecules and the efficacy of the bariatric surgery procedures to induce the beneficial metabolic changes and to sustain body weight loss.     

Improvement of Exercise Capacity and Peripheral Metaboreflex After Bariatric Surgery

Background

Bariatric surgery is the only predictable method to obtain weight loss in severe obesity. Poor physical performance of obese individuals may be mediated by the peripheral metaboreflex, which controls blood flow redistribution to exercising muscles. Weight reduction improves exercise capacity through several possible mechanisms that are insufficiently understood. We hypothesized that the metaboreflex is one among the causes of improvement in exercise capacity after weight loss. This study thus aimed to examine the effect of bariatric surgery on exercise performance and metaboreflex.

Methods

Severely obese patients were assessed before and 3 months after bariatric surgery. Metaboreflex was evaluated by the technique of selective induction by post-exercise circulatory occlusion (PECO+) after isometric handgrip exercise at 30 % of maximum voluntary contraction. The exercise capacity was assessed by 6-min walking test.

Results

Seventeen patients completed the protocol. Body mass index decreased from 46.4?±?2 to 36.6?±?2 kg/m² (P?<?0.001). The distance walked in 6 min increased from 489?±?14 to 536?±?14 m (P?<?0.001). The peripheral metaboreflex activity, expressed by the area under the curve of vascular resistance, was lower after than before bariatric surgery (42?±?5 to 20?±?4 units, P?=?0.003). Heart rate, blood pressure, and vascular resistance were also significantly decreased. The correlation between change in distance walked in 6 min and change in peripheral metaboreflex activity was not significant.

Conclusions

Weight loss after bariatric surgery increases exercise capacity and reduces peripheral metaboreflex, heart rate, and blood pressure. Further investigation on the role of metaboreflex regarding mechanisms of exercise capacity of individuals with obesity is warranted.     

Shortening of the QT Interval is Observed Soon after Sleeve Gastrectomy in Morbidly Obese Patients

Background

Morbidly obese patients have an increased risk of sudden cardiac death. It is well known that obesity prolongs the QT interval, which in turn may cause ventricular arrhythmia and sudden cardiac death. The objective of this study was to establish whether sleeve gastrectomy shortens the QT interval.

Methods

Twenty-eight consecutive patients underwent sleeve gastrectomy at our institution between September 2010 and March 2011 and were included in the study. The indications for bariatric surgery were in accordance with French national guidelines. For each patient, an electrocardiogram was recorded before and then 3 months after surgery. The corrected QT (QTc) was determined independently by two physicians.

Results

The mean body mass index was 45.27?±?6.09 kg/m² before surgery and 38.32?±?5.19 kg/m² 3 months after surgery. The mean weight loss over this period was 20.71?±?7.57 kg. The QTc interval was 427?±?18.6 ms (415.7?±?12.06 in men and 428.4?±?18.96 in women) prior to surgery and was significantly lower 3 months after surgery (398.6?±?15.5 ms overall, 391.3?±?7.63 in men, and 399.6?±?16.02 in women). The QTc interval decreased in all individual patients (by an average of 28.5?±?15.6 ms overall, 24.3?±?8.38 in men, and 29?±?16.23 in women). Weight loss and decreased QTc interval were not significantly correlated (p?=?0.88).

Conclusion

Sleeve gastrectomy in morbidly obese patients was associated with a significantly lower QTc interval 3 months after surgery. These findings imply that bariatric surgery might reduce the risk of sudden cardiac death in this patient population.     

Impact of Restrictive (Sleeve Gastrectomy) vs Hybrid Bariatric Surgery (Roux-en-Y Gastric Bypass) on Lipid Profile

Background

Few studies have evaluated the impact of hybrid versus purely restrictive bariatric surgery on lipid profile, with the results being contradictory. The effect of laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) on lipid profile was compared.

Methods

A nonrandomized prospective cohort study was conducted on severely obese patients undergoing bariatric surgery. Indication for the type of surgical procedure was based on clinical criteria. Patients on lipid-lowering drugs and those that could not be matched for age, sex, and body mass index were excluded. Finally, 51 patients who underwent LSG and 51 undergoing LRYGB completed this study.

Results

During the first year post-surgery, no differences in percentage of excess weight loss and triglyceride reduction were found between groups. After LRYGR, low-density lipoprotein (LDL) cholesterol concentrations fell significantly (125.9?±?29.3 to 100.3?±?26.4?mg/dl, p?p?=?0.220). High-density lipoprotein (HDL) cholesterol increase was significantly greater after LSG (15.4?±?13.1?mg/dl) compared with LRYGB (9.4?±?14.0?mg/dl, p?=?0.032). Factors independently associated with LDL cholesterol reduction were higher baseline total cholesterol and undergoing LRYGB. A greater increase in HDL cholesterol was associated with LSG, older age, and baseline HDL cholesterol.

Conclusions

LRYGB produces an overall improvement in lipid profile, with a clear benefit in all lipid fractions. Although LSG does not alter LDL cholesterol levels, its effect on HDL cholesterol is comparable to or greater than that obtained with malabsorptive techniques.     

High Frequency of Serum Chromium Deficiency and Association of Chromium with Triglyceride and Cholesterol Concentrations in Patients Awaiting Bariatric Surgery

Background

To our knowledge, the frequency of serum chromium deficiency in patients awaiting bariatric surgery has not been determined. This study was designed to assess chromium concentration and its association with glycemic levels and lipid profile in patients prior to bariatric surgery.

Methods

This study recruited 73 candidates for bariatric surgery between March and September 2012. Their sociodemographic, anthropometric, and biochemical data were collected.

Results

Of the 73 patients, 55 (75.3 %) were women (75.34 %). Mean patient age was 37.20?±?9.92 years, and mean body mass index was 47.48 kg/m² (range, 43.59 to 52.50 kg/m²). Chromium deficiency was observed in 64 patients (87.7 %). Correlation analysis showed significant negative relationships between chromium concentration and BMI and zinc concentration and a significant positive relationship between chromium and glycated hemoglobin. Multiple linear regression analysis showed that serum chromium concentration was significantly associated with total cholesterol (β?=?0.171, p?=?0.048) and triglyceride (β?=??0.181, p?=?0.039) concentrations.

Conclusions

Serum chromium deficiency is frequent in candidates for bariatric surgery and is associated with total cholesterol and triglyceride concentrations. Early nutritional interventions are needed to reduce nutritional deficiencies and improve the lipid profile of these patients.     

Prevalence of Defaecatory Disorders in Morbidly Obese Patients Before and After Bariatric Surgery

Background

The prevalence of obesity is increasing worldwide and has lately reached epidemic proportions in western countries. Several epidemiological studies have consistently shown that both overweight and obesity are important risk factors for the development of various functional defaecatory disorders (DDs), including faecal incontinence and constipation. However, data on their prevalence as well as effectiveness of bariatric surgery on their correction are scant. The primary objective of this study was to estimate the effect of morbid obesity on DDs in a cohort of patients listed for bariatric surgery. We also evaluated preliminary results of the effects of sleeve gastrectomy on these disorders.

Patients and methods

A questionnaire-based study was proposed to morbidly obese patients having bariatric surgery. Data included demographics, past medical, surgical and obstetrics histories, as well as obesity related co-morbidities. Wexner Constipation Score (WCS) and the Faecal Incontinence Severity Index (FISI) questionnaires were used to evaluate constipation and incontinence. For the purpose of this study, we considered clinically relevant a WCS ??5 and a FISI score ??10. The same questionnaires were completed at 3 and 6?months follow-up after surgery.

Results

A total of 139 patients accepted the study and 68 underwent sleeve gastrectomy and fully satisfied our inclusion criteria with a minimum follow-up of 6?months. Overall, mean body mass index (BMI) at listing was 47?±?7?kg/m² (range 35?C67?kg/m²). Mean WCS was 4.1?±?4 (range 0?C17), while mean FISI score (expressed as mean±standard deviation) was 9.5?±?9 (range 0?C38). Overall, 58.9% of the patients reported DDs according to the above-mentioned scores. Twenty-eight patients (20%) had WCS ??5. Thirty-five patients (25%) had a FISI ??10 while 19 patients (13.7%) reported combined abnormal scores. Overall, DDs were more evident with the increase of obesity grade: Mean BMI decreased significantly from 47?±?7 to 36?±?6 and to 29?±?4?kg/m² respectively at 3 and 6?months after surgery (p?p?=?0.02). Similarly, the FISI score decreased from 10?±?8 to 3?±?4 and to 1?±?2 respectively at 3 and 6?months (p?=?0.0001).

Conclusions

Defaecatory disorders are common in morbidly obese patients. The risk of DDs increases with BMI. Bariatric surgery reduces DDs, mainly faecal incontinence, and these findings correlated with BMI reduction.     

Revisional Bariatric Surgery for Unsuccessful Weight Loss and Complications

Background

There are growing numbers of patients who require revisional bariatric surgery due to the undesirable results of their primary procedures. The aim of this study was to review our experience with bariatric patients undergoing revisional surgery.

Methods

We conducted a retrospective analysis to review the indications for revisional bariatric procedures and assess their postoperative outcomes.

Results

From 04/04 to 01/11, 2,918 patients underwent bariatric surgery at our institution. A total of 154 patients (5.3 %) of these cases were coded as revisional procedures. The mean age at revision was 49.1?±?11.3 and the mean BMI was 44.0?±?13.7 kg/m². Revisional surgery was performed laparoscopically in 121 patients (78.6 %). Laparoscopic revisions had less blood loss, shorter length of hospital stay, and fewer complications compared to open revisions. Two groups (A and B) were defined by the indication for revision: patients with unsuccessful weight loss (group A, n?=?106) and patients with complications of their primary procedures (group B, n?=?48). In group A, 74.5 % of the patients were revised to a bypass procedure and 25.5 % to a restrictive procedure. Mean excess weight loss was 53.7?±?29.3 % after revision of primary restrictive procedures and 37.6?±?35.1 % after revision of bypass procedures at >1-year follow-up (p?<?0.05). In group B, the complications prompting revision were effectively treated by revisional surgery.

Conclusions

Revisional bariatric surgery effectively treated the undesirable results from primary bariatric surgery. Laparoscopic revisional surgery can be performed after both failed open and laparoscopic bariatric procedures without a prohibitive complication rate. Carefully selected patients undergoing revision for weight regain have satisfactory additional weight loss.     

Trends in adolescent bariatric surgery evaluated by UHC database collection

Background

With increasing childhood obesity, adolescent bariatric surgery has been increasingly performed. We used a national database to analyze current trends in laparoscopic bariatric surgery in the adolescent population and related short-term outcomes.

Methods

Discharge data from the University Health System Consortium (UHC) database was accessed using International Classification of Disease codes during a 36?month period. UHC is an alliance of more than 110 academic medical centers and nearly 250 affiliate hospitals. All adolescent patients between 13 and 18?years of age, with the assorted diagnoses of obesity, who underwent laparoscopic adjustable gastric banding (LAGB), sleeve gastrectomy (SG), and laparoscopic Roux-en-Y gastric bypass (LRYGB) were evaluated. The main outcome measures analyzed were morbidity, mortality, length of hospital stay (LOS), overall cost, intensive care unit (ICU) admission rate, and readmission rate. These outcomes were compared to those of adult bariatric surgery.

Results

Adolescent laparoscopic bariatric surgery was performed on 329 patients. At the same time, 49,519 adult bariatric surgeries were performed. One hundred thirty-six adolescent patients underwent LAGB, 47 had SG, and 146 patients underwent LRYGB. LAGB has shown a decreasing trend (n?=?68, 34, and 34), while SG has shown an increasing trend (n?=?8, 15, and 24) over the study years. LRYGB remained stable (n?=?44, 60, and 42) throughout the study period. The individual and summative morbidity and mortality rates for these procedures were zero. Compared to adult bariatric surgery, 30?day in-hospital morbidity (0 vs. 2.2?%, p?<?0.02), the LOS (1.99?±?1.37 vs. 2.38?±?3.19, p?<?0.03), and 30?day readmission rate (0.30 vs. 2.02?%, p?<?0.05) are significantly better for adolescent bariatric surgery, while the ICU admission rate (9.78 vs. 6.30?%, p?<?0.02) is higher and overall cost ($9,375?±?6,452 vs. $9,600?±?8,016, p?=?0.61) is comparable.

Conclusion

Trends in adolescent laparoscopic bariatric surgery reveal the increased use of sleeve gastrectomy and adjustable gastric banding falling out of favor.     

Time Course of Blood Pressure Decrease After Bariatric Surgery in Normotensive and Hypertensive Patients

Background

Bariatric surgery leads to remission of several obesity-related comorbidities, including hypertension. Although antihypertensive medication use is decreased after bariatric surgery, the exact time course of decrease in blood pressure after surgery is not known.

Methods

A database of patients undergoing bariatric surgery at our institute was used to study the effect of surgery on time course of blood pressure changes. Data from surgeries performed between January 2010 and December 2012 were used.

Results

Maximum blood pressure and body weight decreases were observed at 2 weeks and 1 year after surgery, respectively. Average decrease in the mean arterial pressure (MAP) was 4.46 mmHg (61.5?±?17.1% of maximal decrease) and 7.17 mmHg (maximum decrease) at 1 and 2 weeks after surgery, when the decrease in body weight is 22.8?±?1.6 and 28?±?1.4% of maximal weight loss, respectively. In hypertensive patients, MAP decreased from 98.5?±?0.78 to 92.3?±?1.76 and 93.1?±?0.92 mmHg at 1 and 2 weeks post-surgery, respectively. In normotensive patients, the MAP decreased from 96.2?±?0.79 to 88.7?±?1.25, 90.0?±?0.94, 86.5?±?1.35, 88.0?±?1.13, and 86.4?±?2.13 mmHg at 2 weeks, 3 and 6 months, and 1 and 3 years after surgery, respectively.

Conclusions

These data demonstrate that significant decrease in MAP occurs within 2 weeks after bariatric surgery in hypertensive as well as normotensive patients. Future studies are required to investigate the weight-independent mechanisms of blood pressure decreases after bariatric surgery.

     

Acute and Chronic Effects of Biliopancreatic Diversion with Duodenal Switch Surgery on Plasma Visfatin and Apelin Levels in Patients with Severe Obesity

Background

Visfatin is an adipokine linked to obesity and inflammation, and it has insulin-mimetic properties. Apelin is an adipokine with positive cardiac inotropic effects, and it may be related to inflammatory molecules. Variations in plasma visfatin and apelin levels following bariatric surgery remain controversial.

Methods

In this study, patients who underwent a biliopancreatic diversion with duodenal switch (BPD-DS) were compared to a severely obese group (control group). Anthropometric measures and blood samples were taken before surgery, on days 1 and 5, as well as at 6 and 12 months after surgery in the BDP-DS group. For the control group, the tests were performed at baseline and at 6 and 12 months.

Results

Seventy subjects in the BPD-DS group and 28 in the control group were included. The expected reduction in body weight at 1 year after a BPD-DS was observed (85.9?±?18.5 vs. 136.6?±?27.7 kg at baseline; p?<?0.001). Plasma visfatin levels decreased at day 1 (16.13?±?5.56 vs. 18.82?±?7.36 ng/mL at baseline; p?=?0.001), while plasma apelin levels decreased at day 5 (0.50?±?0.28 vs. 0.55?±?0.33 ng/mL at baseline; p?=?0.040) after surgery. There were no changes at 6 and 12 months compared to baseline, and no changes were observed in the control group.

Conclusions

Our data show that 1-year weight loss induced by BPD-DS did not influence the overall plasma visfatin and apelin levels in severely obese patients.     

Validity of the Beck Depression Inventory as a Screening Tool for a Clinical Mood Disorder in Bariatric Surgery Candidates

Background

The Beck Depression Inventory (BDI) is one of the most commonly used instruments to assess depression in persons with obesity. While it has been validated in normal and psychiatric populations, in obese populations, its validity remains uncertain. This study aimed to investigate the validity and reliability of the BDI-IA and BDI-II in severely obese bariatric surgery candidates.

Methods

Consecutive new candidates at a bariatric surgery clinic were invited to participate in the study by their consulting surgeon. All candidates were assessed using the Structured Clinical Interview for DSM-IV Disorders (SCID-I); 118 completed the BDI-IA and 83 completed the BDI-II. Two hundred one patients (response rate, 88?%) participated in the study. The current sample (82?% female) had an average body mass index of 42.83?±?6.34 and an average age of 45?±?12?years.

Results

Based on the SCID-I, 54 candidates (26.9?%) met the criteria for a mood disorder, with 37 meeting the criteria for current major depressive disorder. Individuals diagnosed with a clinical mood disorder had significantly higher scores on the BDI (BDI-IA, 23.59?±?9.69 vs. 12.76?±?8.29; BDI-II, 22.93?±?5.22 vs. 11.25?±?8.44). Our results indicated that, as a screening tool for a clinical mood disorder, the BDI-II had an optimal cutoff of 13, with a sensitivity of 100 and specificity of 67.75.

Conclusions

Results indicated that the BDI-IA should not be used as a tool to measure depressive symptomatology in obese bariatric surgery candidates. No cutoff was identified with adequate sensitivity and specificity, and over 20?% of patients were misclassified. As a screening tool for a clinical mood disorder, the BDI-II was adequate; however, prevalence rates were significantly overestimated.     

Fracture risk following bariatric surgery: a population-based study

Summary

The effects of bariatric surgery on skeletal health are poorly understood. We found that bariatric surgery patients are more prone to fracture when compared to the general population. While further studies of fracture risk in this population are needed, bone health should be discussed in bariatric surgery clinics.

Introduction

Bariatric surgery is an increasingly common treatment for medically complicated obesity. Adverse skeletal changes after bariatric surgery have been reported, but their clinical importance remains unknown. We hypothesized that bariatric surgery patients are at increased risk of fracture.

Methods

We conducted a historical cohort study of fracture incidence among 258 Olmsted County, Minnesota, residents who underwent a first bariatric surgery in 1985–2004. Relative fracture risk was expressed as standardized incidence ratios (SIRs), while potential risk factors were evaluated by hazard ratios (HR) obtained from a time-to-fracture regression model.

Results

The mean (±SD) body mass index at bariatric surgery was 49.0?±?8.4 kg/m², with an average age of 44?±?10 years and 82 % (212) females. Gastric bypass surgery was performed in 94 % of cases. Median follow-up was 7.7 years (range, 6 days to 25 years), during which 79 subjects experienced 132 fractures. Relative risk for any fracture was increased 2.3-fold (95 % confidence interval (CI), 1.8–2.8) and was elevated for a first fracture at the hip, spine, wrist, or humerus (SIR, 1.9; 95 % CI, 1.1–2.9), as well as for a first fracture at any other site (SIR, 2.5; 95 % CI, 2.0–3.2). Better preoperative activity status was associated with a lower age-adjusted risk (HR, 0.4; 95 % CI, 0.2–0.8) while prior fracture history was not associated with postoperative fracture risk.

Conclusions

Bariatric surgery, which is accompanied by substantial biochemical, hormonal, and mechanical changes, is associated with an increased risk of fracture.     

Improvement of Nonalcoholic Fatty Liver Disease After Bariatric Surgery in Morbidly Obese Chinese Patients

Background

Obesity is a risk factor for nonalcoholic fatty liver disease (NAFLD), which appears to improve after weight loss induced by bariatric surgery in Western countries. The present study aims to determine the alterations of clinical measurements and liver histology of NAFLD after bariatric surgery in morbidly obese Chinese patients.

Methods

Between November 2006 and December 2007, 21 morbidly obese patients receiving intra-operative liver biopsy and follow-up liver biopsy 1?year after laparoscopic Roux-en-Y gastric bypass were enrolled. NAFLD activity score (NAS) and fibrosis stage were histologically evaluated.

Results

The mean body mass index fell from 43.8?±?7.5 to 28.3?±?4.6?kg/m² (P?P?P?<?0.01), but not aspartate aminotransferase (P?=?0.66). Histological improvement was noted in NAS (P?P?P?P?=?0.02). Pre-operatively, 4 (19.0%), 11 (52.4%), and 6 (28.6%) patients were found to have NAS ?R5, 3 or 4, and ?Q2, respectively. All patients had NAS ?Q2 after surgery. Fibrosis stage also showed significant improvement (P?Conclusions Bariatric surgery can achieve a dramatic improvement of NAFLD both biochemically and histologically in morbidly obese Chinese patients.     

Reduced Circulating Androgen Levels After Gastric Bypass Surgery in Severely Obese Women

Background

Previous studies have shown a reduction of elevated androgen levels in premenopausal women after marked weight loss induced by bariatric surgery. In this study, we aimed to assess whether circulating androgen levels also decline after bariatric surgery in women displaying normal values preoperatively as well as in postmenopausal women.

Methods

In 36 severely obese women (six postmenopausal), levels of total testosterone, dehydroepiandresterone sulfate (DHEA-S), and sex hormone-binding globulin (SHBG) were assessed before and at ~1 year after gastric bypass. Free and bioavailable testosterone levels as well as the free androgen index were calculated by established formulas.

Results

After the surgery, women had lost on average 43.1?±?1.8 kg. Independently of the pre/postmenopausal state, women showed a marked reduction in all testosterone-related androgen markers and DHEA-S levels, while SHBG levels markedly increased (all P?<?0.001). Respective changes were found in both women with and without preoperatively elevated levels. Changes after the surgery in testosterone-related markers as well as in SHBG levels but not in DHEA-S levels were correlated with changes in insulin levels independently of body weight changes.

Conclusions

Data show a marked reduction of androgen levels in severely obese women after a surgically induced weight loss, which is independent from the menopausal state and preoperative levels. The mechanisms and consequences of these hormonal changes induced by bariatric surgery should be addressed in further studies.     

Adipogenic differentiation of adipose tissue-derived human mesenchymal stem cells: effect of gastric bypass surgery

Background

Adipose tissue dysfunction is an important feature of obesity characterized by enlarged adipocytes and marked changes in secretion of cytokines. These changes result in insulin resistance, chronic vascular inflammation, oxidative stress, and activation of the renin?Cangiotensin system (RAS), eventually leading to type 2 diabetes, obesity-related hypertension, and cardiovascular disease (CVD). Several trials have shown that bariatric surgery significantly reduces these comorbidities. However, there is a gap in knowledge regarding the mechanisms whereby bariatric surgery reduces the burden of CVD in obese individuals.

Method

Mesenchymal stem cells (MSCs) were isolated from adipose tissue collected from three groups: (1) nonobese control subjects, (2) obese subjects undergoing gastric bypass surgery (GBS), and (3) subjects 1?year or more after GBS. In the study, MSCs were induced to adipogenic differentiation, and RAS-related gene expressions were determined by quantitative polymerase chain reaction. The effect of angiotensin II (Ang II) on adipogenic differentiation of MSCs also was investigated.

Results

Angiotensinogen mRNA levels in MSCs and differentiated adipocytes were significantly higher in the obese group than in the nonobese control subjects. Renin mRNA levels were significantly higher in the obese group MSCs than in the nonobese and post-GBS groups. Angiotensin-converting enzyme mRNA levels were significantly lower in the MSCs derived from the post-GBS group than in the obese and nonobese control subjects. Serum Ang II levels were significantly lower in the post-GBS group (52.1?±?4.2?pg/ml) than in the nonobese (85.4?±?12.4?pg/ml) and obese (84.7?±?10.0?pg/ml) groups. Ang II treatment inhibited adipogenesis of MSCs in a dose-dependent manner. The inhibitory effect of Ang II was mainly abolished by PD123319, a receptor 2 blocker.

Conclusions

The adipogenesis of MSCs is inhibited by Ang II treatment. Obese individuals are characterized by an upregulation of the RAS-related gene expressions in adipose tissue. This upregulation resolves in post-GBS subjects.     

Functioning of Obese Individuals in Pre- and Postoperative Periods of Bariatric Surgery

Background

Obesity is a pathologic condition that causes functional incapacity, with reduction of quality of life and life expectancy and an increase in mortality. Bariatric surgery is indicated to alleviate associated comorbidities and increase physical capacity. The objective of this work was to evaluate the functional capacity of patients with morbid obesity before and after (3 months) bariatric surgery.

Methods

This was a cross-sectional study involving 67 patients, where 61 were women and six men, with a mean age of 38?±?10 years and mean BMI of 50.45?±?8.5 kg/m². All patients were assessed before surgery and 3 months afterwards. The following assessments were performed: 6-min walk test (6MWT), functional independence measure (FIM), and test for risk of falling and transfer capacity, called the timed up-and-go test.

Results

The study demonstrated a reduction in parameters evaluated in 6MWT with a statistically significant difference at two times (rest and final) when evaluated before and after bariatric surgery (p?<?0.001). In relation to the FIM and timed up-and-go test, the patients showed a statistically significant improvement (p?<?0.001) for both when comparing the tasks evaluated at the pre- and postoperative moments.

Conclusions

Obesity has an impact on the functioning and quality of life of patients. We observed an improvement in all instruments used for assessment before and after bariatric surgery, where a linear component was demonstrated in relation to diminution of body mass index and functioning.     

Increased Plasma Magnesium Concentrations 3?Years After Biliopancreatic Diversion with Duodenal Switch

Background

Biliopancreatic diversion with duodenal switch, BPD-DS, is a surgical procedure for treatment of super obese patients. It renders very good weight results and it strongly reduces the incidence of type 2 diabetes. One important mechanism of weight reduction after BPD-DS is malabsorption. Hypomagnesemia is an established cardiovascular risk factor. While it is well-known that magnesium levels decline after jejuno-ileal bypass and increase after gastric bypass surgery, information on how magnesium status is affected by BPD-DS is scant. The aim of the present study was to evaluate plasma magnesium concentrations (P-Mg) after BPD-DS.

Methods

Thirty-one patients, all Caucasians (9 diabetics, 12 men, age 38?±?8?years, weight 159?±?22?kg, body mass index (BMI) 53.9?±?5.2?kg/m²) underwent BPD-DS. We evaluated weight, glycated hemoglobin levels (HbA1c) and P-Mg preoperatively as well as at 1 and 3?years after surgery. All subjects were treated with vitamin and mineral substitution after surgery, including 100?mg of magnesium salt. P-Mg was analyzed with respect to changes over time, correlation to BMI and HbA1c levels before and 3?years after surgery.

Results

The plasma magnesium concentrations increased by 15?% from 0.77?±?0.07 to 0.88?±?0.09?mmol/l over 3?years (p?<?0.001). The weight loss was 71?±?25?kg. No patient had diabetes at follow-up. No correlations between P-Mg and BMI or HbA1c were seen.

Conclusions

Although exerting much of its weight-reducing effect by a malabsorptive mechanism, BPD-DS yields a rise in P-Mg 3?years postoperatively, possibly contributing to the improved metabolic state after this operation.     

Accelerated Gastric Emptying but No Carbohydrate Malabsorption 1 Year After Gastric Bypass Surgery (GBP)

Background

Following gastric bypass surgery (GBP), there is a post-prandial rise of incretin and satiety gut peptides. The mechanisms of enhanced incretin release in response to nutrients after GBP is not elucidated and may be in relation to altered nutrient transit time and/or malabsorption.

Methods

Seven morbidly obese subjects (BMI?=?44.5?±?2.8?kg/m²) were studied before and 1?year after GBP with a d-xylose test. After ingestion of 25?g of d-xylose in 200?mL of non-carbonated water, blood samples were collected at frequent time intervals to determine gastric emptying (time to appearance of d-xylose) and carbohydrate absorption using standard criteria.

Results

One year after GBP, subjects lost 45.0?±?9.7?kg and had a BMI of 27.1?±?4.7?kg/m². Gastric emptying was more rapid after GBP. The mean time to appearance of d-xylose in serum decreased from 18.6?±?6.9?min prior to GBP to 7.9?±?2.7?min after GBP (p?=?0.006). There was no significant difference in absorption before (serum d-xylose concentrations?=?35.6?±?12.6?mg/dL at 60?min and 33.9?±?9.1?mg/dL at 180?min) or 1?year after GBP (serum d-xylose?=?31.5?±?18.1?mg/dL at 60?min and 27.2?±?11.9?mg/dL at 180?min).

Conclusions

These data confirm the acceleration of gastric emptying for liquid and the absence of carbohydrate malabsorption 1?year after GBP. Rapid gastric emptying may play a role in incretin response after GBP and the resulting improved glucose homeostasis.     

Antibiotic Prophylaxis in Bariatric Surgery with Continuous Infusion of Cefazolin: Determination of Concentration in Adipose Tissue

Background

The aim of this study was to evaluate the concentration of cefazolin in adipose tissue of patients undergoing bariatric surgery.

Methods

Eighteen patients undergoing bariatric surgery were evaluated during the period from October 2011 to May 2012. All patients had a dosage schedule of antibiotic prophylaxis with cefazolin administered as follows: first, 2 g in anesthetic induction, followed by continuous infusion of 1 g diluted in 250 ml of saline solution. Adipose samples, collected soon after the incision (initial) and before the skin synthesis (final), were analyzed using reverse phase high-pressure liquid chromatography. The level of significance adopted was 5 %.

Results

The cefazolin concentration in the adipose tissue samples at the beginning of surgery was an average of 6.66?±?2.56 ug/ml. The mean concentration before the skin synthesis was 7.93?±?2.54 ug/ml. Patients with BMI?2 had higher initial and final sample concentrations of cefazolin than patients with BMI?≥?40 kg/m². There was no surgical site infection (SSI) in any of the patients.

Conclusions

In bariatric surgeries, addition of a 1 g increase of cefazolin, administered through continuous intravenous infusion, to the currently recommended dose of 2 g administered in anesthetic induction provided a concentration in the adipose tissue above the minimum inhibitory concentration (MIC) of the main causal agents of SSI. An inverse correlation between BMI and concentration of cefazolin in adipose tissue was observed.