Insulin resistance, inflammation, and the metabolic syndrome following Roux-en-Y gastric bypass surgery in severely obese subjects

Galectin-3 levels and inflammatory response in patients undergoing bariatric surgery

PURPOSE

Obesity, a low-grade systemic inflammatory disease, causes inflammation in metabolic tissues. Galectin-3(Gal-3) is one of the lectin molecules involved in inflammatory processes. We evaluated the possible relationship between Gal-3 level and the metabolic inflammatory process before and after obesity surgery.

METHODS

One hundred participants were included in the study and classified as normal weight, overweight, Class I, II, and III obese. Class III obese group underwent bariatric surgery and evaluated in the 3rd and 6th months after surgery. Glucose, insulin, glycated hemoglobin A1c (HbA1c), homeostatic model assessment of insulin resistance (HOMA-IR), high sensitivity C-reactive protein (hsCRP), Gal-3, interleukin (IL)-6, IL-10, adiponectin, and leptin levels were determined.

RESULTS

Gal-3 levels were higher in Class III obese compared to the normal weight group. Postoperative leptin and hsCRP levels were decreased significantly, but the decrease in IL-6 and Gal-3 levels were not significant. Postoperative increased adiponectin and IL-10 levels were significant. Gal-3 was found significantly higher in insulin resistant group. The correlation between Gal-3 with BMI, adiponectin, leptin, hsCRP levels, and HOMA-IR was found weak.

CONCLUSION

These findings might support the fact that Gal-3 is one of the molecules involved in the linkage between insulin resistance and meta-inflammation in morbid obese.

Metabolic shift precedes the resolution of inflammation in a cohort of patients undergoing bariatric and metabolic surgery

Bariatric and metabolic surgery has shown to promote weight loss and reduce systemic inflammation. However, the sequence and timing of events regarding metabolic improvement and inflammation resolution has been rarely explored. Furthermore, data on inflammatory markers of Th17 and Th1 cell responses after bariatric surgery is scarce. We conducted a prospective study in subjects with obesity that underwent bariatric and metabolic surgery, with follow-ups at 3 and 6 months. Anthropometric and metabolic markers such as insulin levels, HOMA-IR, and lipid parameters declined significantly 3 months after surgery; while hs-CRP, TNF-α, IL-1β, IL-6, and IL-8 serum concentrations decreased 6 months after the procedure. Concentrations of Th1 signature and driver cytokines, particularly IFN-γ, IL-12, and IL-18, and of Th17 driver IL-23 also decreased significantly after 6 months. Significant positive correlations between triglyceride levels and hs-CRP, IL-1β, and IFN-γ concentrations, and between Apo B and IFN-γ levels were observed 6 months after bariatric and metabolic surgery. In addition, BMI was associated with hs-CRP and TNF-α concentrations. Fat mass correlated with hs-CRP, TNF-α, and IL-12. Analysis of the temporality of metabolic and inflammatory events suggests that improvement in the metabolic status occurs before resolution of systemic inflammation and may be a requisite for the later event.

The Positive Impact of Resistance Training on Muscle Mass and Serum Leptin Levels in Patients 2-7 Years Post-Roux-en-Y Gastric Bypass: A Controlled Clinical Trial

PURPOSE

Resistance training program (RTP) assist the maintenance of optimal body composition and inflammatory response modulation in individuals in late Roux-en-Y gastric bypass (RYGB). This study aimed to investigate the effect of RTP on body composition and serum inflammatory profile in individuals 2-7 years post-RYGB.

METHODS

Volunteers were matched on body mass index (BMI), age, sex, and years after surgery, and they were allocated as control or RTP group. Body composition, visceral fat area (VFA), and inflammatory serum markers were measured at baseline and after 12 weeks of RTP.

RESULTS

The sample baseline characteristics (n = 63; BMI = 29.7 ± 5.3 kg/m²) were similar between the groups. After intervention, the RTP group presented higher fat-free mass (Δ 1.17 ± 1.12 kg, p = 0.003) and skeletal muscle mass (Δ 0.77 ± 0.66 kg, p = 0.002) and decreased leptin levels (Δ -0.15 ± 0.60 pg/mL, p = 0.028). Ultrasensitive C-reactive protein (CRPus), interleukin-6, adiponectin, and monocyte chemotactic protein-1 showed no significant time-by-group interaction. After the categorization of RTP group individuals by VFA median values (129.8 cm², IQR 90.9; 152.5), participants with VFA values above the median presented a significant decrease in CRPus (Δ -0.20 mg/L, IQR -7.59; -0.03, p = 0.022) when compared to the participants with VFA values below the median.

CONCLUSION

The RTP improved individuals' body composition by a modest but significant enhancing muscle mass and decreasing serum leptin and CRPus levels, especially in individuals with VFA values above the median. RTPs assist in maintaining the adequate body composition as they contribute to a decrease in proinflammatory markers in long-term RYGB.

Preoperative Chemerin Level Is Predictive of Inflammatory Status 1 Year After Bariatric Surgery

BACKGROUND

Obesity is associated with chronic low-grade inflammation, which has been linked to increased morbidity. However, inflammation variably and unpredictably improves after bariatric surgery. This study aimed at (1) evaluating the relationship between amplitude of weight loss and variation of inflammatory parameters after bariatric surgery, and (2) identifying, among clinical and biological baseline parameters, predictive factors of variation in inflammatory parameters.

METHODS

In a prospective cohort of patients who underwent bariatric surgery, serum concentrations of interleukin (IL)-6, IL-10, resistin, leptin, adiponectin chemerin, and C-reactive protein (CRP) were measured preoperatively and 1 year after surgery, and routine clinical and biochemical parameters were retrieved. Univariate and multivariate analyses (partial least square method) were performed to assess how parameters were associated with weight loss and to predict improvement of inflammatory parameters.

RESULTS

Eighty-seven patients were included (mean weight ± SD 136.3 ± 3.2 kg, 35 gastric bypasses, 52 sleeve gastrectomies). In parallel with weight loss (39.5 ± 13.8 kg), pro-inflammatory markers (IL-6, CRP, leptin, resistin) significantly decreased, and anti-inflammatory markers (IL-10, adiponectin) increased. Multivariate analysis revealed a significant association between weight loss and improvement in inflammatory parameters. Among all the clinical and biological preoperative parameters, baseline chemerin level was the only parameter that was significantly associated with global improvement of the inflammatory status after surgery.

CONCLUSION

The amplitude of weight loss 1 year after bariatric surgery was strongly correlated with improvement of inflammatory profile, which could be predicted by baseline plasma level of chemerin. This suggests a key role of chemerin in obesity-driven inflammation, and a potential use as a biomarker.

Contribution of Adipose Tissue Inflammation to the Development of Type 2 Diabetes Mellitus

The objective of this comprehensive review is to summarize and discuss the available evidence of how adipose tissue inflammation affects insulin sensitivity and glucose tolerance. Low-grade, chronic adipose tissue inflammation is characterized by infiltration of macrophages and other immune cell populations into adipose tissue, and a shift toward more proinflammatory subtypes of leukocytes. The infiltration of proinflammatory cells in adipose tissue is associated with an increased production of key chemokines such as C-C motif chemokine ligand 2, proinflammatory cytokines including tumor necrosis factor α and interleukins 1β and 6 as well as reduced expression of the key insulin-sensitizing adipokine, adiponectin. In both rodent models and humans, adipose tissue inflammation is consistently associated with excess fat mass and insulin resistance. In humans, associations with insulin resistance are stronger and more consistent for inflammation in visceral as opposed to subcutaneous fat. Further, genetic alterations in mouse models of obesity that reduce adipose tissue inflammation are-almost without exception-associated with improved insulin sensitivity. However, a dissociation between adipose tissue inflammation and insulin resistance can be observed in very few rodent models of obesity as well as in humans following bariatric surgery- or low-calorie-diet-induced weight loss, illustrating that the etiology of insulin resistance is multifactorial. Taken together, adipose tissue inflammation is a key factor in the development of insulin resistance and type 2 diabetes in obesity, along with other factors that likely include inflammation and fat accumulation in other metabolically active tissues. © 2019 American Physiological Society. Compr Physiol 9:1-58, 2019.

Systemic Inflammation in Severe Obese Patients Undergoing Surgery for Obesity and Weight-Related Diseases

BACKGROUND

Obesity is a worldwide disease related to genetic, environmental, and behavioral factors, and it is associated with high rates of morbidity and mortality. Recently, obesity has been characterized by a low-grade inflammatory state known as inflammome indicated by chronic increases in circulating concentrations of inflammatory markers. The purpose of this study was to evaluate the effect of weight loss induced by surgery for obesity and weight-related diseases on pro-inflammatory cytokine (TNF-α) and anti-inflammatory adipokine (adiponectin) levels, and on an adipose-derived hormone (leptin) in severely obese subjects.

METHODS

This randomized, controlled trial involved 55 severe obese patients (50 women, age 18-63 years, and body mass index of 35.7-63 kg/m2) who underwent bariatric surgery (BS). Patients with a BMI > 65 kg/m2 and clinical and mental instability, or significant and unrealistic expectations of surgery were excluded. Blood samples were collected during the fasting period to analyze tumor necrosis factor alpha (TNF-α), adiponectin, and leptin levels by enzyme-linked immunosorbent assay.

RESULTS

At baseline, no significant difference was observed in the anthropometric, demographic, clinical characteristics and biochemistry and inflammatory markers between the control group (CG) and bariatric surgery group (BSG). The same finding was also observed when we compared the baseline variables to those at the 6-month follow-up in the CG. However, the same variables in the BSG group were significantly different between baseline and the 6-month follow-up after BS.

CONCLUSIONS

Weight loss induced by surgery for obesity and weight-related diseases reduced the inflammome state in severely obese patients.

The short-term and long-term effects of bariatric/metabolic surgery on subcutaneous adipose tissue inflammation in humans

CONTEXT

The mechanisms mediating the short- and long-term improvements in glucose homeostasis following bariatric/metabolic surgery remain incompletely understood.

OBJECTIVE

To investigate whether a reduction in adipose tissue inflammation plays a role in the metabolic improvements seen after bariatric/metabolic surgery, both in the short-term and longer-term.

DESIGN

Fasting blood and subcutaneous abdominal adipose tissue were obtained before (n=14), at one month (n=9), and 6-12months (n=14) after bariatric/metabolic surgery from individuals with obesity who were not on insulin or anti-diabetes medication. Adipose tissue inflammation was assessed by a combination of whole-tissue gene expression and flow cytometry-based quantification of tissue leukocytes.

RESULTS

One month after surgery, body weight was reduced by 13.5±4.4kg (p<0.001), with improvements in glucose tolerance reflected by a decrease in area-under-the-curve (AUC) glucose in 3-h oral glucose tolerance tests (-105±98mmol/L * min; p=0.009) and enhanced pancreatic β-cell function (insulinogenic index: +0.8±0.9pmol/mmol; p=0.032), but no change in estimated insulin sensitivity (Matsuda insulin sensitivity index [ISI]; p=0.720). Furthermore, although biomarkers of systemic inflammation and pro-inflammatory gene expression in adipose tissue remained unchanged, the number of neutrophils increased in adipose tissue 15-20 fold (p<0.001), with less substantial increases in other leukocyte populations. By the 6-12month follow-up visit, body weight was reduced by 34.8±10.8kg (p<0.001) relative to baseline, and glucose tolerance was further improved (AUC glucose -276±229; p<0.001) along with estimated insulin sensitivity (Matsuda ISI: +4.6±3.2; p<0.001). In addition, improvements in systemic inflammation were reflected by reductions in circulating C-reactive protein (CRP; -2.0±5.3mg/dL; p=0.002), and increased serum adiponectin (+1358±1406pg/mL; p=0.003). However, leukocyte infiltration of adipose tissue remained elevated relative to baseline, with pro-inflammatory cytokine mRNA expression unchanged, while adiponectin mRNA expression trended downward (p=0.069).

CONCLUSION

Both the short- and longer-term metabolic improvements following bariatric/metabolic surgery occur without significant reductions in measures of adipose tissue inflammation, as assessed by measuring the expression of genes encoding key mediators of inflammation and by flow cytometric immunophenotyping and quantification of adipose tissue leukocytes.

Improvements in glycemic control after gastric bypass occur despite persistent adipose tissue inflammation

OBJECTIVE

Type 2 diabetes commonly goes into remission following Roux-en-Y gastric bypass (RYGB). As the mechanisms remain incompletely understood, a reduction in adipose tissue inflammation may contribute to these metabolic improvements. Therefore, whether RYGB reduces adipose tissue inflammation compared with equivalent weight loss from an intensive lifestyle intervention was investigated.

METHODS

Sixteen people with obesity and type 2 diabetes were randomized to RYGB or lifestyle intervention. Fasting blood and subcutaneous abdominal adipose tissue were obtained before and after the loss of ∼7% of baseline weight. Adipose tissue inflammation was assessed by whole-tissue gene expression and flow cytometry-based quantification of tissue leukocytes.

RESULTS

At 7% weight loss, insulin and metformin use were reduced among the RYGB but not the Lifestyle cohort, while fasting glucose and insulin declined in both. Adipose tissue inflammation increased modestly after RYGB and to a similar extent following nonsurgical weight loss. In both groups, the number of neutrophils increased severalfold (P < 0.001), mRNA levels of the proinflammatory cytokine interleukin-1β increased (P = 0.037), and mRNA expression of the anti-inflammatory and insulin-sensitizing adipokine adiponectin decreased (P = 0.010).

CONCLUSIONS

A reduction in adipose tissue inflammation is not one of the acute weight loss-independent mechanisms through which RYGB exerts its antidiabetes effects.

Airway Hyperresponsiveness to Mannitol in Obesity Before and After Bariatric Surgery

BACKGROUND

The relationship between airway hyperresponsiveness (AHR) and obesity, a low-grade systemic inflammatory condition, remains largely unknown. It is established that AHR to indirect stimuli is associated with active airway inflammation. The objectives were to investigate the rate of AHR to mannitol in obese subjects and its changes 1 year after bariatric surgery (BS).

METHODS

We enrolled 58 candidates to BS severely obese (33 nonsmokers and 25 smokers) without history of asthma and 20 healthy, nonobese participants and related AHR to functional findings and serum and exhaled biomarkers.

RESULTS

Before surgery, AHR was observed in 16 (28 %) obese with the provocation doses of mannitol to induce a 15 % fall in FEV1 (PD15) of (geometric mean [95 % CI]) 83 (24-145) mg. Compared to control participants, obese participants had lower spirometric values and higher serum and exhaled biomarkers (p < 0.05 each). After surgery, AHR was abolished (p < 0.01) in all but four obese subjects.

CONCLUSIONS

Weight loss induced by BS was the key independent factor associated to AHR improvement. AHR to mannitol is highly prevalent in obesity, and it is largely abolished by BS.

Predictors of metabolic syndrome persistence 1 year after laparoscopic Roux-en-Y gastric bypass

BACKGROUND

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is effective in reversing the metabolic syndrome (MS) in up to 90% of patients.

OBJECTIVES

The aim of this study was to determine predictors of MS persistence 1 year after LRYGB.

SETTING

University Hospital, France.

METHODS

Ninety-one patients with a mean age of 44.4 years and a mean body mass index (BMI) of 43.1 kg/m² meeting the criteria for MS were enrolled in this prospective study. Anthropometric, metabolic, and inflammatory biological parameters were assessed before and 1 year after LRYGB. Patients were divided into 2 groups according to the persistence (MS nonresponders) or resolution of MS (MS responders) 1 year after LRYGB and a comparison was performed at baseline and 1 year after surgery.

RESULTS

Sixty-nine patients (75.8%) underwent remission, while 22 (24.2%) showed persistence of MS 1 year after LRYGB. At baseline the MS nonresponders group presented significantly higher values of fasting plasma glucose (7.8 versus 5.3 mmol/L, P = .004), glycosylated hemoglobin (HbA1c, 7.3% versus 5.9%, P = .0004), triglycerides (TG, 2.37 versus 1.33 mmol/L, P = .006), and homeostasis model assessment of insulin resistance (HOMA-IR, 442.5 versus 256, P = .006). The rate of diabetes was significantly higher in this group (68.2% versus 36.8%, P = .0086), as well as the number of MS components per patient. One year after LRYGB, the MS nonresponders showed a significantly lower excess BMI lost (EBMIL) (56.1% versus 82.4%, P = .00008). On multivariate analysis, baseline levels of TG, glucose metabolism markers and EBMIL were associated with the persistence of MS.

CONCLUSION

Baseline levels of TG, plasma fasting glucose, and HbA1c, as well as history of type 2 diabetes and EBMIL, represent predictors of MS persistence 1 year after LRYGB.

Proteomics in obesity research

Obesity has emerged as one of the major global epidemics of the 21st century and is now reaching alarming proportions. Obese subjects have an increased morbidity and mortality, decreased quality of life and a major risk of developing pathologies such as diabetes mellitus, insulin resistance and cardiovascular disease. Obesity is a complex disease characterised by an increase in body fat mass resulting from an imbalance between energy intake and expenditure. Signal integration between adipose tissue, other peripheral organs and the CNS seems to regulate energy homeostasis. Proteomics may be useful in unravelling the pathogenesis of obesity, since a combination of genetic predisposition and environmental factors account for its development. Most of the proteomic studies performed to date have focused on protein profiling of adipose tissue in different models of experimental obesity and the study of the adipocyte differentiation process. Another issue that has recently attracted attention is the characterisation of the adipocyte secretome, which may be important in signalling to other organs and in regulating energy balance. Target identification of potential therapies has also been investigated by proteomics. This review focuses on the contributions of proteomics to understanding the molecular mechanisms of obesity and their potential therapies.

Anaemia and related nutrient deficiencies after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis

OBJECTIVE

To obtain a pooled risk estimate on the long-term impact of anaemia and related nutritional deficiencies in patients receiving Roux-en-Y gastric bypass (RYGB) surgery.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE and Cochrane databases were searched to identify English reports published before 16 May 2014.

ELIGIBILITY CRITERIA

Articles with case numbers >100, follow-up period >12 months, and complete data from both before and after surgery were selected. Outcomes of interest were changes in baseline measurements of proportion of patients with anaemia, by haemoglobin, haematocrit, ferritin, iron, vitamin B12 and folate levels.

DATA COLLECTION AND ANALYSIS

Two reviewers independently reviewed data and selected six prospective and nine retrospective studies with a total of 5909 patients. A random effect model with inverse variance weighting was used to calculate summary estimates of outcomes at 6, 12, 24 and 36 months postoperatively.

RESULTS

Proportion of patients with anaemia was 12.2% at baseline, which, respectively, increased to 20.9% and 25.9% at 12 and 24 months follow-up, consistent with decreases in haemoglobin and haematocrit levels. Although the serum iron level did not change substantially after surgery, the frequency of patients with ferritin deficiency increased from 7.9% at baseline to 13.4% and 23.0% at 12 and 24 months, respectively, postoperation. Vitamin B12 deficiency increased from 2.3% at baseline to 6.5% at 12 months after surgery in those subjects receiving RYGB. There was no obvious increase in folate deficiency.

CONCLUSIONS

RYGB surgery is associated with an increased risk of anaemia and deficiencies of iron and vitamin B12, but not folate. Ferritin is more sensitive when serum iron level is within normal range.

Changes in intestinal permeability after Roux-en-Y gastric bypass

BACKGROUND

Roux-en-Y gastric bypass (RYGB) interferes considerably with the anatomy and physiology of the gastrointestinal tract. The study of intestinal permeability can provide important information regarding changes in the structure and function of the mucosal barrier after the procedure.

METHODS

The urinary excretion rates of lactulose and mannitol after oral intake of both substances were evaluated. We also evaluated the lactulose/mannitol excretion ratio. Tests were performed during the preoperative period (T0), at the first postoperative month (T1), and at the sixth postoperative month (T6).

RESULTS

The study included 16 morbidly obese patients. The excretion rate of mannitol was significantly lower at T1 compared with T0 and T6 (p = 0.003). There was no significant difference in the excretion rates of lactulose or in the lactulose/mannitol ratio during the three periods. Six patients (37.5%) exhibited a considerable increase in the excretion rate of lactulose at T6 (4-73 times higher than the preoperative value), accompanied by proportional variations in the lactulose/mannitol ratio.

CONCLUSIONS

The significant increase in mannitol excretion rate from T1 to T6 most likely reflects the occurrence of intestinal adaptation (mucosal hyperplasia), which would tend to minimize the malabsorption of macronutrients. A subgroup of patients who undergo RYGB exhibit pronounced increase in their intestinal permeability (assessed by the lactulose/mannitol ratio and the lactulose excretion rate) at T6.

The systemic inflammome of severe obesity before and after bariatric surgery

Introduction

Obesity is associated with low-grade systemic inflammation. The “inflammome” is a network layout of the inflammatory pattern. The systemic inflammome of obesity has not been described as yet. We hypothesized that it can be significantly worsened by smoking and other comorbidities frequently associated with obesity, and ameliorated by bariatric surgery (BS). Besides, whether or not these changes are mirrored in the lungs is unknown, but obesity is often associated with pulmonary inflammation and bronchial hyperresponsiveness.

Objectives

We sought to: (1) describe the systemic inflammome of morbid obesity; (2) investigate the effects of sex, smoking, sleep apnea syndrome, metabolic syndrome and BS upon this systemic inflammome; and, (3) determine their interplay with pulmonary inflammation.

Methods

We studied 129 morbidly obese patients (96 females; age 46±12 years; body mass index [BMI], 46±6 kg/m²) before and one year after BS, and 20 healthy, never-smokers, (43±7 years), with normal BMI and spirometry.

Results

Before BS, compared with controls, all obese subjects displayed a strong and coordinated (inflammome) systemic inflammatory response (adiponectin, C-reactive protein, interleukin (IL)-8, IL-10, leptin, soluble tumor necrosis factor-receptor 1(sTNF-R1), and 8-isoprostane). This inflammome was not modified by sex, smoking, or coexistence of obstructive sleep apnea and/or metabolic syndrome. By contrast, it was significantly ameliorated, albeit not completely abolished, after BS. Finally, obese subjects had evidence of pulmonary inflammation (exhaled condensate) that also decreased after BS.

Conclusions

The systemic inflammome of morbid obesity is independent of sex, smoking status and/or comorbidities, it is significantly reduced by BS and mirrored in the lungs.

Excess body mass index loss predicts metabolic syndrome remission after gastric bypass

BACKGROUND

Metabolic syndrome (MS) is a condition associated with obesity that identifies individuals with increased cardiovascular risk. Gastric bypass improves several MS components, such as glucose, lipid metabolism and hypertension. The aim of this study was to evaluate the effect of long-limb gastric bypass on the remission of MS criteria associated with morbid obesity.

METHODS

Obese patients who met the "harmonized" criteria for MS (n = 153) that underwent laparoscopic Roux-en-Y gastric bypass (LRYGB) with a long biliopancreatic limb were prospectively evaluated with regards to body weight, body mass index (BMI), percentage of excess BMI lost (% EBMIL), fasting glucose, blood pressure and lipid profile up to 36 months after surgery.

RESULTS

Before surgery, patients had a BMI of 44.3 ± 0.5 kg/m2; 66% were under anti-diabetic treatment; 78.4% were under anti-hypertensive treatment and 44.3% were under anti-dyslipidemic treatment. After a mean follow-up time of 2.4 ± 0.1 years, MS remission rates were 32.7% at 6 months, 69.7% at 12 months, 63.4% at 24 months, and 59.2% at 36 months; when only 32.9%, 43.4% and 15.8% of patients were still under anti-diabetic, anti-hypertensive and anti-dyslipidemic treatment, respectively. The %EBMIL and BMI were the parameters that showed the highest accuracy to predict the MS remission at all-time points after the surgery.

CONCLUSIONS

Long limb gastric bypass in obese patients results in significant and sustained weight loss which predicts a high remission rate of MS and allows the discontinuation of drug therapy for several metabolic disturbances in most patients.

Changes in post-prandial glucose and pancreatic hormones, and steady-state insulin and free fatty acids after gastric bypass surgery

BACKGROUND

Changes in the multiple mechanisms that regulate glucose metabolism after gastric bypass (RYGB) are still being unveiled. The objective of this study was to compare the changes of glucose and pancreatic hormones [C-peptide, glucagon, and pancreatic polypeptide (PP)] during a meal tolerance test (MTT) and steady-state insulin and free fatty acid (FFA) concentrations during euglycemic-hyperinsulinemic clamp 14 days and 6 months after RYGB in morbidly obese nondiabetic patients.

METHODS

Two groups were studied at baseline and at 14 days: the RYGB followed by caloric restriction group (RYGB, n = 12) and the equivalent caloric restriction alone group (Diet, n = 10), to control for energy intake and weight loss. The RYGB group was studied again at 6 months to assess the changes after substantial weight loss. During MTT, the early and overall changes in glucose and pancreatic hormone concentrations were determined, and during the clamp, steady-state insulin and FFA concentrations were assessed.

RESULTS

After 14 days, RYGB patients had enhanced postprandial glucose, C-peptide, and glucagon responses, and decreased postprandial PP concentrations. Steady-state insulin concentrations were decreased at 14 days only in RYGB patients, and FFA increased in both groups. Six months after RYGB and substantial weight loss, the decrease in insulin concentrations during clamp persisted, and there were further changes in postprandial glucose and glucagon responses. FFA concentrations during clamp were significantly lower at 6 months, relative to presurgical values.

CONCLUSIONS

In morbidly obese nondiabetic patients, RYGB produces early changes in postmeal glucose, C-peptide, glucagon, and PP responses, and it appears to enhance insulin clearance early after RYGB and improve insulin sensitivity in adipose tissue at 6 months postsurgery. The early changes cannot be explained by caloric restriction alone.

Anemia and iron deficiency before and after bariatric surgery

BACKGROUND

Iron deficiency and anemia are changes often associated with obesity. Bariatric surgery is responsible for increasing the iron loss and reducing its absorption. The objective of this study was to evaluate anemia and iron deficiency before and after bariatric surgery and to relate them to possible predisposing factors.

METHODS

A retrospective study was conducted on obese patients submitted to open Roux-en-Y gastric bypass, in which clinical and laboratory data were obtained up to 48 months postoperatively. Patients were divided into groups according to the presence or absence of anemia and to the presence or absence of iron deficiency (even without anemia), and all data were compared between these groups.

RESULTS

Preoperatively, 21.5% of patients had anemia and 20% had iron deficiency. The number of patients with anemia did not vary through the 4 years of the study, but ferritin levels significantly decreased with time (P<.01). Younger patients and patients with greater weight loss had a higher incidence of anemia. Female gender was a variable associated with a greater incidence of iron deficiency.

CONCLUSIONS

Anemia and iron deficiency are frequent in obese patients and must be treated before surgery. Medical and nutritional surveillance is important in the postoperative period of bariatric surgery. Management of each condition must be directed at correcting the 2 major sources of iron deficiency and anemia: food intolerance (mostly meat intolerance) and losses (frequently due to menstruation). These are the factors more related to iron deficient anemia.

Vitamin, mineral, and drug absorption following bariatric surgery

The prevalence of obesity continues to rise throughout the world. Increasingly, bariatric surgery is used for those with morbid obesity as a pivotal approach to achieve weight loss. Along with substantial weight loss, malabsorption of essential vitamins, minerals, and drugs also occurs. Therefore, more than ever, a better understanding of the physiology and mechanisms by which these deficiencies occur is essential. We review the normal physiology of vitamin, mineral, and drug absorption. This is followed by a description of currently performed bariatric surgeries in the United States. A detailed review of specific nutrient and mineral deficiency states is presented, based on the most significant studies published in the last two decades. Of note, screening and supplementation recommendations have been included. Drug absorption data after these procedures is presented and discussed. Studies were identified by searching the Cochrane Registry and MEDLINE using relevant search terms, as well as through review of the reference section of included manuscripts.

CONCLUSIONS

Bariatric surgery can be effectively used to achieve sustainable weight-loss in morbidly obese patients. It simultaneously brings forth important functional consequences on nutrient deficiencies and drug absorption that clinician's must be aware of. Further prospective, randomized research on specific procedures and deficiencies is required.

Weight loss is a major contributor to improved sexual function after bariatric surgery

BACKGROUND

The relative contribution of anthropometric, hormonal, and metabolic changes after bariatric surgery (BS) on sexual function (SF) in severely obese subjects is not well established.

METHODS

Prospective observational case series study of 39 men undergoing BS. SF was assessed by means of the international index of erectile function (IIEF) before and at 1 year after surgery. At the same time points, anthropometric (body mass index, waist circumference), hormonal (testosterone, sex hormone binding globulin, estradiol, gonadotropins, inhibin B, prolactin, leptin), and metabolic parameters (insulin sensitivity, C-reactive protein, lipid profile, hemoglobin A1c, presence of hypertension or sleep apnea) were assessed.

RESULTS

BS was associated with marked weight loss (77.18% excess weight loss), improved IIEF score (baseline: 54.85 ± 16.59, 1 year: 61.21 ± 14.10; p < 0.01), gonadal function (testosterone: baseline 256.36 ± 120.98, 1 year: 508.01 ± 161.90; p < 0.001), and improved metabolic profile. However, on multivariate regression analysis whereas changes in body mass index (beta: -0.677, p = 0.001), and baseline IIEF score (beta: -0.397, p = 0.023), were independent predictors of the changes in the IIEF score at 1 year after surgery, changes in hormonal and metabolic factors were not. Variables in the model accounted for 66% of the postsurgical variation in the IIEF score. Similar results were found when the different IIEF-sexual domains were evaluated, except for intercourse satisfaction for which no independent predictor was identified.

CONCLUSIONS

Weight loss's beneficial effects on SF occurring after BS are beyond the parallel improvement in gonadal and metabolic profiles.

Alterações dos parâmetros clínicos e laboratoriais em pacientes obesos com diabetes melito tipo 2 submetidos à derivação gastrojejunal em y de Roux sem anel

OBJETIVOS: Verificar as alterações do peso e índice de massa corporal em pacientes obesos grau II e III com diabete melito tipo 2 nos períodos pré e pós-operatório e as alterações dos parâmetros laboratoriais de glicemia de jejum, glicemia pós-prandial, hemoglobina glicada, insulina nos períodos pré e pós-operatório. MÉTODOS: Realizou-se estudo prospectivo selecionando 40 pacientes com obesidade grau II e III, submetidos à derivação gastrojejunal em Y-de-Roux sem anel. Analisou-se no pré e pós-operatório de 60 dias o peso, índice de massa corporal, glicemia de jejum, glicemia pós-prandial, hemoglobina glicada e insulina. RESULTADOS: O peso médio pré-operatório foi de 107,3Kg diminuindo para 89,5Kg no pós-operatório. O índice de massa corporal médio inicial foi de 39,5Kg/m2 e 32,9Kg/m2 com 60 dias de pós-operatório. A glicemia de jejum no pré-operatório foi de 132 mg/dl e no pós-operatório diminuiu 40,4 mg/dl em média. A glicemia pós-prandial foi de 172 mg/dl no pré-operatório e 111,6 mg/dl no controle pós-operatório. A hemoglobina glicada inicial foi de 7% declinando para 5,7% no pós-operatório. A insulina pré-operatória foi 29,6 uIU/ml e a pós-operatória 13,9 uIU/ml. Todas as variáveis apresentaram significância estatística com p<0,001. CONCLUSÃO: Houve significante diminuição de peso e no índice de massa corporal entre os períodos pré e pós-operatórios e diminuição também significante dos parâmetros laboratoriais de glicemia de jejum, glicemia pós-prandial, hemoglobina glicada, insulina entre os mesmos períodos.

The effect of different hormone therapies on anti-müllerian hormone serum levels in anovulatory women of reproductive age

OBJECTIVE

To investigate the effect of oral contraceptives (OC), metformin and ovulation induction with gonadotropins on circulating anti-müllerian hormone (AMH).

DESIGN

Prospective clinical study.

PATIENTS

Thirty patients with PCOS (Group 1), 15 normogonadotropic anovulatory infertile women (WHO 2) (Group 2) and 15 normoovulatory control women (Group 3). Patients in Group 1 received OC (n = 12), metformin (n = 11) or no-treatment (n = 7) for 6 months. Ovulation induction with FSH or hMG was used in Group 2.

MAIN OUTCOME MEASURES

Total follicle number (TFN) and hormonal (fasting insulin and glucose, testosterone, SHBG, LH, androstenedione and AMH) measurements at baseline and during therapy.

RESULTS

Basal AMH and TFN were higher in Groups 1 and 2 than in controls. Only TFN was significantly related to AMH level in Groups 1 and 2. AMH level was significantly reduced during OC treatment, and there was a trend for AMH decrease during metformin therapy. No significant changes in AMH level were observed during ovulation induction. TFN was the only parameter showing a significant positive correlation with circulating AMH over the 6-month treatment period in patients in Group 2.

CONCLUSIONS

AMH is an accurate marker of the antral follicle pool in WHO-2/PCOS women but the measurement of AMH is not likely to be helpful in the management of those patients.

Bariatric surgery and its impact on sleep architecture, sleep-disordered breathing, and metabolism

Over the last several decades, the prevalence of obesity has increased significantly worldwide. This has translated into an increased prevalence of obesity-associated morbidities including sleep-disordered breathing and metabolic disorders. While the medical management of obesity is relatively ineffective, bariatric surgery is the most successful method for sustained weight loss and markedly reduces obesity-related morbidity and mortality. The anatomical changes created with different types of procedures lead to variable weight loss and improvement of co-morbidities; however the latter does not appear to be exclusively dependent on the amount of weight loss. Bariatric surgery does not always lead to complete resolution of obstructive sleep apnea and age, gender and severity of the obstructive sleep apnea predict the residual disease after peak weight loss. Metabolic disorders and specifically diabetes often improve dramatically early after the procedure, before any significant weight loss has occurred. The modified gastrointestinal anatomy and physiology may explain this phenomenon.

Potential additional effect of omentectomy on metabolic syndrome, acute-phase reactants, and inflammatory mediators in grade III obese patients undergoing laparoscopic Roux-en-Y gastric bypass: a randomized trial

OBJECTIVE

To assess the additional effect of sudden visceral fat reduction by omentectomy on metabolic syndrome, acute-phase reactants, and inflammatory mediators in patients with grade III obesity (G-III O) undergoing laparoscopic Roux-en-Y gastric bypass (LRYGB).

RESEARCH DESIGN AND METHODS

Twenty-two patients were randomized into two groups, LRYGB alone or with omentectomy. Levels of interleukin-6, C-reactive protein, tumor necrosis factor-alpha, leptin, adiponectin, glucose, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides, as well as clinical characteristics, were evaluated before surgery and at 1, 3, 6, and 12 months after surgery. Results were compared between groups.

RESULTS

Baseline characteristics were comparable in both groups. Mean operative time was significantly higher in the group of patients who underwent omentectomy (P < 0.001). Median weight of the omentum was 795 +/- 341 g. In one patient, a duodenal perforation occurred at the time of omentectomy. BMI, blood pressure, glucose, total cholesterol, LDL, and triglycerides significantly improved in both groups at 1, 3, 6, and 12 months of follow-up when compared with basal values. However, there were no consistent statistically significant differences among the groups in terms of metabolic syndrome components, acute-phase reactants, and inflammatory mediators.

CONCLUSIONS

Omentectomy does not have an ancillary short-term significant impact on the components of metabolic syndrome and does not induce important changes in the inflammatory mediators in patients undergoing LRYGB. Operative time is more prolonged when omentectomy is performed.

Improvement in peripheral glucose uptake after gastric bypass surgery is observed only after substantial weight loss has occurred and correlates with the magnitude of weight lost

INTRODUCTION

Altered gut and pancreatic hormone secretion may bolster resolution of insulin resistance after Roux-en-Y gastric bypass (RYGB), but the independent effects of weight loss and hormonal secretion on peripheral glucose disposal are unknown.

METHODS

Two groups of nondiabetic morbidly obese patients were studied: RYGB followed by standardized caloric restriction (RYGB, n = 12) or caloric restriction alone (diet, n = 10). Metabolic evaluations (euglycemic-hyperinsulinemic clamp, meal tolerance test) were done at baseline and 14 days (both groups) and 6 months after RYGB.

RESULTS

At baseline, body composition, fasting insulin, and glucose and peripheral glucose disposal did not differ between groups. At 14 days, excess weight loss (EWL) was similar (RYGB, 12.7% vs. diet, 10.9%; p = 0.12), fasting insulin and glucose decreased to a similar extent, and RYGB subjects had altered postmeal patterns of gut and pancreatic hormone secretion. However, peripheral glucose uptake (M value) was unchanged in both groups. Six months after RYGB, EWL was 49.7%. The changes in fasting glucose and insulin levels and gut hormone secretion persisted. M values improved significantly, and changes in M values correlated with the % EWL (r = 0.68, p = 0.02).

CONCLUSIONS

Improvement in peripheral glucose uptake following RYGB was observed only after substantial weight loss had occurred and correlated with the magnitude of weight lost.

Alterações nos parâmetros pré e pós-operatórios de pacientes com síndrome metabólica, submetidos a Bypass gastrointestinal em Y de Roux

RACIONAL: A epidemia mundial de sobrepeso e obesidade afeta aproximadamente 1,7 bilhão de pessoas, havendo aumento nos casos de obesidade mórbida de 80% para mulheres e de 400% para homens desde 1970. A síndrome metabólica é transtorno complexo relacionado com resistência à insulina e obesidade abdominal, provocando alterações no metabolismo da glicose em vários tecidos e hiperinsulinemia. OBJETIVO: Verificar as alterações nos parâmetros pré e pós-operatórios em pacientes obesos mórbidos com síndrome metabólica, submetidos a bypass gastrointestinal em Y de Roux. MÉTODO: Casuística de 74 pacientes obesos, que apresentavam síndrome metabólica e submetidos a procedimento cirúrgico. Foram avaliados, além do IMC, a relação cintura-quadril, pressão arterial, colesterol total, HDL, LDL, triglicerídeos, glicemia de jejum no pré-operatório e no 1º e 4º meses de pós-operatório. Para variáveis que apresentaram simetria na sua distribuição, foi usado o teste t de Student para amostras pareadas. Para variáveis com distribuição assimétrica, foi usado o teste não-paramétrico de Wilcoxon. Valores de P<0,05 indicaram significância estatística. RESULTADOS: Obteve-se redução no 1º mês do pós-operatório no peso de 7,96%, IMC de 8%, relação cintura/quadril de 1,35%, colesterol total de 17,95%, HDL de 14,5%, LDL de 15,31%, TAG's de 30,29% e glicemia de 9,75%; no 4º mês, observou-se redução no peso de 14,94%, IMC de 20,08%, relação cintura/quadril de 5,96%, colesterol total de 21,27%, HDL de 3,53%, LDL de 23,72%, TAG's de 29,6% e na glicemia de 10,34%. CONCLUSÃO: Os parâmetros avaliados neste estudo tiveram melhora estatisticamente significante, com exceção do HDL-colesterol.

Adolescent obesity and bariatric surgery

PURPOSE OF REVIEW

Examines the effects of bariatric surgery on adolescent obesity.

RECENT FINDINGS

The risks and outcomes of bariatric surgery in adolescence are presently being defined and may be somewhat different from those in adults. Adolescents may have a greater risk of weight regain, and greater risk of noncompliance to treatment after surgery. However, long-term outcomes are not yet available, and the underlying metabolic benefits appear to be substantial and similar to those of adults.

SUMMARY

Morbid obesity in adolescents has severe acute and chronic complications. Bariatric surgery in adolescents seems as well tolerated as in adults when performed in centers with appropriate experience and adequate surgical volume. The pathophysiologic implications of bariatric surgery are profound. A better understanding of the mechanisms leading to postsurgical improvement in insulin resistance and weight loss could lead to the development of other therapies to achieve the same effects with lesser morbidities.

Effect of bariatric surgery on the metabolic syndrome: a population-based, long-term controlled study

OBJECTIVE

To assess the effect of weight loss by bariatric surgery on the prevalence of the metabolic syndrome (MetS) and to examine predictors of MetS resolution.

PATIENTS AND METHODS

We performed a population-based, retrospective study of patients evaluated for bariatric surgery between January 1, 1990, and December 31, 2003, who had MetS as defined by the American Heart Association/National Heart, Lung, and Blood Institute (increased triglycerides, low high-density lipoprotein, increased blood pressure, increased fasting glucose, and a measure of obesity). Of these patients, 180 underwent Roux-en-Y gastric bypass, and 157 were assessed in a weight-reduction program but did not undergo surgery. We determined the change in MetS prevalence and used logistic regression models to determine predictors of MetS resolution. Mean follow-up was 3.4 years.

RESULTS

In the surgical group, all MetS components improved, and medication use decreased. Nonsurgical patients showed improvements in high-density lipoprotein cholesterol levels. After bariatric surgery, the number of patients with MetS decreased from 156 (87%) of 180 patients to 53 (29%); of the 157 nonsurgical patients, MetS prevalence decreased from 133 patients (85%) to 117 (75%). A relative risk reduction of 0.59 (95% confidence interval [CI], 0.48-0.67; P<.001) was observed in patients who underwent bariatric surgery and had MetS at follow-up. The number needed to treat with surgery to resolve 1 case of MetS was 2.1. Results were similar after excluding patients with diabetes or cardiovascular disease or after using diagnostic criteria other than body mass index for MetS. Significant predictors of MetS resolution included a 5% loss in excess weight (odds ratio, 1.26; 95% CI, 1.19-1.34; P<.001) and diabetes mellitus (odds ratio, 0.32; 95% CI, 0.15-0.68; P=.003).

CONCLUSION

Roux-en-Y gastric bypass induces considerable and persistent improvement in MetS prevalence. Our results suggest that reversibility of MetS depends more on the amount of excess weight lost than on other parameters.