Wendy A. Brown

Bio: Wendy A. Brown is an academic researcher from Monash University. The author has contributed to research in topics: Weight loss & Adjustable gastric band. The author has an hindex of 35, co-authored 145 publications receiving 5328 citations. Previous affiliations of Wendy A. Brown include Monash University, Clayton campus & University of California, San Francisco.

Pro-Inflammatory CD11c+CD206+ Adipose Tissue Macrophages Are Associated With Insulin Resistance in Human Obesity

Abstract: OBJECTIVE Insulin resistance and other features of the metabolic syndrome have been causally linked to adipose tissue macrophages (ATMs) in mice with diet-induced obesity. We aimed to characterize macrophage phenotype and function in human subcutaneous and omental adipose tissue in relation to insulin resistance in obesity. RESEARCH DESIGN AND METHODS Adipose tissue was obtained from lean and obese women undergoing bariatric surgery. Metabolic markers were measured in fasting serum and ATMs characterized by immunohistology, flow cytometry, and tissue culture studies. RESULTS ATMs comprised CD11c+CD206+ cells in “crown” aggregates and solitary CD11c−CD206+ cells at adipocyte junctions. In obese women, CD11c+ ATM density was greater in subcutaneous than omental adipose tissue and correlated with markers of insulin resistance. CD11c+ ATMs were distinguished by high expression of integrins and antigen presentation molecules; interleukin (IL)-1β, -6, -8, and -10; tumor necrosis factor-α; and CC chemokine ligand-3, indicative of an activated, proinflammatory state. In addition, CD11c+ ATMs were enriched for mitochondria and for RNA transcripts encoding mitochondrial, proteasomal, and lysosomal proteins, fatty acid metabolism enzymes, and T-cell chemoattractants, whereas CD11c− ATMs were enriched for transcripts involved in tissue maintenance and repair. Tissue culture medium conditioned by CD11c+ ATMs, but not CD11c− ATMs or other stromovascular cells, impaired insulin-stimulated glucose uptake by human adipocytes. CONCLUSIONS These findings identify proinflammatory CD11c+ ATMs as markers of insulin resistance in human obesity. In addition, the machinery of CD11c+ ATMs indicates they metabolize lipid and may initiate adaptive immune responses.

Long-term outcomes after bariatric surgery: fifteen-year follow-up of adjustable gastric banding and a systematic review of the bariatric surgical literature.

Abstract: Objective:To describe the long-term outcomes after laparoscopic adjustable gastric banding (LAGB) and compare these with the published literature on bariatric surgery.Background:Because obesity is a chronic disease, any proposed obesity treatment should be expected to demonstrate long-term durabilit

Long-Term Outcomes After Bariatric Surgery: a Systematic Review and Meta-analysis of Weight Loss at 10 or More Years for All Bariatric Procedures and a Single-Centre Review of 20-Year Outcomes After Adjustable Gastric Banding

Abstract: Durability is a key requirement for the broad acceptance of bariatric surgery. We report on durability at and beyond 10 years with a systematic review and meta-analysis of all reports providing data at 10 or more years and a single-centre study of laparoscopic adjustable gastric banding (LAGB) with 20 years of follow-up. Systematic review with meta-analysis was performed on all eligble reports containing 10 or more years of follow-up data on weight loss after bariatric surgery. In addition, a prospective cohort study of LAGB patients measuring weight loss and reoperation at up to 20 years is presented. Systematic review identified 57 datasets of which 33 were eligible for meta-analysis. Weighted means of the percentage of excess weight loss (%EWL) were calculated for all papers included in the systematic review. Eighteen reports of gastric bypass showed a weighted mean of 56.7%EWL, 17 reports of LAGB showed 45.9%EWL, 9 reports of biliopancreatic bypass +/− duodenal switch showed 74.1%EWL and 2 reports of sleeve gastrectomy showed 58.3%EWL. Meta-analyses of eligible studies demonstrated comparable results. Reoperations were common in all groups. At a single centre, 8378 LAGB patients were followed for up to 20 years with an overall follow-up rate of 54%. No surgical deaths occurred. Weight loss at 20 years (N = 35) was 30.1 kg, 48.9%EWL and 22.2% total weight loss (%TWL). Reoperation rate was initially high but reduced markedly with improved band and surgical and aftercare techniques. All current procedures are associated with substantial and durable weight loss. More long-term data are needed for one-anastomosis gastric bypass and sleeve gastrectomy. Reoperation is likely to remain common across all procedures.

The laparoscopic adjustable gastric band (Lap-Band): a prospective study of medium-term effects on weight, health and quality of life.

Abstract: Background: Obesity is now one of our major public health problems. Effective and acceptable treatment options are needed.The Lap-Band® system is placed laparoscopically and allows adjustment of the level of gastric restriction. Methods: A prospective study of 709 severely obese patients was conducted over a 6-year period at a university-based multidisciplinary referral center. After extensive preoperative evaluation, patients with a body mass index >35 were treated by LapBand® placement. Close follow-up with progressive adjustment of gastric restriction continued permanently. Medical co-morbidities were monitored as part of comprehensive prospective data collection. Results: There have been no deaths perioperatively or during follow-up. Significant perioperative adverse events occurred in 1.2% only. Reoperation has been needed for prolapse (slippage) in 12.5%, erosion of the band into the stomach in 2.8% and for tubing breaks in 3.6%. A steady progression of weight loss has occurred through the duration of the study with 52 ± 19 %EWL at 24 months (n=333), 53±22 %EWL at 36 months (n=264), 52 ± 24 %EWL at 48 months (n=108), 54 ± 24 %EWL at 60 months (n=30), and 57 ± 15% EWL at 72 months (n=10). Major improvements have occurred in diabetes, asthma, gastroesophageal reflux, dyslipidemia, sleep apnea and depression. Quality of life as measured by Rand SF-36 shows highly significant improvement. Conclusions: Placement of the Lap-Band® system provides safe and effective control of severe obesity. The effect on weight loss is durable and is associated with major improvement in health and quality of life. It has the potential to provide a broadly acceptable option for this common and serious disease.

Laparoscopic adjustable gastric banding in severely obese adolescents: a randomized trial.

Abstract: Context Adolescent obesity is a common and serious health problem affecting more than 5 million young people in the United States alone. Bariatric surgery is being evaluated as a possible treatment option. Laparoscopic adjustable gastric banding (gastric banding) has the potential to provide a safe and effective treatment. Objective To compare the outcomes of gastric banding with an optimal lifestyle program on adolescent obesity. Design, Setting, and Patients A prospective, randomized controlled trial of 50 adolescents between 14 and 18 years with a body mass index (BMI) higher than 35, recruited from the Melbourne, Australia, community, assigned either to a supervised lifestyle intervention or to undergo gastric banding, and followed up for 2 years. The study was performed between May 2005 and September 2008. Main Outcome Measures Weight loss. Secondary outcomes included change in metabolic syndrome, insulin resistance, quality of life, and adverse outcomes. Results Twenty-four of 25 patients in the gastric banding group and 18 of 25 in lifestyle group completed the study. Twenty-one (84%) in the gastric banding and 3 (12%) in the lifestyle groups lost more than 50% of excess weight, corrected for age. Overall, the mean changes in the gastric banding group were a weight loss of 34.6 kg (95% CI, 30.2-39.0), representing an excess weight loss of 78.8% (95% CI, 66.6%-91.0%), 12.7 BMI units (95% CI, 11.3-14.2), and a BMI z score change from 2.39 (95% CI, 2.05-2.73) to 1.32 (95% CI, 0.98-1.66). The mean losses in the lifestyle group were 3.0 kg (95% CI, 2.1-8.1), representing excess weight loss of 13.2% (95% CI, 2.6%-21.0%), 1.3 BMI units (95% CI, 0.4-2.9), and a BMI z score change from 2.41 (95% CI, 2.21-2.66) to 2.26 (95% CI, 1.91-2.43). At entry, 9 participants (36%) in the gastric banding group and 10 (40%) in the lifestyle group had the metabolic syndrome. At 24 months, none of the gastric banding group had the metabolic syndrome (P = .008; McNemar χ 2 ) compared with 4 of the 18 completers (22%) in the lifestyle group (P = .13). The gastric banding group experienced improved quality of life with no perioperative adverse events. However, 8 operations (33%) were required in 7 patients for revisional procedures either for proximal pouch dilatation or tubing injury during follow-up. Conclusions Among obese adolescent participants, use of gastric banding compared with lifestyle intervention resulted in a greater percentage achieving a loss of 50% of excess weight, corrected for age. There were associated benefits to health and quality of life. Trial Registration ANZCTR Identifier: 12605000160639

Bariatric surgery: a systematic review and meta-analysis.

Abstract: ContextAbout 5% of the US population is morbidly obese. This disease remains largely refractory to diet and drug therapy, but generally responds well to bariatric surgery.ObjectiveTo determine the impact of bariatric surgery on weight loss, operative mortality outcome, and 4 obesity comorbidities (diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea).Data Sources and Study SelectionElectronic literature search of MEDLINE, Current Contents, and the Cochrane Library databases plus manual reference checks of all articles on bariatric surgery published in the English language between 1990 and 2003. Two levels of screening were used on 2738 citations.Data ExtractionA total of 136 fully extracted studies, which included 91 overlapping patient populations (kin studies), were included for a total of 22 094 patients. Nineteen percent of the patients were men and 72.6% were women, with a mean age of 39 years (range, 16-64 years). Sex was not reported for 1537 patients (8%). The baseline mean body mass index for 16 944 patients was 46.9 (range, 32.3-68.8).Data SynthesisA random effects model was used in the meta-analysis. The mean (95% confidence interval) percentage of excess weight loss was 61.2% (58.1%-64.4%) for all patients; 47.5% (40.7%-54.2%) for patients who underwent gastric banding; 61.6% (56.7%-66.5%), gastric bypass; 68.2% (61.5%-74.8%), gastroplasty; and 70.1% (66.3%-73.9%), biliopancreatic diversion or duodenal switch. Operative mortality (≤30 days) in the extracted studies was 0.1% for the purely restrictive procedures, 0.5% for gastric bypass, and 1.1% for biliopancreatic diversion or duodenal switch. Diabetes was completely resolved in 76.8% of patients and resolved or improved in 86.0%. Hyperlipidemia improved in 70% or more of patients. Hypertension was resolved in 61.7% of patients and resolved or improved in 78.5%. Obstructive sleep apnea was resolved in 85.7% of patients and was resolved or improved in 83.6% of patients.ConclusionsEffective weight loss was achieved in morbidly obese patients after undergoing bariatric surgery. A substantial majority of patients with diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea experienced complete resolution or improvement.

BRIEF COMMUNICATION ARISING: Gut hormone PYY3-36 physiologically inhibits food intake

Abstract: Food intake is regulated by the hypothalamus, including the melanocortin and neuropeptide Y (NPY) systems in the arcuate nucleus. The NPY Y2 receptor (Y2R), a putative inhibitory presynaptic receptor, is highly expressed on NPY neurons in the arcuate nucleus, which is accessible to peripheral hormones. Peptide YY3-36 (PYY3-36), a Y2R agonist, is released from the gastrointestinal tract postprandially in proportion to the calorie content of a meal. Here we show that peripheral injection of PYY3-36 in rats inhibits food intake and reduces weight gain. PYY3-36 also inhibits food intake in mice but not in Y2r-null mice, which suggests that the anorectic effect requires the Y2R. Peripheral administration of PYY3-36 increases c-Fos immunoreactivity in the arcuate nucleus and decreases hypothalamic Npy messenger RNA. Intra-arcuate injection of PYY3-36 inhibits food intake. PYY3-36 also inhibits electrical activity of NPY nerve terminals, thus activating adjacent pro-opiomelanocortin (POMC) neurons. In humans, infusion of normal postprandial concentrations of PYY3-36 significantly decreases appetite and reduces food intake by 33% over 24 h. Thus, postprandial elevation of PYY3-36 may act through the arcuate nucleus Y2R to inhibit feeding in a gut–hypothalamic pathway.

Bariatric Surgery versus Intensive Medical Therapy for Diabetes — 5-Year Outcomes

Abstract: BackgroundLong-term results from randomized, controlled trials that compare medical therapy with surgical therapy in patients with type 2 diabetes are limited. MethodsWe assessed outcomes 5 years after 150 patients who had type 2 diabetes and a body-mass index (BMI; the weight in kilograms divided by the square of the height in meters) of 27 to 43 were randomly assigned to receive intensive medical therapy alone or intensive medical therapy plus Roux-en-Y gastric bypass or sleeve gastrectomy. The primary outcome was a glycated hemoglobin level of 6.0% or less with or without the use of diabetes medications. ResultsOf the 150 patients who underwent randomization, 1 patient died during the 5-year follow-up period; 134 of the remaining 149 patients (90%) completed 5 years of follow-up. At baseline, the mean (±SD) age of the 134 patients was 49±8 years, 66% were women, the mean glycated hemoglobin level was 9.2±1.5%, and the mean BMI was 37±3.5. At 5 years, the criterion for the primary end point was met by 2...

Bariatric surgery. A systematic review and meta-analysis

Abstract: CONTEXT About 5% of the US population is morbidly obese. This disease remains largely refractory to diet and drug therapy, but generally responds well to bariatric surgery. OBJECTIVE To determine the impact of bariatric surgery on weight loss, operative mortality outcome, and 4 obesity comorbidities (diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea). DATA SOURCES AND STUDY SELECTION Electronic literature search of MEDLINE, Current Contents, and the Cochrane Library databases plus manual reference checks of all articles on bariatric surgery published in the English language between 1990 and 2003. Two levels of screening were used on 2738 citations. DATA EXTRACTION A total of 136 fully extracted studies, which included 91 overlapping patient populations (kin studies), were included for a total of 22,094 patients. Nineteen percent of the patients were men and 72.6% were women, with a mean age of 39 years (range, 16-64 years). Sex was not reported for 1537 patients (8%). The baseline mean body mass index for 16 944 patients was 46.9 (range, 32.3-68.8). DATA SYNTHESIS A random effects model was used in the meta-analysis. The mean (95% confidence interval) percentage of excess weight loss was 61.2% (58.1%-64.4%) for all patients; 47.5% (40.7%-54.2%) for patients who underwent gastric banding; 61.6% (56.7%-66.5%), gastric bypass; 68.2% (61.5%-74.8%), gastroplasty; and 70.1% (66.3%-73.9%), biliopancreatic diversion or duodenal switch. Operative mortality (< or =30 days) in the extracted studies was 0.1% for the purely restrictive procedures, 0.5% for gastric bypass, and 1.1% for biliopancreatic diversion or duodenal switch. Diabetes was completely resolved in 76.8% of patients and resolved or improved in 86.0%. Hyperlipidemia improved in 70% or more of patients. Hypertension was resolved in 61.7% of patients and resolved or improved in 78.5%. Obstructive sleep apnea was resolved in 85.7% of patients and was resolved or improved in 83.6% of patients. CONCLUSIONS Effective weight loss was achieved in morbidly obese patients after undergoing bariatric surgery. A substantial majority of patients with diabetes, hyperlipidemia, hypertension, and obstructive sleep apnea experienced complete resolution or improvement.

Cyclooxygenase Isozymes: The Biology of Prostaglandin Synthesis and Inhibition

Abstract: Nonsteroidal anti-inflammatory drugs (NSAIDs) represent one of the most highly utilized classes of pharmaceutical agents in medicine. All NSAIDs act through inhibiting prostaglandin synthesis, a catalytic activity possessed by two distinct cyclooxygenase (COX) isozymes encoded by separate genes. The discovery of COX-2 launched a new era in NSAID pharmacology, resulting in the synthesis, marketing, and widespread use of COX-2 selective drugs. These pharmaceutical agents have quickly become established as important therapeutic medications with potentially fewer side effects than traditional NSAIDs. Additionally, characterization of the two COX isozymes is allowing the discrimination of the roles each play in physiological processes such as homeostatic maintenance of the gastrointestinal tract, renal function, blood clotting, embryonic implantation, parturition, pain, and fever. Of particular importance has been the investigation of COX-1 and -2 isozymic functions in cancer, dysregulation of inflammation, and Alzheimer's disease. More recently, additional heterogeneity in COX-related proteins has been described, with the finding of variants of COX-1 and COX-2 enzymes. These variants may function in tissue-specific physiological and pathophysiological processes and may represent important new targets for drug therapy.