John B. Dixon

Adjustable gastric banding and conventional therapy for type 2 diabetes: a randomized controlled trial.

CONTEXTnObservational studies suggest that surgically induced loss of weight may be effective therapy for type 2 diabetes.nnnOBJECTIVEnTo determine if surgically induced weight loss results in better glycemic control and less need for diabetes medications than conventional approaches to weight loss and diabetes control.nnnDESIGN, SETTING, AND PARTICIPANTSnUnblinded randomized controlled trial conducted from December 2002 through December 2006 at the University Obesity Research Center in Australia, with general community recruitment to established treatment programs. Participants were 60 obese patients (BMI >30 and <40) with recently diagnosed (<2 years) type 2 diabetes.nnnINTERVENTIONSnConventional diabetes therapy with a focus on weight loss by lifestyle change vs laparoscopic adjustable gastric banding with conventional diabetes care.nnnMAIN OUTCOME MEASURESnRemission of type 2 diabetes (fasting glucose level <126 mg/dL [7.0 mmol/L] and glycated hemoglobin [HbA1c] value <6.2% while taking no glycemic therapy). Secondary measures included weight and components of the metabolic syndrome. Analysis was by intention-to-treat.nnnRESULTSnOf the 60 patients enrolled, 55 (92%) completed the 2-year follow-up. Remission of type 2 diabetes was achieved by 22 (73%) in the surgical group and 4 (13%) in the conventional-therapy group. Relative risk of remission for the surgical group was 5.5 (95% confidence interval, 2.2-14.0). Surgical and conventional-therapy groups lost a mean (SD) of 20.7% (8.6%) and 1.7% (5.2%) of weight, respectively, at 2 years (P < .001). Remission of type 2 diabetes was related to weight loss (R2 = 0.46, P < .001) and lower baseline HbA1c levels (combined R2 = 0.52, P < .001). There were no serious complications in either group.nnnCONCLUSIONSnParticipants randomized to surgical therapy were more likely to achieve remission of type 2 diabetes through greater weight loss. These results need to be confirmed in a larger, more diverse population and have long-term efficacy assessed.nnnTRIAL REGISTRATIONnactr.org Identifier: ACTRN012605000159651.

Nonalcoholic fatty liver disease: Improvement in liver histological analysis with weight loss

The effect of significant weight loss on nonalcoholic fatty liver disease remains unclear. In this case series of 36 selected obese patients, we examined the effect of weight loss on nonalcoholic fatty liver disease, including nonalcoholic steatohepatitis (NASH) and hepatic fibrosis. These 36 patients (11 males, 25 females) had paired liver biopsies, the first at the time of laparoscopic adjustable gastric band placement and the second after weight loss. Second biopsies were obtained from two groups: those requiring a subsequent laparoscopic procedure (n = 19) and those with index biopsy score of 2 or greater for zone 3‐centric hepatic fibrosis (n = 17). All biopsies were scored, blinded to the patients identity and clinical condition, for individual histological features and for NASH stage and grade. Initial biopsies demonstrated NASH in 23 patients and steatosis in 12 patients. Repeat biopsies were taken at 25.6 ± 10 months (range, 9–51 months) after band placement. Mean weight loss was 34.0 ± 17 kg, and percentage of excess weight loss was 52 ± 17%. There were major improvements in lobular steatosis, necroinflammatory changes, and fibrosis at the second biopsy (P < .001 for all). Portal abnormalities remained unchanged. Only four of the repeat biopsies fulfilled the criteria for NASH. There were 18 patients with an initial fibrosis score of 2 or more compared with 3 patients at follow‐up (P < .001). Those with the metabolic syndrome (n = 23) had more extensive changes before surgery and greater improvement with weight loss. In conclusion, weight loss after surgery provides major improvement or resolution of obesity and metabolic syndrome‐associated abnormal liver histological features in severely obese subjects. (HEPATOLOGY 2004;39:1647–1654.)

The effect of obesity on health outcomes

The prevalence of obesity has progressively increased globally over the last 30 years. The determinants of this pandemic are many, poorly defined and priorities debated. While public health measures to prevent obesity have largely failed we are presented with a growing burden of disease and disability. Cardiovascular disease, type-2 diabetes, obesity related cancers, osteoarthritis and psychological disturbance generate much of the morbidity and years of life lost associated with increasing levels of obesity. Obesity has a clearly measurable impact on physical and mental health, health related quality of life, and generates considerable direct and indirect costs. The evolving obesity pandemic is exacting a considerable toll on those affected, the treating health services, and on our communities. Weight loss appears to be the most effective therapy for obesity and obesity related comorbidity. As health care researchers and providers we are likely to play a peripheral role in the prevention of obesity, but a central role in effectively treating those afflicted by the obesity pandemic.

Grazing and Loss of Control Related to Eating: Two High‐risk Factors Following Bariatric Surgery

Background: Gastric restrictive surgery induces a marked change in eating behavior. However, the relationship between preoperative and postoperative eating behavior and weight loss outcome has received limited attention.

Bariatric surgery for type 2 diabetes.

Bariatric surgery provides substantial, sustained weight loss and major improvements in glycaemic control in severely obese individuals with type 2 diabetes. However, uptake of surgery in eligible patients is poor, and the barriers are difficult to surmount. We examine the indications for and efficacy and safety of conventional bariatric surgical procedures and their effect on glycaemic control in type 2 diabetes. How surgical gastrointestinal interventions achieve these changes is of great research interest, and is evolving rapidly. Old classifications about restriction and malabsorption are inadequate, and we explore understanding of putative mechanisms. Some bariatric procedures improve glycaemic control in people with diabetes beyond that expected for weight loss, and understanding this additional effect could provide insights into the pathogenesis of type 2 diabetes and assist in the development of new procedures, devices, and drugs both for obese and non-obese patients.

Factors associated with percent change in visceral versus subcutaneous abdominal fat during weight loss: findings from a systematic review

Background:Visceral adipose tissue (VAT) is associated with greater obesity-related metabolic disturbance. Many studies have reported preferential loss of VAT with weight loss.Objective:This systematic review looks for factors associated with preferential loss of VAT relative to subcutaneous abdominal fat (SAT) during weight loss.Design:Medline and Embase were searched for imaging-based measurements of VAT and subcutaneous abdominal adipose tissue (SAT) before and after weight loss interventions. We examine for factors that influences the percentage change in VAT versus SAT (%δV/%δS) with weight loss. Linear regression analyses were performed on the complete data set and on subgroups of studies. Factors examined included percentage weight loss, degree of caloric restriction, exercise, initial body mass index (BMI), gender, time of follow-up and baseline VAT/SAT.Results:There were 61 studies with a total of 98 cohort time points extracted. Percentage weight loss was the only variable that influenced %δV/%δS (r=−0.29, P=0.005). Modest weight loss generated preferential loss of VAT, but with greater weight loss this effect was attenuated. The method of weight loss was not an influence with one exception. Very-low-calorie diets (VLCDs) provided exceptional short-term (<4 weeks) preferential VAT loss. But this effect was lost by 12–14 weeks.Conclusions:Visceral adipose tissue is lost preferentially with modest weight loss, but the effect is attenuated with greater weight loss. Acute caloric restriction, using VLCD, produces early preferential loss of VAT. These observations may help to explain the metabolic benefits of modest weight loss.

Predicting the Glycemic Response to Gastric Bypass Surgery in Patients With Type 2 Diabetes

OBJECTIVE To find clinically meaningful preoperative predictors of diabetes remission and conversely inadequate glycemic control after gastric bypass surgery. Predicting the improvement in glycemic control in those with type 2 diabetes after bariatric surgery may help in patient selection. RESEARCH DESIGN AND METHODS Preoperative details of 154 ethnic Chinese subjects with type 2 diabetes were examined for their influence on glycemic outcomes at 1 year after gastric bypass. Remission was defined as HbA1c ≤6%. Analysis involved binary logistic regression to identify predictors and provide regression equations and receiver operating characteristic curves to determine clinically useful cutoff values. RESULTS Remission was achieved in 107 subjects (69.5%) at 12 months. Diabetes duration <4 years, body mass >35 kg/m2, and fasting C-peptide concentration >2.9 ng/mL provided three independent preoperative predictors and three clinically useful cutoffs. The regression equation classification plot derived from continuous data correctly assigned 84% of participants. A combination of two or three of these predictors allows a sensitivity of 82% and specificity of 87% for remission. Duration of diabetes (with different cutoff points) and C-peptide also predicted those cases in which HbA1c ≤7% was not attained. Percentage weight loss after surgery was also predictive of remission and of less satisfactory outcomes. CONCLUSIONS The glycemic response to gastric bypass is related to BMI, duration of diabetes, fasting C-peptide (influenced by insulin resistance and residual β-cell function), and weight loss. These data support and refine previous findings in non-Asian populations. Specific ethnic and procedural regression equations and cutoff points may vary.

Loss of control is central to psychological disturbance associated with binge eating disorder.

Objective: Binge eating disorder (BED) is positively associated with obesity and psychological distress, yet the behavioral features of BED that drive these associations are largely unexplored. The primary aim of this study was to investigate which core behavioral features of binge eating are most strongly related to psychological disturbance.

Daytime Sleepiness in the Obese: Not as Simple as Obstructive Sleep Apnea

Objective: Excessive daytime sleepiness is a common symptom in obese patients, but what drives this condition is unclear. The objective was to look for clinical, anthropometric, biochemical, and polysomnographic predictors of excessive daytime sleepiness as measured by the Epworth Sleepiness Scale (ESS) in obese patients.

Hunger control and regular physical activity facilitate weight loss after laparoscopic adjustable gastric banding

BackgroundBariatric surgery facilitates substantial and durable weight loss; however, outcomes vary. In addition to physiological and technical factors, weight loss efficacy is dependent on modification of behavior to maintain a long-term change in energy balance. This study aimed to assess the extent and nature of change in energy intake and physical activity and identify factors associated with percentage weight loss (%WL) 12xa0months after laparoscopic adjustable gastric banding (LAGB).Methods129 bariatric surgery candidates (26 men/103 women, mean age 45.2u2009±u200911.5, mean body mass index [BMI] 44.3u2009±u20096.8, range 31.9 to 66.7) completed the study. Data were collected at baseline and 12xa0months. Validated questionnaires included the Cancer Council Victoria Food Frequency Questionnaire, Three Factor Eating Questionnaire, Short Form-36, Baecke Physical Activity Questionnaire, and Beck Depression Inventory. Symptoms of “non-hungry eating,” “emotional eating,” and “grazing” were assessed.ResultsMean %WL was 20.8u2009±u20098.5%, and excess weight loss was 50.0u2009±u200920.7 (pu2009<u20090.001). Mean total energy intake reduced from 9,991u2009±u20093,986xa0kj to 4,077u2009±u20091,493xa0kj (pu2009<u20090.001). Average leisure time and sport-related physical activity scores increased (both pu2009<u20090.001). Regression analysis identified baseline BMI (βu2009=u20090.241; pu2009=u20090.002), subjective hunger (βu2009=u2009−0.275; pu2009=u20090.001), physical function (βu2009=u20090.309; pu2009<u20090.001), and leisure time physical activity (βu2009=u20090.213; pu2009=u20090.010) as independent predictors of %WL, total R2 0.34%. “Non-hungry eating” and symptoms of depression were also related to poorer %WL.ConclusionLAGB affects marked behavior change and facilitates substantial weight loss in the first 12xa0months. However, variations in adopted behaviors can affect energy balance and weight loss success. Achievement and maintenance of favorable behaviors should be an important consideration during on-going postsurgical review and counseling. Management should include adequate band adjustment to control physical hunger, optimization of physical function and activity, and reinforcement of strategies to reduce energy intake.