Evaluating appetite/satiety hormones and eating behaviours as predictors of weight loss maintenance with GLP-1RA therapy in adolescents with severe obesity

INTRODUCTION

Whilst glucagon-like peptide-1 receptor agonists (GLP1-RAs) are effective for treating adolescent obesity, weight loss maintenance (WLM; preventing weight regain) remains a challenge. Our goal was to investigate appetite/satiety hormones and eating behaviours that may predict WLM with exenatide (a GLP1-RA) versus placebo in adolescents with severe obesity.

METHODS

Adolescents who had ≥5% body mass index (BMI) reduction with meal replacement therapy were randomized to 52 weeks of once-weekly exenatide extended release or placebo. In this secondary analysis, eating behaviours and appetite/satiety regulation hormones post-meal replacement therapy (pre-randomization to exenatide or placebo) were evaluated as possible predictors of WLM. Percent change in BMI from randomization to 52 weeks served as the primary measure of WLM.

RESULTS

The analysis included 66 adolescents (mean age 16.0 years; 47% female). Lower leptin response to meal testing was associated with greater WLM in terms of BMI percent change in those receiving exenatide compared to placebo (p = 0.007) after adjusting for sex, age and BMI. There were no other significant predictors of WLM.

CONCLUSIONS

Prior to exenatide, lower leptin response to meals was associated with improved WLM with exenatide compared to placebo. The mostly null findings of this study suggest that GLP1-RA treatment may produce similar WLM for adolescents with obesity regardless of age, BMI, sex and eating behaviours.

Successful use of split-dose intravenous daratumumab in a multiple myeloma patient after a first-dose life-threatening infusion-related reaction

INTRODUCTION

Daratumumab is a humanized IgG1 kappa monoclonal antibody directed against CD38 used to treat myeloma. The recommended dose of daratumumab is 16 mg/kg, with no lower or upper threshold. Here, we present the first split-dose daratumumab infusion experience in a myeloma patient with morbid obesity in whom daratumumab was interrupted because of grade 3 infusion-related reaction.

CASE REPORT

A female myeloma patient with morbid obesity received a combination of chemotherapy with daratumumab because of disease relapse. The calculated dose for the first intravenous daratumumab infusion was 1840 mg/day based on the weight of the patient, which was measured as 115 kilograms. Daratumumab infusion was initiated as appropriate but needed to be stopped because of a severe sudden presentation of shortness of breath and hypoxemia.

MANAGEMENT AND OUTCOME

After daratumumab was stopped, premedication was repeated, and oxygen, intravenous and inhaler steroids, inhaler β2 agonists and intravenous diphenhydramine were given in repeated doses. She was monitored and followed up in the emergency critical care unit. Daratumumab treatment with a split-dose schedule was planned after she fully recovered from all signs and symptoms. The total dose was divided into two doses and was given without any complications on two consecutive days. After that, she was also able to tolerate once a week 1840 mg of daratumumab in a single day.

DISCUSSION

There is a paucity of data regarding the best practice for instituting intravenous daratumumab in patients with morbid obesity regarding the infusion rate and duration, optimal dosing, and ideal way to cope with infusion-related reactions. Our case suggests a potential role for a split-dose schedule for patients with obesity and potential dose reductions and infusion-related reactions.

Antiretroviral Drug Exposure and Response in Obese and Morbidly Obese People With Human Immunodeficiency Virus (HIV): A Study Combining Modelling and Swiss HIV Cohort Data

BACKGROUND

Obesity is increasingly prevalent among people with HIV (PWH) and can possibly result in suboptimal antiretroviral drug (ARV) exposure and response. However, this has not been thoroughly evaluated given that obese PWH are underrepresented in clinical trials. We performed virtual trials using physiologically based pharmacokinetic (PBPK) modelling combined with observed clinical data to provide ARV dosing guidance in obese individuals.

METHODS

Each trial included a cohort of virtual adults with a body mass index (BMI) between 18.5 and 60 kg/m2. Therapeutic drug-monitoring data from the Swiss HIV Cohort Study (SHCS) were used to verify the predictive performance of the model. Subsequently, the model was applied to predict the pharmacokinetics of ARVs for different obesity classes. The association between ARV plasma concentrations and virological response was investigated in obese and nonobese individuals.

RESULTS

The PBPK model predicted an average reduction in ARV exposure of ∼20% and trough concentrations of ∼6% in obese (BMI ≥30 kg/m2) compared with nonobese (BMI: 18.5-25 kg/m2) individuals, consistent with observed clinical data. Etravirine and rilpivirine were the most impacted, especially in individuals with BMI >40 kg/m2 whose trough concentrations were below the clinical target threshold. Obese PWH in the SHCS did not have a higher rate of unsuppressed viral load than nonobese PWH.

CONCLUSIONS

The concentrations of ARVs are modestly reduced in obese individuals, with no negative impact on the virological response. Our data provide reassurance that standard doses of ARVs are suitable in obese PWH, including those who gained substantial weight with some of the first-line ARVs.

Could setmelanotide be the game-changer for acquired hypothalamic obesity?

Children with acquired hypothalamic obesity, e.g. following treatment for pediatric craniopharyngioma are at great risk for metabolic syndrome, cardiovascular health problems and premature mortality. Treatment for acquired hypothalamic obesity has thus far been disappointing. Several interventions were reported to be partially successful, including dextro-amphetamine and GLP-1R agonists, although results in acquired hypothalamic obesity are conflicting. Disruption of signaling through the melanocortin-4 receptor (MC4R) pathway results in hyperphagia and severe early-onset hypothalamic obesity. Recently, the MC4R agonist setmelanotide has shown promising results in children with genetic forms of hypothalamic obesity; POMC, PCSK1 and LEPR. Patient quotes such as "we have our family life back" illustrate the magnitude of the effect. Targeted hormone replacement therapy with a MC4R agonist for acquired hypothalamic obesity could be a game-changer. Preliminary results of setmelanotide treatment in 14, mostly pediatric, patients with acquired hypothalamic obesity are promising. The FDA has recommended that a prospective, randomized, blinded trial be conducted over a 12 months treatment period, comparable to pivotal trials for other obesity drugs. It may be discussed whether setmelanotide should be regarded as an obesity drug or whether it may be envisioned as an agent for hypothalamic substitution therapy. In this commentary we discuss the trial that is currently recruiting patients with acquired hypothalamic obesity.

Direct oral anticoagulants and the risk of adverse clinical outcomes among patients with different body weight categories: a large hospital-based study

OBJECTIVE

Through predictable pharmacokinetics-including a convenient fixed-dose regimen, direct oral anticoagulants (DOACs) are preferred over previous treatments in anticoagulation for various indications. However, the association between higher body weight and the risk of adverse consequences is not well studied among DOAC users. We aim to explore the association of body weight and adverse clinical outcomes in DOAC users.

METHODS

A total of 97,413 anonymised DOAC users in a tertiary care setting were identified following structured queries on the electronic health records (EHRs) to extract the feature-rich anonymised dataset. The prepared dataset was analysed, and the features identified with machine learning (ML) informed the adjustments of covariates in the multivariate regression analysis to examine the association. Kaplan-Meier analysis was performed to evaluate the mortality benefits of DOACs.

RESULTS

Among DOAC users, the odds of adverse clinical outcomes, such as clinically relevant non-major bleeding (CRNMB), ischaemic stroke, all-cause mortality, and prolonged hospital stay, were lower in patients with overweight, obesity, or morbid obesity than in patients with normal body weight. The odds of ischaemic stroke (OR 0.42, 95% CI: 0.36-0.88, p = 0.001) and all-cause mortality (OR 0.87, 95% CI: 0.81-0.95, p = 0.001) were lower in patients with morbid obesity than in patients with normal body weight. In the Kaplan-Meier analysis, apixaban was associated with a significantly lower rate of mortality overall and in obesity and overweight subgroups than other DOACs (p < 0.001). However, rivaroxaban performed better than apixaban in the morbid obesity subgroup (p < 0.001).

CONCLUSION

This study shows the positive effects of DOAC therapy on clinical outcomes, particularly in patients with high body weight. However, this still needs validation by further studies particularly among patients with morbid obesity.

Semaglutide 2.4 mg/wk for weight loss in patients with severe obesity and with or without a history of bariatric surgery

OBJECTIVE

This retrospective cohort study aimed to assess the effectiveness of semaglutide 2.4 mg in patients with severe obesity (BMI ≥ 40 kg/m2 ) who had previously undergone bariatric surgery (BS) but failed to achieve satisfactory weight loss or experienced weight regain compared with patients without a history of BS with similar BMI.

METHODS

The authors analyzed data from 129 patients with a BMI ≥ 40 kg/m2 , including 39 with (BS+) and 90 without (BS-) a history of BS. The patients received semaglutide treatment for 24 weeks starting at 0.25 mg/wk and gradually increasing to reach a final dose of 2.4 mg/wk. The treatment outcomes were assessed based on the percentage of weight loss, changes in BMI, and waist circumference.

RESULTS

Semaglutide treatment resulted in significant 9.1% weight loss in the BS+ group, with no significant difference in weight loss between the BS+ and BS- groups.

CONCLUSIONS

This study is the first, to the authors' knowledge, to compare the effectiveness of semaglutide treatment in patients with versus those without a history of BS, providing valuable evidence of its efficacy. By focusing on individuals with severe obesity (BMI > 40 kg/m2 and associated comorbidities), it fills a gap in the current literature and highlights the potential of semaglutide 2.4 mg as a treatment option for this specific population.

Effect of Swallow Balloon Therapy with the Combination of Semaglutide Oral Formulation: a Randomised Double-Blind Single-Centre Study

BACKGROUND

Obesity is a significant public health issue; new therapies and pharmaceutical approaches to weight management are needed.

OBJECTIVE

This study assesses weight reduction efficacy in the novel swallow balloon procedure and semaglutide, both promising non-surgical and pharmaceutical options, addressing obesity's critical public health challenge.

METHODS

This was a computer-generated, blocked randomisation, double-blind, single-centre study. Fifty-seven participants were assigned to swallow balloon therapy group I (with semaglutide), and 58 were assigned to swallow balloon therapy group II (without semaglutide). All treatment doses were orally administered once daily (3 mg for the 1st month, 7 mg for the 2nd month, and 14 mg for the 3rd and 4th months after the placement of the swallow balloon). All the data were statistically analysed.

RESULTS

The groups were highly well-matched. The %TWL in group I was 7.9%, 12.5%, 15.2%, and 17.6% and in group II was 6.1%, 10.5%, 12.8%, and 13.7% at 1, 2, 3, and 4 months, respectively. The most common adverse events (AEs) were nausea and vomiting, observed within the week. The resolution of T2DM, HTN, and OSA was 64.7% vs 55.5%, 64.3% vs 58.8%, and 72.0 vs 57.8% in groups I vs II, respectively. QoL significantly improved 4 months postoperatively in both groups. No major late complications occurred in either of the groups.

CONCLUSION

The study supports the efficacy of swallow balloon therapy combined with semaglutide oral formulation in promoting weight loss and improving comorbid conditions. The findings highlight the potential of this combined approach in managing obesity and its associated health issues.

Trends in prescribing and outcomes in obese versus non-obese patients receiving rivaroxaban therapy: an observational study using real-world data

PURPOSE

To investigate real-world prescribing trends and clinical outcomes based on body mass index (BMI) categorization in patients who received rivaroxaban therapy.

METHODS

This was a retrospective cohort study involving all patients who received rivaroxaban therapy across all Hamad Medical Corporation (HMC) hospitals from 2015 to 2020.

RESULTS

The number of patients initiated on rivaroxaban therapy significantly increased from 152 (3.3%) in 2015 to 1342 (28.9%) in 2020 (p <0.001). Within BMI categories, a similar increasing trend was observed in underweight, normal, and overweight patients, while from 2018 to 2020, there was a decreasing trend in rivaroxaban prescribing in all obese classes. The prevalence rate of all-cause mortality differed significantly between the BMI groups, with the highest mortality being among morbidly obese patients (BMI ≥ 40 kg/m2) (p< 0.001). On the other hand, no significant differences were found between the BMI groups in terms of bleeding, pulmonary embolism, deep vein thrombosis and stroke incidences. Multivariate logistic regression analyses showed that the likelihood of all-cause mortality was significantly higher in overweight and all categories of obese patients compared to underweight patients: overweight (OR: 5.3, 95% CI: 2.3-11.9, p< 0.001); obese class 1 (OR: 5.4, 95% CI: 2.3 - 12.2, p< 0.001); obese class 2 (OR: 6.5, 95% CI: 2.7 - 15.6, p< 0.001); and obese class 3 (OR: 3.7, 95% CI: 1.6 - 8.7, p = 0.003).

CONCLUSIONS

Rivaroxaban prescribing has significantly increased over the years across general population, with a noticeable decline in obese population during the last few years (from 2018 onwards). Furthermore, an appreciable association was evident between all-cause mortality and BMI of these patients.

Postoperative Remission of Diabetes Mellitus After Gastrectomy in Patients With Diabetes Mellitus and Gastric Cancer

BACKGROUND/AIM

We investigated the postoperative treatment status for diabetes mellitus and perioperative HbA1c levels in patients with diabetes mellitus and examined the effects of clinical factors on the remission of diabetes mellitus.

PATIENTS AND METHODS

In this study, 126 patients with gastric cancer were considered to have diabetes mellitus preoperatively, of whom 79 were treated with oral antidiabetic drugs and/or insulin treatment. We compared diabetic treatment status and HbA1c values between the preoperative and postoperative periods in patients who underwent gastrectomy and examined the effects of clinical factors on improving diabetes mellitus.

RESULTS

Of the 79 patients treated preoperatively for diabetes mellitus, 34 (43%) discontinued all medications for diabetes mellitus and for 37 (47%) the therapeutic dose was reduced or switched from insulin to oral antidiabetic drugs. Total gastrectomy was an independent factor for remission of antidiabetic treatments after gastrectomy. Concerning HbA1c levels, only the absence of preoperative insulin use was an independent factor for improvement. However, reconstruction was not a significantly correlated factor for the improvement of postoperative HbA1c levels and reduction of antidiabetic medications after distal gastrectomy.

CONCLUSION

Almost all patients discontinued or had their dose of antidiabetic medications reduced after gastrectomy in clinical practice, and special attention should be paid in the management methods for diabetes mellitus in patients who underwent total gastrectomy for gastric cancer.

Bronchodilator reversibility testing in morbidly obese non-smokers: fluticasone/salmeterol efficacy versus salbutamol bronchodilator

A positive response in reversibility testing is widely used to diagnose patients with airway limitations. However, despite its simple procedure, it doesn't accurately reflect the exact airway irreversibility. This study aimed to investigate the efficacy of a bronchodilation reversibility test using salbutamol and fluticasone/salmeterol combination in obese non-smoker subjects.The study included patients without a history of obstructive lung disease or bronchodilators. A sub-classification of patients based on body mass index (BMI) was carried out into normal (< 24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (BMI ≥ 30). Spirometry measurements were performed before and after salbutamol or fluticasone/salmeterol administration.The study included 415 (49.9% male) patients with a mean age of 40.92 ± 10.86 years. Obese subjects showed a high prevalence of restrictive patterns (23.4%), with non-significantly lower spirometric values compared to normal and overweight subjects (p > 0.05). The magnitude of bronchodilation, as identified by spirometry, following fluticasone/salmeterol was higher in all participants, with a significant increase in obese subjects with a p-value of 0.013, 0.002, and 0.035 for FEV1, FEV1% predicted, and FEV1/FVC, respectively.Fluticasone/salmeterol combination increases FEV1, FEV1% of predicted, and FEV1/FVC ratio than the conventional test using salbutamol inhaler, and it can be a potential candidate for assessment of airway obstruction using reversibility test, especially among the obese population.

Cost-Effectiveness of Antiobesity Drugs for Adolescents With Severe Obesity

Importance

Although the American Academy of Pediatrics has recommended treatment with antiobesity drugs for adolescents, the cost-effectiveness of antiobesity drugs for this population is still unknown.

Objective

To quantify cost-effectiveness of different antiobesity drugs available for pediatric use.

Design, Setting, and Participants

This economic evaluation used a Markov microsimulation model with health states defined by obesity levels. Effectiveness was measured by quality-adjusted life-years (QALYs) and costs were calculated from third-party payer perspective, estimated in 2023 US dollars over a 10-year horizon. Data were obtained from the published literature.

Intervention

Antiobesity drugs orlistat, liraglutide, semaglutide, and phentermine-topiramate vs no treatment. Metformin hydrochloride and 2 types of bariatric surgical procedures (sleeve gastrectomy and gastric bypass) were considered in sensitivity analysis.

Main Outcomes and Measures

Incremental cost-effectiveness ratio.

Results

Among the 4 antiobesity drugs currently approved for pediatric use, phentermine-topiramate was the most cost-effective with an incremental cost-effectiveness ratio of $93 620 per QALY relative to no treatment in this simulated cohort of 10 000 adolescents aged 12 to 17 years (mode, 15 years) with severe obesity (62% female). While semaglutide offered more QALYs than phentermine-topiramate, its higher cost resulted in an incremental cost-effectiveness ratio ($1 079 480/QALY) that exceeded the commonly used willingness-to-pay threshold of $100 000 to $150 000/QALY. Orlistat and liraglutide cost more and were less effective than phentermine-topiramate and semaglutide, respectively. Sleeve gastrectomy and gastric bypass were more effective than phentermine-topiramate but were also more costly, rendering them not cost-effective compared with phentermine-topiramate at the willingness-to-pay threshold of $100 000 to $150 000/QALY.

Conclusions and Relevance

In this economic evaluation of weight loss drugs for adolescents with severe obesity, we found phentermine-topiramate to be a cost-effective treatment at a willingness-to-pay threshold of $100 000 to $150 000/QALY. Further research is needed to determine long-term drug efficacy and how long adolescents continue treatment.

Impact of body mass index and its change on survival outcomes in patients with early breast cancer: A pooled analysis of individual-level data from BCIRG-001 and BCIRG-005 trials

INTRODUCTION

The relationships between body mass index (BMI) and survival rates are complex, and have not been thoroughly investigated in breast cancer patients who received adjuvant chemotherapy.

METHODS

We collected data on 2394 patients from two randomized, phase III clinical trials that investigated adjuvant chemotherapy in breast cancer identified in Project Data Sphere. The objective was to examine the effect of baseline BMI, BMI after adjuvant chemotherapy, and BMI change from baseline to post-adjuvant chemotherapy on disease-free survival (DFS) and overall survival (OS). Restricted cubic splines were used to examine potential non-linear associations between continuous BMI value and survival. Stratified analyses involved chemotherapy regimens.

RESULTS

Severe obesity (BMI≥40.0 kg/m2) at baseline was independently associated with worse DFS (hazard ration [HR] = 1.48, 95% confidence interval [CI] 1.02-2.16, P = 0.04) and OS (HR = 1.79, 95%CI 1.17-2.74, P = 0.007) compared with underweight/normal weight (BMI≤24.9 kg/m2). A BMI loss >10% was also an independent prognostic factor for adverse OS (HR = 2.14, 95%CI 1.17-3.93, P = 0.014). Stratified analyses revealed that severe obesity adversely affected DFS (HR = 2.38, 95%CI 1.26-4.34, P = 0.007) and OS (HR = 2.90, 95%CI 1.46-5.76, P = 0.002) in the docetaxel-based group, but not in the non-docetaxel-based group. Restricted cubic splines revealed a "J-shaped" association of baseline BMI with risk of recurrence or all-cause death, and this relationship was more pronounced in the docetaxel-based group.

CONCLUSIONS

In early breast cancer patients treated with adjuvant chemotherapy, baseline severe obesity was significantly linked to worse DFS and OS, and a BMI loss over 10% from baseline to post-adjuvant chemotherapy also negatively affected OS. Moreover, the prognostic role of BMI might differ between docetaxel-based and non-docetaxel-based groups.

The effect of bariatric surgery on opioid consumption in patients with obesity: a registry-based cohort study

BACKGROUND

Misuse of opioid medication has become a major health crisis in several countries. A significant number of patients with obesity use opioid medications, mostly to alleviate symptoms due to obesity-related co-morbidities.

OBJECTIVE

To compare patterns of opioid drug usage before and after bariatric surgery in this population, hypothesizing that weight loss and improvement of obesity-related co-morbidities could reduce opioid consumption.

SETTING

The Ontario Bariatric Registry (Ontario, Canada).

METHODS

In this retrospective cohort study, the Ontario Bariatric Registry was used to compare opioid consumption in adult patients undergoing bariatric surgery between 2010 and 2021. The primary outcome was the number of patients using opioid medication at 1 year after surgery. Multiple logistic regression analyses were performed to identify potential predictors of opioid consumption.

RESULTS

Data of 11,179 patients were analyzed. Mean age was 45.7 ± 10.2 years, mean baseline body mass index was 48.9 ± 8 kg/m2, and 83.6% of patients were female. Roux-en-Y gastric bypass was performed in the majority of patients (85.6%), followed by sleeve gastrectomy (14.2%). At baseline, opioids were used by 7.7% and nonopioid pain medications by 42.3% of patients. At 1 year after surgery, these numbers significantly decreased (Δ-1.9% and Δ-18.0%, respectively). The decrease in the consumption of nonopioid pain medication needs to be interpreted in the context of the contraindication to nonsteroidal anti-inflammatory drugs after Roux-en-Y gastric bypass, which was the most commonly performed procedure. Presence of musculoskeletal pain and use of nonopioid pain medication at baseline were identified as independent predictors of opioid consumption at 1 year after surgery.

CONCLUSIONS

At 1 year after bariatric surgery, a significant decrease in opioid and nonopioid pain medication consumption was seen among patients with obesity. Aggressive management of excess weight, especially with bariatric surgery, can potentially reduce the impact of the opioid crisis in this population.

Effectiveness of semaglutide versus liraglutide for treating post-metabolic and bariatric surgery weight recurrence

OBJECTIVE

The aim of this study was to compare the effectiveness of semaglutide versus liraglutide for treating post-metabolic and bariatric surgery (MBS) weight recurrence.

METHODS

A retrospective analysis of 207 adults with post-MBS weight recurrence treated with semaglutide 1.0 mg weekly (n = 115) or liraglutide 3.0 mg daily (n = 92) at an academic center from January 1, 2015, through April 1, 2021, was conducted. The primary end point was percentage body weight change at 12 months of treatment with regimens containing semaglutide or liraglutide.

RESULTS

The mean sample age was 55.2 years; mean BMI was 40.4 kg/m2 ; 89.9% were female; and 50% completed sleeve gastrectomy, 29% completed Roux-en-Y gastric bypass, and 21% completed adjustable gastric banding. Least-squares mean weight change at 12 months was -12.92% versus -8.77% in the semaglutide and liraglutide groups, respectively (p < 0.001). The adjusted odds ratios were 2.34 (95% CI: 1.28-4.29) for ≥10% weight loss and 2.55 (95% CI: 1.22-5.36) for ≥15% weight loss over 12 months in the semaglutide group versus liraglutide group, respectively. Weight-loss efficacy of semaglutide (vs. liraglutide) did not differ by subgroups explored, including age, sex, and MBS procedure.

CONCLUSIONS

These results show that treatment regimens including semaglutide 1.0 mg weekly lead to superior weight loss compared with liraglutide 3.0 mg daily for treating post-MBS weight recurrence, regardless of procedure type or the magnitude of weight recurrence.

Early metabolomic, lipid and lipoprotein changes in response to medical and surgical therapeutic approaches to obesity

BACKGROUND

Glucagon-like peptide-1 receptor agonists (GLP-1RA) and bariatric surgery have proven to be effective treatments for obesity and cardiometabolic conditions. We aimed to explore the early metabolomic changes in response to GLP-1RA (liraglutide) therapy vs. placebo and in comparison to bariatric surgery.

METHODS

Three clinical studies were conducted: a bariatric surgery cohort study of participants with morbid obesity who underwent either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) studied over four and twelve weeks, and two randomized placebo-controlled, crossover double blind studies of liraglutide vs. placebo administration in participants with type 2 diabetes (T2D) and participants with obesity studied for three and five weeks, respectively. Nuclear magnetic resonance spectroscopy-derived metabolomic data were assessed in all eligible participants who completed all the scheduled in-clinic visits. The primary outcome of the study was to explore the changes of the metabolome among participants with obesity with and without T2D receiving the GLP-1RA liraglutide vs. placebo and participants with obesity undergoing bariatric surgery during the three to five-week study period. In addition, we assessed the bariatric surgery effects longitudinally over the twelve weeks of the study and the differences between the bariatric surgery subgroups on the metabolome. The trials are registered with ClinicalTrials.gov, numbers NCT03851874, NCT01562678 and NCT02944500.

RESULTS

Bariatric surgery had a more pronounced effect on weight and body mass index reduction (-14.19 ± 5.27 kg and - 5.19 ± 5.27, respectively, p < 0.001 for both) and resulted in more pronounced metabolomic and lipidomic changes compared to liraglutide therapy at four weeks postoperatively. Significant changes were observed in lipoprotein parameters, inflammatory markers, ketone bodies, citrate, and branched-chain amino acids after the first three to five weeks of intervention. After adjusting for the amount of weight loss, a significant difference among the study groups remained only for acetoacetate, β-hydroxybutyrate, and citrate (p < 0.05 after FDR correction). Glucose levels were significantly reduced in all intervention groups but mainly in the T2D group receiving GLP-1RA treatment. After adjusting for weight loss, only glucose levels remained significant (p = 0.001 after FDR correction), mainly due to the glucose change in the T2D group receiving GLP-1RA. Similar results with those observed at four weeks were observed in the surgical group when delta changes at twelve weeks were assessed. Comparing the two types of bariatric surgery, an intervention effect was more pronounced in the RYGB subgroup regarding total triglycerides, triglyceride-rich lipoprotein size, and trimethylamine-N-oxide (p for intervention: 0.031, 0.028, 0.036, respectively). However, after applying FDR correction, these changes deemed to be only suggestive; only time effects remained significant with no significant changes persisting in relation to the types of bariatric surgery.

CONCLUSIONS

The results of this study suggest that the early metabolomic, lipid and lipoprotein changes observed between liraglutide treatment and bariatric surgery are similar and result largely from the changes in patients' body weight. Specific changes observed in the short-term post-surgical period between bariatric vs. nonsurgical treated participants, i.e., acetoacetate, β-hydroxybutyrate, and citrate changes, may reflect changes in patient diets and calorie intake indicating potential calorie and diet-driven metabolomics/lipidomic effects in the short-term postoperatively. Significant differences observed between SG and RYGB need to be confirmed and extended by future studies.

Exenatide for weight-loss maintenance in adolescents with severe obesity: A randomized, placebo-controlled trial

OBJECTIVE

This study sought to evaluate the effect of 52 weeks of exenatide extended release (XR) on the maintenance of meal replacement therapy (MRT)-induced BMI reduction in adolescents with severe obesity.

METHODS

In this randomized, double-blind, placebo-controlled trial, 100 participants aged 12 to 18 years with BMI ≥ 1.2 × 95th percentile were enrolled in a short-term MRT run-in phase. Those who achieved ≥5% BMI reduction during the run-in were then randomized to 52 weeks of exenatide XR 2.0 mg or placebo weekly. Both groups also received lifestyle therapy. The prespecified primary end point was mean percent change in BMI from randomization (post run-in) to 52 weeks in the intention-to-treat population.

RESULTS

A total of 100 participants were enrolled, and 66 (mean age 16 = [SD 1.5] years; 47% female) achieved ≥5% BMI reduction with MRT and were randomized (33 to exenatide XR and 33 to placebo). From randomization (post run-in) to 52 weeks, mean BMI increased 4.6% and 10.1% in the exenatide XR and placebo groups, respectively. The placebo-subtracted exenatide XR treatment effect was -4.1% (95% CI: -8.6% to 0.5%, p = 0.078).

CONCLUSIONS

Although not achieving statistical significance, exenatide XR, compared with placebo, may partly mitigate the propensity toward BMI rebound in adolescents who achieved initial weight loss with dietary intervention.

Pharmacologic management of weight regain following bariatric surgery

While bariatric surgery restults in significant long-term weight loss for most patients with obesity, post-surgical weight gain affects a considerable percentage of patients to varying degrees of severity. Furthermore, a small but significant percentage of patients experience inadequate post-surgical weight loss. Although many studies have examined the role of anti-obesity medications to address post-operative weight regain, an evidence-based consensus has not yet been achieved because of the heterogeneity of populations studied and the studies themselves. Observational studies in the post-bariatric surgery population consistently demonstrate the benefit of medical weight management after bariatric surgery, with most evidence highlighting liraglutide, topiramate, and phentermine/topiramate. New anti-obesity medications are anticipated to be helpful for post-surgical weight optimization given their efficacy in the non-surgical population.

Implications for IV posaconazole dosing in the era of obesity

BACKGROUND

The prevalence of obesity has shown a dramatic increase over recent decades. Obesity is associated with underdosing of antimicrobial drugs for prophylaxis and treatment. Posaconazole is a broad-spectrum triazole antifungal drug licensed for prophylaxis and treatment of invasive fungal infections. It is unclear how posaconazole should be dosed in obese patients.

METHODS

We performed a prospective study investigating the pharmacokinetics of posaconazole in morbidly obese (n = 16) and normal-weight (n = 8) subjects, with a weight ranging between 61.4 and 190 kg, after a 300 or 400 mg IV dose. Population pharmacokinetic modelling was used to assess the effect of body size on posaconazole pharmacokinetics. ClinicalTrials.gov Identifier: NCT03246386.

RESULTS

Total body weight best predicted changes in CL and V. Model-based simulations demonstrated that, for treatment of fungal infections, a daily IV dose of 300 mg will result in a PTA of ≥90% in individuals up to 140 kg, after which both twice daily loading and the daily maintenance dose should be increased to 400 mg. For prophylaxis, a 300 mg IV dose is adequate in patients up to 190 kg.

CONCLUSIONS

Body size has a significant impact on posaconazole CL and V, resulting in a lower exposure in obese subjects compared with normal-weight subjects. For therapeutic use of posaconazole, a dose increase is required in patients above 140 kg. For prophylaxis, a 300 mg IV dose is adequate. For oral treatment, these recommendations can act as a starting point followed by therapeutic drug monitoring.

Pulmonary Artery Intervention for Submassive Pulmonary Embolism From an Arm Superficial Venous Access

Pulmonary embolism (PE) endovascular interventions are often approached from an internal jugular or femoral venous access. There are multiple advantages of right basilic vein (RBV) access for both patient and operator, especially in the setting of morbid obesity. We hereby describe the case of a 48-year-old, morbidly obese man who presented with acute respiratory insufficiency and was found to have bilateral submassive subocclusive PE, worse on the right. The right ventricular to left ventricular ratio was 2.1 and troponin was elevated. A 7 Fr sheath was placed in the RBV under ultrasound guidance. Selective bilateral pulmonary arteriography was then performed. A 106 x 12 cm EKOS catheter was placed in the segment of highest thrombotic burden for a 6-hour protocol of catheter-directed ultrasound-facilitated thrombolytic therapy. The patient recovered well on a direct oral anticoagulant and his acute symptoms resolved. Treating massive/submassive PE from a RBV access offers the convenience and safety of superficial venous access (for patient and operator), better patient comfort, less venous stasis during therapy with ability to ambulate, less potential for bleeding and vascular complications, less potential for operator radiation exposure when compared with the jugular approach, and better operator ergonomics.

Effects of Manipulating Circulating Bile Acid Concentrations on Postprandial GLP-1 Secretion and Glucose Metabolism After Roux-en-Y Gastric Bypass

BACKGROUND

Altered bile acid (BA) turnover has been suggested to be involved in the improved glucose regulation after Roux-en-Y gastric bypass (RYGB), possibly via stimulation of GLP-1 secretion. We investigated the role of exogenous as well as endogenous BAs for GLP-1 secretion after RYGB by administering chenodeoxycholic acid (CDCA) and the BA sequestrant colesevelam (COL) both in the presence and the absence of a meal stimulus.

METHODS

Two single-blinded randomized cross-over studies were performed. In study 1, eight RYGB operated participants ingested 200 ml water with 1) CDCA 1.25 g or 2) CDCA 1.25 g + colesevelam 3.75 g on separate days. In study 2, twelve RYGB participants ingested on separate days a mixed meal with addition of 1) CDCA 1.25 g, 2) COL 3.75 g or 3) COL 3.75 g × 2, or 4) no additions.

RESULTS

In study 1, oral intake of CDCA increased circulating BAs, GLP-1, C-peptide, glucagon, and neurotensin. Addition of colesevelam reduced all responses. In study 2, addition of CDCA enhanced meal-induced increases in plasma GLP-1, glucagon and FGF-19 and lowered plasma glucose and C-peptide concentrations, while adding colesevelam lowered circulating BAs but did not affect meal-induced changes in plasma glucose or measured gastrointestinal hormones.

CONCLUSION

In RYGB-operated persons, exogenous CDCA enhanced meal-stimulated GLP-1 and glucagon secretion but not insulin secretion, while the BA sequestrant colesevelam decreased CDCA-stimulated GLP-1 secretion but did not affect meal-stimulated GLP-1, C-peptide or glucagon secretion, or glucose tolerance. These findings suggest a limited role for endogenous bile acids in the acute regulation of postprandial gut hormone secretion or glucose metabolism after RYGB.

Case Report: Off Label Utilization of Topiramate and Metformin in Patients With BMI ≥50 kg/m2 Prior to Bariatric Surgery

FDA approved anti-obesity medications may not be cost effective for patients struggling with pre-operative weight loss prior to bariatric surgery. Metformin, a biguanide, and Topiramate, a carbonic anhydrase inhibitor, both cost effective medications, have demonstrated weight loss when used for the treatment of type 2 diabetes or seizures, respectively. The aim of the three cases is to demonstrate the clinical utility of topiramate and metformin for preoperative weight loss in patients with a body mass index (BMI) ≥ 50 kg/m² prior to bariatric surgery who are unable to follow the bariatric nutritional prescription due to a dysregulated appetite system Each patient was prescribed metformin and/or topiramate in an off-label manner in conjunction with lifestyle modifications and achieved >8% total body weight loss during the preoperative period.

Effects of Extra Virgin Olive Oil (EVOO) and the Traditional Brazilian Diet on Sarcopenia in Severe Obesity: A Randomized Clinical Trial

BACKGROUND

Nutritional interventions may have positive effects on sarcopenia and body composition.

OBJECTIVE

to evaluate the effectiveness of extra virgin olive oil (EVOO) consumption and a healthy traditional Brazilian diet (DieTBra) on improving sarcopenia indicators and reducing total body fat in severe obesity.

METHODS

A randomized controlled trial registered at ClinicalTrials.gov (NCT02463435) conducted with 111 severely obese participants randomized into three treatment groups-(1) EVOO (52 mL/day), (2) DieTBra, (3) DieTBra + EVOO (52 mL/day)-for 12 weeks. Body composition was assessed by dual-energy X-ray absorptiometry and sarcopenia by walking speed and handgrip strength.

RESULTS

Significant reductions in total body fat (p = 0.041) and body weight (p = 0.003) were observed in the DieTBra group. In the DietBra + olive oil group there was also a significant reduction in body weight (0.001) compared to the olive oil-only group. ANCOVA analyses showed reductions in total body fat in the DieTBra (p = 0.016) and DieTBra + olive oil (p = 0.004) groups. Individuals in the DieTBra group had significant improvements in their walking speed (p = 0.042) and handgrip strength (p = 0.044).

CONCLUSIONS

DieTBra contributes to improvements in handgrip strength, walking speed, and total body fat in severely obese adults. The major study was registered at ClinicalTrials.gov (NCT02463435).

Lifestyle and pharmacologic management before and after bariatric surgery

As metabolic and bariatric surgery (MBS) increasingly becomes a treatment of choice for adolescents with severe obesity, there is a need to understand how to deliver pre- and postoperative care in ways that maximize long-term safety and efficacy. This article describes major pre- and postoperative goals, lifestyle modification targets, and, when necessary, pharmacologic management strategies for adolescents undergoing MBS. Three categories of evidence were used-studies of pre- and postoperative interventions and factors influencing MBS outcomes in adolescents, studies of pre- and postoperative associations and interventions in adults, and studies of non-surgical weight management applicable to adolescents pursuing MBS. Finally, priority areas for future research within this topic are identified.

In Vitro Evaluation of Different Prebiotics on the Modulation of Gut Microbiota Composition and Function in Morbid Obese and Normal-Weight Subjects

The gut microbiota remains relatively stable during adulthood; however, certain intrinsic and environmental factors can lead to microbiota dysbiosis. Its restoration towards a healthy condition using best-suited prebiotics requires previous development of in vitro models for evaluating their functionality. Herein, we carried out fecal cultures with microbiota from healthy normal-weight and morbid obese adults. Cultures were supplemented with different inulin-type fructans (1-kestose, Actilight, P95, Synergy1 and Inulin) and a galactooligosaccharide. Their impact on the gut microbiota was assessed by monitoring gas production and evaluating changes in the microbiota composition (qPCR and 16S rRNA gene profiling) and metabolic activity (gas chromatography). Additionally, the effect on the bifidobacterial species was assessed (ITS-sequencing). Moreover, the functionality of the microbiota before and after prebiotic-modulation was determined in an in vitro model of interaction with an intestinal cell line. In general, 1-kestose was the compound showing the largest effects. The modulation with prebiotics led to significant increases in the Bacteroides group and Faecalibacterium in obese subjects, whereas in normal-weight individuals, substantial rises in Bifidobacterium and Faecalibacterium were appreciated. Notably, the results obtained showed differences in the responses among the tested compounds but also among the studied human populations, indicating the need for developing population-specific products.

Plasma N-Acetylaspartate Is Related to Age, Obesity, and Glucose Metabolism: Effects of Antidiabetic Treatment and Bariatric Surgery

Background: N-acetylaspartate (NAA) is synthesized only by neurons and is involved in neuronal metabolism and axonal myelination. NAA is the strongest signal on brain magnetic resonance spectroscopy, and its concentration have been associated with cognitive dysfunction in neurodegenerative diseases, obesity, and type 2 diabetes (T2D). Materials and Methods: We explored the impact of obesity and T2D on circulating NAA as well as the impact of bariatric surgery and antidiabetic treatments. We developed an LC-MS method for the accurate measurements of fasting plasma NAA levels in 505 subjects (156 subjects with normal glucose tolerance, 24 subjects with impaired glucose tolerance, and 325 patients with T2D) to examine the associations of NAA with obesity and dysglycemia. To validate cross-sectional findings, plasma NAA was measured 6 months after Roux-en-Y Gastric Bypass (RYGB) in 55 morbidly obese subjects, and after 1 year of antidiabetic treatment (with dapagliflozin, exenatide, or dapagliflozin plus exenatide) in 192 T2D patients. Results: In the whole population, NAA was associated with age (r = 0.31, p <0.0001) and BMI (r = -0.20, p <0.0001). Independently of age and BMI, NAA was reciprocally related to HbA1c and fasting plasma glucose (partial r = -0.13, both p = 0.01). Surgically-induced weight loss raised NAA (by 18 nmol/L on average, p <0.02). Glucose lowering treatment increased NAA in proportion to the drop in HbA1c (r = 0.31, p <0.0001) regardless of the agent used. Conclusions: Circulating NAA concentrations are modulated by age, obesity, and glycemic control. Whether they may mark for the corresponding metabolic effects on brain function remains to be established by joint measurements of spectroscopic signal and cognitive function.

Liraglutide 3.0 mg for the management of insufficient weight loss or excessive weight regain post-bariatric surgery

To assess the effectiveness of liraglutide 3.0 mg in post-bariatric surgery patients, and to determine whether this would differ based on the type of bariatric surgery. One hundred seventeen post-bariatric surgery patients from the Wharton Medical Clinic were analysed. Changes in weight while taking liraglutide 3.0 mg were examined for all patients, and by three types of bariatric surgery-Roux-en-Y gastric bypass, gastric banding and gastric sleeve. Patients primarily underwent Roux-en-Y gastric bypass (n = 53, 45.3%) or gastric banding (n = 50, 42.7%). Over 7.6 ± 7.1 months taking liraglutide 3.0 mg, patients lost a statistically significant amount of weight (-6.3 ± 7.7 kg, P < .05) regardless of the type of surgery they had (P > .05). This decrease in weight remained significant after 1-year of taking liraglutide 3.0 mg (P < .05). Nausea was the most prevalent side effect, reported by 29.1% patients. While options for excess weight management in post-bariatric surgery patients are limited, results of this study suggest that post-bariatric surgery patients can lose a significant amount of weight while taking liraglutide 3.0 mg regardless of the type of surgery they had. Further, similar to non-surgical populations, post-bariatric surgery patients taking liraglutide 3.0 mg may experience gastrointestinal side effects such as nausea and can continue to lose weight up to 1 year.

Are Nonnutritive Sweeteners Obesogenic? Associations between Diet, Faecal Microbiota, and Short-Chain Fatty Acids in Morbidly Obese Subjects

Obesity has been associated with changes in the gut microbiota and its metabolites. The study explored changes in the faecal microbiota and short-chain fatty acids (SCFA) associated with the diet (including nonnutritive sweeteners (NNSs)) and evaluated metabolic consequences in subjects with morbid obesity. The diet was assessed with a validated food frequency questionnaire. One unit of NNSs was 100 mL beverage with NNSs or 2 tablets/teaspoons of NNSs. The faecal microbiota was assessed with GA-map® dysbiosis test and SCFA with gas chromatography and flame ionisation detection. Fourteen men and 75 women with a mean age of 44.6 (SD 8.7) years, BMI 41.8 (SD 3.6) kg/m², and intake of NNSs 7.5 units/day (SD 3.2; range 0-43) were included. Faecal butyric acid was positively and negatively associated with the intake of starch (partial correlation = 0.264; p=0.015) and NNSs (partial correlation = -0.274; p=0.011), respectively. NNSs were associated with changes in four out of 39 bacterial groups. Butyric acid has antiobesogenic effects, reduces insulin resistance, and improves dyslipidaemia. Since the weight-reducing effect of NNSs on obese adults trying to lose weight is dubious, it seems imprudent to use NNSs that might counteract the favourable effects of butyric acid.

Treatment of Hypothalamic Obesity with Dextroamphetamine: A Case Series

BACKGROUND

A limited number of published case reports suggest a positive effect of dextroamphetamine, an adrenergic agonist affecting both the central nervous system (CNS) and peripheral nervous system, on physical activity and weight in patients with hypothalamic obesity (intractable obesity following CNS insult). Here, we present our clinical experience with dextroamphetamine treatment for hypothalamic obesity.

METHODS

The clinical course of all patients started on dextroamphetamine treatment for severe hypothalamic obesity at our institution between 2010 and 2013 is reported. Dextroamphetamine administration was initiated at a single dose of 5 mg per day and titrated to effect up to a dose of 20 mg/day. BMI z-score velocity was calculated as change in BMI z-score over standardized intervals of 12 months. Parameters of treatment success and adverse events were assessed in a standardized fashion.

RESULTS

Seven patients (2 males; mean age 17.6 years [range 12.9-24.5]) underwent individual treatment attempts with dextroamphetamine between 2010 and 2013. The primary diagnoses were craniopharyngioma (n = 4), ganglioglioma WHO I (n = 1), astrocytoma (n = 1), and neonatal meningitis (n = 1). Time from initial CNS insult to initiation of dextroamphetamine treatment averaged 5.2 years (range 2.4 months to 16.5 years). All patients demonstrated a steady increase in BMI z-score from the time of initial diagnosis until initiation of dextroamphetamine treatment. Mean baseline BMI z-score was +3.17 ± 0.93 (+1.9 to +4.4). Mean BMI z-score velocity decelerated to -0.18 ± 0.12 per year during the first year of treatment and stabilized at +0.05 ± 0.32 per year during the second year of treatment. No significant adverse events were reported.

CONCLUSION

Dextroamphetamine treatment led to stabilization or reduction of BMI z-score in a cohort of 7 patients with hypothalamic obesity, with no adverse effects. Considering the projected increase in BMI z-score according to the natural course of the disease, these findings are promising and warrant further study.

Bariatric surgery, lifestyle interventions and orlistat for severe obesity: the REBALANCE mixed-methods systematic review and economic evaluation

BACKGROUND

Adults with severe obesity [body mass index (BMI) of ≥ 35 kg/m2] have an increased risk of comorbidities and psychological, social and economic consequences.

OBJECTIVES

Systematically review bariatric surgery, weight-management programmes (WMPs) and orlistat pharmacotherapy for adults with severe obesity, and evaluate the feasibility, acceptability, clinical effectiveness and cost-effectiveness of treatment.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials and the NHS Economic Evaluation Database were searched (last searched in May 2017).

REVIEW METHODS

Four systematic reviews evaluated clinical effectiveness, cost-effectiveness and qualitative evidence for adults with a BMI of ≥ 35 kg/m2. Data from meta-analyses populated a microsimulation model predicting costs, outcomes and cost-effectiveness of Roux-en-Y gastric bypass (RYGB) surgery and the most effective lifestyle WMPs over a 30-year time horizon from a NHS perspective, compared with current UK population obesity trends. Interventions were cost-effective if the additional cost of achieving a quality-adjusted life-year is < £20,000-30,000.

RESULTS

A total of 131 randomised controlled trials (RCTs), 26 UK studies, 33 qualitative studies and 46 cost-effectiveness studies were included. From RCTs, RYGB produced the greatest long-term weight change [-20.23 kg, 95% confidence interval (CI) -23.75 to -16.71 kg, at 60 months]. WMPs with very low-calorie diets (VLCDs) produced the greatest weight loss at 12 months compared with no WMPs. Adding a VLCD to a WMP gave an additional mean weight change of -4.41 kg (95% CI -5.93 to -2.88 kg) at 12 months. The intensive Look AHEAD WMP produced mean long-term weight loss of 6% in people with type 2 diabetes mellitus (at a median of 9.6 years). The microsimulation model found that WMPs were generally cost-effective compared with population obesity trends. Long-term WMP weight regain was very uncertain, apart from Look AHEAD. The addition of a VLCD to a WMP was not cost-effective compared with a WMP alone. RYGB was cost-effective compared with no surgery and WMPs, but the model did not replicate long-term cost savings found in previous studies. Qualitative data suggested that participants could be attracted to take part in WMPs through endorsement by their health-care provider or through perceiving innovative activities, with WMPs being delivered to groups. Features improving long-term weight loss included having group support, additional behavioural support, a physical activity programme to attend, a prescribed calorie diet or a calorie deficit.

LIMITATIONS

Reviewed studies often lacked generalisability to UK settings in terms of participants and resources for implementation, and usually lacked long-term follow-up (particularly for complications for surgery), leading to unrealistic weight regain assumptions. The views of potential and actual users of services were rarely reported to contribute to service design. This study may have failed to identify unpublished UK evaluations. Dual, blinded numerical data extraction was not undertaken.

CONCLUSIONS

Roux-en-Y gastric bypass was costly to deliver, but it was the most cost-effective intervention. Adding a VLCD to a WMP was not cost-effective compared with a WMP alone. Most WMPs were cost-effective compared with current population obesity trends.

FUTURE WORK

Improved reporting of WMPs is needed to allow replication, translation and further research. Qualitative research is needed with adults who are potential users of, or who fail to engage with or drop out from, WMPs. RCTs and economic evaluations in UK settings (e.g. Tier 3, commercial programmes or primary care) should evaluate VLCDs with long-term follow-up (≥ 5 years). Decision models should incorporate relevant costs, disease states and evidence-based weight regain assumptions.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016040190.

FUNDING

The National Institute for Health Research Health Technology Assessment programme. The Health Services Research Unit and Health Economics Research Unit are core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.

Naltrexone/bupropion for obesity

Naltrexone/bupropion (Mysimba - Orexigen Therapeutics Ireland Limited) is a fixed-dose combination product for the treatment of adults who are obese or overweight with at least one weight-related comorbidity, as an adjunct to diet and lifestyle modifications. Originally licensed by the European Medicines Agency (EMA) in 2015, it has recently been launched in the UK. Here, we review the evidence for its efficacy and safety and consider its place in therapy.

Future Pharmacotherapy for Obesity: New Anti-obesity Drugs on the Horizon

PURPOSE OF REVIEW

Obesity is a global health crisis with detrimental effects on all organ systems leading to worsening disease state and rising costs of care. Persons with obesity failing lifestyle therapies need to be escalated to appropriate pharmacological treatment modalities, medical devices, and/or bariatric surgery if criteria are met and more aggressive intervention is needed. The progression of severe obesity in the patient population coupled with related co-morbidities necessitates the development of novel therapies for the treatment of obesity. This development is preceded by increased understanding of the underpinnings of energy regulation and neurohormonal pathways involved in energy homeostasis.

RECENT FINDINGS

Though there are approved anti-obesity drugs available in the USA, newer drugs are now in the pipeline for development given the urgent need. This review focuses on anti-obesity drugs in the pipeline including centrally acting agents (setmelanotide, neuropeptide Y antagonist [velneperit], zonisamide-bupropion [Empatic], cannabinoid type-1 receptor blockers), gut hormones and incretin targets (new glucagon-like-peptide-1 [GLP-1] analogues [semaglutide and oral equivalents], amylin mimetics [davalintide, dual amylin and calcitonin receptor agonists], dual action GLP-1/glucagon receptor agonists [oxyntomodulin], triple agonists [tri-agonist 1706], peptide YY, leptin analogues [combination pramlintide-metreleptin]), and other novel targets (methionine aminopeptidase 2 inhibitor [beloranib], lipase inhibitor [cetilistat], triple monoamine reuptake inhibitor [tesofensine], fibroblast growth factor 21), including anti-obesity vaccines (ghrelin, somatostatin, adenovirus36). With these new drugs in development, anti-obesity therapeutics have potential to vastly expand allowing better treatment options and personalized approach to obesity care.

Association of Bariatric Surgery vs Medical Obesity Treatment With Long-term Medical Complications and Obesity-Related Comorbidities

IMPORTANCE

The association of bariatric surgery and specialized medical obesity treatment with beneficial and detrimental outcomes remains uncertain.

OBJECTIVE

To compare changes in obesity-related comorbidities in patients with severe obesity (body mass index ≥40 or ≥35 and at least 1 comorbidity) undergoing bariatric surgery or specialized medical treatment.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study with baseline data of exposures from November 2005 through July 2010 and follow-up data from 2006 until death or through December 2015 at a tertiary care outpatient center, Vestfold Hospital Trust, Norway. Consecutive treatment-seeking adult patients (n = 2109) with severe obesity assessed (221 patients excluded and 1888 patients included).

EXPOSURES

Bariatric surgery (n = 932, 92% gastric bypass) or specialized medical treatment (n = 956) including individual or group-based lifestyle intervention programs.

MAIN OUTCOMES AND MEASURES

Primary outcomes included remission and new onset of hypertension based on drugs dispensed according to the Norwegian Prescription Database. Prespecified secondary outcomes included changes in comorbidities. Adverse events included complications retrieved from the Norwegian Patient Registry and a local laboratory database.

RESULTS

Among 1888 patients included in the study, the mean (SD) age was 43.5 (12.3) years (1249 women [66%]; mean [SD] baseline BMI, 44.2 [6.1]; 100% completed follow-up at a median of 6.5 years [range, 0.2-10.1]). Surgically treated patients had a greater likelihood of remission and lesser likelihood for new onset of hypertension (remission: absolute risk [AR], 31.9% vs 12.4%); risk difference [RD], 19.5% [95% CI, 15.8%-23.2%], relative risk [RR], 2.1 [95% CI, 2.0-2.2]; new onset: AR, 3.5% vs 12.2%, RD, 8.7% [95% CI, 6.7%-10.7%], RR, 0.4 [95% CI, 0.3-0.5]; greater likelihood of diabetes remission: AR, 57.5% vs 14.8%; RD, 42.7% [95% CI, 35.8%-49.7%], RR, 3.9 [95% CI, 2.8-5.4]; greater risk of new-onset depression: AR, 8.9% vs 6.5%; RD, 2.4% [95% CI, 1.3%-3.5%], RR, 1.5 [95% CI, 1.4-1.7]; and treatment with opioids: AR, 19.4% vs 15.8%, RD, 3.6% [95% CI, 2.3%-4.9%], RR, 1.3 [95% CI, 1.2-1.4]). Surgical patients had a greater risk for undergoing at least 1 additional gastrointestinal surgical procedure (AR, 31.3% vs 15.5%; RD, 15.8% [95% CI, 13.1%-18.5%]; RR, 2.0 [95% CI, 1.7-2.4]). The proportion of patients with low ferritin levels was significantly greater in the surgical group (26% vs 12%, P < .001).

CONCLUSIONS AND RELEVANCE

Among patients with severe obesity followed up for a median of 6.5 years, bariatric surgery compared with medical treatment was associated with a clinically important increased risk for complications, as well as lower risks of obesity-related comorbidities. The risk for complications should be considered in the decision-making process.

Hepcidin in morbidly obese women with non-alcoholic fatty liver disease

Background

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in Western countries. Both iron and lipid metabolism seem to be involved in its pathogenesis. We aimed to assess the relationship between levels of hepcidin, the master iron-regulatory protein, in plasma and the presence of NAFLD in morbidly obese (MO) patients, and to investigate the association between the hepatic expression of the main iron and lipid metabolism -related genes.

Materials and methods

Enzyme-linked immunosorbent assay was used to measure plasma hepcidin levels in 49 normal-weight control women, 23 MO women with normal liver (NL) histology and 46 MO women with NAFLD. The mRNA expression of hepcidin, the main iron metabolism-related genes, and the main lipid-metabolism genes was quantified by qRT-PCR in liver biopsies from members of the MO group undergoing bariatric surgery.

Results

Circulating hepcidin levels were significantly greater in MO than in normal-weight control women. However, there were no significant differences between MO women with NL and those with NAFLD. PCR analysis showed increased expression of hepcidin, FPN1, TfR1 and TfR2 in the liver of MO NAFLD women compared to those with NL. Moreover, a positive association of hepatic hepcidin mRNA expression and the iron metabolism-related genes was found with some key genes involved in the lipid metabolism.

Conclusion

These findings suggest that circulating hepcidin levels are associated with obesity but not with the presence of NAFLD. However, the hepatic expression of hepcidin and the iron metabolism-related genes seem to play a role in regulating lipid metabolism pathways in liver, which has implications for NAFLD pathogenesis.

Metabolic responses to exogenous ghrelin in obesity and early after Roux-en-Y gastric bypass in humans

AIMS

Ghrelin is a gastric-derived hormone that stimulates growth hormone (GH) secretion and has a multi-faceted role in the regulation of energy homeostasis, including glucose metabolism. Circulating ghrelin concentrations are modulated in response to nutritional status, but responses to ghrelin in altered metabolic states are poorly understood. We investigated the metabolic effects of ghrelin in obesity and early after Roux-en-Y gastric bypass (RYGB).

MATERIALS AND METHODS

We assessed central and peripheral metabolic responses to acyl ghrelin infusion (1 pmol kg^-1  min^-1 ) in healthy, lean subjects (n = 9) and non-diabetic, obese subjects (n = 9) before and 2 weeks after RYGB. Central responses were assessed by GH and pancreatic polypeptide (surrogate for vagal activity) secretion. Peripheral responses were assessed by hepatic and skeletal muscle insulin sensitivity during a hyperinsulinaemic-euglycaemic clamp.

RESULTS

Ghrelin-stimulated GH secretion was attenuated in obese subjects, but was restored by RYGB to a response similar to that of lean subjects. The heightened pancreatic polypeptide response to ghrelin infusion in the obese was attenuated after RYGB. Hepatic glucose production and hepatic insulin sensitivity were not altered by ghrelin infusion in RYGB subjects. Skeletal muscle insulin sensitivity was impaired to a similar degree in lean, obese and post-RYGB individuals in response to ghrelin infusion.

CONCLUSIONS

These data suggest that obesity is characterized by abnormal central, but not peripheral, responsiveness to ghrelin that can be restored early after RYGB before significant weight loss. Further work is necessary to fully elucidate the role of ghrelin in the metabolic changes that occur in obesity and following RYGB.

A randomized, placebo-controlled trial of beloranib for the treatment of hypothalamic injury-associated obesity

AIMS

Hypothalamic injury-associated obesity (HIAO) results from damage to the hypothalamus that often occurs with surgical removal/radiation therapy of tumours in the hypothalamic region, such as craniopharyngioma. There is currently no rigorously studied pharmaceutical treatment for the intractable weight gain and cardiometabolic consequences that occur in patients with HIAO. We aimed to assess efficacy, safety and tolerability of beloranib treatment for 4 to 8 weeks in patients with HIAO.

MATERIALS AND METHODS

This Phase 2a, double-blind, placebo-controlled study included 14 patients with HIAO, randomized to receive beloranib 1.8 mg or placebo subcutaneously twice weekly for 4 weeks with an optional 4-week open-label extension in which all patients received beloranib. The primary endpoint was change in weight from baseline to Week 4.

RESULTS

Participants were 64% female, with a mean (SD) age of 32 (9) years, BMI of 43 (7) kg/m² and weight of 126 (22) kg. Compared with placebo (N = 4), beloranib 1.8 mg (N = 8) resulted in a mean (95% CI) difference in weight of -3.2 (-5.4, -0.9) kg after 4 weeks. Weight loss continued through the 8 weeks in patients randomized to beloranib (mean -6.2 [-8.2, -4.1] kg). Beloranib treatment was associated with improvements in high-sensitivity CRP. Adverse events were mild to moderate. No patients who received beloranib discontinued treatment.

CONCLUSION

Beloranib treatment resulted in progressive weight loss in patients with HIAO that was comparable to that observed with beloranib in patients with exogenous obesity. These findings indicate a novel mechanism for treating obesity in patients with HIAO.

Acute Vitamin D₃ Supplementation in Severe Obesity: Evaluation of Multimeric Adiponectin

Obesity predisposes to vitamin D deficiency (VDD) and glucose abnormalities. It is currently debated if vitamin D administration may improve glucose homeostasis by interacting with modulators of insulin sensitivity, such as adiponectin and its oligomers. In a 4-week inpatient study on a metabolic rehabilitation program, consisting of individualized caloric restriction and aerobic physical exercise in obese subjects with VDD, we assessed the acute effects of 600,000 IU cholecalciferol given per os VD group, 12 subjects; body mass index (BMI) 42.7 ± 1.3 kg/m²) or placebo per os (PL group, 12 subjects, BMI 39.8 ± 0.9 kg/m²) on high (HWM-A), medium (MMW-A), and low molecular weight adiponectin (LMW-A), as quantified by western immunoblot (WIB) and ELISA. During the 4-week study, dieting promoted a similar magnitude of weight loss in VD and PL groups. Compared to the PL group, cholecalciferol administration increased 25(OH)Vit D levels (p < 0.001) and promoted a significant increase of HMW-A expression analyzed by WIB (p = 0.02). In parallel, a significant decrease of leptin/HMW-A ratio (p < 0.05), a biomarker of metabolic homeostasis, was observed. During the study, changes of MMW-A and LMW-A occurred independently of cholecalciferol administration, and were likely explained by weight loss. At odds with these findings, the ELISA assessment of adiponectin oligomers showed no modifications in the VD group or PL group. Current findings suggest that acute cholecalciferol administration selectively modifies HMW-A and the leptin/HMW-A ratio.

[ADJUSTMENTS IN THE ORAL DRUG TREATMENT OF BARIATRIC PATIENTS]

Bariatric surgery continues to be a durable therapeutic option for a growing number of obese patients. The patients that are admitted to our hospital for elective bariatric procedures often suffer from multiple co-morbidities and are therefore treated with a significant number of chronic medications. These operations lead to drastic modifications of the anatomy and physiology of the gastro-intestinal tract that may change the pharmacokinetics of drugs. In addition, the natural post-operative course of a bariatric procedure may lead to amelioration or even resolution of some of the obesity-related chronic diseases, consequently eliminating the need for drug therapy. In this article we review various common situations which we face when managing bariatric patients' drug therapy and discuss possible solutions while optimizing drug therapy in this challenging patient population.

Serum Piperacillin/Tazobactam Pharmacokinetics in a Morbidly Obese Individual

Objective:

To report pharmacokinetic alterations and optimal dosing of piperacillin/tazobactam in an obese patient.

Case Summary:

A 39-year-old morbidly obese (weight 167 kg, body mass index 50 kg/m2) man was treated with piperacillin/tazobactam 3.375 g every 4 hours for recurrent cellulitis. The wound culture grew Groups A and B Streptococcus and rare Pseudomonas aeruginosa. Blood samples were obtained at steady-state from a peripheral venous catheter at 0, 0.5, 1, 2, 3, and 4 hours after the start of the infusion. Population pharmacokinetics were generated from a previously published data set. The serum concentrations of piperacillin/tazobactam obtained in the patient were compared with the 95% confidence interval from the representative population. Pharmacokinetic parameters such as maximal serum concentration, minimal serum concentration, average steady-state concentration, half-life, elimination rate constant, volume of distribution (Vd), clearance, area under the curve at steady-state, and percent of time greater than the minimum inhibitory concentration (%t>MIC) were calculated and qualitatively compared between the sample and the population.

Discussion:

Substantial differences were noted in both the absolute values at the times of sample collection and the overall concentration-versus-time profile of both compounds. The morbidly obese individual compared with the population demonstrated a reduced average serum steady-state concentration: 39.8 mg/L versus 123.6 mg/L, an increased Vd: 54.3 L versus 12.7 L, and an increased half-life: 1.4 hours versus 0.6 hours, respectively. The %t>MIC of piperacillin for the patient, assuming MICs of 2, 4, 8, 16, 32, 64, and 128 mg/L, was 100%. 100%, 90.9%, 55.4%. 19.9%, 0%, and 0%, respectively.

Conclusions:

Pathogens with elevated MICs may require altered dosing schemes with piperacillin/tazobactam. Future studies are warranted to assess increased dosages, more frequent dosing intervals, or continuous infusion dosing schemes for obese individuals with serious infections.

Lorcaserin Use in the Management of Morbid Obesity in a Pre-Liver Transplant Patient

Management of obesity and decompensated cirrhosis in those requiring liver transplantation (LT) is a challenging dilemma. Because of concerns for perioperative complications, many centers avoid transplant in those with a body mass index (BMI) greater than 40 kg/m(2) . Bariatric surgery is associated with increased risk attributable to complications of portal hypertension, including variceal rupture. Therefore, weight loss and LT options are limited. Several new classes of weight loss drugs are commercially available, including the anoretic, lorcaserin. This case illustrates the successful use of lorcaserin in a morbidly obese individual with decompensated cirrhosis evaluated for LT listing. (Hepatology 2016;64:301-302).

Effects of orlistat vs. metformin on weight loss-related clinical variables in women with PCOS: systematic review and meta-analysis

AIMS

The aim of this study was to assess the effects of orlistat on weight loss-related clinical variables in overweight/obese women with polycystic ovary syndrome (PCOS) and to compare treatment with orlistat vs. metformin in this group.

METHODS

We conducted a systematic review and meta-analysis of the evidence about the use of orlistat in women with PCOS. We searched the literature published until May 2015 in MEDLINE, Cochrane Central Register of Controlled Trials and LILACS.

RESULTS

Of 3951 studies identified, nine were included in the systematic review (three prospective, non-randomised studies and six randomised control trials). Eight studies used the Rotterdam criteria and 1 used NIH criteria to diagnose PCOS. Data suggest that orlistat promotes a significant reduction in BMI/weight in overweight/obese PCOS women. Eight studies evaluated orlistat impact on testosterone. Seven reported an improvement in testosterone levels. Eight studies evaluated impact on insulin resistance, and five reported improvement. Finally, five studies evaluated impact on lipid profile, and four reported improvement. Three randomised control trials were included in the fixed effects model meta-analysis for a total of 121 women with PCOS. Orlistat and metformin had similar positive effects on BMI (-0.65%, 95% CI: -2.03 to 0.73), HOMA (-3.60%, 95% CI: -16.99 to 9.78), testosterone (-2.08%, 95% CI: -13.08 to 8.93) and insulin (-5.51%, 95% CI: -22.27 to 11.26).

CONCLUSION(S)

The present results suggest that orlistat leads to significant reduction in BMI/body weight in PCOS. In addition, the available evidence indicates that orlistat and metformin have similar effects in reducing BMI, HOMA, testosterone and insulin in overweight/obese PCOS women. This study was registered in PROSPERO under number CRD42014012877.

Fluoxetine, topiramate, and combination of both to stabilize eating behavior before bariatric surgery

INTRODUCTION

Pharmacotherapy for the management of obesity is primarily aimed at weight loss, weight loss maintenance and risk reduction (reduction in body fat, risk factors for cardiovascular disease and the incidence of diabetes mellitus). Among drugs that have been evaluated for weight loss include antidepressants (fluoxetine) and antiepileptic (topiramate).

MATERIAL AND METHODS

We analyzed eating behavior and weight loss in a sample of morbid obesity patients before bariatric surgery. The patients suffering eating disturbances symptoms were grouped into three groups: one group received 40 mg of flouxetine/day (Group A); another group received topiramate 200 mg/day (Group B); and the third group of patients were treated with fluoxetine 40 mg and 200 mg of topiramate/day (Group C).

RESULTS

Patients treated with fluoxetine plus topiramate lost more weight at 3 and 6 months before surgery.

CONCLUSIONS

The use of the psychopharmaceutical drug (fluoxetine and topiramate) in morbid obese patients with eating disorders could represent a new approach to the management of eating behavior before bariatric surgery.

What Is the Prevalence of Symptomatic Obstructive Sleep Apnea Syndrome in Chronic Spinal Pain Patients? An Assessment of the Correlation of OSAS with Chronic Opioid Therapy, Obesity, and Smoking

BACKGROUND

In modern medicine, obstructive sleep apnea syndrome (OSAS) is a commonly described sleep disorder with airway obstruction, disrupted sleep, and excessive daytime sleepiness. Since its description in 1976 by Guilleminault et al, numerous epidemiologic studies and systematic reviews, with multiple comorbidities related to cardiovascular sequelae, altered cognitive function, and multiple other potential complications have been described. Multiple risk factors have been identified included obesity, smoking, alcohol consumption, and other factors. Chronic pain and chronic opioid therapy also have been described to contribute to a large proportion of patients with OSAS. Chronic pain, obesity, smoking, and chronic opioid therapy are often found together, yet there is a paucity of literature describing OSAS in chronic pain patients.

OBJECTIVES

To assess the prevalence of symptomatic OSAS in chronic spinal pain patients receiving chronic opioid therapy and determine the association of OSAS with multiple risk factors and comorbidities.

STUDY DESIGN

A retrospective assessment of patients who attend a single interventional pain management practice from January 1, 2010to December 31, 2014.

SETTING

A private interventional pain management practice in the United States.

METHODS

The data were collected from 4,036 consecutive patients presenting for assessment to a pain management center from January 1, 2010 to December 31, 2014. All assessments were comprehensive and performed by 2 physicians. The comprehensive assessment included a complete history, a physical examination, and a review of records.

RESULTS

The prevalence of OSAS in patients with chronic spinal pain was 13.8%. The results showed a higher prevalence in males compared to females (15.1% versus 12.8%), a higher prevalence in those aged 45 or older compared to those 25-45 years and those 18-25 years (16.3% versus 10.7% or 2.5%), higher prevalence in Hispanics and Asians compared to African Americans and whites (23.7% versus 16.2% versus 13.4%), higher prevalence in patients with combined back and neck pain compared to patients with thoracic pain only or back pain only (16.3% versus 8.2% to 11%). Prevalence also varied by body mass index (BMI): 32.4% in morbidly obese patients, 20.3% in severely obese patients, 15.7% in obese patients, 9.2% in those who were overweight, and only 5.7% in those with normal weight. A significant correlation with OSAS was also observed in patients smoking more than 40 pack years and multiple respiratory symptoms except for chronic bronchitis and multiple cardiovascular ailments.

LIMITATIONS

The retrospective nature of the assessment.

CONCLUSION

This retrospective assessment of over 4,000 patients suffering from chronic pain and receiving chronic opioid therapy indicated a prevalence of sleep apnea syndrome as 13.8%. Multiple risk factors including obesity, chronic obstructive pulmonary disease (COPD), chronic sinus and nasal discharge, and multiple comorbidities including cardiovascular and related ailments have been identified.

KEY WORDS

Obstructive sleep apnea syndrome, chronic pain, chronic spinal pain, chronic opioid therapy, obesity, smoking, cardiovascular risk factors, pulmonary risk factors.

Predictors of weight-loss response with glucagon-like peptide-1 receptor agonist treatment among adolescents with severe obesity

In two previous, separate clinical trials, we demonstrated significant reductions in body mass index (BMI) with exenatide in adolescents with severe obesity. In the present study, we pooled data from these near identical trials to evaluate factors that may predict BMI reduction at 3 months. Data from 32 patients (mean age 14.3 ± 2.2 years; 69% female; mean BMI 39.8 ± 5.8 kg m(-2)) were included. Exenatide treatment consisted of 5 mcg twice daily for 1 month, followed by an increase to 10 mcg twice daily for 2 additional months. Predictor variables included baseline BMI, BMI percent change at 1 month, incidence of nausea or vomiting and baseline appetite and satiety measures. Treatment effects of percent change in BMI from baseline were estimated within predictor subgroups using generalized estimating equations with exchangeable working correlation and robust variance estimation for confidence intervals and P-values to account for paired observations. The pooled data treatment effect on absolute BMI at 3 months was -3.42% (95% confidence interval: -5.41%, -1.42%) compared to placebo. Within treated participants, appetite at baseline (treatment effect in high [-4.28%] vs. low [1.02%], P = 0.028) and sex (treatment effect in female [-4.78%] vs. male [0.76%], P = 0.007) were significant predictors of change in BMI at 3 months. Baseline BMI, BMI percent change at 1 month, age, incidence of nausea, vomiting, or other gastrointestinal symptoms and satiety scores did not predict 3-month responses. Sex and measures of appetite may serve as useful predictors of glucagon-like peptide-1 receptor agonist treatment response among adolescents with severe obesity.

Weight loss predictability by plasma metabolic signatures in adults with obesity and morbid obesity of the DiOGenes study

OBJECTIVE

Aim is to predict successful weight loss by metabolic signatures at baseline and to identify which differences in metabolic status may underlie variations in weight loss success.

METHODS

In DiOGenes, a randomized, controlled trial, weight loss was induced using a low-calorie diet (800 kcal) for 8 weeks. Men (N = 236) and women (N = 431) as well as groups with overweight/obesity and morbid obesity were studied separately. The relation between the metabolic status before weight loss and weight loss was assessed by stepwise regression on multiple data sets, including anthropometric parameters, NMR-based plasma metabolites, and LC-MS-based plasma lipid species.

RESULTS

Maximally, 57% of the variation in weight loss success can be predicted by baseline parameters. The most powerful predictive models were obtained in subjects with morbid obesity. In these models, the metabolites most predictive for weight loss were acetoacetate, triacylglycerols, phosphatidylcholines, specific amino acids, and creatine and creatinine. This metabolic profile suggests that high energy metabolism activity results in higher amounts of weight loss.

CONCLUSIONS

Possible predictive (pre-diet) markers were found for amount of weight loss for specific subgroups.

Adjustable Gastric Band Surgery or Medical Management in Patients With Type 2 Diabetes: A Randomized Clinical Trial

CONTEXT

Recommendations for surgical, compared with lifestyle and pharmacologically based, approaches for type 2 diabetes (T2D) management remain controversial.

OBJECTIVE

The objective was to compare laparoscopic adjustable gastric band (LAGB) to an intensive medical diabetes and weight management (IMWM) program for T2D.

DESIGN

This was designed as a prospective, randomized clinical trial.

SETTING

The setting was two Harvard Medical School-affiliated academic institutions. INTERVENTIONS AND PARTICIPANTS: A 12-month randomized trial comparing LAGB (n = 23) vs IMWM (n = 22) in persons aged 21-65 years with body mass index of 30-45 kg/m(2), T2D diagnosed more than 1 year earlier, and glycated hemoglobin (HbA(1c)) ≥ 6.5% on antihyperglycemic medication(s).

MAIN OUTCOME MEASURE

The proportion meeting the prespecified primary glycemic endpoint, defined as HbA(1c) < 6.5% and fasting glucose < 7.0 mmol/L at 12 months, on or off medication.

RESULTS

After randomization, five participants did not undergo the surgical intervention. Of the 40 initiating intervention (22 males/18 females; age, 51 ± 10 y; body mass index, 36.5 ± 3.7 kg/m(2); diabetes duration, 9 ± 5 y; HbA(1c), 8.2 ± 1.2%; 40% on insulin), the proportion meeting the primary glycemic endpoint was achieved in 33% of the LAGB patients and 23% of the IMWM patients (P = .457). HbA(1c) reduction was similar between groups at both 3 and 12 months (-1.2 ± 0.3 vs -1.0 ± 0.3%; P = .496). Weight loss was similar at 3 months but greater 12 months after LAGB (-13.5 ± 1.7 vs -8.5 ± 1.6 kg; P = .027). Systolic blood pressure reduction was greater after IMWM than LAGB, whereas changes in diastolic blood pressure, lipids, fitness, and cardiovascular risk scores were similar between groups. Patient-reported health status, assessed using the Short Form-36, Impact of Weight on Quality of Life, and Problem Areas in Diabetes, all improved similarly between groups.

CONCLUSIONS

LAGB and a multidisciplinary IMWM program have similar 1-year benefits on diabetes control, cardiometabolic risk, and patient satisfaction, which should be considered in the context of other factors, such as personal preference, when selecting treatment options with obese T2D patients. Longer duration studies are important to understand emergent differences.