Impact of bariatric surgery on circulating irisin levels: a systematic review and meta‑analysis

This systematic review and meta-analysis evaluated changes in circulating irisin levels after bariatric surgery. A systematic search was performed across Embase, Scopus, PubMed, and Web of Science for this study. The meta-analysis was conducted using Comprehensive Meta-Analysis (CMA) V4 software. The overall effect size was depicted through a random-effects meta-analysis and the leave-one-out method. The meta-analysis, which included 13 studies with a total of 407 participants, showed a statistically non-significant reduction in circulating irisin levels following bariatric surgery (SMD:  - 0.089, 95% CI  - 0.281, 0.102, 95% PI:  - 0.790, 0.611, p = 0.360; I2:70.56). Our research found no significant change in irisin levels after bariatric surgery. Moreover, these findings were not associated with the type of surgery or the duration of follow-up.

Bariatric Surgery Improves Serum CD40L Levels as a Predictor of Cardiovascular Risk: Systematic Review and Meta-analysis

CD40 and its ligand have been recently implicated in the pathogenesis of cardiovascular disease (CVD). This meta-analysis examined the effect of bariatric surgery in reducing circulating CD40L levels. A systematic review was performed using Embase, Google Scholar, PubMed, Scopus, and Web of Science. The meta-analysis was provided by Comprehensive Meta-Analysis (CMA) V4 software. The overall effect size was detected by a random-effects meta-analysis and the leave-one-out approach. Random-effects meta-analysis of 7 studies including 191 subjects showed a significant reduction in CD40L after bariatric surgery (standardized mean difference (SMD), - 0.531; 95% CI, - 0.981, - 0.082; p = 0.021; I2, 87.00). Circulating levels of CD40L are decreased after bariatric surgery which may represent a mechanism for improvement of metabolic profile.

Prevalence and predictors of female sexual dysfunction among sexually active women in the diabetes prevention program outcomes study

OBJECTIVE

To determine the burden and identify correlates of female sexual dysfunction (FSD) among women with prediabetes (PreD) and type 2 diabetes (T2D) enrolled in the Diabetes Prevention Program (DPP) Outcomes Study (DPPOS).

METHODS

The DPPOS visit included the Female Sexual Function Index (FSFI) to determine sexual function. Of 1464 participants, 1320 (90%) completed the (FSFI) and 426 were sexually active. A backward selection multivariable logistic regression model estimated the odds of FSD for sociodemographic, clinical, and diabetes-related covariates.

RESULTS

One hundred and eighty-five (43%) had a score of ≤26.55 and met the criteria for FSD. After adjustment for DPP treatment and age, urinary incontinence (UI) (odds ratio [OR] = 1.91, 95% confidence interval [CI] = 1.15-3.17) and hysterectomy (OR = 1.89, 95% CI = 1.01-3.53) were associated with increased odds of FSD. Increased body mass index was protective for FSD (OR = 0.93 per kg/m2, 95% CI = 0.89-0.96). Michigan Neuropathy Screening Instrument-based peripheral neuropathy (mean±SD scores 1.1±1.3 vs. 0.9±1.1, p < 0.0001) and Electrocardiogram (ECG)-based autonomic dysfunction measures (mean ± SD heart rate levels 64.3 ± 6.8 vs. 65.6 ± 10.2, p = 0.008) were associated with FSD. There were no differences in diabetes rates between women who did (66.5%) and did not (66%) have (p = 0.7).

CONCLUSIONS

FSD is prevalent in women with PreD and T2D. Our findings suggest that FSD is associated with neuropathic complications commonly observed in PreD and T2D.

Improvement of Triglyceride-Glucose Index Following Bariatric Surgery: a Systematic Review and Meta-analysis

BACKGROUND

Bariatric surgery is an effective intervention for the management of severe obesity and its associated comorbidities, including metabolic abnormalities. This meta-analysis aimed to evaluate the impact of bariatric surgery on the triglyceride-glucose (TyG) index, a novel marker of insulin resistance and metabolic syndrome.

METHODS

A systematic search was conducted in Embase, PubMed, Web of Science, and Scopus. The meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V4 software. The overall effect size was determined by a random-effects meta-analysis and the leave-one-out approach.

RESULTS

A total of 9 trials including 1620 individuals confirmed a significant reduction in TyG following bariatric surgery (weighted mean difference (WMD) - 0.770, 95% CI - 1.006, - 0.534, p < 0.001). In a sub-analysis according to the type of bariatric surgery there was a significant reduction in TyG index for Roux-en-Y gastric bypass (WMD - 0.775, 95% CI - 1.000, - 0.550, p < 0.001), and sleeve gastrectomy (WMD - 0.920, 95% CI - 1.368, - 0.473, p < 0.001). In a sub-analysis according to the follow-up duration there was similarly a significant reduction in TyG index for both < 12 months (WMD - 1.645, 95% CI - 2.123, - 1.167, p < 0.001), and ≥ 12 months follow-up (WMD - 0.954, 95% CI - 1.606, - 0.303, p < 0.001).

CONCLUSION

The results of this meta-analysis demonstrated a significant reduction in the TyG index following bariatric surgery, indicating improved insulin sensitivity and metabolic health. These findings highlight the potential of bariatric surgery as a valuable therapeutic option for individuals with obesity and its metabolic consequences.

Effects of testosterone enanthate on aggression, risk-taking, competition, mood, and other cognitive domains during 28 days of severe energy deprivation

RATIONALE

Behavioral effects of testosterone depend on dose, acute versus sustained formulation, duration of administration, personality, genetics, and endogenous levels of testosterone. There are also considerable differences between effects of endogenous and exogenous testosterone.

OBJECTIVES

This study was the secondary behavioral arm of a registered clinical trial designed to determine if testosterone protects against loss of lean body mass and lower-body muscle function induced by a severe energy deficit typical of sustained military operations.

METHODS

Behavioral effects of repeated doses of testosterone on healthy young men whose testosterone was reduced by severe energy deficit were examined. This was a double-blind, placebo-controlled, between-group study. Effects of four weekly intramuscular injections of testosterone enanthate (200 mg/week, N = 24) or matching placebo (N = 26) were evaluated. Determination of sample size was based on changes in lean body mass. Tasks assessing aggression, risk-taking, competition, social cognition, vigilance, memory, executive function, and mood were repeatedly administered.

RESULTS

During a period of artificially induced, low testosterone levels, consistent behavioral effects of administration of exogenous testosterone were not observed.

CONCLUSIONS

Exogeneous testosterone enanthate (200 mg/week) during severe energy restriction did not reliably alter the measures of cognition. Study limitations include the relatively small sample size compared to many studies of acute testosterone administration. The findings are specific to healthy males experiencing severe energy deficit and should not be generalized to effects of other doses, formulations, or acute administration of endogenous testosterone or studies conducted with larger samples using tests of cognitive function designed to detect specific effects of testosterone.

Prevalence and predictors of erectile dysfunction among men in the diabetes prevention program outcomes study

OBJECTIVE

To determine burden and identify correlates of erectile dysfunction (ED) among men with prediabetes (PreD) and type 2 diabetes (T2D) enrolled in the Diabetes Prevention Program (DPP) Outcomes Study (DPPOS).

RESEARCH DESIGN AND METHODS

The 2017 DPPOS visit included administration of the International Index of Erectile Function. Of 648 male participants, 88 % (n = 568) completed the survey. Associations between sociodemographic, behavioral, clinical, and glycemic measures at time of ED assessment, and ED were examined using multivariable logistic regression models in men with PreD and T2D separately.

RESULTS

Overall, 218 (38 %) men met ED criteria. Prevalence was similar in men with PreD (41 %) and T2D (37 %) (p = 0.4). In all men, age (p < 0.001) increased odds of ED. Among men with PreD, those assigned to intensive lifestyle intervention (ILS), but not metformin, had decreased odds of ED compared with the placebo group (OR = 0.35, 95 % CI = 0.13, 0.94). Non-Hispanic White race was associated with increased odds of ED compared with other races (OR = 4.3; 95 % CI = 1.92, 9.65). Among men with T2D, ED risk did not differ by DPP treatment assignment; however, individuals with metabolic syndrome defined by National Cholesterol Education Program criteria, had increased odds of ED (OR = 1.85, 95 % CI = 1.14, 3.01), as did individuals with depression (OR = 2.05; 95 % CI = 1.10, 3.79).

CONCLUSIONS

ED is prevalent in men with PreD and T2D. Our finding of reduced odds of ED in men randomized to ILS and with PreD suggests a potential opportunity for risk mitigation in the prediabetes interval. In men who have progressed to T2D, metabolic factors appear to be associated with ED.

Coronary Artery Calcium and Cognitive Decline in the Diabetes Prevention Program Outcomes Study

Background Our aim was to investigate the association of coronary artery calcium (CAC) with cognitive function in adults with impaired glucose tolerance or type 2 diabetes. Methods and Results The Diabetes Prevention Program was a randomized controlled trial comparing an intensive lifestyle intervention, metformin, or placebo for prevention of type 2 diabetes among patients with prediabetes. After 3 years, intensive lifestyle intervention and placebo were stopped, the metformin arm was unmasked, and participants continued in the DPPOS (Diabetes Prevention Program Outcomes Study). Approximately 14 years after randomization (Y14), CAC (Agatston score) was assessed with computed tomography, and cognitive performance was assessed with the Spanish English Verbal Learning Test (SEVLT) and Digit Symbol Substitution Test. SEVLT and Digit Symbol Substitution Test were reassessed 5 years later (Y19) along with the Modified Mini-Mental State Exam. We examined cross-sectional and longitudinal associations between CAC and cognition among 1931 participants using linear and logistic regression. In unadjusted analyses, compared with no calcification, CAC score >300 was associated with decreased performance on all cognitive tests at Y14 in both sexes. Additionally, CAC >300 was associated with a greater 5-year decline in SEVLT Immediate Recall in both sexes and SEVLT Delayed Recall in women. After adjustment for demographic, genetic, metabolic, vascular, and behavioral covariates, CAC score >300 remained associated with greater decline in only SEVLT Delayed Recall in women. Conclusions In women with prediabetes or diabetes, CAC >300, compared with no calcification, was independently associated with greater decline in verbal memory. Registration information clinicaltrials.gov. Identifier: NCT00038727.

Pharmacotherapy for obesity: recent evolution and implications for cardiovascular risk reduction

INTRODUCTION

Obesity is highly prevalent in the U.S. and is associated with an increased risk of major adverse cardiovascular events (MACE). Modalities for the management of obesity include lifestyle intervention, pharmacotherapy, and bariatric surgery.

AREAS COVERED

This review describes the evidence on the effects of weight loss therapies on MACE risk. Lifestyle interventions and older antiobesity pharmacotherapies have been associated with <12% body weight reduction and no clear benefit to reduce MACE risk. Bariatric surgery is associated with substantial weight reduction (20-30%) and markedly lower subsequent risk for MACE. Newer antiobesity pharmacotherapies, particularly semaglutide and tirzepatide, have shown greater efficacy for weight reduction compared with older medications and are being evaluated in cardiovascular outcomes trials.

EXPERT OPINION

Current practice for cardiovascular risk reduction in patients with obesity is lifestyle intervention for weight loss, combined with the treatment of obesity-related cardiometabolic risk factors individually. The use of medications to treat obesity is relatively rare. In part, this reflects concerns about long-term safety and weight loss effectiveness, possible provider bias, as well as lack of clear evidence of MACE risk reduction. If ongoing outcomes trials demonstrate the efficacy of newer agents in reducing MACE risk, this will likely lead to expanded use in obesity management.

Analysis of Veno-Venous Extracorporeal Membrane Oxygenation for COVID-19 Compared to Non-COVID Etiologies

OBJECTIVE

This study analyzed the characteristics and outcomes of veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) due to COVID-19 versus non-COVID causes at US academic centers.

BACKGROUND DATA

V-V ECMO support has been utilized for COVID-19 patients with ARDS since the beginning of the pandemic. Mortality for ECMO in COVID-19 has been reported to be high but similar to reported mortality for ECMO support for non-COVID causes of respiratory failure.

METHODS

Using ICD-10 codes, data of patients who underwent V-V ECMO for COVID-19 ARDS were compared with patients who underwent V-V ECMO for non-COVID causes between April 2020 and December 2022. The primary outcome was in-hospital mortality. Secondary outcome measures included length of stay and direct cost. Multivariate logistic regression modeling was performed to analyze differences in mortality between COVID and non-COVID groups, adjusting for other important risk factors (age, sex, and race/ethnicity).

RESULTS

We identified and compared 6382 patients who underwent V-V ECMO for non-COVID causes to 6040 patients who underwent V-V ECMO for COVID-19. There was a significantly higher proportion of patients aged ≥ 65 years who underwent V-V ECMO in the non-COVID group compared with the COVID group (19.8% vs. 3.7%, respectively, P <0.001). Compared with patients who underwent V-V ECMO for non-COVID causes, patients who underwent V-V ECMO for COVID had increased in-hospital mortality (47.6% vs. 34.5%, P <0.001), length of stay (46.5±41.1 days vs. 40.6±46.1, P <0.001), and direct hospitalization cost ($207,022±$208,842 vs. $198,508±205,510, P =0.02). Compared with the non-COVID group, the adjusted odds ratio (OR) for in-hospital mortality in the COVID group was 2.03 (95% CI: 1.87-2.20, P <0.001). In-hospital mortality for V-V ECMO in COVID-19 improved during the study time period (50.3% in 2020, 48.6% in 2021, and 37.3% in 2022). However, there was a precipitous drop in the ECMO case volume for COVID starting in quarter 2 of 2022.

CONCLUSIONS

In this nationwide analysis, COVID-19 patients with ARDS requiring V-V ECMO support had increased mortality compared with patients who underwent V-V ECMO for non-COVID etiologies.

Weight Regain After Bariatric Surgery: Scope of the Problem, Causes, Prevention, and Treatment

PURPOSE OF REVIEW

Although bariatric surgery is the most effective treatment of severe obesity, a proportion of patients experience clinically significant weight regain (WR) with further out from surgery. The purpose of this review is to summarize the prevalence, predictors, and causes of weight regain.

RECENT FINDINGS

Estimating the prevalence of WR is limited by a lack of consensus on its definition. While anatomic failures such as dilated gastric fundus after sleeve gastrectomy and gastro-gastric fistula after Roux-en-Y gastric bypass can lead to WR, the most common causes appear to be dysregulated/maladaptive eating behaviors, lifestyle factors, and physiological compensatory mechanisms. To date, dietary, supportive, behavioral, and exercise interventions have not demonstrated a clinically meaningful impact on WR, and there is limited evidence for pharmacotherapy. Future studies should be aimed at better defining WR to begin to understand the etiologies. Additionally, there is a need for non-surgical interventions with demonstrated efficacy in rigorous randomized controlled trials for the prevention and reversal of WR after bariatric surgery.

Association of Metformin With the Development of Age-Related Macular Degeneration

Importance

Age-related macular degeneration (AMD) is a leading cause of blindness with no treatment available for early stages. Retrospective studies have shown an association between metformin and reduced risk of AMD.

Objective

To investigate the association between metformin use and age-related macular degeneration (AMD).

Design, Setting, and Participants

The Diabetes Prevention Program Outcomes Study is a cross-sectional follow-up phase of a large multicenter randomized clinical trial, Diabetes Prevention Program (1996-2001), to investigate the association of treatment with metformin or an intensive lifestyle modification vs placebo with preventing the onset of type 2 diabetes in a population at high risk for developing diabetes. Participants with retinal imaging at a follow-up visit 16 years posttrial (2017-2019) were included. Analysis took place between October 2019 and May 2022.

Interventions

Participants were randomly distributed between 3 interventional arms: lifestyle, metformin, and placebo.

Main Outcomes and Measures

Prevalence of AMD in the treatment arms.

Results

Of 1592 participants, 514 (32.3%) were in the lifestyle arm, 549 (34.5%) were in the metformin arm, and 529 (33.2%) were in the placebo arm. All 3 arms were balanced for baseline characteristics including age (mean [SD] age at randomization, 49 [9] years), sex (1128 [71%] male), race and ethnicity (784 [49%] White), smoking habits, body mass index, and education level. AMD was identified in 479 participants (30.1%); 229 (14.4%) had early AMD, 218 (13.7%) had intermediate AMD, and 32 (2.0%) had advanced AMD. There was no significant difference in the presence of AMD between the 3 groups: 152 (29.6%) in the lifestyle arm, 165 (30.2%) in the metformin arm, and 162 (30.7%) in the placebo arm. There was also no difference in the distribution of early, intermediate, and advanced AMD between the intervention groups. Mean duration of metformin use was similar for those with and without AMD (mean [SD], 8.0 [9.3] vs 8.5 [9.3] years; P = .69). In the multivariate models, history of smoking was associated with increased risks of AMD (odds ratio, 1.30; 95% CI, 1.05-1.61; P = .02).

Conclusions and Relevance

These data suggest neither metformin nor lifestyle changes initiated for diabetes prevention were associated with the risk of any AMD, with similar results for AMD severity. Duration of metformin use was also not associated with AMD. This analysis does not address the association of metformin with incidence or progression of AMD.

Risk of Type 2 Diabetes Among Individuals with Excess Weight: Weight Trajectory Effects

PURPOSE OF REVIEW

Increased risk of type 2 diabetes mellitus (T2D) among individuals with overweight or obesity is well-established; however, questions remain about the temporal dynamics of weight change (gain or loss) on the natural course of T2D in this at-risk population. Existing epidemiologic evidence is limited to studies that discretely sample and assess excess weight and T2D risk at different ages with limited follow-up, yet changes in weight may have time-varying and possibly non-linear effects on T2D risk. Predicting the impact of weight change on the risk of T2D is key to informing primary prevention. We critically review the relationship between weight change, trajectory groups (i.e., distinct weight change patterns), and T2D risk among individuals with excess weight in recently published T2D prevention randomized controlled trials (RCTs) and longitudinal cohort studies.

RECENT FINDINGS

Overall, weight trajectory groups have been shown to differ by age of onset, sex, and patterns of insulin resistance or beta-cell function biomarkers. Lifestyle (diet and physical activity), pharmacological, and surgical interventions can modify an individual's weight trajectory. Adolescence is a critical etiologically relevant window during which onset of excess weight may be associated with higher risk of T2D. Changes in insulin resistance and beta-cell function biomarkers are distinct but related correlates of weight trajectory groups that evolve contemporaneously over time. These multi-trajectory markers are differentially associated with T2D risk. T2D risk may differ by the age of onset and duration of excess body weight, and the type of weight loss intervention. A better understanding of the changes in weight, insulin sensitivity, and beta-cell function as distinct but related correlates of T2D risk that evolve contemporaneously over time has important implications for designing and targeting primary prevention efforts.

Effects of Long-term Metformin and Lifestyle Interventions on Cardiovascular Events in the Diabetes Prevention Program and Its Outcome Study

BACKGROUND

Lifestyle intervention and metformin have been shown to prevent diabetes; however, their efficacy in preventing cardiovascular disease associated with the development of diabetes is unclear. We examined whether these interventions reduced the incidence of major cardiovascular events over a 21-year median follow-up of participants in the DPP trial (Diabetes Prevention Program) and DPPOS (Diabetes Prevention Program Outcomes Study).

METHODS

During DPP, 3234 participants with impaired glucose tolerance were randomly assigned to metformin 850 mg twice daily, intensive lifestyle or placebo, and followed for 3 years. During the next 18-year average follow-up in DPPOS, all participants were offered a less intensive group lifestyle intervention, and unmasked metformin was continued in the metformin group. The primary outcome was the first occurrence of nonfatal myocardial infarction, stroke, or cardiovascular death adjudicated by standard criteria. An extended cardiovascular outcome included the primary outcome or hospitalization for heart failure or unstable angina, coronary or peripheral revascularization, coronary heart disease diagnosed by angiography, or silent myocardial infarction by ECG. ECGs and cardiovascular risk factors were measured annually.

RESULTS

Neither metformin nor lifestyle intervention reduced the primary outcome: metformin versus placebo hazard ratio 1.03 (95% CI, 0.78-1.37; P = 0.81) and lifestyle versus placebo hazard ratio 1.14 (95% CI, 0.87-1.50; P = 0.34). Risk factor adjustment did not change these results. No effect of either intervention was seen on the extended cardiovascular outcome.

CONCLUSIONS

Neither metformin nor lifestyle reduced major cardiovascular events in DPPOS over 21 years despite long-term prevention of diabetes. Provision of group lifestyle intervention to all, extensive out-of-study use of statin and antihypertensive agents, and reduction in the use of study metformin together with out-of-study metformin use over time may have diluted the effects of the interventions.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifiers: DPP (NCT00004992) and DPPOS (NCT00038727).

The Role of Calorie Restriction in the Prevention of Cardiovascular Disease

PURPOSE OF REVIEW

Calorie restriction (CR) has emerged as a non-pharmacological treatment to prevent cardiovascular disease (CVD). This article reviews recent progress regarding the role of CR in CVD prevention via reduction of cardiometabolic risk factors and promoting atherosclerotic stability.

RECENT FINDINGS

Calorie restriction may be an approach to reduce the development of atherosclerosis. CR promotes eNOS activity and SIRT1 expression which in turn improves vasodilation resulting in greater regulation of blood pressure and blood flow. Modest CR in nonobese young and middle-aged adults results in improved cardiometabolic risk profile. The evidence for CR in CVD prevention has accumulated in the recent years. Most evidence, however, is from rodent or small human trials. Our understanding of the magnitude of calorie reduction that leads to the long-term therapeutic effects on cardiovascular health is limited. More well-designed controlled trials conducted in diverse populations with larger sample sizes and longer follow-ups are warranted.

Obesity, Body Composition, and Sex Hormones: Implications for Cardiovascular Risk

Cardiovascular disease (CVD) continues to be the leading cause of death in adults, highlighting the need to develop novel strategies to mitigate cardiovascular risk. The advancing obesity epidemic is now threatening the gains in CVD risk reduction brought about by contemporary pharmaceutical and surgical interventions. There are sex differences in the development and outcomes of CVD; premenopausal women have significantly lower CVD risk than men of the same age, but women lose this advantage as they transition to menopause, an observation suggesting potential role of sex hormones in determining CVD risk. Clear differences in obesity and regional fat distribution among men and women also exist. While men have relatively high fat in the abdominal area, women tend to distribute a larger proportion of their fat in the lower body. Considering that regional body fat distribution is an important CVD risk factor, differences in how men and women store their body fat may partly contribute to sex-based alterations in CVD risk as well. This article presents findings related to the role of obesity and sex hormones in determining CVD risk. Evidence for the role of sex hormones in determining body composition in men and women is also presented. Lastly, the clinical potential for using sex hormones to alter body composition and reduce CVD risk is outlined. © 2022 American Physiological Society. Compr Physiol 12:1-45, 2022.

Effect of Metformin and Lifestyle Interventions on Mortality in the Diabetes Prevention Program and Diabetes Prevention Program Outcomes Study

OBJECTIVE

To determine whether metformin or lifestyle modification can lower rates of all-cause and cause-specific mortality in the Diabetes Prevention Program and Diabetes Prevention Program Outcomes Study.

RESEARCH DESIGN AND METHODS

From 1996 to 1999, 3,234 adults at high risk for type 2 diabetes were randomized to an intensive lifestyle intervention, masked metformin, or placebo. Placebo and lifestyle interventions stopped in 2001, and a modified lifestyle program was offered to everyone, but unmasked study metformin continued in those originally randomized. Causes of deaths through 31 December 2018 were adjudicated by blinded reviews. All-cause and cause-specific mortality hazard ratios (HRs) were estimated from Cox proportional hazards regression models and Fine-Gray models, respectively.

RESULTS

Over a median of 21 years (interquartile range 20-21), 453 participants died. Cancer was the leading cause of death (n = 170), followed by cardiovascular disease (n = 131). Compared with placebo, metformin did not influence mortality from all causes (HR 0.99 [95% CI 0.79, 1.25]), cancer (HR 1.04 [95% CI 0.72, 1.52]), or cardiovascular disease (HR 1.08 [95% CI 0.70, 1.66]). Similarly, lifestyle modification did not impact all-cause (HR 1.02 [95% CI 0.81, 1.28]), cancer (HR 1.07 [95% CI 0.74, 1.55]), or cardiovascular disease (HR 1.18 [95% CI 0.77, 1.81]) mortality. Analyses adjusted for diabetes status and duration, BMI, cumulative glycemic exposure, and cardiovascular risks yielded results similar to those for all-cause mortality.

CONCLUSIONS

Cancer was the leading cause of mortality among adults at high risk for type 2 diabetes. Although metformin and lifestyle modification prevented diabetes, neither strategy reduced all-cause, cancer, or cardiovascular mortality rates.

Effects of Cotadutide on Metabolic and Hepatic Parameters in Adults With Overweight or Obesity and Type 2 Diabetes: A 54-Week Randomized Phase 2b Study

OBJECTIVE

Cotadutide, a dual GLP-1 and glucagon receptor agonist, is under development for nonalcoholic steatohepatitis (NASH) and chronic kidney disease with type 2 diabetes. The effects of cotadutide on hepatic and metabolic parameters were evaluated in participants with overweight/obesity and type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this phase 2b study, 834 adults with BMI ≥25 kg/m² and type 2 diabetes inadequately controlled with metformin (glycated hemoglobin A_1c [HbA_1c] of 7.0%-10.5% [53-91 mmol/mol]) were randomized to double-blind cotadutide 100 μg (n = 100), 200 μg (n = 256), or 300 μg (n = 256); placebo (n = 110); or open-label liraglutide 1.8 mg (n = 110)-all administered subcutaneously. Coprimary end points were changes in HbA_1c and body weight at week 14. The originally randomized interventions were continued to week 54. Liver damage biomarkers and liver fibrosis algorithms were assessed.

RESULTS

Cotadutide significantly decreased HbA_1c and body weight at weeks 14 and 54 versus placebo (all P < 0.001). Improvements in lipid profile, AST and ALT levels, propeptide of type III collagen level, fibrosis-4 index, and nonalcoholic fatty liver disease fibrosis score were observed with cotadutide 300 μg versus placebo, but not with liraglutide. Weight loss with cotadutide 200 μg was similar to that with liraglutide 1.8 mg and greater with cotadutide 300 μg versus liraglutide 1.8 mg. The most common adverse events with cotadutide (nausea, 35%; vomiting, 17%) decreased over time.

CONCLUSIONS

Cotadutide treatment for 54 weeks improved glycemic control and weight loss in participants with overweight/obesity and type 2 diabetes. Ad hoc analyses demonstrated improvements in hepatic parameters and support further evaluation of cotadutide in NASH.

Testosterone supplementation upregulates androgen receptor expression and translational capacity during severe energy deficit

Testosterone supplementation during energy deficit promotes whole body lean mass accretion, but the mechanisms underlying that effect remain unclear. To elucidate those mechanisms, skeletal muscle molecular adaptations were assessed from muscle biopsies collected before, 1 h, and 6 h after exercise and a mixed meal (40 g protein, 1 h postexercise) following 14 days of weight maintenance (WM) and 28 days of an exercise- and diet-induced 55% energy deficit (ED) in 50 physically active nonobese men treated with 200 mg testosterone enanthate/wk (TEST) or placebo (PLA) during the ED. Participants (n = 10/group) exhibiting substantial increases in leg lean mass and total testosterone (TEST) were compared with those exhibiting decreases in both of these measures (PLA). Resting androgen receptor (AR) protein content was higher and fibroblast growth factor-inducible 14 (Fn14), IL-6 receptor (IL-6R), and muscle ring-finger protein-1 gene expression was lower in TEST vs. PLA during ED relative to WM (P < 0.05). Changes in inflammatory, myogenic, and proteolytic gene expression did not differ between groups after exercise and recovery feeding. Mechanistic target of rapamycin signaling (i.e., translational efficiency) was also similar between groups at rest and after exercise and the mixed meal. Muscle total RNA content (i.e., translational capacity) increased more during ED in TEST than PLA (P < 0.05). These findings indicate that attenuated proteolysis at rest, possibly downstream of AR, Fn14, and IL-6R signaling, and increased translational capacity, not efficiency, may drive lean mass accretion with testosterone administration during energy deficit.

The limits and challenges of antiobesity pharmacotherapy

INTRODUCTION

Pharmacotherapy is a useful adjunct when patients with obesity are unable to achieve adequate benefit from lifestyle interventions.

AREAS COVERED

This review covers the history of antiobesity drugs, efficacy, and risks of currently approved drugs, limits of their usefulness in clinical practice, gaps in knowledge, methodological limitations of clinical trials, and reasons for underutilization.

EXPERT OPINION

In randomized controlled trials, currently approved antiobesity drugs have yielded an average weight loss ranging from approximately 3% to 9% relative to placebo at 1 year. Inadequate inclusion of racial and ethnic minorities and men, and high dropout rates in clinical trials limit generalizability of these findings to clinical practice. Weight loss achieved with antiobesity drugs is generally associated with lowered glycemia, but improvements in blood pressure and lipid measures tend to be marginal. There is limited evidence for sustained weight loss beyond 1 year and for safety and efficacy of antiobesity drugs in children and adolescents, and in post-bariatric surgery patients. None have demonstrated reduction in major adverse cardiovascular events or other significant disease outcomes. Limited health insurance coverage and negative perceptions of physicians have hindered the utilization of antiobesity drugs.

Effects of Testosterone Supplementation on Ghrelin and Appetite During and After Severe Energy Deficit in Healthy Men

Background

Severe energy deficits cause interrelated reductions in testosterone and fat free mass. Testosterone supplementation may mitigate those decrements, but could also reduce circulating concentrations of the orexigenic hormone ghrelin, thereby exacerbating energy deficit by suppressing appetite.

Objective

To determine whether testosterone supplementation during severe energy deficit influences fasting and postprandial ghrelin concentrations and appetite.

Design and methods

Secondary analysis of a randomized, double-blind trial that determined the effects of testosterone supplementation on body composition changes during and following severe energy deficit in nonobese, eugonadal men. Phase 1 (PRE-ED): 14-day run-in; phase 2: 28 days, 55% energy deficit with 200 mg testosterone enanthate weekly (TEST; n = 24) or placebo (PLA; n = 26); phase 3: free-living until body mass recovered (end-of-study; EOS). Fasting and postprandial acyl ghrelin and des-acyl ghrelin concentrations and appetite were secondary outcomes measured during the final week of each phase.

Results

Fasting acyl ghrelin concentrations, and postprandial acyl and des-acyl ghrelin concentrations increased in PLA during energy deficit then returned to PRE-ED values by EOS, but did not change in TEST (phase-by-group, P < 0.05). Correlations between changes in free testosterone and changes in fasting acyl ghrelin concentrations during energy deficit (ρ = -0.42, P = 0.003) and body mass recovery (ρ = -0.38; P = 0.01) were not mediated by changes in body mass or body composition. Transient increases in appetite during energy deficit were not affected by testosterone treatment.

Conclusions

Testosterone supplementation during short-term, severe energy deficit in healthy men prevents deficit-induced increases in circulating ghrelin without blunting concomitant increases in appetite.

Clinical Trials Registration

www.clinicaltrials.gov NCT02734238 (registered 12 April 2016).

Obesity: Pathophysiology and Management

Obesity continues to be among the top health concerns across the globe. Despite our failure to contain the high prevalence of obesity, we now have a better understanding of its pathophysiology, and how excess adiposity leads to type 2 diabetes, hypertension, and cardiovascular disease. Lifestyle modification is recommended as the cornerstone of obesity management, but many patients do not achieve long-lasting benefits due to difficulty with adherence as well as physiological and neurohormonal adaptation of the body in response to weight loss. Fortunately, 5 drug therapies-orlistat, lorcaserin, liraglutide, phentermine/topiramate, and naltrexone/bupropion-are available for long-term weight management. Additionally, several medical devices are available for short-term and long-term use. Bariatric surgery yields substantial and sustained weight loss with resolution of type 2 diabetes, although due to the high cost and a small risk of serious complications, it is generally recommended for patients with severe obesity. Benefit-to-risk balance should guide treatment decisions.

Long-Term Weight Loss With Metformin or Lifestyle Intervention in the Diabetes Prevention Program Outcomes Study

BACKGROUND

Identifying reliable predictors of long-term weight loss (LTWL) could lead to improved weight management.

OBJECTIVE

To identify some predictors of LTWL.

DESIGN

The DPP (Diabetes Prevention Program) was a randomized controlled trial that compared weight loss with metformin, intensive lifestyle intervention (ILS), or placebo. Its Outcomes Study (DPPOS) observed patients after the masked treatment phase ended. (ClinicalTrials.gov: NCT00004992 and NCT00038727).

SETTING

27 DPP and DPPOS clinics.

PARTICIPANTS

Of the 3234 randomly assigned participants, 1066 lost at least 5% of baseline weight in the first year and were followed for 15 years.

MEASUREMENTS

Treatment assignment, personal characteristics, and weight.

RESULTS

After 1 year, 289 (28.5%) participants in the metformin group, 640 (62.6%) in the ILS group, and 137 (13.4%) in the placebo group had lost at least 5% of their weight. After the masked treatment phase ended, the mean weight loss relative to baseline that was maintained between years 6 and 15 was 6.2% (95% CI, 5.2% to 7.2%) in the metformin group, 3.7% (CI, 3.1% to 4.4%) in the ILS group, and 2.8% (CI, 1.3% to 4.4%) in the placebo group. Independent predictors of LTWL included greater weight loss in the first year in all groups, older age and continued metformin use in the metformin group, older age and absence of either diabetes or a family history of diabetes in the ILS group, and higher fasting plasma glucose levels at baseline in the placebo group.

LIMITATION

Post hoc analysis; examination of nonrandomized subsets of randomized groups after year 1.

CONCLUSION

Among persons with weight loss of at least 5% after 1 year, those originally randomly assigned to metformin had the greatest loss during years 6 to 15. Older age and the amount of weight initially lost were the most consistent predictors of LTWL maintenance.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Relationship Between Perceptions of Obesity Causes and Weight Loss Expectations Among Adults

OBJECTIVE

To examine relationships between the demographic characteristics of subjects with obesity seeking pharmaceutical-assisted weight loss and their weight loss expectations and perceptions of the causes of their obesity.

METHODS

A total of 225 adults with obesity completed an obesity perceptions questionnaire (OPQ), which included 4 attribution subscales: biological, psychological, environmental, and lifestyle. Relations were analyzed among OPQ subscales, subject characteristics, and self-perceived ideal 12-month weight loss.

RESULTS

Subjects desired to lose 26.4% (SD, 7.7%) of their body weight (ideal weight loss). Ideal weight loss correlated positively with the OPQ biological subscale (P = .008), body mass index (P < .001), female sex (P < .001), and past weight loss attempts (P < .001). Cronbach α was good (>.70) only for the psychological subscale. White race (P = .02), married status (P = .01), and high school or higher education (P = .02) were negatively correlated with ideal weight loss.

CONCLUSIONS AND IMPLICATIONS

When designing interventions for preventing and treating obesity, patient perceptions should be considered.

Pharmacotherapy for Patients with Obesity

BACKGROUND

Although pharmacotherapy is not the cornerstone of obesity treatment, it is a valuable tool that could be considered for patients who have not had adequate benefit from lifestyle interventions or who have difficulty maintaining initial weight loss over longer periods.

CONTENT

This review focuses on the role of antiobesity drugs, the mechanisms by which the drugs work, potential pharmacological targets in the neural control of food intake and regulation of body weight, the history of antiobesity drugs, a summary of efficacy and safety data from clinical trials, and the clinical application of pharmacotherapy. Currently, 5 approved drug therapies are available in the US for long-term weight management, with only 2 of these meeting the stronger Food and Drug Administration (FDA) criteria of 5% weight loss relative to a placebo after 1 year and others receiving approval based on the categorical criterion of the proportions of patients achieving 5% weight loss. Interpretation of the results of clinical trials conducted before regulatory agency approval is limited by high dropout rates; thus, the results might not be replicable in clinical practice settings. Many patients who are suitable candidates for pharmacotherapy are not using the new drugs due to lack of insurance coverage and high out-of-pocket costs.

SUMMARY

With the availability of 4 new drugs since 2012, clinicians in the US now have more tools for long-term weight management. The quality of pharmacotherapy clinical investigations needs considerable improvement. Future research should focus on examining the mediators and moderators of response.

Efficacy and safety of autoinjected exenatide once-weekly suspension versus sitagliptin or placebo with metformin in patients with type 2 diabetes: The DURATION-NEO-2 randomized clinical study

AIMS

Glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors treat type 2 diabetes through incretin-signaling pathways. This study compared the efficacy and safety of the glucagon-like peptide-1 receptor agonist exenatide once-weekly (Miglyol) suspension for autoinjection (QWS-AI) with the dipeptidyl peptidase-4 inhibitor sitagliptin or placebo.

MATERIALS AND METHODS

In this open-label, multicentre study of patients with type 2 diabetes who had suboptimal glycaemic control on metformin monotherapy, 365 patients were randomized to receive exenatide 2.0 mg QWS-AI, sitagliptin 100 mg once daily or oral placebo (3:2:1 ratio). The primary endpoint was change in glycated hemoglobin (HbA1c) from baseline to 28 weeks.

RESULTS

At 28 weeks, exenatide QWS-AI significantly reduced HbA1c from baseline compared to sitagliptin (-1.13% vs -0.75% [baseline values, 8.42% and 8.50%, respectively]; P  = .02) and placebo (-0.40% [baseline value, 8.50%]; P = .001). More exenatide QWS-AI-treated patients achieved HbA1c <7.0% than did sitagliptin- or placebo-treated patients (43.1% vs 32.0% and 24.6%; both P  < .05). Exenatide QWS-AI and sitagliptin reduced fasting plasma glucose from baseline to 28 weeks (-21.3 and -11.3 mg/dL) vs placebo (+9.6 mg/dL), with no significant difference between the 2 active treatments. Body weight decreased with both active treatments (-1.12 and -1.19 kg), but not with placebo (+0.15 kg). No improvement in blood pressure was observed in any group. The most common adverse events with exenatide QWS-AI were gastrointestinal events and injection-site reactions.

CONCLUSIONS

This study demonstrated that exenatide QWS-AI reduced HbA1c more than sitagliptin or placebo and was well tolerated.

Physiological and psychological effects of testosterone during severe energy deficit and recovery: A study protocol for a randomized, placebo-controlled trial for Optimizing Performance for Soldiers (OPS)

BACKGROUND

The physiological consequences of severe energy deficit include hypogonadism and the loss of fat-free mass. Prolonged energy deficit also impacts physical performance, mood, attentiveness, and decision-making capabilities. This study will determine whether maintaining a eugonadal state during severe, sustained energy deficit attenuates physiological decrements and maintains mental performance. This study will also assess the effects of normalizing testosterone levels during severe energy deficit and recovery on gut health and appetite regulation.

METHODS

Fifty physically active men will participate in a 3-phase, randomized, placebo-controlled study. After completing a 14-d, energy-adequate, diet acclimation phase (protein: 1.6g∙kg^-1∙d^-1; fat: 30% total energy intake), participants will be randomized to undergo a 28-d, 55% energy deficit phase with (DEF+TEST: 200mg testosterone enanthate per week) or without (DEF) exogenous testosterone. Diet and physical activity will be rigorously controlled. Recovery from the energy deficit (ad libitum diet, no testosterone) will be assessed until body mass has been recovered within ±2.5% of initial body mass. Body composition, stable isotope methodologies, proteomics, muscle biopsies, whole-room calorimetry, molecular biology, activity/sleep monitoring, personality and cognitive function assessments, functional MRI, and comprehensive biochemistries will be used to assess physiological and psychological responses to energy restriction and recovery feeding while volunteers are in an expected hypogonadal versus eugonadal state.

DISCUSSION

The Optimizing Performance for Soldiers (OPS) study aims to determine whether preventing hypogonadism will mitigate declines in physical and mental function that typically occur during prolonged energy deficit, and the efficacy of testosterone replacement on recovery from severe underfeeding.

TRIAL REGISTRATION

NCT02734238.

Pharmacotherapy of Obesity: Clinical Trials to Clinical Practice

PURPOSE OF REVIEW

This review provides an overview of the current state of drug therapy for obesity, with a focus on four new drug therapies-lorcaserin, phentermine/topiramate, naltrexone/bupropion, and liraglutide 3.0 mg-which have been approved by the US Food and Drug Administration (FDA) for long-term management of obesity since 2012. Topics discussed in this paper include rationale for pharmacotherapy, history of antiobesity drugs, and efficacy and safety data from randomized controlled trials with implications for clinical practice.

RECENT FINDINGS

Weight loss achieved by currently approved drugs ranges from approximately 3 to 9%, above and beyond weight loss with lifestyle counseling alone, after a year. Response and attrition rates in clinical trials indicate that the benefits of pharmacotherapy range from substantial for some patients, modest for others, and no benefits for others still. Decisions regarding selection of a suitable drug from the available pharmacotherapy options and duration of treatment should be based on the expected and observed benefit-to-risk balance and tailored to the needs of each individual patient using the principles of shared decision-making.

Weight changes in obese adults 6-months after discontinuation of double-blind zonisamide or placebo treatment

We evaluated weight changes in obese patients at 6-months after they ended participation in a 12-month randomised controlled trial in which they received daily placebo, zonisamide 200 mg or zonisamide 400 mg, in addition to lifestyle counselling. Of the originally randomised 225 patients, 218 completed month-12 when study interventions were discontinued. For the 154 patients who returned for 6-month follow-up off-treatment, weight changes between month-12 and month-18 for placebo (n = 53), zonisamide 200 mg (n = 49) and zonisamide 400 mg groups (n = 52) were 0.5 kg [95% confidence interval (CI), -0.8 to 1.8; 0.7%], 1.5 kg (0.2-2.8; 1.6%; p = 0.26 vs. placebo) and 2.4 kg (1.1-3.7; 2.6%; p = 0.04 vs. placebo), respectively. Our results suggest that although zonisamide 400 mg daily for 12-months resulted in greater weight loss than with placebo, weight regain after discontinuation of interventions was greater in the zonisamide 400 mg group than placebo group.

Combination phentermine/topiramate for obesity treatment in primary care: a review

The treatment of obesity is often met with a myriad of challenges in the primary care setting. Nevertheless, a modest 5% weight loss is considered clinically significant and may be associated with health benefits. Phentermine/topiramate (Qsymia), available in the United States since September 2012, achieves clinically meaningful weight loss along with improvements in weight-related comorbidities. This combination drug therapy could be an additional tool for primary care providers in their quest for effective management of obesity. Special precautions and close monitoring are indicated when prescribing phentermine/topiramate for women of childbearing potential. Monitoring of heart rate and psychiatric and cognitive side effects is important.

Current pharmacotherapy for obesity: extrapolation of clinical trials data to practice

INTRODUCTION

When used prudently and in combination with lifestyle modification, pharmacotherapy has an important role in the management of obesity.

AREAS COVERED

This review covers targets for antiobesity drugs, challenges and limitations, failed translation of basic science to clinical practice, methodological and regulatory issues in clinical trials of pharmacotherapy, efficacy and risks of drugs currently approved for obesity, and clinical practice issues when using antiobesity drugs with emphasis on recently approved drugs.

EXPERT OPINION

Drugs currently approved for long-term therapy of obesity offer modest benefits for most patients, substantial benefits for some and no benefits for others. Numerous methodological problems including exclusion of the type of patients who are most often seen in clinical practices, inadequate enrollment of men and minorities, exclusion of patients taking antidepressants, high dropout rates, lack of follow-up after treatment discontinuation, and less than ideal imputation methods in data analysis limit the interpretation of clinical trials data and generalizability. Single-drug therapies offer small to moderate weight-loss benefits, but are generally better tolerated. Efficacy is enhanced with combination drug therapies, but so are the hazards. Clinicians should base their decisions on the expected and observed benefit-to-risk balance.

Evaluation of phentermine and topiramate versus phentermine/topiramate extended-release in obese adults

OBJECTIVE

A 28-week, randomized, controlled trial compared the combination of phentermine and topiramate extended-release (PHEN/TPM ER) with its components as monotherapies and with placebo in obese adults.

DESIGN AND METHODS

Subjects were randomized to placebo, phentermine 7.5 mg, phentermine 15 mg, topiramate ER 46 mg, topiramate ER 92 mg, PHEN/TPM ER 7.5/46 mg, or PHEN/TPM ER 15/92 mg. All subjects received lifestyle intervention counseling. Primary endpoints were percent weight loss (WL) and achievement of ≥5% WL.

RESULTS

At week 28, PHEN/TPM ER 7.5/46 (-8.5%) and 15/92 (-9.2%) achieved greater percentage WL versus placebo (-1.7%; P < 0.0001) and their respective monotherapies (P < 0.05). The percentage of subjects achieving ≥5% WL was 15.5% for placebo, 43.3% for phentermine 7.5, 46.2% for phentermine 15, 39.2% for topiramate ER 46, 48.6% for topiramate ER 92, 62.1% for PHEN/TPM ER 7.5/46, and 66.0% for PHEN/TPM ER 15/92. PHEN/TPM ER was generally well tolerated; comprehensive assessment of cognitive functions with the Repeatable Battery for Assessment of Neuropsychological Status revealed impairment only in the attention domain.

CONCLUSIONS

PHEN/TPM ER demonstrated greater WL when used in combination than when used as monotherapies, suggesting enhanced ability of the combination formulation to induce WL at doses lower than with available monotherapies.

Zonisamide for weight reduction in obese adults: a 1-year randomized controlled trial

BACKGROUND

Obese individuals who have failed to achieve adequate weight loss with lifestyle changes have limited nonsurgical therapeutic options. We evaluated the efficacy and tolerability of zonisamide, an antiepileptic drug, for enhancing weight loss in obese patients receiving diet and lifestyle guidance.

METHODS

This was a 1-year, randomized, double-blind, placebo-controlled trial conducted from January 9, 2006, through September 20, 2011, at Duke University Medical Center. A total of 225 obese (mean [SD] body mass index, 37.6 [4.9]) participants included 134 women (59.6%) and 91 men (40.4%) without diabetes mellitus. (Body mass index is calculated as weight in kilograms divided by height in meters squared.) Interventions were daily dosing with placebo (n = 74), 200 mg of zonisamide (n = 76), or 400 mg of zonisamide (n = 75), in addition to diet and lifestyle counseling by a dietitian for 1 year. Primary outcome was change in body weight at 1 year.

RESULTS

Of the 225 randomized patients, 218 (96.9%) provided 1-year follow-up assessments. Change in body weight was -4.0 kg (95% CI, -5.8 to -2.3 kg; least squares mean, -3.7%) for placebo, -4.4 kg (-6.1 to -2.6 kg; -3.9%; P = .79 vs placebo) for 200 mg of zonisamide, and -7.3 kg (-9.0 to -5.6 kg; -6.8%; P = .009 vs placebo) for 400 mg of zonisamide. In the categorical analysis, 23 (31.1%) assigned to placebo, 26 (34.2%; P = .72) assigned to 200 mg of zonisamide, and 41 (54.7%; P = .007) assigned to 400 mg of zonisamide achieved 5% or greater weight loss; for 10% or greater weight loss, the corresponding numbers were 6 (8.1%), 17 (22.4%; P = .02), and 24 (32.0%; P < .001). Gastrointestinal, nervous system, and psychiatric adverse events occurred at a higher incidence with zonisamide than with placebo.

CONCLUSION

Zonisamide at the daily dose of 400 mg moderately enhanced weight loss achieved with diet and lifestyle counseling but had a high incidence of adverse events.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00275834

Clinical utility of phentermine/topiramate (Qsymia™) combination for the treatment of obesity

Qsymia™ (Vivus Inc, Mountain View, CA, USA), a combination of phentermine and delayed-release topiramate, has been available in the US since September 2012 for the treatment of obesity. Phentermine is an anorexigenic agent, which is approved for the short-term treatment of obesity, while topiramate is approved for nonweight loss indications - seizure disorders and migraine prophylaxis. The amount of weight loss achieved with combination therapy is of a greater magnitude than what could be achieved with either agent alone. Adverse events that occur with the combination therapy are in line with the known side effect profiles of the constituent drugs; teratogenicity, a slight increase in heart rate, psychiatric and cognitive adverse effects, and metabolic acidosis are concerns.

Controlled-release phentermine/topiramate in severely obese adults: a randomized controlled trial (EQUIP)

A 56-week randomized controlled trial was conducted to evaluate safety and efficacy of a controlled-release combination of phentermine and topiramate (PHEN/TPM CR) for weight loss (WL) and metabolic improvements. Men and women with class II and III obesity (BMI ≥ 35 kg/m(2)) were randomized to placebo, PHEN/TPM CR 3.75/23 mg, or PHEN/TPM CR 15/92 mg, added to a reduced-energy diet. Primary end points were percent WL and proportions of patients achieving 5% WL. Secondary end points included waist circumference (WC), systolic and diastolic blood pressure (BP), fasting glucose, and lipid measures. In the primary analysis (randomized patients with at least one postbaseline weight measurement who took at least one dose of assigned drug or placebo), patients in the placebo, 3.75/23, and 15/92 groups lost 1.6%, 5.1%, and 10.9% of baseline body weight (BW), respectively, at 56 weeks (P < 0.0001). In categorical analysis, 17.3% of placebo patients, 44.9% of 3.75/23 patients, and 66.7% of 15/92 patients, lost at least 5% of baseline BW at 56 weeks (P < 0.0001). The 15/92 group had significantly greater changes relative to placebo for WC, systolic and diastolic BP, fasting glucose, triglycerides, total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL). The most common adverse events were paresthesia, dry mouth, constipation, dysgeusia, and insomnia. Dropout rate from the study was 47.1% for placebo patients, 39.0% for 3.75/23 patients, and 33.6% of 15/92 patients. PHEN/TPM CR demonstrated dose-dependent effects on weight and metabolic variables in the direction expected to be beneficial with no evidence of serious adverse events induced by treatment.

Two-year sustained weight loss and metabolic benefits with controlled-release phentermine/topiramate in obese and overweight adults (SEQUEL): a randomized, placebo-controlled, phase 3 extension study

BACKGROUND

Obesity is a serious chronic disease. Controlled-release phentermine/topiramate (PHEN/TPM CR), as an adjunct to lifestyle modification, has previously shown significant weight loss compared with placebo in a 56-wk study in overweight and obese subjects with ≥2 weight-related comorbidities.

OBJECTIVE

This study evaluated the long-term efficacy and safety of PHEN/TPM CR in overweight and obese subjects with cardiometabolic disease.

DESIGN

This was a placebo-controlled, double-blind, 52-wk extension study; volunteers at selected sites continued with original randomly assigned treatment [placebo, 7.5 mg phentermine/46 mg controlled-release topiramate (7.5/46), or 15 mg phentermine/92 mg controlled-release topiramate (15/92)] to complete a total of 108 wk. All subjects participated in a lifestyle-modification program.

RESULTS

Of 866 eligible subjects, 676 (78%) elected to continue in the extension. Overall, 84.0% of subjects completed the study, with similar completion rates between treatment groups. At week 108, PHEN/TPM CR was associated with significant, sustained weight loss (intent-to-treat with last observation carried forward; P < 0.0001 compared with placebo); least-squares mean percentage changes from baseline in body weight were -1.8%, -9.3%, and -10.5% for placebo, 7.5/46, and 15/92, respectively. Significantly more PHEN/TPM CR-treated subjects at each dose achieved ≥5%, ≥10%, ≥15%, and ≥20% weight loss compared with placebo (P < 0.001). PHEN/TPM CR improved cardiovascular and metabolic variables and decreased rates of incident diabetes in comparison with placebo. PHEN/TPM CR was well tolerated over 108 wk, with reduced rates of adverse events occurring between weeks 56 and 108 compared with rates between weeks 0 and 56.

CONCLUSION

PHEN/TPM CR in conjunction with lifestyle modification may provide a well-tolerated and effective option for the sustained treatment of obesity complicated by cardiometabolic disease. This trial was registered at clinicaltrials.gov as NCT00796367.

Effects of low-dose, controlled-release, phentermine plus topiramate combination on weight and associated comorbidities in overweight and obese adults (CONQUER): a randomised, placebo-controlled, phase 3 trial

BACKGROUND

Obesity is associated with a reduction in life expectancy and an increase in mortality from cardiovascular diseases, cancer, and other causes. We therefore assessed the efficacy and safety of two doses of phentermine plus topiramate controlled-release combination as an adjunct to diet and lifestyle modification for weight loss and metabolic risk reduction in individuals who were overweight and obese, with two or more risk factors.

METHODS

In this 56-week phase 3 trial, we randomly assigned overweight or obese adults (aged 18-70 years), with a body-mass index of 27-45 kg/m(2) and two or more comorbidities (hypertension, dyslipidaemia, diabetes or prediabetes, or abdominal obesity) to placebo, once-daily phentermine 7·5 mg plus topiramate 46·0 mg, or once-daily phentermine 15·0 mg plus topiramate 92·0 mg in a 2:1:2 ratio in 93 centres in the USA. Drugs were administered orally. Patients were randomly assigned by use of a computer-generated algorithm that was implemented through an interactive voice response system, and were stratified by sex and diabetic status. Investigators, patients, and study sponsors were masked to treatment. Primary endpoints were the percentage change in bodyweight and the proportion of patients achieving at least 5% weight loss. Analysis was by intention to treat. This study is registered with Clinical Trials.gov, number NCT00553787.

FINDINGS

Of 2487 patients, 994 were assigned to placebo, 498 to phentermine 7·5 mg plus topiramate 46·0 mg, and 995 to phentermine 15·0 mg plus topiramate 92·0 mg; 979, 488, and 981 patients, respectively, were analysed. At 56 weeks, change in bodyweight was -1·4 kg (least-squares mean -1·2%, 95% CI -1·8 to -0·7), -8·1 kg (-7·8%, -8·5 to -7·1; p<0·0001), and -10·2 kg (-9·8%, -10·4 to -9·3; p<0·0001) in the patients assigned to placebo, phentermine 7·5 mg plus topiramate 46·0 mg, and phentermine 15·0 mg plus topiramate 92·0 mg, respectively. 204 (21%) patients achieved at least 5% weight loss with placebo, 303 (62%; odds ratio 6·3, 95% CI 4·9 to 8·0; p<0·0001) with phentermine 7·5 mg plus topiramate 46·0 mg, and 687 (70%; 9·0, 7·3 to 11·1; p<0·0001) with phentermine 15·0 mg plus topiramate 92·0 mg; for ≥10% weight loss, the corresponding numbers were 72 (7%), 182 (37%; 7·6, 5·6 to 10·2; p<0·0001), and 467 (48%; 11·7, 8·9 to 15·4; p<0·0001). The most common adverse events were dry mouth (24 [2%], 67 [13%], and 207 [21%] in the groups assigned to placebo, phentermine 7·5 mg plus topiramate 46·0 mg, and phentermine 15·0 mg plus topiramate 92·0 mg, respectively), paraesthesia (20 [2%], 68 [14%], and 204 [21%], respectively), constipation (59 [6%], 75 [15%], and 173 [17%], respectively), insomnia (47 [5%], 29 [6%], and 102 [10%], respectively), dizziness (31 [3%], 36 [7%], 99 [10%], respectively), and dysgeusia (11 [1%], 37 [7%], and 103 [10%], respectively). 38 (4%) patients assigned to placebo, 19 (4%) to phentermine 7·5 mg plus topiramate 46·0 mg, and 73 (7%) to phentermine 15·0 mg plus topiramate 92·0 mg had depression-related adverse events; and 28 (3%), 24 (5%), and 77 (8%), respectively, had anxiety-related adverse events.

INTERPRETATION

The combination of phentermine and topiramate, with office-based lifestyle interventions, might be a valuable treatment for obesity that can be provided by family doctors.

FUNDING

Vivus.

Sexual functioning in obese adults enrolling in a weight loss study

The authors assessed sexual functioning among treatment-seeking obese men (n = 91) and women (n = 134) using the comprehensive validated Sexual Functioning Questionnaire. Scores were lower for women than for men, indicating reduced sexual functioning. Men's scores fell between those of a group of cancer survivors and a general population group, whereas women generally had lower scores than both of these groups. Increasing body mass index was associated with decreasing sexual functioning only for arousal and behavior. Sexual functioning was also reduced on most subscales for individuals who reported sexual inactivity in the past month.

Combination therapy for obesity and metabolic disease

PURPOSE OF REVIEW

There is a growing interest in developing combination therapies for treatment and management of obesity and related metabolic diseases.

RECENT FINDINGS

Emerging data from recently completed and ongoing randomized clinical trials suggest that certain combination-drug therapies in development have greater efficacy than currently available single-drug therapies in terms of achieved weight loss and reduction in risk factors.

SUMMARY

Combination-drug therapy may have a role in the treatment of obesity and related diseases as well as for prevention of risk factors. As we await safety data from studies with larger samples, the demonstrated efficacy of some of the combination drug therapies in late-stage development appears to be robust and clinically meaningful.

Combination pharmaceutical therapies for obesity

The anti-obesity medications available at present achieve a rather modest degree of weight loss that falls below the expectations of clinicians as well as consumers. Several combination drug therapies are in development with the aim of achieving better results that would be clinically more meaningful in the reduction of obesity-related health risks. This paper discusses the pros and cons of combination therapies, and the ongoing research in this area.

Missing data in randomized clinical trials for weight loss: scope of the problem, state of the field, and performance of statistical methods

Background

Dropouts and missing data are nearly-ubiquitous in obesity randomized controlled trails, threatening validity and generalizability of conclusions. Herein, we meta-analytically evaluate the extent of missing data, the frequency with which various analytic methods are employed to accommodate dropouts, and the performance of multiple statistical methods.

Methodology/Principal Findings

We searched PubMed and Cochrane databases (2000–2006) for articles published in English and manually searched bibliographic references. Articles of pharmaceutical randomized controlled trials with weight loss or weight gain prevention as major endpoints were included. Two authors independently reviewed each publication for inclusion. 121 articles met the inclusion criteria. Two authors independently extracted treatment, sample size, drop-out rates, study duration, and statistical method used to handle missing data from all articles and resolved disagreements by consensus. In the meta-analysis, drop-out rates were substantial with the survival (non-dropout) rates being approximated by an exponential decay curve (e^−λt) where λ was estimated to be .0088 (95% bootstrap confidence interval: .0076 to .0100) and t represents time in weeks. The estimated drop-out rate at 1 year was 37%. Most studies used last observation carried forward as the primary analytic method to handle missing data. We also obtained 12 raw obesity randomized controlled trial datasets for empirical analyses. Analyses of raw randomized controlled trial data suggested that both mixed models and multiple imputation performed well, but that multiple imputation may be more robust when missing data are extensive.

Conclusion/Significance

Our analysis offers an equation for predictions of dropout rates useful for future study planning. Our raw data analyses suggests that multiple imputation is better than other methods for handling missing data in obesity randomized controlled trials, followed closely by mixed models. We suggest these methods supplant last observation carried forward as the primary method of analysis.

Sample size in obesity trials: patient perspective versus current practice

OBJECTIVE

To evaluate patient opinions on acceptable risks in exchange for a given degree of weight loss and their implications for sample size determination in obesity randomized clinical trials (RCTs).

DESIGN

. Survey of patients entering RCTs for weight loss in a university-based clinical research setting and power calculations based on their responses. Participants. Men (n = 8) and women (n = 66) between 24 and 73 years of age with body mass indices ranging from 26.8 to 40.5 kg/m(2). Measurements. Survey responses to questions assessing the added risk of serious adverse events (SAEs) or death one is willing to assume for a given degree of weight loss.

RESULTS

For 5% and 10% weight loss against risk for death per se, the mean acceptable risk tended to be about 3.5%, but the median (0.00) and mode (0.00) suggested that for most individuals, only a risk of < or = 1% would be acceptable. Figures, estimated dropout rates, and base rates of SAEs (including deaths) from recent obesity trials indicate that 1-year 2-group obesity RCTs would need tens of thousands of participants per group to have 80% power to detect risks that are meaningful to patients at the 2-tailed 0.05 alpha level.

CONCLUSION

Patient education is needed to explain which risks are realistically detectable in RCTs so that patients may provide truly informed consent, or RCT standards should be modified to meet patients' implicit expectations.

The effect of acute tryptophan depletion on emotional distraction and subsequent memory

Serotonin is a key neurotransmitter involved in emotional regulation and memory. A number of studies using acute tryptophan depletion (ATD) in healthy subjects have shown that a temporary serotonin reduction both induces a negative emotional bias and impairs long-term memory. However, little is known about the specific effects of ATD on emotional memory. Using functional magnetic resonance imaging (fMRI), we investigated the effect of ATD on negative memory and executive function in healthy volunteers. Our emotional oddball task required participants to distinguish infrequently presented targets from distracting negative and neutral pictures. Memory for the distracting pictures was tested 1 h following the fMRI session. ATD selectively enhanced memory for negative distractors relative to neutral distractors and increased activation in response to the negative distractors in the left orbital-inferior frontal, dorsomedial prefrontal and bilateral angular gyri. ATD also induced greater activation in the left inferior frontal gyrus and anterior cingulate across all stimuli. Stronger frontal activation to distractors was positively correlated with memory performance on ATD but not control days, indicating a possible compensatory mechanism for coping with increased task demand under the ATD challenge. These findings highlight the importance of serotonin in negative memory with implications for mood disorders.