The liver-heart axis in patients with severe obesity: The association between liver fibrosis and chronic myocardial injury may be explained by shared risk factors of cardiovascular disease

BACKGROUND

Severe obesity is associated with increased risk of non-alcoholic fatty liver disease and cardiovascular disease. We hypothesized that liver fibrosis as quantified by the Enhanced Liver Fibrosis (ELF) test would be predictive of myocardial injury and fibrosis, expressed by higher concentrations of cardiac troponin T and I measured by high-sensitivity assays (hs-cTnT and hs-cTnI, respectively).

MATERIAL AND METHODS

We performed cross-sectional analyses of baseline data from 136 patients (mean age 45 years, 38 % male) with severe obesity participating in the non-randomized clinical trial Prevention of Coronary Heart Disease in Morbidly Obese Patients (ClinicalTrials.gov NCT00626964). Associations between ELF scores, hs-cTnT, and hs-cTnI concentrations were assessed using linear regression analysis.

RESULTS

ELF scores were associated with hs-cTnT in the unadjusted model (B 0.381, 95 % Confidence Interval [CI] 0.247, 0.514), but the association was attenuated upon adjustment for potential confounders (B -0.031, 95 % CI -0.155, 0.093). Similarly, for hs-cTnI, an observed association with ELF scores in the unadjusted model was attenuated upon adjustment for potential confounders ((B 0.432, 95 % CI 0.179, 0.685) and (B 0.069, 95 % CI -0.230, 0.367), respectively). Age, sex, hypertension, and estimated glomerular filtration rate were amongst the shared predictors of ELF score, hs-cTnT, and hs-cTnI that provided the univariable models with the highest R-squared and lowest Akaike Information Criterion values.

CONCLUSIONS

Contrary to our hypothesis, ELF score did not predict myocardial injury and fibrosis, but we rather demonstrated an association between liver fibrosis and myocardial injury and fibrosis may be explained by shared risk factors of cardiovascular disease.

Digoxin Pharmacokinetics in Patients with Obesity Before and After a Gastric Bypass or a Strict Diet Compared with Normal Weight Individuals

BACKGROUND AND OBJECTIVE

Several drugs on the market are substrates for P-glycoprotein (P-gp), an efflux transporter highly expressed in barrier tissues such as the intestine. Body weight, weight loss, and a Roux-en-Y gastric bypass (RYGB) may influence P-gp expression and activity, leading to variability in the drug response. The objective of this study was therefore to investigate digoxin pharmacokinetics as a measure of the P-gp phenotype in patients with obesity before and after weight loss induced by an RYGB or a strict diet and in normal weight individuals.

METHODS

This study included patients with severe obesity preparing for an RYGB (n = 40) or diet-induced weight loss (n = 40) and mainly normal weight individuals scheduled for a cholecystectomy (n = 18). Both weight loss groups underwent a 3-week low-energy diet (<1200 kcal/day) followed by an additional 6 weeks of <800 kcal/day induced by an RYGB (performed at week 3) or a very-low-energy diet. Follow-up time was 2 years, with four digoxin pharmacokinetic investigations at weeks 0, 3, and 9, and year 2. Hepatic and jejunal P-gp levels were determined in biopsies obtained from the patients undergoing surgery.

RESULTS

The RYGB group and the diet group had a comparable weight loss in the first 9 weeks (13 ± 2.3% and 11 ± 3.6%, respectively). During this period, we observed a minor increase (16%) in the digoxin area under the concentration-time curve from zero to infinity in both groups: RYGB: 2.7 µg h/L [95% confidence interval (CI) 0.67, 4.7], diet: 2.5 µg h/L [95% CI 0.49, 4.4]. In the RYGB group, we also observed that the time to reach maximum concentration decreased after surgery: from 1.0 ± 0.33 hours at week 3 to 0.77 ± 0.08 hours at week 9 (-0.26 hours [95% CI -0.47, -0.05]), corresponding to a 25% reduction. Area under the concentration-time curve from zero to infinity did not change long term (week 0 to year 2) in either the RYGB (1.1 µg h/L [-0.94, 3.2]) or the diet group (0.94 µg h/L [-1.2, 3.0]), despite a considerable difference in weight loss from baseline (RYGB: 30 ± 7%, diet: 3 ± 6%). At baseline, the area under the concentration-time curve from zero to infinity was -5.5 µg h/L [95% CI -8.5, -2.5] (-26%) lower in patients with obesity (RYGB plus diet) than in normal weight individuals scheduled for a cholecystectomy. Further, patients undergoing an RYGB had a 0.05 fmol/µg [95% CI 0.00, 0.10] (29%) higher hepatic P-gp level than the normal weight individuals.

CONCLUSIONS

Changes in digoxin pharmacokinetics following weight loss induced by a pre-operative low-energy diet and an RYGB or a strict diet (a low-energy diet plus a very-low-energy diet) were minor and unlikely to be clinically relevant. The lower systemic exposure of digoxin in patients with obesity suggests that these patients may have increased biliary excretion of digoxin possibly owing to a higher expression of P-gp in the liver.

Proteome deconvolution of liver biopsies reveals hepatic cell composition as an important marker of fibrosis

Human liver tissue is composed of heterogeneous mixtures of different cell types and their cellular stoichiometry can provide information on hepatic physiology and disease progression. Deconvolution algorithms for the identification of cell types and their proportions have recently been developed for transcriptomic data. However, no method for the deconvolution of bulk proteomics data has been presented to date. Here, we show that proteomes, which usually contain less data than transcriptomes, can provide useful information for cell type deconvolution using different algorithms. We demonstrate that proteomes from defined mixtures of cell lines, isolated primary liver cells, and human liver biopsies can be deconvoluted with high accuracy. In contrast to transcriptome-based deconvolution, liver tissue proteomes also provided information about extracellular compartments. Using deconvolution of proteomics data from liver biopsies of 56 patients undergoing Roux-en-Y gastric bypass surgery we show that proportions of immune and stellate cells correlate with inflammatory markers and altered composition of extracellular matrix proteins characteristic of early-stage fibrosis. Our results thus demonstrate that proteome deconvolution can be used as a molecular microscope for investigations of the composition of cell types, extracellular compartments, and for exploring cell-type specific pathological events. We anticipate that these findings will allow the refinement of retrospective analyses of the growing number of proteome datasets from various liver disease states and pave the way for AI-supported clinical and preclinical diagnostics.

Single-centre, non-randomised clinical trial at a tertiary care centre to investigate 1-year changes in social experiences and biomarkers of well-being after bariatric surgery in individuals with severe obesity: protocol for the Bariatric Surgery and Social Experiences (BaSES) study

INTRODUCTION

Obesity is linked to increased loneliness and less enjoyment of social interactions. While bariatric surgery is the most effective treatment targeting severe obesity, there is limited understanding as to whether patients experience social interactions differently after surgery. The Bariatric Surgery and Social Experiences study is designed to assess potential changes in how much patients enjoy and engage in daily social interactions 1 year after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG).

METHODS AND ANALYSIS

Single-centre, non-randomised clinical trial carried out at the Department of Endocrinology, Obesity and Nutrition at Vestfold Hospital Trust, Norway. Eligible patients (N=113) will undergo either RYGB, SG or single anastomosis sleeve ileal (SASI) bypass. The primary outcome measure is change in the social experience score (assessed with a questionnaire) from a presurgery to a follow-up assessment 1 year after RYGB and SG. The respective changes after SASI bypass will be assessed and considered exploratory.

ETHICS AND DISSEMINATION

The most recent protocol version of this study was reviewed and approved by the Regional Committee for Medical Research Ethics South East Norway (REK sør-øst A) on 29 August 2022 (ref: 238406). The results will be disseminated to academic and health professional audiences and the public via publications in international peer-reviewed journals and conferences.

TRIAL REGISTRATION NUMBER

NCT05207917.

Patient-reported outcomes, weight loss, and remission of type 2 diabetes 3 years after gastric bypass and sleeve gastrectomy (Oseberg); a single-centre, randomised controlled trial

BACKGROUND

Little is known about the comparative effects of various bariatric procedures on patient-reported outcomes. We aimed to compare 3-year effects of gastric bypass and sleeve gastrectomy on patient-reported outcome measures in patients with obesity and type 2 diabetes.

METHODS

The Oseberg trial was a single-centre, parallel-group, randomised trial at Vestfold Hospital Trust, a public tertiary obesity centre in Tønsberg, Norway. Eligible patients were aged 18 years or older with previously verified BMI 35·0 kg/m² or greater. Diabetes was diagnosed if glycated haemoglobin was at least 6·5% (48 mmol/mol) or by their use of anti-diabetic medications with glycated haemoglobin at least 6·1% (43 mmol/mol). Eligible patients were randomly assigned (1:1) to gastric bypass or sleeve gastrectomy. All patients received identical preoperative and postoperative treatment. Randomisation was done with a computerised random number generator and a block size of ten. Study personnel, patients, and the primary outcome assessor were blinded to allocations for 1 year. The prespecified secondary outcomes reported here were 3-year changes in several clinically important patient-reported outcomes, weight loss, and diabetes remission. Analyses were done in the intention to treat population. This trial is ongoing, closed to recruitment and is registered with ClinicalTrials.gov, NCT01778738.

FINDINGS

Between Oct 15, 2012 and Sept 1, 2017, 319 consecutive patients with type 2 diabetes scheduled for bariatric surgery were assessed for eligibility. 101 patients were not eligible (29 did not have type 2 diabetes according to inclusion criteria and 72 other exclusion criteria) and 93 declined to participate. 109 patients were enrolled and randomly assigned to sleeve gastrectomy (n=55) or gastric bypass (n=54). 72 (66%) of 109 patients were female and 37 (34%) were male. 104 (95%) of patients were White. 16 patients were lost to follow up and 93 (85%) patients completed the 3-year follow-up. Three additional patients were contacted by phone for registration of comorbidities Compared with sleeve gastrectomy, gastric bypass was associated with a greater improvement in weight-related quality of life (between group difference 9·4, 95% CI 3·3 to 15·5), less reflux symptoms (0·54, 0·17 to -0·90), greater total bodyweight loss (8% difference, 25% vs 17%), and a higher probability of diabetes remission (67% vs 33%, risk ratio 2·00; 95% CI 1·27 to 3·14). Five patients reported postprandial hypoglycaemia in the third year after gastric bypass versus none after sleeve-gastrectomy (p=0·059). Symptoms of abdominal pain, indigestion, diarrhoea, dumping syndrome, depression, binge eating, and appetitive drive did not differ between groups.

INTERPRETATION

At 3 years, gastric bypass was superior to sleeve gastrectomy in patients with type 2 diabetes and obesity regarding weight related quality of life, reflux symptoms, weight loss, and remission of diabetes, while symptoms of abdominal pain, indigestion, diarrhoea, dumping, depression and binge eating did not differ between groups. This new patient-reported knowledge can be used in the shared decision-making process to inform patients about similarities and differences between expected outcomes after the two surgical procedures.

FUNDING

Morbid Obesity Centre, Vestfold Hospital Trust.

TRANSLATION

For the Norwegian translation of the abstract see Supplementary Materials section.

A pilot study of implementation of endoscopic sleeve gastroplasty (ESG) in Norway

BACKGROUND AND AIM

Bariatric surgery is the most effective treatment for obesity but is invasive and associated with serious complications. Endoscopic sleeve gastroplasty (ESG) is a less invasive weight loss procedure to reduce the stomach volume by full-thickness sutures. ESG has been adopted in many countries, but implementation at Scandinavian centres has not yet been documented. We performed a clinical pilot trial at a Norwegian centre with the primary objective to assess the feasibility of the ESG procedure.

PATIENTS AND METHODS

We included the first 10 patients treated with ESG at a Norwegian centre in a single-arm pilot study. The eligibility criteria were either a body mass index (BMI) of 40-49.9 kg/m2, BMI 35-39.9 kg/m2 and at least one obesity-related comorbidity, or BMI 30-34.9 kg/m2 and type 2 diabetes. Patient follow-up resembled the scheme used for bariatric surgery at the center, including dietary plans and outpatient visits.

RESULTS

All procedures were technically successful except for one patient who had adhesions between the stomach and anterior abdominal wall, related to a prior hernia repair, resulting in less-than-intended stomach volume reduction. Mean total body weight loss (TBWL) after 26 and 52 weeks was 12.2% (95% CI 8.1-16.2) and 9.1% (95% CI 3.3 - 15.0). One patient experienced a minor suture-induced diaphragmatic injury, which was successfully managed conservatively.

CONCLUSIONS

This first Scandinavian clinical trial of ESG, documenting the implementation of the procedure at a Norwegian center, demonstrated acceptable feasibility and safety, with large variations in individual weight loss during the 52-week follow-up period.

Neither Gastric Bypass Surgery Nor Diet-Induced Weight-Loss Affect OATP1B1 Activity as Measured by Rosuvastatin Oral Clearance

INTRODUCTION

Rosuvastatin pharmacokinetics is mainly dependent on the activity of hepatic uptake transporter OATP1B1. In this study, we aimed to investigate and disentangle the effect of Roux-en-Y gastric bypass (RYGB) and weight loss on oral clearance (CL/F) of rosuvastatin as a measure of OATP1B1-activity.

METHODS

Patients with severe obesity preparing for RYGB (n = 40) or diet-induced weight loss (n = 40) were included and followed for 2 years, with four 24-hour pharmacokinetic investigations. Both groups underwent a 3-week low-energy diet (LED; < 1200 kcal/day), followed by RYGB or a 6-week very-low-energy diet (VLED; < 800 kcal/day).

RESULTS

A total of 80 patients were included in the RYGB group (40 patients) and diet-group (40 patients). The weight loss was similar between the groups following LED and RYGB. The LED induced a similar (mean [95% CI]) decrease in CL/F in both intervention groups (RYGB: 16% [0, 31], diet: 23% [8, 38]), but neither induced VLED resulted in any further changes in CL/F. At Year 2, CL/F had increased by 21% from baseline in the RYGB group, while it was unaltered in the diet group. Patients expressing the reduced function SLCO1B1 variants (c.521TC/CC) showed similar changes in CL/F over time compared with patients expressing the wild-type variant.

CONCLUSIONS

Neither body weight, weight loss nor RYGB per se seem to affect OATP1B1 activity to a clinically relevant degree. Overall, the observed changes in rosuvastatin pharmacokinetics were minor, and unlikely to be of clinical relevance.

Changes in dietary intake, food tolerance, hedonic hunger, binge eating problems, and gastrointestinal symptoms after sleeve gastrectomy compared with after gastric bypass; 1-year results from the Oseberg study-a randomized controlled trial

BACKGROUND

The randomized Oseberg study compared the effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), on the 1-y remission of type 2 diabetes and β-cell function (primary outcomes). However, little is known about the comparable effects of SG and RYGB on the changes in dietary intakes, eating behavior, and gastrointestinal discomfort.

OBJECTIVES

To compare 1-y changes in intakes of macro- and micronutrients, food groups, food tolerance, hedonic hunger, binge eating, and gastrointestinal symptoms after SG and RYGB.

METHODS

Among others, prespecified secondary outcomes were dietary intake, food tolerance, hedonic hunger, binge eating, and gastrointestinal symptoms assessed with a food frequency questionnaire, food tolerance questionnaire, Power of food scale, Binge eating scale, and Gastrointestinal symptom rating scale, respectively.

RESULTS

A total of 109 patients (66% females), with mean (SD) age 47.7 (9.6) y and body mass index of 42.3 (5.3) kg/m², were allocated to SG (n = 55) or RYGB (n = 54). The SG group had, compared with the RYGB group, greater 1-y reductions in the intakes of: protein, mean (95% CI) between-group difference, -13 (-24.9, -1.2) g; fiber, -4.9 (-8.2, -1.6) g; magnesium, -77 (-147, -6) mg; potassium, -640 (-1237, -44) mg; and fruits and berries, -65 (-109, -20) g. Further, the intake of yogurt and fermented milk products increased by >2-folds after RYGB but remained unchanged after SG. In addition, hedonic hunger and binge eating problems declined similarly after both surgeries, whereas most gastrointestinal symptoms and food tolerance remained stable at 1 y.

CONCLUSIONS

The 1-y changes in dietary intakes of fiber and protein after both surgical procedures, but particularly after SG, were unfavorable with regard to current dietary guidelines. For clinical practice, our findings suggest that health care providers and patients should focus on sufficient intakes of protein, fiber, and vitamin and mineral supplementation after both SG and RYGB. This trial was registered at [clinicaltrials.gov] as [NCT01778738].

Differential effects of bariatric surgery and lifestyle interventions on plasma levels of Lp(a) and fatty acids

BACKGROUND

Limited evidence suggests that surgical and non-surgical obesity treatment differentially influence plasma Lipoprotein (a) [Lp(a)] levels. Further, a novel association between plasma arachidonic acid and Lp(a) has recently been shown, suggesting that fatty acids are a possible target to influence Lp(a). Here, the effects of bariatric surgery and lifestyle interventions on plasma levels of Lp(a) were compared, and it was examined whether the effects were mediated by changes in plasma fatty acid (FA) levels.

METHODS

The study includes two independent trials of patients with overweight or obesity. Trial 1: Two-armed intervention study including 82 patients who underwent a 7-week low energy diet (LED), followed by Roux-en-Y gastric bypass and 52-week follow-up (surgery-group), and 77 patients who underwent a 59-week energy restricted diet- and exercise-program (lifestyle-group). Trial 2: A clinical study including 134 patients who underwent a 20-week very-LED/LED (lifestyle-cohort).

RESULTS

In the surgery-group, Lp(a) levels [median (interquartile range)] tended to increase in the pre-surgical LED-phase [17(7-68)-21(7-81)nmol/L, P = 0.05], but decreased by 48% after surgery [21(7-81)-11(7-56)nmol/L, P < 0.001]. In the lifestyle-group and lifestyle-cohort, Lp(a) increased by 36%[14(7-77)-19(7-94)nmol/L, P < 0.001] and 14%[50(14-160)-57(19-208)nmol/L, P < 0.001], respectively. Changes in Lp(a) were independent of weight loss. Plasma levels of total saturated FAs remained unchanged after surgery, but decreased after lifestyle interventions. Arachidonic acid and total n-3 FAs decreased after surgery, but increased after lifestyle interventions. Plasma FAs did not mediate the effects on Lp(a).

CONCLUSION

Bariatric surgery reduced, whereas lifestyle interventions increased plasma Lp(a), independent of weight loss. The interventions differentially influenced changes in plasma FAs, but these changes did not mediate changes in Lp(a).

TRIAL REGISTRATION

Trial 1: Clinicaltrials.gov NCT00626964. Trial 2: Netherlands Trial Register NL2140 (NTR2264).

Impact of type 2 diabetes on in vivo activities and protein expressions of cytochrome P450 in patients with obesity

Previous studies have not accounted for the close link between type 2 diabetes mellitus (T2DM) and obesity when investigating the impact of T2DM on cytochrome P450 (CYP) activities. The aim was to investigate the effect of T2DM on in vivo activities and protein expressions of CYP2C19, CYP3A, CYP1A2, and CYP2C9 in patients with obesity. A total of 99 patients from the COCKTAIL study (NCT02386917) were included in this cross-sectional analysis; 29 with T2DM and obesity (T2DM-obesity), 53 with obesity without T2DM (obesity), and 17 controls without T2DM and obesity (controls). CYP activities were assessed after the administration of a cocktail of probe drugs including omeprazole (CYP2C19), midazolam (CYP3A), caffeine (CYP1A2), and losartan (CYP2C9). Jejunal and liver biopsies were also obtained to determine protein concentrations of the respective CYPs. CYP2C19 activity and jejunal CYP2C19 concentration were 63% (-0.39 [95% CI: -0.82, -0.09]) and 40% (-0.09 fmol/μg protein [95% CI: -0.18, -0.003]) lower in T2DM-obesity compared with the obesity group, respectively. By contrast, there were no differences in the in vivo activities and protein concentrations of CYP3A, CYP1A2, and CYP2C9. Multivariable regression analyses also indicated that T2DM was associated with interindividual variability in CYP2C19 activity, but not CYP3A, CYP1A2, and CYP2C9 activities. The findings indicate that T2DM has a significant downregulating impact on CYP2C19 activity, but not on CYP3A, CYP1A2, and CYP2C9 activities and protein concentrations in patients with obesity. Hence, the effect of T2DM seems to be isoform-specific.

Correlations between 4β-hydroxycholesterol and hepatic and intestinal CYP3A4: protein expression, microsomal ex vivo activity, and in vivo activity in patients with a wide body weight range

PURPOSE

Variability in cytochrome P450 3A4 (CYP3A4) metabolism is mainly caused by non-genetic factors, hence providing a need for accurate phenotype biomarkers. Although 4β-hydroxycholesterol (4βOHC) is a promising endogenous CYP3A4 biomarker, additional investigations are required to evaluate its ability to predict CYP3A4 activity. This study investigated the correlations between 4βOHC concentrations and hepatic and intestinal CYP3A4 protein expression and ex vivo microsomal activity in paired liver and jejunum samples, as well as in vivo CYP3A4 phenotyping (midazolam) in patients with a wide body weight range.

METHODS

The patients (n = 96; 78 with obesity and 18 normal or overweight individuals) were included from the COCKTAIL-study (NCT02386917). Plasma samples for analysis of 4βOHC and midazolam concentrations, and liver (n = 56) and jejunal (n = 38) biopsies were obtained. The biopsies for determination of CYP3A4 protein concentration and microsomal activity were obtained during gastric bypass or cholecystectomy. In vivo CYP3A4 phenotyping was performed using semi-simultaneous oral (1.5 mg) and intravenous (1.0 mg) midazolam.

RESULTS

4βOHC concentrations were positively correlated with hepatic microsomal CYP3A4 activity (ρ = 0.53, p < 0.001), and hepatic CYP3A4 concentrations (ρ = 0.30, p = 0.027), but not with intestinal CYP3A4 concentrations (ρ = 0.18, p = 0.28) or intestinal microsomal CYP3A4 activity (ρ = 0.15, p = 0.53). 4βOHC concentrations correlated weakly with midazolam absolute bioavailability (ρ =  - 0.23, p = 0.027) and apparent oral clearance (ρ = 0.28, p = 0.008), but not with systemic clearance (ρ =  - 0.03, p = 0.81).

CONCLUSION

These findings suggest that 4βOHC concentrations reflect hepatic, but not intestinal, CYP3A4 activity. Further studies should investigate the potential value of 4βOHC as an endogenous biomarker for individual dose requirements of intravenously administered CYP3A4 substrate drugs.

TRIAL REGISTRATION

Clinical.

TRIALS

gov identifier: NCT02386917.

Effect of aerobic exercise intensity on health-related quality of life in severe obesity: a randomized controlled trial

Background

Aerobic exercise is an important part of obesity treatment and may improve health-related quality of life (HRQOL). The objective of this study was to compare the effect of two different exercise programs on health-related quality of life in patients with severe obesity.

Methods

This was a single-center, open-label, randomized, parallel-group study comparing the effects of a 24-week moderate-intensity continuous training (MICT) program and a combined high-intensity interval training program with MICT (HIIT/MICT). The primary objective (specified secondary outcome) was to assess HRQOL by using the general health dimension of the Short Form Health Survey (SF-36). The secondary objectives were to assess other dimensional SF-36 scores, the impact of weight on the physical and psychosocial aspects of quality of life (IWQOL-Lite), and the burden of obesity-specific weight symptoms (WRSM).

Results

73 patients were enrolled and reported patient reported outcome measures, with 71 patients (55% females) allocated to either MICT (n = 34) or HIIT/MICT (n = 37). In the intention-to-treat analysis, general health scores increased between baseline and 24-week follow-up in both the HIIT/MICT group and the MICT group, with a mean change of 13 (95% CI 6–21) points and 11 (95% CI 5–17) points, respectively, with no difference between the groups. The effect sizes of these changes were moderate. The vitality and social functioning scores of SF-36, and the physical function and self-esteem scores of IWQOL-Lite increased moderately in both groups, with no difference between groups. The tiredness, back pain, and physical stamina scores based on WRSM showed moderate to strong changes in both the groups.

Conclusions

Patients who had completed a combined HIIT/MICT program did not experience larger improvements in general health compared with those completing a clean 24-week MICT program. Exercise may confer general health benefits independent of intensity.

Trials registration

Regional Committees for Medical and Health Research Ethics south east, Norway, October 23, 2013 (identifier: 2013/1849) and ClinicalTrials.gov December 8, 2014 (identifier: NCT02311738).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12955-022-01940-y.

Combining Persuasive System Design Principles and Behavior Change Techniques in Digital Interventions Supporting Long-term Weight Loss Maintenance: Design and Development of eCHANGE (Preprint)

Background

Long-term weight maintenance after weight loss is challenging, and innovative solutions are required. Digital technologies can support behavior change and, therefore, have the potential to be an effective tool for weight loss maintenance. However, to create meaningful and effective digital behavior change interventions that support end user values and needs, a combination of persuasive system design (PSD) principles and behavior change techniques (BCTs) might be needed.

Objective

This study aimed to investigate how an evidence-informed digital behavior change intervention can be designed and developed by combining PSD principles and BCTs into design features to support end user values and needs for long-term weight loss maintenance.

Methods

This study presents a concept for how PSD principles and BCTs can be translated into design features by combining design thinking and Agile methods to develop and deliver an evidence-informed digital behavior change intervention aimed at supporting weight maintenance. Overall, 45 stakeholders participated in the systematic and iterative development process comprising co-design workshops, prototyping, Agile development, and usability testing. This included prospective end users (n=17, 38%; ie, people with obesity who had lost ≥8% of their weight), health care providers (n=9, 20%), healthy volunteers (n=4, 9%), a service designer (n=1, 2%), and stakeholders from the multidisciplinary research and development team (n=14, 31%; ie, software developers; digital designers; and eHealth, behavior change, and obesity experts). Stakeholder input on how to operationalize the design features and optimize the technology was examined through formative evaluation and qualitative analyses using rapid and in-depth analysis approaches.

Results

A total of 17 design features combining PSD principles and BCTs were identified as important to support end user values and needs based on stakeholder input during the design and development of eCHANGE, a digital intervention to support long-term weight loss maintenance. The design features were combined into 4 main intervention components: Week Plan, My Overview, Knowledge and Skills, and Virtual Coach and Smart Feedback System. To support a healthy lifestyle and continued behavior change to maintain weight, PSD principles such as tailoring, personalization, self-monitoring, reminders, rewards, rehearsal, praise, and suggestions were combined and implemented into the design features together with BCTs from the clusters of goals and planning, feedback and monitoring, social support, repetition and substitution, shaping knowledge, natural consequences, associations, antecedents, identity, and self-belief.

Conclusions

Combining and implementing PSD principles and BCTs in digital interventions aimed at supporting sustainable behavior change may contribute to the design of engaging and motivating interventions in line with end user values and needs. As such, the design and development of the eCHANGE intervention can provide valuable input for future design and tailoring of evidence-informed digital interventions, even beyond digital interventions in support of health behavior change and long-term weight loss maintenance.

Trial Registration

ClinicalTrials.gov NCT04537988; https://clinicaltrials.gov/ct2/show/NCT04537988

A novel intragastric balloon for treatment of obesity and type 2 diabetes. A two-center pilot trial

BACKGROUND AND AIMS

Obesity with type-2 diabetes is a global challenge. Lifestyle interventions have limited effect for most patients. Bariatric surgery is highly effective, but resource-demanding, invasive and associated with serious complications. Recently, a new intragastric balloon was introduced, not requiring endoscopy for placement or removal (Elipse™, Allurion Inc., Natick, MA). The balloon is swallowed in a capsule and filled with water once in the stomach. The balloon self-deflates after 4 months and is naturally excreted. The present trial investigated balloon feasibility, safety and efficacy in patients with obesity and type-2 diabetes.

PATIENTS AND METHODS

We treated 19 patients, with type-2 diabetes and body mass index (BMI) of 30.0-39.9 kg/m² at two Norwegian centers with the Elipse balloon. Patient follow-up during balloon treatment mimicked real-world clinical practice, including dietary plan and outpatient visits. The primary efficacy endpoints were total body weight loss (TBWL) and HbA1c at weeks 16 and 52.

RESULTS

All patients underwent balloon insertion uneventfully as out-patients. Mean TBWL and HbA1c reduction after 16 and 52 weeks of balloon insertion was 3.9% (95%CI 2.1-5.7) and 0.8% (95%CI 1.9-3.5); and 7 (95%CI 4-10), and 1 (95%CI -6 to 9) mmol/mol, respectively. Adverse events occurred in two patients (10.5%): one developed gastric outlet obstruction, managed by endoscopic balloon removal; the other excessive vomiting and dehydration, managed conservatively.

CONCLUSIONS

This first Scandinavian real-world clinical trial with a new minimally invasive intragastric balloon system demonstrated good feasibility, but did not confirm expected efficacy for weight loss and diabetes control.

Gastrointestinal Hormones and β-Cell Function After Gastric Bypass and Sleeve Gastrectomy: A Randomized Controlled Trial (Oseberg)

CONTEXT

Whether Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) differentially affect postprandial gastrointestinal hormones and β-cell function in type 2 diabetes remains unclear.

OBJECTIVE

We aimed to compare gastrointestinal hormones and β-cell function, assessed by an oral glucose tolerance test (OGTT) 5 weeks and 1 year after surgery, hypothesizing higher glucagon-like peptide-1 (GLP-1) levels and greater β-cell response to glucose after RYGB than after SG.

METHODS

This study was a randomized, triple-blind, single-center trial at a tertiary care center in Norway. The primary outcomes were diabetes remission and IVGTT-derived β-cell function. Participants with obesity and type 2 diabetes were allocated (1:1) to RYGB or SG. We measured gastrointestinal hormone profiles and insulin secretion as β-cell glucose sensitivity (β-GS) derived from 180-minute OGTTs.

RESULTS

Participants were 106 patients (67% women), mean (SD) age 48 (10) years. Diabetes remission rates at 1 year were higher after RYGB than after SG (77% vs 48%; P = 0.002). Incremental area under the curve (iAUC0-180) GLP-1 and β-GS increased more after RYGB than after SG, with 1-year between-group difference 1173 pmol/L*min (95% CI, 569-1776; P = 0.0010) and 0.45 pmol/kg/min/mmol (95% CI, 0.15-0.75; P = 0.0032), respectively. After surgery, fasting and postprandial ghrelin levels were higher and decremental AUC0-180 ghrelin, iAUC0-180 glucose-dependent insulinotropic polypeptide, and iAUC0-60 glucagon were greater after RYGB than after SG. Diabetes remission at 1 year was associated with higher β-GS and higher GLP-1 secretion.

CONCLUSION

RYGB was associated with greater improvement in β-cell function and higher postprandial GLP-1 levels than SG.

Validation of Ad-DiaRem and ABCD Diabetes Remission Prediction Scores at 1-Year After Roux-en-Y Gastric Bypass and Sleeve Gastrectomy in the Randomized Controlled Oseberg Trial

BACKGROUND

Prediction of type 2 diabetes (T2DM) remission is an important part of risk-benefit assessment before bariatric surgery.

STUDY DESIGN

Advanced-DiaRem (Ad-DiaRem) and ABCD diabetes remission scores for sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) were calculated using baseline data. Differences in model discrimination using area under the curve of receiver operating curve (AUC-ROC) and model calibration were tested for complete remission (HbA1c ≤ 6.0% without antidiabetic medications) in the two groups. Optimal cutoff scores were calculated using the Youden index.

RESULTS

We randomized 109 patients to either SG or RYGB. With one patient lost to follow-up in each group, the scores were calculated for 54 patients in the SG group and 53 patients in the RYGB group. Both models showed moderate predictive power without any significant difference between the groups: AUC-ROCs (95% CI) for the Ad-DiaRem score (SG versus RYGB) were 0.872 (0.780-0.964) versus 0.843 (0.733-0.954), p = 0.69, and for the ABCD score 0.849 (0.752-0.946) versus 0.750 (0.580-0.920), p = 0.32, respectively. Using optimal cutoff points derived from the whole study population, the actual proportion of diabetes remission was significantly higher than predicted for both the Ad-DiaRem and ABCD scores in the RYGB group. Diabetes duration and glycated haemoglobin predicted diabetes remission in the entire Oseberg population.

CONCLUSION

Both the Ad-DiaRem and ABCD scores showed moderate ability to discriminate between those who achieved remission of T2DM and those who did not after SG and RYGB. Larger studies are needed for the identification of procedure-specific optimal cutoffs. Trial Registration ClinicalTrials.gov Identifier: NCT01778738.

Gastric Bypass Versus Sleeve Gastrectomy in Type 2 Diabetes: Effects on Hepatic Steatosis and Fibrosis : A Randomized Controlled Trial

BACKGROUND

Weight loss improves fatty liver disease. No randomized trial has compared the effects of sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) on liver fat content and fibrosis.

OBJECTIVE

To compare the 1-year effects of SG and RYGB on hepatic steatosis and fibrosis.

DESIGN

Single-center, randomized, controlled trial (Oseberg [ObesitySurgery in Tønsberg]). (ClinicalTrials.gov: NCT01778738).

SETTING

Tertiary care obesity center in Norway.

PARTICIPANTS

100 patients (65% female; mean age, 47.5 years; mean body mass index, 42 kg/m²) with type 2 diabetes mellitus (T2DM).

INTERVENTION

From January 2013 to February 2018, patients were randomly assigned (1:1 ratio) to SG or RYGB.

MEASUREMENTS

The primary outcome was remission of T2DM (previously published). Predefined secondary outcomes in the present study were hepatic steatosis and fibrosis assessed by magnetic resonance imaging (liver fat fraction), enhanced liver fibrosis (ELF) test, noninvasive indices, and liver enzymes.

RESULTS

Liver fat fraction declined similarly after SG (-19.7% [95% CI, -22.5% to -16.9%]) and RYGB (-21.5% [CI, -24.3% to -18.6%]) from surgery to 1-year follow-up, and almost all patients (SG, 94%; RYGB, 100%) had no or low-grade steatosis at 1 year. The ELF score category remained stable in 77% of patients, but 18% experienced worsening of fibrosis at 1 year, with no substantial between-group difference.

LIMITATIONS

Single-center study, short follow-up time, and lack of power for secondary outcomes.

CONCLUSION

With an almost complete clearance of liver fat 1 year after surgery, RYGB and SG were both highly effective in reducing hepatic steatosis. Bariatric surgery had less influence on degree of fibrosis in the short term, but assessment of long-term progression is warranted.

PRIMARY FUNDING SOURCE

Vestfold Hospital Trust and the South-Eastern Norway Regional Health Authority.

Standard versus distal Roux-en-Y gastric bypass in patients with BMI 50-60 kg/m2: 5-year outcomes of a double-blind, randomized clinical trial

Background

The optimal surgical weight loss procedure for patients with a BMI of 50 kg/m² or more is uncertain. This study compared distal Roux-en-Y gastric bypass (RYGB) with standard RYGB.

Methods

In this double-blind RCT, patients aged 18–60 years with a BMI of 50–60 kg/m² were allocated randomly to receive standard (150 cm alimentary, 50 cm biliopancreatic limb) or distal (150 cm common channel, 50 cm biliopancreatic limb) RYGB. The primary outcome (change in BMI at 2 years) has been reported previously. Secondary outcomes 5 years after surgery, such as weight loss, health-related quality of life, and nutritional outcomes are reported.

Results

Between May 2011 and April 2013, 123 patients were randomized, 113 received an intervention, and 92 attended 5-year follow-up. Mean age was 40 (95 per cent c.i. 38 to 41) years and 73 patients (65 per cent) were women; 57 underwent standard RYGB and 56 distal RYGB. BMI was reduced by 15.1 (95 per cent c.i. 13.9 to 16.2) kg/m² after standard and 15.7 (14.5 to 16.9) kg/m² after distal RYGB; the between-group difference was −0.64 (−2.3 to 1.0) kg/m² (P = 0.447). Total cholesterol, low-density lipoprotein cholesterol, and haemoglobin A1c levels declined more after distal than after standard RYGB. High-density lipoprotein cholesterol levels increased more after standard RYGB. Vitamin A and vitamin D levels were lower after distal RYGB. Changes in bone mineral density, resting metabolic rate, and total energy intake were comparable.

Conclusion

Distal RYGB did not enable greater weight loss than standard RYGB. Differences in other outcomes favouring distal RYGB may not justify routine use of this procedure in patients with a BMI of 50–60 kg/m². Registration number: NCT00821197 (http://www.clinicaltrials.gov).

Presented in part as abstract to the IFSO (International Federation for the Surgery of Obesity and Metabolic disorders) conference, Madrid, Spain, August 2019.

Effect of Aerobic Exercise Intensity on Energy Expenditure and Weight Loss in Severe Obesity-A Randomized Controlled Trial

OBJECTIVE

This study aimed to compare the effects of two aerobic exercise programs of different intensities on energy expenditure.

METHODS

This was a single-center randomized controlled trial of patients with severe obesity allocated to a 24-week moderate-intensity continuous training (MICT) program or a combined MICT with high-intensity interval training (HIIT/MICT) program. The primary outcome was energy expenditure during exercise (EEDE). Secondary outcomes included resting metabolic rate, cardiorespiratory fitness, and body composition.

RESULTS

A total of 82 (56% females) patients were screened, and 71 (55% females) patients were allocated to HIIT/MICT (n = 37) or MICT (n = 34). Per-protocol analysis showed that EEDE increased by 10% (95% CI: 3%-17%) in the HIIT/MICT group (n = 16) and 7.5% (95% CI: 4%-10%) in the MICT group (n = 24), with no differences between groups. In the 8- to 16- week per-protocol analysis, the HIIT/MICT group had a significantly larger increase in EEDE compared with the MICT group. Resting metabolic rate remained unchanged in both groups. HIIT/MICT and MICT were associated with significant weight loss of 5 kg and 2 kg, respectively.

CONCLUSIONS

Patients completing a 24-week combined HIIT/MICT program did not achieve a higher EEDE compared with those who completed a 24-week MICT program. The HIIT/MICT group experienced, on average, a 3-kg-larger weight loss than the MICT group.

Bone Mineral Density and Turnover After Sleeve Gastrectomy and Gastric Bypass: A Randomized Controlled Trial (Oseberg)

CONTEXT

Bariatric surgery, particularly Roux-en-Y gastric bypass (RYGB), is associated with an increased risk of osteoporotic fractures. It is unknown whether RYGB or sleeve gastrectomy (SG) have different effects on bone health.

OBJECTIVE

To compare changes in bone mineral density and markers of bone turnover 1 year after SG and RYGB.

DESIGN, SETTING, PATIENTS, AND INTERVENTIONS

Randomized, triple-blind, single-center trial at a tertiary care center in Norway. The primary outcome was diabetes remission. Patients with severe obesity and type 2 diabetes were randomized and allocated (1:1) to SG or RYGB.

MAIN OUTCOME MEASURES

Changes in areal bone mineral density (aBMD) and bone turnover markers.

RESULTS

Femoral neck, total hip, and lumbar spine aBMD, but not total body aBMD, decreased significantly more after RYGB (n = 44) than after SG (n = 48) (mean [95% confidence interval] between group differences -2.8% [-4.7 to -0.8], -3.0% [-5.0 to -0.9], -4.2% [-6.4 to -2.1], and -0.5% [-1.6 to 0.6], respectively). The increase in procollagen type 1 N-terminal propeptide (P1NP) and C-telopeptide of type I collagen (CTX-1) were approximately 100% higher after RYGB than after SG (between group difference at 1 year, both P < 0.001). The changes in femoral neck, total hip, and lumbar spine aBMDs and the changes in P1NP and CTX-1 were independently associated with the surgical procedure (all P < 0.05) and not weight change.

CONCLUSIONS

Roux-en-Y gastric bypass was associated with a greater reduction in aBMD and a greater increase in bone turnover markers compared with SG. This finding could suggest greater skeletal fragility after RYGB.

Identifying Persuasive Design Principles and Behavior Change Techniques Supporting End User Values and Needs in eHealth Interventions for Long-Term Weight Loss Maintenance: Qualitative Study

BACKGROUND

An increasing number of eHealth interventions aim to support healthy behaviors that facilitate weight loss. However, there is limited evidence of the effectiveness of the interventions and little focus on weight loss maintenance. Knowledge about end user values and needs is essential to create meaningful and effective eHealth interventions, and to identify persuasive system design (PSD) principles and behavior change techniques (BCTs) that may contribute to the behavior change required for successful long-term weight loss maintenance.

OBJECTIVE

This study aimed to provide insight into the design of eHealth interventions supporting behavior change for long-term weight maintenance. The study sought to identify the values and needs of people with obesity aiming to maintain weight after weight loss, and to identify PSD principles, BCTs, and design requirements that potentially enable an eHealth intervention to meet end user values and needs.

METHODS

This study presents the concept of integrating PSD principles and BCTs into the design process of eHealth interventions to meet user values and needs. In this study, individual interviews and focus groups were conducted with people with obesity (n=23) and other key stakeholders (n=27) to explore end user values and needs related to weight loss maintenance. Design thinking methods were applied during the focus group sessions to identify design elements and to explore how eHealth solutions can support the needs to achieve sustainable weight loss maintenance. The PSD model and behavior change taxonomy by Michie were used to identify PSD principles and BCT clusters to meet end user values and needs.

RESULTS

A total of 8 key end user values were identified, reflecting user needs for weight loss maintenance support: self-management, personalized care, autonomy, feel supported, positive self-image, motivation, happiness, and health. Goals and planning, feedback and monitoring, repetition and substitution, shaping knowledge, social support, identity, and self-belief were some of the BCT clusters identified to address these concepts, together with PSD principles such as personalization, tailoring, self-monitoring, praise, and suggestions.

CONCLUSIONS

The process of translating end user values and needs into design elements or features of eHealth technologies is an important part of the design process. To our knowledge, this is the first study to explore how PSD principles and BCTs can be integrated when designing eHealth self-management interventions for long-term weight loss maintenance. End users and other key stakeholders highlighted important factors to be considered in the design of eHealth interventions supporting sustained behavior change. The PSD principles and BCTs identified provide insights and suggestions about design elements and features to include for supporting weight loss maintenance. The findings indicate that a combination of BCTs and PSD principles may be needed in evidence-based eHealth interventions to stimulate motivation and adherence to support healthy behaviors and sustained weight loss maintenance.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04537988; https://clinicaltrials.gov/ct2/show/NCT04537988.

Laparoscopic gastric bypass versus lifestyle intervention for adolescents with morbid obesity

BACKGROUND

There is limited evidence for the effectiveness of bariatric surgery in adolescents, and the associated complications. The main objective of the 4XL study was to clarify whether laparoscopic Roux-en-Y gastric bypass (LGBP) combined with lifestyle intervention is a safe and effective treatment method.

MATERIAL AND METHOD

Data were retrieved from an ongoing non-randomised intervention study of adolescents with morbid obesity that is comparing the effects of gastric bypass combined with lifestyle intervention versus lifestyle intervention alone.

RESULTS

Altogether 39 patients (64 % girls) treated with a gastric bypass, and 96 patients (57 % girls) treated with lifestyle intervention were examined prior to the start of treatment and one year later. The average age at inclusion (SD) was 16.7 (1.0) years vs. 15.6 (1.3) years, and average BMI was 45.6 (4.4) vs. 43.3 (4.1) kg/m2 in the two groups. Average (95 % CI) percentage weight loss was 30 % (27 %-33 %) after surgery versus weight gain of 1 % (-1 % to 3 %) in the control group. The difference between the groups was 31 % (95 % CI 27 %-34 %, p<0.001). Cardiometabolic risk factors improved only after surgery. After gastric bypass, two early (<6 weeks) minor complications were recorded. One year after surgery, 4 (10 %), 8 (21 %) and 4 (10 %) of patients had anaemia, iron deficiency or low vitamin B12 levels respectively, and 20 of 33 patients (61 %) had low two-hour blood glucose (<2.8 mmol/l) after oral glucose tolerance testing.

INTERPRETATION

The results support previous studies showing that gastric bypass is associated with significant weight loss in adolescent patients with morbid obesity. The 4XL study is currently too small and the follow-up time too short to allow the risk of long-term complications to be assessed.

Patient complaints following bariatric surgery 2012-18

BACKGROUND

We examined complaints submitted to the Norwegian System of Patient Injury Compensation (NPE) following bariatric surgery, including the background for the complaint, the proportion of patients whose complaints were upheld, and the characteristics of complaints that were upheld.

MATERIAL AND METHOD

All complaints relating to bariatric surgery performed in the period 2012-18 were reviewed and categorised according to symptoms, findings and events relevant to the outcome of the complaint. Anonymous summaries from the experts' statements were reviewed and categorised according to year of decision, gender, age, basis for compensation or rejection, and whether the intervention was carried out in the public or private health service.

RESULTS

Forty-four (26 %) of a total of 171 applications for patient injury compensation were upheld. These applications represented 25 patients who had surgery in the public health service (19 % upheld) and 19 patients who were operated on in the private health service (51 % upheld). The single most common reason for a complaint being upheld (n = 18) was lack of indication for bariatric surgery.

INTERPRETATION

More post-bariatric surgery complaints were upheld for lack of indication than for surgical errors. Proper patient selection, good preoperative preparation, good information and shared decision-making are important factors for achieving the best possible bariatric surgery outcome. An interdisciplinary team that monitors patients over time can help ensure the quality of the entire treatment chain.

Correlation of Body Weight and Composition With Hepatic Activities of Cytochrome P450 Enzymes

Obesity is associated with comorbidities of which pharmacological treatment is needed. Physiological changes associated with obesity may influence the pharmacokinetics of drugs, but the effect of body weight on drug metabolism capacity remains uncertain. The aim of this study was to investigate ex vivo activities of hepatic drug metabolizing CYP enzymes in patients covering a wide range of body weight. Liver biopsies from 36 individuals with a body mass index (BMI) ranging from 18 to 63 kg/m² were obtained. Individual hepatic microsomes were prepared and activities of CYP3A, CYP2B6, CYP2C8, CYP2D6, CYP2C9, CYP2C19 and CYP1A2 were determined. The unbound intrinsic clearance (CL_int,u) values for CYP3A correlated negatively with body weight (r = -0.43, p < 0.01), waist circumference (r = -0.47, p < 0.01), hip circumference (r = -0.51, p < 0.01), fat percent (r = -0.41, p < 0.05), fat mass (r = -0.48, p < 0.01) and BMI (r = -0.46, p < 0.01). Linear regression analysis showed that CL_int,u values for CYP3A decreased with 5% with each 10% increase in body weight (r² = 0.12, β = -0.558, p < 0.05). There were no correlations between body weight measures and CL_int,u values for the other CYP enzymes investigated. These results indicate reduced hepatic metabolizing capacity of CYP3A substrates in patients with increasing body weight.

Gastric bypass surgery is associated with reduced subclinical myocardial injury and greater activation of the cardiac natriuretic peptide system than lifestyle intervention

AIMS

Morbid obesity is a risk factor for cardiovascular disease. The relative effects of Roux-en-Y gastric bypass surgery (GBS) and intensive lifestyle intervention (ILI) on subclinical myocardial injury, the activity of the cardiac natriuretic system, and systemic inflammation remain unclear.

METHODS

In a 59-week non-randomized clinical trial that included 131 patients with morbid obesity, we compared the effects ofGBS and ILI on concentrations of cardiac troponin T (cTnT) and I (cTnI), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and C-reactive protein (CRP).

RESULTS

In the GBS and ILI group, median body mass index (BMI) was reduced by 14.4 kg/m² versus 3.9 kg/m², respectively (p value < 0.001). Cardiac troponins decreased after GBS, p = 0.014 (cTnT) and p = 0.065 (cTnI) and increased significantly in those treated with ILI (p values ≤ 0.021) (between-group differences for deltas: p ≤ 0.003). NT-proBNP increased in both groups, but significantly more in the GBS than in the ILI group (between-group differences for deltas: p = 0.008). CRP decreased significantly within the GBS and the ILI group, with this change significantly greater in the GBS group (between-group differences for deltas p < 0.001). The dominating mediator of the biomarker changes was weight loss. Prior coronary artery disease and diabetes were predictive of the magnitude of the changes in cTnI and NT-proBNP, respectively.

CONCLUSION

Compared to ILI, GBS was associated with reduced subclinical myocardial injury and systemic inflammation, and enhancement of the cardiac natriuretic peptide system. The biomarker changes were predominantly mediated by weight loss.

Lifestyle intervention for children and adolescents with severe obesity - results after one year

BACKGROUND

Lifestyle interventions for children and adolescents with severe obesity show moderate short-term effects on weight reduction internationally. We evaluated treatment results at two Norwegian specialist outpatient clinics.

MATERIAL AND METHOD

We performed a retrospective analysis of data from children and adolescents between 3 and 18 years of age collected in 2012-2016. Children and adolescents with severe obesity who attended their one-year follow-up were included. We included in the analyses the following body weight measures: percentage overweight as defined by the International Obesity Task Force cut-off (% IOTF-25); BMI standard deviation score; waist circumference standard deviation score; and body fat percentage at the start of treatment and at one-year follow-up.

RESULTS

Of 568 children and adolescents who started treatment, 416 (73 %) attended the one-year check-up. A total of 271 (65 %) patients achieved a reduction in %IOTF-25, while 228 patients (55 %) reduced their BMI standard deviation score. There was a statistically significant mean reduction of all four registered body weight measurements. Altogether 54 of 325 children (17 %) changed category from severe obesity to obesity, 8 (2 %) went from severe obesity to overweight, and 8 of 91 children (9 %) changed category from obesity to overweight or normal weight. The proportion of participants with a reduction of more than 5 % in %IOTF-25 was 43 % (177/416), and a reduction in BMI standard deviation score of more than 0.25 was observed in 23 % (95/416) of participants. Girls responded on average more poorly to the intervention than boys. There was no clinically significant difference in results between the treatment centres.

INTERPRETATION

After one year of treatment of children and adolescents with severe obesity in two specialist healthcare centres, we found a moderate mean reduction in weight, waist circumference and body fat percentage, but with large interindividual variation.

Bone Turnover Markers After Standard and Distal Roux-en-Y Gastric Bypass: Results from a Randomized Controlled Trial

BACKGROUND

Roux-en-Y gastric bypass is associated with increased risk of bone fractures. Malabsorptive procedures may be associated with secondary hyperparathyroidism and detrimental effects on bone health. We aimed to compare the effects of standard and distal gastric bypass on bone turnover markers 2 years after surgery.

METHODS

Patients with body mass index (BMI) 50-60 kg/m² (n = 113) were randomized to standard or distal gastric bypass, 105 patients (95%) completed 2-year follow-up. Serum C-terminal telopeptide of type I collagen (CTX-1), procollagen type I N-propeptide (PINP), and bone-derived alkaline phosphatase (BALP) was measured at baseline and up to 2 years after surgery. ANCOVA and linear mixed models were used to compare groups.

RESULTS

The levels of bone turnover markers increased significantly in both groups, with no statistically significant difference between groups. Two years after standard and distal gastric bypass mean (SD) CTX-1 were 0.81 (0.32) and 0.83 (0.31) μg/L (p = 0.38), mean PINP was 77.6 (23.2) and 77.7 (29.3) μg/L (p = 0.42), and BALP 47.9 (21.9) vs. 50.7 (19.6) μg/L (p = 0.38), respectively. Multiple linear regression analyses showed that PINP and BALP correlated positively (p = 0.01 and p < 0.001) with PTH, but only BALP was significantly higher in patients with secondary hyperparathyroidism (p = 0.001). Type of surgery, vitamin D serum concentrations, and 2-year BMI were all independently associated with PTH levels.

CONCLUSION

A comparable increase in bone turnover markers 2 years after standard and distal gastric bypass was observed. There was a higher prevalence of secondary hyperparathyroidism after distal gastric bypass, but this did not impact bone turnover markers.

TRIAL REGISTRATION

Clinical Trials.gov number NCT00821197.

Global variability analysis of mRNA and protein concentrations across and within human tissues

Genes and proteins show variable expression patterns throughout the human body. However, it is not clear whether relative differences in mRNA concentrations are retained on the protein level. Furthermore, inter-individual protein concentration variability within single tissue types has not been comprehensively explored. Here, we used the Gini index for in-depth concentration variability analysis of publicly available transcriptomics and proteomics data, and of an in-house proteomics dataset of human liver and jejunum from 38 donors. We found that the transfer of concentration variability from mRNA to protein is limited, that established 'reference genes' for data normalization vary markedly at the protein level, that protein concentrations cover a wide variability spectrum within single tissue types, and that concentration variability analysis can be a convenient starting point for identifying disease-associated proteins and novel biomarkers. Our results emphasize the importance of considering individual concentration levels, as opposed to population averages, for personalized systems biology analysis.

Monitoring children and adolescents with severe obesity: body mass index (BMI), BMI z-score or percentage above the International Obesity Task Force overweight cut-off?

AIM

Body mass index (BMI) metrics are widely used as a proxy for adiposity in children with severe obesity. The BMI expressed as the percentage of a cut-off percentile for overweight or obesity has been proposed as a better alternative than BMI z-scores when monitoring children and adolescents with severe obesity.

METHODS

Annual changes in BMI, BMI z-score and the percentage above the International Obesity Task Force overweight cut-off (%IOTF-25) were compared with dual-energy X-ray absorptiometry (DXA) derived body fat (%BF-DXA) in 59 children and adolescents with severe obesity.

RESULTS

The change in %BF-DXA was correlated with the change in %IOTF-25 (r = 0.68) and BMI (r = 0.70), and somewhat less with the BMI z-score (r = 0.57). Cohen's Kappa statistic to detect an increase or decrease in %BF-DXA was fair for %IOTF-25 (κ = 0.25; p = 0.04) and BMI (κ = 0.33; p = 0.01), but not for the BMI z-score (κ = 0.08; p = 0.5). The change in BMI was positively biased due to a natural increase with age.

CONCLUSION

Changes in the BMI metrics included in the study are associated differently with changes in %BF-DXA. The BMI z-score is widely used to monitor changes in adiposity in children and adolescents with severe obesity, but the %IOTF-25 might be a better alternative.

Gastric bypass versus sleeve gastrectomy in patients with type 2 diabetes (Oseberg): a single-centre, triple-blind, randomised controlled trial

BACKGROUND

For patients with obesity and type 2 diabetes, weight loss improves insulin sensitivity and β-cell function, and can induce remission of diabetes. The comparative efficacy of various bariatric procedures for the remission of type 2 diabetes has not been fully elucidated. We aimed to compare the effects of the two most common bariatric procedures, gastric bypass and sleeve gastrectomy, on remission of diabetes and β-cell function.

METHODS

We conducted a single-centre, triple-blind, randomised trial at Vestfold Hospital Trust (Tønsberg, Norway), in which patients (aged ≥18 years) with type 2 diabetes and obesity were randomly assigned (1:1) to receive gastric bypass or sleeve gastrectomy (the Oseberg study). Randomisation was performed with a computerised random number generator and a block size of 10. Treatment allocation was masked from participants, study personnel, and outcome assessors and was concealed with sealed opaque envelopes. Surgeons used identical skin incisions during both surgeries and were not involved in patient follow-up. The primary clinical outcome was the proportion of participants with complete remission of type 2 diabetes (HbA_1c of ≤6·0% [42 mmol/mol] without the use of glucose-lowering medication) at 1 year after surgery. The primary physiological outcome was disposition index (a measure of β-cell function) at 1 year after surgery, as assessed by an intravenous glucose tolerance test. Primary outcomes were analysed in the intention-to-treat and per-protocol populations. This trial is ongoing and closed to recruitment, and is registered with ClinicalTrials.gov, NCT01778738.

FINDINGS

Between Oct 15, 2012, and Sept 1, 2017, 1305 patients who were preparing for bariatric surgery were screened, of whom 319 consecutive patients with type 2 diabetes were assessed for eligibility. 109 patients were enrolled and randomly assigned to gastric bypass (n=54) or sleeve gastrectomy (n=55). 107 (98%) of 109 patients completed 1-year follow-up, with one patient in each group withdrawing after surgery (per-protocol population). In the intention-to-treat population, diabetes remission rates were higher in the gastric bypass group than in the sleeve gastrectomy group (risk difference 27% [95% CI 10 to 44]; relative risk [RR] 1·57 [1·14 to 2·16], p=0·0054); results were similar in the per-protocol population (risk difference 27% [95% CI 10 to 45]; RR 1·57 [1·14 to 2·15], p=0·0036). In the intention-to-treat population, disposition index increased in both groups (between-group difference 55 [-111 to 220], p=0·52); results were similar in the per-protocol population (between-group difference 21 [-214 to 256], p=0.86). In the gastric bypass group, ten of 54 participants had early complications and 17 of 53 had late side-effects. In the sleeve gastrectomy group, eight of 55 participants had early complications and 22 of 54 had late side-effects. No deaths occurred in either group.

INTERPRETATION

Gastric bypass was found to be superior to sleeve gastrectomy for remission of type 2 diabetes at 1 year after surgery, and the two procedures had a similar beneficial effect on β-cell function. The use of gastric bypass as the preferred bariatric procedure for patients with obesity and type 2 diabetes could improve diabetes care and reduce related societal costs.

FUNDING

Morbid Obesity Centre, Vestfold Hospital Trust.

Obesity Management Task Force of the European Association for the Study of Obesity Released "Practical Recommendations for the Post-Bariatric Surgery Medical Management"

Bariatric patients may face specific clinical problems after surgery, and multidisciplinary long-term follow-up is usually provided in specialized centers. However, physicians, obstetricians, dieticians, nurses, clinical pharmacists, midwives, and physical therapists not specifically trained in bariatric medicine may encounter post-bariatric patients with specific problems in their professional activity. This creates a growing need for dissemination of first level knowledge in the management of bariatric patients. Therefore, the Obesity Management Task Force (OMTF) of the European Association for the Study of Obesity (EASO) decided to produce and disseminate a document containing practical recommendations for the management of post-bariatric patients. The list of practical recommendations included in the EASO/OMTF document is reported in this brief communication.

Associations between cardiorespiratory fitness and weight loss in patients with severe obesity undergoing an intensive lifestyle intervention program: retrospective cohort study

BACKGROUND

To assess the association between cardiorespiratory fitness (CRF) and weight changes in treatment seeking patients with severe obesity who underwent a 1-year intensive lifestyle intervention (ILI) program.

METHODS

Retrospective cohort study conducted at a tertiary care outpatient rehabilitation center from November 1, 2013 through January 1, 2017. CRF was measured as maximal oxygen consumption during a maximal oxygen uptake (VO_2max) test on a treadmill or bicycle at baseline and after 3 months.

RESULTS

A total of 180 patients had a baseline mean (SD) BMI 41.1 (4.8) kg/m² and CRF of 79.4 (14.9) mL·kg^-0.75·min^- 1. Patients with a baseline CRF above median achieved a greater 3-month and 1-year weight loss compared with patients with CRF below median; mean (95% CI) 2.5 kg (1.3, 3.8) and 4.0 kg (0.8, 7.2), respectively. In addition, patients with 3-month changes of CRF above median had 4.0 kg (0.9, 7.1) greater weight loss at 1-year follow-up than those below median.

CONCLUSIONS

Among patients with severe obesity who underwent a 1-year ILI program, higher baseline CRF was associated with significantly larger weight loss after 3 months and 1 year. In addition, those with higher initial 3-month CRF changes had greater weight loss at 1 year.

TRIAL REGISTRATION

Retrospectively registered in Regional Committees for Medical and Health Research Ethics (REC) south east September 22, 2016 (2016/1414) and clinicaltials.gov August 13, 2018 (identifier: NCT03593798 ).