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.

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.

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.

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.

Women's Reasons to Seek Bariatric Surgery and Their Expectations on the Surgery Outcome - a Multicenter Study from Five European Countries

Purpose

Understanding patients’ reasons for having bariatric surgery and their expectation on surgery outcomes is important to provide the best clinical practice and reduce unrealistic expectations. It is unknown if reasons and expectations differ between countries. We aimed to investigate the reasons for seeking bariatric surgery and expectations of surgical outcomes among patients in five European countries.

Methods

In total, 250 women accepted for bariatric surgery were recruited: 50 women each from Finland, Germany, Norway, Sweden, and the Netherlands. Participants ranked 14 reasons for seeking surgery, and reported the three primary reasons. They also reported expectations on weight loss and impact of surgery vs. lifestyle on weight loss outcomes.

Results

Mean age and body mass index were 42.9 ± 11.5 years and 45.1 ± 6.2 kg/m², respectively. Weight loss and improved co-morbidity were ranked as the most important reasons. Participants expected to lose between 70.8 and 94.3% of their excessive weight. The expected impact of surgery as a driver of weight loss was higher in Germany and the Netherlands compared to in Finland, Norway, and Sweden where participants expected lifestyle changes to also have an impact.

Conclusion

Weight loss and improved co-morbidities were the main reasons for undergoing bariatric surgery. Expectations on weight loss were generally very high, but expectations of surgery vs. lifestyle as the main driver of weight loss differed between countries. While some patients understand the importance of lifestyle change and maintenance of a healthy lifestyle after surgery in order to obtain a successful weight loss, other may need additional counselling.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-022-06280-w.

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.

Short- and long-term effects of body weight, calorie restriction, and gastric bypass on CYP1A2-, CYP2C19-, and CYP2C9 activity

Aim

Roux‐en‐Y gastric bypass (RYGB) may influence drug disposition due to surgery‐induced gastrointestinal alterations and/or subsequent weight loss. The objective was to compare short‐ and long‐term effects of RYGB and diet on the metabolic ratios of paraxanthine/caffeine (cytochrome P450 [CYP] 1A2 activity), 5‐hydroxyomeprazole/omeprazole (CYP2C19 activity) and losartan/losartan carboxylic acid (CYP2C9 activity), and cross‐sectionally compare these CYP‐activities with normal‐to‐overweight controls.

Methods

This trial included patients with severe obesity preparing for RYGB (n = 40) or diet‐induced (n = 41) weight loss, and controls (n = 18). Both weight loss groups underwent a 3‐week low‐energy diet (<1200 kcal/day, weeks 0‐3) followed by a 6‐week very‐low‐energy diet or RYGB (both <800 kcal/day, weeks 3‐9). Follow‐up time was 2 years, with four pharmacokinetic investigations.

Results

Mean ± SD weight loss from baseline was similar in the RYGB‐group (13 ± 2.4%) and the diet group (10.5 ± 3.9%) at week 9, but differed at year 2 (RYGB −30 ± 6.9%, diet −3.1 ± 6.3%). From weeks 0 to 3, mean (95% confidence interval [CI]) CYP2C19 activity similarly increased in both groups (RYGB 43% [16, 55], diet 48% [22, 60]). Mean CYP2C19 activity increased by 30% (2.6, 43) after RYGB (weeks 3‐9), but not in the diet‐group (between‐group difference −0.30 [−0.63, 0.03]). CYP2C19 activity remained elevated in the RYGB group at year 2. Baseline CYP2C19 activity was 2.7‐fold higher in controls compared with patients with obesity, whereas no difference was observed in CYP1A2 and CYP2C9 activities.

Conclusion

Our findings suggest that CYP2C19 activity is lower in patients with obesity and increases following weight loss. This may be clinically relevant for drug dosing. No clinically significant effect on CYP1A2 and CYP2C9 activities was observed.

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.

Short- and long-term effects of body weight loss following calorie restriction and gastric bypass on CYP3A-activity - a non-randomized three-armed controlled trial

It remains uncertain whether pharmacokinetic changes following Roux-en-Y gastric bypass (RYGB) can be attributed to surgery-induced gastrointestinal alterations per se and/or the subsequent weight loss. The aim was to compare short- and long-term effects of RYGB and calorie restriction on CYP3A-activity, and cross-sectionally compare CYP3A-activity with normal weight to overweight controls using midazolam as probe drug. This three-armed controlled trial included patients with severe obesity preparing for RYGB (n = 41) or diet-induced (n = 41) weight-loss, and controls (n = 18). Both weight-loss groups underwent a 3-week low-energy-diet (<1200 kcal/day) followed by a 6-week very-low-energy-diet or RYGB (both <800 kcal/day). Patients were followed for 2 years, with four pharmacokinetic investigations using semisimultaneous oral and intravenous dosing to determine changes in midazolam absolute bioavailability and clearance, within and between groups. The RYGB and diet groups showed similar weight-loss at week 9 (13 ± 2.4% vs. 11 ± 3.6%), but differed substantially after 2 years (-30 ± 7.0% vs. -3.1 ± 6.3%). At baseline, mean absolute bioavailability and clearance of midazolam were similar in the RYGB and diet groups, but higher compared with controls. On average, absolute bioavailability was unaltered at week 9, but decreased by 40 ± 7.5% in the RYGB group and 32 ± 6.1% in the diet group at year 2 compared with baseline, with no between-group difference. No difference in clearance was observed over time, nor between groups. In conclusion, neither RYGB per se nor weight loss impacted absolute bioavailability or clearance of midazolam short term. Long term, absolute bioavailability was similarly decreased in both groups despite different weight loss, suggesting that the recovered CYP3A-activity is not only dependent on weight-loss through RYGB.

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.

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.

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.

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.

The influence of bariatric surgery on oral drug bioavailability in patients with obesity: A systematic review

Anatomical changes in the gastrointestinal tract and subsequent weight loss may influence drug disposition and thus drug dosing following bariatric surgery. This review systematically examines the effects of bariatric surgery on drug pharmacokinetics, focusing especially on the mechanisms involved in restricting oral bioavailability. Studies with a longitudinal before-after design investigating the pharmacokinetics of at least one drug were reviewed. The need for dose adjustment following bariatric surgery was examined, as well as the potential for extrapolation to other drugs subjected to coinciding pharmacokinetic mechanisms. A total of 22 original articles and 32 different drugs were assessed. The majority of available data is based on Roux-en-Y gastric bypass (RYGBP) (18 of 22 studies), and hence, the overall interpretation is more or less limited to RYGBP. In the case of the majority of studied drugs, an increased absorption rate was observed early after RYGBP. The effect on systemic exposure allows for a low degree of extrapolation, including between drugs subjected to the same major metabolic and transporter pathways. On the basis of current understanding, predicting the pharmacokinetic change for a specific drug following RYGBP is challenging. Close monitoring of each individual drug is therefore recommended in the early postsurgical phase. Future studies should focus on the long-term effects of bariatric surgery on drug disposition, and they should also aim to disentangle the effects of the surgery itself and the subsequent weight loss.

Single-centre, triple-blinded, randomised, 1-year, parallel-group, superiority study to compare the effects of Roux-en-Y gastric bypass and sleeve gastrectomy on remission of type 2 diabetes and β-cell function in subjects with morbid obesity: a protocol for the Obesity surgery in Tønsberg (Oseberg) study

INTRODUCTION

Bariatric surgery is increasingly recognised as an effective treatment option for subjects with type 2 diabetes and obesity; however, there is no conclusive evidence on the superiority of Roux-en-Y gastric bypass or sleeve gastrectomy. The Oseberg study was designed to compare the effects of gastric bypass and sleeve gastrectomy on remission of type 2 diabetes and β-cell function.

METHODS AND ANALYSIS

Single-centre, randomised, triple-blinded, two-armed superiority trial carried out at the Morbid Obesity Centre at Vestfold Hospital Trust in Norway. Eligible patients with type 2 diabetes and obesity were randomly allocated in a 1:1 ratio to either gastric bypass or sleeve gastrectomy. The primary outcome measures are (1) the proportion of participants with complete remission of type 2 diabetes (HbA1c≤6.0% in the absence of blood glucose-lowering pharmacologic therapy) and (2) β-cell function expressed by the disposition index (calculated using the frequently sampled intravenous glucose tolerance test with minimal model analysis) 1 year after surgery.

ETHICS AND DISSEMINATION

The protocol of the current study was reviewed and approved by the regional ethics committee on 12 September 2012 (ref: 2012/1427/REK sør-øst B). The results will be disseminated to academic and health professional audiences and the public via publications in international peer-reviewed journals and conferences. Participants will receive a summary of the main findings.

TRIAL REGISTRATION NUMBER

NCT01778738;Pre-results.

Patient-Reported Outcome Measures 2 Years After Standard and Distal Gastric Bypass-a Double-Blind Randomized Controlled Trial

BACKGROUND

The preferred surgical procedure for treating morbid obesity is debated. Patient-reported outcome measures (PROMs) are relevant for evaluation of the optimal bariatric procedure.

METHODS

A total of 113 patients with BMI from 50 to 60 were randomly assigned to standard (n = 57) or distal (n = 56) Roux-en-Y gastric bypass (RYGB). Validated PROMS questionnaires were completed at baseline and 2 years after surgery. Data were analyzed using mixed models for repeated measures and the results are expressed as estimated means and mean changes.

RESULTS

Obesity-related quality of life improved significantly after both procedures, without significant between-group differences (- 0.4 (95% CI = - 8.4, 7.2) points, p = 0.88, ES = 0.06). Both groups had significant reductions in the number of weight-related symptoms and symptom distress score, with a mean group difference (95% CI) of 1.4 (- 0.3, 3.3) symptoms and 5.0 (2.9. 12.8) symptom distress score points. There were no between-group differences for uncontrolled eating (22.0 (17.2-26.7) vs. 28.9 (23.3-34.5) points), cognitive restraint (57.4 (52.0-62.7) vs. 62.1 (57.9-66.2) points), and emotional eating (26.8 (20.5-33.1) vs. 32.6 (25.5-39.7) points). The prevalence of anxiety was 33% after standard and 25% after distal RYGB (p = 0.53), and for depression 12 and 9%, respectively (p = 0.76).

CONCLUSIONS

There were no statistically significant differences between standard and distal RYGB 2 years post surgery regarding weight loss, obesity-related quality of life, weight-related symptoms, anxiety, depression, or eating behavior.

TRIAL REGISTRATION

Clinical Trials.gov number NCT00821197.

Impact of body weight, low energy diet and gastric bypass on drug bioavailability, cardiovascular risk factors and metabolic biomarkers: protocol for an open, non-randomised, three-armed single centre study (COCKTAIL)

INTRODUCTION

Roux-en-Y gastric bypass (GBP) is associated with changes in cardiometabolic risk factors and bioavailability of drugs, but whether these changes are induced by calorie restriction, the weight loss or surgery per se, remains uncertain. The COCKTAIL study was designed to disentangle the short-term (6 weeks) metabolic and pharmacokinetic effects of GBP and a very low energy diet (VLED) by inducing a similar weight loss in the two groups.

METHODS AND ANALYSIS

This open, non-randomised, three-armed, single-centre study is performed at a tertiary care centre in Norway. It aims to compare the short-term (6 weeks) and long-term (2 years) effects of GBP and VLED on, first, bioavailability and pharmacokinetics (24 hours) of probe drugs and biomarkers and, second, their effects on metabolism, cardiometabolic risk factors and biomarkers. The primary outcomes will be measured as changes in: (1) all six probe drugs by absolute bioavailability area under the curve (AUC_oral/AUC_iv) of midazolam (CYP3A4 probe), systemic exposure (AUC_oral) of digoxin and rosuvastatin and drug:metabolite ratios for omeprazole, losartan and caffeine, levels of endogenous CYP3A biomarkers and genotypic variation, changes in the expression and activity data of the drug-metabolising, drug transport and drug regulatory proteins in biopsies from various organs and (2) body composition, cardiometabolic risk factors and metabolic biomarkers.

ETHICS AND DISSEMINATION

The COCKTAIL protocol was reviewed and approved by the Regional Committee for Medical and Health Research Ethics (Ref: 2013/2379/REK sørøst A). The results will be disseminated to academic and health professional audiences and the public via presentations at conferences, publications in peer-reviewed journals and press releases and provided to all participants.

TRIAL REGISTRATION NUMBER

NCT02386917.

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

IMPORTANCE

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

OBJECTIVE

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

DESIGN, SETTING, AND PARTICIPANTS

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

EXPOSURES

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

Standard vs Distal Roux-en-Y Gastric Bypass in Patients With Body Mass Index 50 to 60: A Double-blind, Randomized Clinical Trial

Importance

Up to one-third of patients undergoing bariatric surgery have a body mass index (BMI) of more than 50. Following standard gastric bypass, many of these patients still have a BMI greater than 40 after peak weight loss.

Objective

To assess the efficacy and safety of standard gastric bypass vs distal gastric bypass in patients with a BMI of 50 to 60.

Design, Setting, and Participants

Double-blind, randomized clinical parallel-group trial at 2 tertiary care centers in Norway (Oslo University Hospital and Vestfold Hospital Trust) between May 2011 and April 2013. The study included 113 patients with a BMI of 50 to 60 aged 20 to 60 years. The 2-year follow-up was completed in May 2015.

Interventions

Standard gastric bypass (alimentary limb, 150 cm) and distal gastric bypass (common channel, 150 cm), both with a biliopancreatic limb of 50 cm and a gastric pouch of about 25 mL.

Main Outcomes and Measures

Primary outcome was the change in BMI from baseline until 2 years after surgery. Secondary outcomes were cardiometabolic risk factors, nutritional outcomes, adverse events, gastrointestinal symptoms, and health-related quality of life.

Results

At baseline, the mean age of the patients was 40 years (95% CI, 38-41 years), 65% were women, mean BMI was 53.5 (95% CI, 52.9-54.0), and mean weight was 158.8 kg (95% CI, 155.3-162.3 kg). The mean reduction in BMI was 17.8 (95% CI, 16.9-18.6) after standard gastric bypass and 17.2 (95% CI, 16.3-18.0) after distal gastric bypass, and the mean between-group difference was 0.6 (95% CI, -0.6 to 1.8; P = .32). Reductions in mean levels of total and low-density lipoprotein cholesterol were greater after distal gastric bypass than standard gastric bypass, and between-group differences were 19 mg/dL (95% CI, 11-27 mg/dL ) and 28 mg/dL (95% CI, 21 to 34 mg/dL), respectively (P < .001 for both). Reductions in fasting glucose levels and hemoglobin A1c were greater after distal gastric bypass. Secondary hyperparathyroidism and loose stools were more frequent after distal gastric bypass. The number of adverse events and changes in health-related quality of life did not differ between the groups. Importantly, 1 patient developed liver failure and 2 patients developed protein-caloric malnutrition treated by elongation of the common channel following distal gastric bypass.

Conclusions and Relevance

Distal gastric bypass was not associated with a greater BMI reduction than standard gastric bypass 2 years after surgery. However, we observed different changes in cardiometabolic risk factors and nutritional markers between the groups.

Trial Registration

Clinicaltrials.gov Identifier: NCT00821197.

The association between severity of King's Obesity Staging Criteria scores and treatment choice in patients with morbid obesity: a retrospective cohort study

Background

The King’s Obesity Staging Criteria (KOSC) comprises of a four-graded set of health related domains. We aimed to examine whether, according to KOSC, patients undergoing bariatric surgery differed from those opting for conservative treatment.

Methods

We graded 2142 consecutive patients with morbid obesity attending our centre from 2005-10 into the following KOSC domains: airway/apnoea, body mass index (BMI), cardiovascular risk (CV-risk), diabetes mellitus, economic complications, functional limitations, gonadal dysfunction, and perceived health status/body image. Both patients and physicians agreed upon treatment choice through a shared decision making process.

Results

A total of 1329 (62%) patients opted for lifestyle intervention and 813 (37%) for bariatric surgery as their first treatment choice. The patients treated with bariatric surgery were younger (42 vs. 44 years, p < 0.001), had a higher BMI (45.4 vs. 43.8 kg/m², p < 0.001) and had a lower ten year estimated CV-risk (9.4 vs. 10.7%, p = 0.004) than the lifestyle intervention group. Compared with having BMI < 40 kg/m², BMI ≥ 40 kg/m² was associated with 85% increased odds of bariatric surgery (OR 1.85 [95% CI 1.48, 2.30]). Conversely, patients with ≥20% ten year CV-risk, had lower odds of bariatric surgery than patients with <20% CV-risk (0.68 [0.53, 0.87]).

Conclusion

BMI was the strongest KOSC-domain associated with subsequent bariatric surgery after a shared decision making process. Prospective studies are required to assess whether the use of KOSC can help guide patients and clinicians to identify the most appropriate choice of treatment for morbid obesity.

Bone resorption following weight loss surgery is associated with treatment procedure and changes in secreted Wnt antagonists

To assess if altered bone turnover following bariatric surgery is related to metabolic consequences of the surgical procedure or weight loss. We evaluated serum markers reflecting bone turnover and metabolic pathways at baseline and after 1-year in a controlled non-randomized clinical trial comparing Roux-en-Y gastric bypass surgery (n = 74) with lifestyle intervention (n = 63) on obesity-related comorbidities. The decrease in body mass index (BMI) was larger in the surgery (-14.0 kg/m(2)) compared to lifestyle (-3.7 kg/m(2)). Markedly increased bone turnover was observed following surgery compared to lifestyle intervention and was correlated with change in BMI. Stepwise multivariable regression analysis revealed that group (β = 0.31, p < 0.01), and changes in BMI (β = -0.28, p < 0.01), dickkopf-1 (β = 0.20, p < 0.001) and sclerostin (β = 0.11, p < 0.05) were predictors of change in the bone resorption marker N-terminal telopeptide. Our data support that mechanisms related to the procedure itself and changes in secreted Wnt antagonists may contribute to increased bone turnover following bariatric surgery.

Plastic surgery after bariatric surgery

BACKGROUND

Massive weight loss after bariatric surgery often results in excess skin, which can lead to stigma due to appearance and pronounced physical and psychological impairments. This review considers the evidence base for post-bariatric plastic surgery and the treatment options that are available.

METHOD

The article is based on a literature search in PubMed with the keywords «bariatric surgery» AND «plastic surgery», in addition to the authors' experience with a large number of patients.

RESULTS

Body contouring surgery after massive weight loss is offered primarily for the treatment of troublesome skin conditions. The surgery can help to improve quality of life and functional status. However, there is little scientific evidence regarding indications for surgery, choice of surgical techniques and risk of complications, and the surgeon's own opinions and clinical experience often play a major role. Many plastic surgeons limit body contouring surgery to those with BMI < 28 kg/m². However, most patients who have undergone bariatric surgery have BMI ≥ 30 kg/m², and requests for body contouring surgery for these individuals are often denied, except when there are compelling medical grounds.

INTERPRETATION

Plastic surgery can lead to improved functioning and increased quality of life. The evidence base with respect to indications, treatment methods and outcomes should be strengthened through well-planned prospective studies and a patient registry. There is a particular need for documentation of treatment outcomes in the large group of patients with BMI ≥ 30 kg/m².

Gastric bypass surgery has a weight-loss independent effect on post-challenge serum glucose levels

BACKGROUND

Gastric bypass surgery seems to have an effect on glucose metabolism beyond what is mediated through weight reduction. The magnitude of this effect on fasting and post-challenge glucose levels remains unknown.

RESULTS

Morbidly obese subjects without known diabetes performed a 75 g oral glucose tolerance test before and after either gastric bypass surgery (n = 64) or an intensive lifestyle intervention programme (n = 55), ClinicalTrials.gov identifier NCT00273104. The age-adjusted effects of the therapeutic procedures and percentage weight change on fasting and 2-h glucose levels at 1 year were explored using multiple linear regression analysis. Mean (SD) serum fasting and 2-h glucose levels at baseline did not differ between the surgery and lifestyle groups. Weight-loss after surgical treatment and lifestyle intervention was 30 (8) and 9 (10) % (p < 0.001). At 1 year, fasting and 2-h glucose levels were significantly lower in the surgery group than in the lifestyle group, 4.7 (0.4) versus 5.4 (0.7) mmol/l and 3.4 (0.8) versus 6.0 (2.4) mmol/l, respectively (both p < 0.001). Gastric bypass and weight-loss had both independent glucose-lowering effects on 2-h glucose levels [B (95 % CI) 1.4 (0.6-2.3) mmol/l and 0.4 (0.1-0.7) mmol/l per 10 % weight-loss, respectively]. Fasting glucose levels were determined by weight change [0.2 (0.1-0.3) mmol/l per 10 % weight-loss] and not by type of treatment.

CONCLUSIONS

Gastric bypass surgery has a clinically relevant glucose-lowering effect on post-challenge glucose levels which is seemingly not mediated through weight-loss alone.

Effects of intensive lifestyle intervention and gastric bypass on aortic stiffness: a 1-year nonrandomized clinical study

OBJECTIVE

To compare the long-term effects of Roux-en-Y gastric bypass (GBS) and intensive lifestyle intervention (ILI) on aortic stiffness.

METHODS

Nonrandomized clinical trial. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (cf PWV) using high-fidelity applanation tonometry.

RESULTS

A total of 159 treatment-seeking morbidly obese patients were included, 82 (54 females) in the GBS-group and 77 (48 females) in the ILI-group. Participants in the GBS-group were younger (42.0 ± 9.9 vs. 46.4 ± 10.5 years), heavier (BMI 45.7 ± 5.3 vs. 42.0 ± 4.9 kg/m(2) ), and had lower systolic pressure (137 ± 19 vs. 145 ± 18 mm Hg) and pulse pressure (57 ± 16 vs. 65 ± 17 mm Hg), all P ≤ 0.006. Mean (SD) cf PWV at baseline was 8.6 ± 1.7 m/s in the GBS-group and 8.6 ± 1.9 m/s in the ILI-group, P = 0.959. At follow-up, mean (95% CI) weight loss was larger in the GBS-group than in the ILI-group -43.3 (-46.0 to -40.7) vs. -12.1 (-14.6 to -9.6) kg, P < 0.001. The mean change in cf PWV was -0.02 (-0.31 to 0.27) m/s in the GBS-group and 0.03 (-0.28 to 0.33) m/s in the ILI-group, both P ≥ 0.412; adjusted between-group difference (ANCOVA) 0.05 (-0.40 to 0.49) m/s, P = 0.836. The adjusted regression analysis showed that weight loss was associated with increased cf PWV in the GBS-group.

CONCLUSIONS

GBS and ILI had no significant long-term effects on aortic stiffness in treatment-seeking morbidly obese individuals.

Patient expectations of bariatric surgery are gender specific--a prospective, multicenter cohort study

BACKGROUND

The effect of bariatric surgery on weight loss and improvement of co-morbidities is no longer doubted. However, little attention has been given to the treatment goals from the patient's point of view (patient expectations). The objective of this study was to examine patients' expectations of bariatric surgery and identify gender differences.

METHODS

Bariatric patients were asked to complete a questionnaire. Statistical analysis was performed using chi-square, Pearson correlation coefficient, and Wilcoxon rank sum test.

RESULTS

Overall, 248 patients participated in this study (69.4% females). The male patients (45.2 yr, SD±11.1) were significantly older than the female (41.8 yr, SD±12.0; P = .04) and suffered significantly more often from diabetes, hypertension, hypercholesterolemia, and sleep apnea. One hundred thirty patients (52.4%) expected to lose at least 45 kg and 39 patients (15.7%)>70 kg. The mean expected excess weight loss was 71.8%. Females expected significantly more often that surgery alone would induce weight loss (P = .03). "Improved co-morbidity" was by far the highest ranked parameter.

CONCLUSION

The male bariatric surgery patients were older and suffered from more co-morbidities. Most of the patients had unrealistic weight loss goals and overestimated the effect of the surgical intervention. However, for both female and male patients, "improved co-morbidity" was the most important issue.

Obstructive sleep apnea after weight loss: a clinical trial comparing gastric bypass and intensive lifestyle intervention

INTRODUCTION

Few studies have compared the effect of surgical and conservative weight loss strategies on obstructive sleep apnea (OSA). We hypothesized that Roux-en-Y gastric bypass (RYGB) would be more effective than intensive lifestyle intervention (ILI) at reducing the prevalence and severity of OSA (apnea-hypopnea-index [AHI] ≥ 5 events/hour).

METHODS

A total of 133 morbidly obese subjects (93 females) were treated with either a 1-year ILI-program (n = 59) or RYGB (n = 74) and underwent repeated sleep recordings with a portable somnograph (Embletta).

RESULTS

Participants had a mean (SD) age of 44.7(10.8) years, BMI 45.1(5.7) kg/m(2), and AHI 17.1(21.4) events/hour. Eighty-four patients (63%) had OSA. The average weight loss was 8% in the ILI-group and 30% in the RYGB-group (p < 0.001). The mean (95%CI) AHI reduced in both treatment groups, although significantly more in the RYGB-group (AHI change -6.0 [ILI] vs -13.1 [RYGB]), between group difference 7.2 (1.3, 13.0), p = 0.017. Twenty-nine RYGB-patients (66%) had remission of OSA, compared to 16 ILI-patients (40%), p = 0.028. At follow-up, after adjusting for age, gender, and baseline AHI, the RYGB-patients had significantly lower adjusted odds for OSA than the ILI-patients-OR (95% CI) 0.33 (0.14, 0.81), p = 0.015. After further adjustment for BMI change, treatment group difference was no longer statistically significant-OR (95% CI) 1.31 (0.32, 5.35), p = 0.709.

CONCLUSION

Our study demonstrates that RYGB was more effective than ILI at reducing the prevalence and severity of OSA. However, our analysis also suggests that weight loss, rather than the surgical procedure per se, explains the beneficial effects.

Health related quality of life after gastric bypass or intensive lifestyle intervention: a controlled clinical study

Background

There is little robust evidence relating to changes in health related quality of life (HRQL) in morbidly obese patients following a multidisciplinary non-surgical weight loss program or laparoscopic Roux-en-Y Gastric Bypass (RYGB). The aim of the present study was to describe and compare changes in five dimensions of HRQL in morbidly obese subjects. In addition, we wanted to assess the clinical relevance of the changes in HRQL between and within these two groups after one year. We hypothesized that RYGB would be associated with larger improvements in HRQL than a part residential intensive lifestyle-intervention program (ILI) with morbidly obese subjects.

Methods

A total of 139 morbidly obese patients chose treatment with RYGB (n=76) or ILI (n=63). The ILI comprised four stays (seven weeks) at a specialized rehabilitation center over one year. The daily schedule was divided between physical activity, psychosocially-oriented interventions, and motivational approaches. No special diet or weight-loss drugs were prescribed. The participants completed three HRQL-questionnaires before treatment and 1 year thereafter. Both linear regression and ANCOVA were used to analyze differences between weight loss and treatment for five dimensions of HRQL (physical, mental, emotional, symptoms and symptom distress) controlling for baseline HRQL, age, age of onset of obesity, BMI, and physical activity. Clinical relevance was assessed by effect size (ES) where ES<.49 was considered small, between .50-.79 as moderate, and ES>.80 as large.

Results

The adjusted between group mean difference (95% CI) was 8.6 (4.6,12.6) points (ES=.83) for the physical dimension, 5.4 (1.5–9.3) points (ES=.50) for the mental dimension, 25.2 (15.0–35.4) points (ES=1.06) for the emotional dimension, 8.7 (1.8–15.4) points (ES=.37) for the measured symptom distress, and 2.5 for (.6,4.5) fewer symptoms (ES=.56), all in favor of RYGB. Within-group changes in HRQOL in the RYGB group were large for all dimensions of HRQL. Within the ILI group, changes in the emotional dimension, symptom reduction and symptom distress were moderate. Linear regression analyses of weight loss on HRQL change showed a standardized beta-coefficient of –.430 (p<.001) on the physical dimension, –.288 (p=.004) on the mental dimension, –.432 (p<.001) on the emotional dimension, .287 (p=.008) on number of symptoms, and .274 (p=.009) on reduction of symptom pressure.

Conclusions

Morbidly obese participants undergoing RYGB and ILI had improved HRQL after 1 year. The weaker response of ILI on HRQL, compared to RYGB, may be explained by the difference in weight loss following the two treatments.

Trial registration

Clinical Trials.gov number NCT00273104

Long-term effects of gastric bypass and duodenal switch on systemic exposure of atorvastatin

Background

A previous study of 22 patients undergoing either gastric bypass or duodenal switch showed increased systemic exposure of atorvastatin acid 3–8 weeks after surgery in the majority of patients. This study aimed to investigate the long-term effects on systemic exposure of atorvastatin acid in the same group of patients.

Methods

An 8-h pharmacokinetic investigation was performed a median of 27 months (range 21–45 months) after surgery. Systemic exposure was measured as the area under the plasma concentration versus the time curve from 0 to 8 h postdose (AUC_0–8). Linear mixed models with AUC_0–8 as the dependent variable were implemented to assess the effect of time, surgical procedure, and body mass index (BMI) as explanatory variables.

Results

The study enrolled 20 patients. The systemic exposure of atorvastatin acid changed significantly over time (p = 0.001), albeit there was substantial variation between subjects. The effect of time was attenuated but remained significant after adjustment for surgical procedure and BMI (p = 0.048). The initial AUC_0–8 increase seen in the majority of patients 3–8 weeks after surgery was normalized long term, with 7 of the 12 gastric bypass patients and 6 of the 8 duodenal switch patients showing decreased AUC_0–8 compared with preoperative values.

Conclusions

The systemic exposure of atorvastatin showed a significant change over time after bariatric surgery, albeit with large inter- and intraindividual variations. The findings indicate that patients using atorvastatin or drugs with similar pharmacokinetic properties should be monitored closely for both therapeutic effects and adverse events the first years after gastric bypass and duodenal switch. ClinicalTrial NCT00331565.

Employment is associated with the health-related quality of life of morbidly obese persons

Background

We aimed to investigate whether employment status was associated with health-related quality of life (HRQoL) in a population of morbidly obese subjects.

Methods

A total of 143 treatment-seeking morbidly obese patients completed the Medical Outcome Study 36-Item Short-Form Health Survey (SF-36) and the Obesity and Weight-Loss Quality of Life (OWLQOL) questionnaires. The former (SF-36) is a generic measure of physical and mental health status and the latter (OWLQOL) an obesity-specific measure of emotional status. Multiple linear regression analyses included various measures of the HRQoL as dependent variables and employment status, education, marital status, gender, age, body mass index (BMI), type 2 diabetes, hypertension, obstructive sleep apnea, and treatment choice as independent variables.

Results

The patients (74% women, 56% employed) had a mean (SD, range) age of 44 (11, 19–66) years and a mean BMI of 44.3 (5.4) kg/m². The employed patients reported significantly higher HRQoL scores within all eight subscales of SF-36, while the OWLQOL scores were comparable between the two groups. Multiple linear regression confirmed that employment was a strong independent predictor of HRQoL according to the SF-36. Based on part correlation coefficients, employment explained 16% of the variation in the physical and 9% in the mental component summaries of SF-36, while gender explained 22% of the variation in the OWLQOL scores.

Conclusion

Employment is associated with the physical and mental HRQoL of morbidly obese subjects, but is not associated with the emotional aspects of quality of life.

[Follow-up after bariatric surgery]

BACKGROUND

The number of bariatric surgical procedures in Norway is increasing. Patients who undergo bariatric surgery may experience surgical, medical and nutritional complications. Follow-up of these patients is therefore important.

METHODS

The article is based on non-systematic literature searches in PubMed and on the clinical experience of the authors.

RESULTS

Bariatric surgery induces significant and sustained weight loss and improves obesity-related disorders. Gastric bypass is the most commonly performed bariatric procedure in Norway. This procedure is associated with a 30-day mortality of below 0.5 %, while severe complications occur in approximately 5 % of patients. Late complications include internal herniation, intestinal ulcers and gallbladder disease. After surgery all patients are given iron, vitamin D/calcium and vitamin B12 supplements to prevent vitamin and mineral deficiencies. Gastrointestinal symptoms and postprandial hypoglycaemia after surgery can be improved by dietary modifications, and the need for anti-diabetic and blood pressure lowering medications is reduced. Dose adjustment of other medications may also be necessary. Pregnancy is not recommended during the first year after bariatric surgery. Many patients need plastic surgery after the operation.

INTERPRETATION

Complications after bariatric surgery may manifest in the long term. Regular follow-up is required. General practitioners should be responsible for follow-up in the long term, and should be familiar with common and serious complications as well as normal symptomatology after bariatric surgery.

Beta cell function after weight loss: a clinical trial comparing gastric bypass surgery and intensive lifestyle intervention

OBJECTIVE

The effects of various weight loss strategies on pancreatic beta cell function remain unclear. We aimed to compare the effect of intensive lifestyle intervention (ILI) and Roux-en-Y gastric bypass surgery (RYGB) on beta cell function.

DESIGN

One year controlled clinical trial (ClinicalTrials.gov identifier NCT00273104).

METHODS

One hundred and nineteen morbidly obese participants without known diabetes from the MOBIL study (mean (s.d.) age 43.6 (10.8) years, body mass index (BMI) 45.5 (5.6) kg/m², 84 women) were allocated to RYGB (n = 64) or ILI (n = 55). The patients underwent repeated oral glucose tolerance tests (OGTTs) and were categorised as having either normal (NGT) or abnormal glucose tolerance (AGT). Twenty-nine normal-weight subjects with NGT (age 42.6 (8.7) years, BMI 22.6 (1.5) kg/m², 19 women) served as controls. OGTT-based indices of beta cell function were calculated.

RESULTS

One year weight reduction was 30% (8) after RYGB and 9% (10) after ILI (P < 0.001). Disposition index (DI) increased in all treatment groups (all P<0.05), although more in the surgery groups (both P < 0.001). Stimulated proinsulin-to-insulin (PI/I) ratio decreased in both surgery groups (both P < 0.001), but to a greater extent in the surgery group with AGT at baseline (P < 0.001). Post surgery, patients with NGT at baseline had higher DI and lower stimulated PI/I ratio than controls (both P < 0.027).

CONCLUSIONS

Gastric bypass surgery improved beta cell function to a significantly greater extent than ILI. Supra-physiological insulin secretion and proinsulin processing may indicate excessive beta cell function after gastric bypass surgery.

Obesity-related cardiovascular risk factors after weight loss: a clinical trial comparing gastric bypass surgery and intensive lifestyle intervention

OBJECTIVE

Weight reduction improves several obesity-related health conditions. We aimed to compare the effect of bariatric surgery and comprehensive lifestyle intervention on type 2 diabetes and obesity-related cardiovascular risk factors.

DESIGN

One-year controlled clinical trial (ClinicalTrials.gov identifier NCT00273104).

METHODS

Morbidly obese subjects (19-66 years, mean (s.d.) body mass index 45.1 kg/m(2) (5.6), 103 women) were treated with either Roux-en-Y gastric bypass surgery (n=80) or intensive lifestyle intervention at a rehabilitation centre (n=66). The dropout rate within both groups was 5%.

RESULTS

Among the 76 completers in the surgery group and the 63 completers in the lifestyle group, mean (s.d.) 1-year weight loss was 30% (8) and 8% (9) respectively. Beneficial effects on glucose metabolism, blood pressure, lipids and low-grade inflammation were observed in both groups. Remission rates of type 2 diabetes and hypertension were significantly higher in the surgery group than the lifestyle intervention group; 70 vs 33%, P=0.027, and 49 vs 23%, P=0.016. The improvements in glycaemic control and blood pressure were mediated by weight reduction. The surgery group experienced a significantly greater reduction in the prevalence of metabolic syndrome, albuminuria and electrocardiographic left ventricular hypertrophy than the lifestyle group. Gastrointestinal symptoms and symptomatic postprandial hypoglycaemia developed more frequently after gastric bypass surgery than after lifestyle intervention. There were no deaths.

CONCLUSIONS

Type 2 diabetes and obesity-related cardiovascular risk factors were improved after both treatment strategies. However, the improvements were greatest in those patients treated with gastric bypass surgery.

Nationwide survey of long-term results of laparoscopic antireflux surgery in Sweden

OBJECTIVE

Excellent results after laparoscopic antireflux surgery (LARS) have been reported from specialized clinics. These good results were not confirmed in a nationwide survey that studied procedures carried out in 1995-96 in Sweden. Critics pointed out that this study included the learning curve of laparoscopy. Therefore, we have repeated the survey after >5000 LARS procedures have been performed.

MATERIAL AND METHODS

A random sample of 236 patients operated on in 2000 was identified (Group I) and compared to the population operated on in 1995-96 (Group II). Both groups received a disease-specific questionnaire 4 years after surgery.

RESULTS

In Group I, 6.8% of patients had had a second procedure, 16.4% used antireflux medications regularly and 14.9% were dissatisfied. The results for Group II were 6.0%, 19.5% and 15.0%, respectively. Patients reporting any of these three conditions were classified as treatment failures. Treatment failure occurred in 25.4% and 29.0% of patients in Groups I and II, respectively.

CONCLUSIONS

The nationwide long-term outcome after LARS in Sweden demonstrates that approximately a quarter of patients experience some sort of treatment failure. The results seem to be consistent, even though the surgical technique ought to be well implemented after >8years of common use.