IMPACT OF WEIGHT LOSS TRAJECTORY FOLLOWING RANDOMIZATION TO BARIATRIC SURGERY ON LONG-TERM DIABETES GLYCEMIC AND CARDIOMETABOLIC PARAMETERS

Despite regression of healthy lifestyle habits, weight loss after bariatric surgery is not affected during the COVID-19 pandemic

BACKGROUND

The coronavirus pandemic has caused a worldwide health crisis. Bariatric patients require extensive pre- and post-operative follow-up, which may be less feasible during public health social distancing mandates. We assessed the impact of the pandemic on the behaviors and weight loss outcomes of our pre- and post-operative bariatric patients.

METHODS

A retrospective review of a prospectively maintained database identified patients who underwent either sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) at a single institution between March 2018 and May 2020. A cohort undergoing surgery within 12 months before the pandemic as well as a cohort undergoing a medically supervised diet prior to surgery was surveyed regarding pre- and post-COVID-19 lifestyle habits. Excess weight loss (EWL) outcomes from a group of pre-COVID surgical patients were compared to that of a group of post-COVID surgical patients. Primary outcome was whether the lockdown changed 1-year weight loss outcomes. Secondary outcome was whether patient lifestyle behaviors were changed during the pandemic.

RESULTS

There was no difference in 1-year EWL between pre- and post-COVID SG patients (51.7% versus 55.9%, p = 0.35), or between pre- and post-COVID RYGB patients (88.9% versus 80.4%, p = 0.42). Pre-stay-at-home order, 91.8% endorsed physical activity compared to 80.3% post-stay-at-home order (p = 0.0025). Mean physical activity decreased from 4.2 h/week to 2.7 h/week after the stay-at-home order (p < 0.0001). Additionally, 41.3% reported worsened dietary habits post-stay-at-home order.

CONCLUSION

The COVID-19 pandemic has greatly impacted the behaviors of bariatric surgery patients. Despite deterioration of lifestyle habits, 1-year weight loss outcomes after bariatric surgery remained the same before and after the instatement of social distancing measures. In the short term, the biological effect of metabolic procedures may mask the effects of suboptimal diet and physical activity, but more studies are necessary to better assess the impact of COVID-19 on outcomes after bariatric surgery.

The influence of gastric bypass surgery on the concentration of high mobility group box 1, nuclear factor erythroid 2-related factor 2 and the genes expression of high mobility group box 1, nuclear factor erythroid2-related factor 2, interleukin 6, and tumor necrosis factor-alpha in the peripheral blood mononuclear cells of patients with morbid obesity

BACKGROUND AND OBJECTIVES

Obesity is known as a disease with a chronic low-grade state of inflammation and high levels of oxidative stress. Given the challenges and consequences caused by obesity, obesity therapy is an essential subject to address. For sustainable weight loss, gastric bypass surgery is the most successful and essential option.

METHODS

This prospective cohort study was performed on 35 patients aged (18-54) with morbid obesity (BMI: 42.06 kg/m²). Volunteers blood was taken, and peripheral blood mononuclear cells (PBMCs) were isolated, high mobility group box 1(HMGB1), nuclear factor erythroid2-related factor 2(Nrf2), Interleukin 6(IL-6), tumor necrosis factor-alpha (TNF-α), and biochemical factors were determined one day before and 4 months after surgery.

RESULTS

Four months following surgery, the BMI, hip and waist circumferences, and waist-to-hip ratio (WHR) all decreased significantly. The lipid profile and antioxidant power were dramatically enhanced after surgery. IL-6 and TNF-α expression in PBMC patients showed a significant decrease after surgery. HMGB1 and Nrf2 expression in PBMC of postoperative patients decreased compared to before surgery, and HMGB1, and Nrf2 protein levels also decreased after surgery.

CONCLUSION

Weight loss indicated the significant function of adipose tissue in the induction of oxidative stress and inflammatory factors. Gastric bypass reduced the inflammation conditions and improved the metabolic status and living situations in the patients with morbid obesity.

Proteome-wide associations with short- and long-term weight loss and regain after Roux-en-Y gastric bypass surgery

OBJECTIVE

Gastric bypass surgery results in long-term weight loss. Small studies have examined protein changes during rapid weight loss (up to 1 or 2 years post surgery). This study tested whether short-term changes were maintained after 12 years.

METHODS

A 12-year follow-up, protein-wide association study of 1,297 SomaLogic aptamer-based plasma proteins compared short- (2-year) and long-term (12-year) protein changes in 234 individuals who had gastric bypass surgery with 144 nonintervened individuals with severe obesity.

RESULTS

There were 51 replicated 12-year protein changes that differed between the surgery and nonsurgery groups. Adjusting for change in BMI, only 12 proteins remained significant, suggesting that BMI change was the primary reason for most protein changes and not non-BMI-related surgical effects. Protein changes were related to BMI changes during both weight-loss and weight-regain periods. The significant proteins were associated primarily with lipid, uric acid, or resting energy expenditure clinical variables and metabolic pathways. Eight protein changes were associated with 12-year diabetes remission, including apolipoprotein M, sex hormone binding globulin, and adiponectin (p < 3.5 × 10^-5 ).

CONCLUSIONS

This study showed that most short-term postsurgical changes in proteins were maintained at 12 years. Systemic protection pathways, including inflammation, complement, lipid, and adipocyte pathways, were related to the long-term benefits of gastric bypass surgery.

Influence of Pre-operative HbA1c on Bariatric Surgery Outcomes-the Sunderland (UK) Experience

PURPOSE

UK guidelines recommend an HbA1c < 8.5% prior to elective surgery. Optimisation of pre-operative glycaemic control can be often difficult. Aim to correlate the effect of pre-operative HbA1c on the peri-operative complication rates and whether elective bariatric surgery should be delayed in poorly controlled diabetics.

MATERIAL AND METHODS

Retrospective data of consecutive patients who underwent laparoscopic Roux-en-Y gastric bypass, one-anastomosis gastric bypass and laparoscopic sleeve gastrectomy during January 2014 and April 2018. Patients were categorised into group 1, non-diabetics with an HbA1c < 6.5%; group 2, well-controlled diabetics with HbA1c between 6.5 and 8.4%; and group 3, poorly controlled diabetics with HbA1c ≥ 8.5%. Primary outcome was peri-operative complication rates.

RESULTS

Group 1 (n = 978), 81.8% female, median (i.q.r.) age 44.0 (34-52) years, median (i.q.r.) BMI 42.0 (38.7-46.7); group 2 (n = 350), 66.3% female, age 51.0 (45-59) years, BMI 41.8 (37.5-46.5); and group 3 (n = 90), 60% female, age 52.0 (45-56) years and BMI 41.4(36.9-44.8). Early complication rates in each group were low, 1.0% vs 1.7% vs 1.1% (p = 0.592). Mean length of stay was 2 days across the groups (p > 0.05). There was no difference in 30-day re-admission rates between groups 2.8%, 2.9% and 3.3% (p = 0.983). At 6 months and 1 year, there was sustained and equal reduction in HbA1c in all groups (p < 0.05).

CONCLUSION

Patients undergoing metabolic surgery for poorly controlled diabetes achieve non-inferior peri-operative outcomes. Hence, delaying metabolic surgery in an attempt to optimise diabetic control is not justifiable.

Diet-dependent sex differences in the response to vertical sleeve gastrectomy

Nearly 80% of patients that receive bariatric surgery are women, yet mechanistic preclinical studies have focused on males. The goal of this study was to determine the metabolic impact of diet- and surgery-induced weight loss in males, females, and ovariectomized females. All mice were fed a 60% high-fat diet (HFD) before undergoing either vertical sleeve gastrectomy (VSG) or sham surgery. Mice either remained on an HFD or were switched to a standard chow diet postsurgically. When maintained on an HFD, males and females decreased fat mass and improved oral glucose tolerance after VSG. After dietary intervention, additional adiposity was lost in both surgical groups. Ovariectomized females showed a blunted decrease in fat mass on an HFD, but lost significant adiposity after dietary intervention. Energy expenditure was impacted by dietary and not surgical intervention across all groups. Males decreased hepatic triglyceride levels after VSG, which was further decreased after dietary intervention. Intact and ovariectomized females had a blunted decrease in hepatic triglycerides after VSG, but a significant decrease after dietary intervention. The more pronounced effect of VSG on hepatic lipids in males is strongly associated with changes in hepatic expression of genes and microRNAs previously linked to hepatic lipid regulation and systemic energy homeostasis. These data highlight the importance of postsurgical diet on metabolic outcomes across sexes. Furthermore, these data suggest the impact of VSG on hepatic triglycerides is diet-dependent in females and support the hypothesis that males and females achieve similar metabolic outcome, at least within the liver, via distinct mechanisms.NEW & NOTEWORTHY These data highlight the interaction of postsurgical diet after bariatric surgery on metabolic outcomes across sexes. These data suggest the impact of VSG on hepatic triglycerides is diet-dependent in females and support the hypothesis that males and females achieve similar metabolic outcome, at least within the liver, via distinct mechanisms.

Do Weight trajectories influence diabetes control? A prospective study in Switzerland (CoLaus study)

Objective

Identify anthropometric trajectories among subjects with type 2 diabetes mellitus (T2DM), and associate them with glycaemic control.

Methods

Prospective study including 268 community-dwelling participants with T2DM (34% women, mean age 68.7 ± 8.9 years) followed for 10.7 years (range: 8.8–13.6 years). T2DM control was considered for 1) fasting plasma glucose (FPG) < 7.0 mmol/L, or 2) HbA₁c < 7.0% (53 nmol/mol). Changes in weight or waist and weight variability were considered.

Results

One half (FPG) and one third (HbA₁c) of participants presented with uncontrolled T2DM. Half of the participants presented with obesity and 75% with abdominal obesity. During follow-up, half of the participants maintained their weight, 25% gained > 5 kg, and 25% lost < 5 kg; almost half increased their waist by > 5 cm. Using FPG as criterion, participants who lost > 5 cm waist were more likely to be controlled: multivariable-adjusted odds ratio (OR) and 95% confidence interval (CI): 3.10 (1.23–7.78). Participants with controlled T2DM also presented with a higher weight variability: multivariable adjusted mean ± standard error 4.8 ± 0.3 vs. 3.9 ± 0.3 kg, p = 0.028. Using HbA₁c as criterion, participants who lost > 5 kg were less likely to be controlled: OR and (95% CI): 0.35 (0.18–0.66). Similar findings were obtained when restricting the analysis to participants who were diabetic throughout the whole study period.

Conclusion

In a Swiss community-based sample of participants with T2DM, T2DM control rates could be implemented. Neither weight nor waist variability was significantly and consistently associated with T2DM control.

Prevalence of insufficient weight loss 5 years after Roux-en-Y gastric bypass: metabolic consequences and prediction estimates: a prospective registry study

OBJECTIVE

The study aimed to investigate the heterogeneity of weight loss 5 years after Roux-en-Y gastric bypass (RYGB) and the association with cardiometabolic health as well as to model prediction estimates of surgical treatment failure.

DESIGN

Retrospective analysis of prospectively collected data from the Scandinavian Obesity Surgery Registry (SOReg).

SETTING

29 surgical units from the whole of Sweden contributed data. Inclusion was restricted to surgical units with a retention rate of >60% five years postsurgery.

PARTICIPANTS

10 633 patients were extracted from SOReg. In total 5936 participants were included in the final sample, 79.1% females. The mean age of participants before surgery was 39.4±9 years and mean body mass index (BMI) 42.9±5.1. 2322 were excluded (death before the 5-year follow-up (n=148), other types of surgery or reoperations (n=637), age at surgery <18 or >55 years (n=1329), presurgery BMI <35 kg/m² (n=208)). In total, 2375 (29%) of eligible individuals were lost to the 5-year follow-up.

MAIN OUTCOME

The occurrence of surgical treatment failure 5 years after surgery was based on the three previously published definitions: per cent excess BMI loss <50%, total weight loss <20% or BMI >35 where initial BMI was <50, or >40 where initial BMI was >50. In addition, we report the association between surgical treatment failure and biochemical markers of obesity-related comorbidity. We also developed predictive models to identify patients with a high risk of surgical treatment failure 5 years postsurgery.

RESULTS

In total, 23.1% met at least one definition of surgical treatment failure at year 5 which was associated with (adjusted OR) with 95% CI): type 2 diabetes (T2D, OR 2.1; 95% CI 1.6 to 2.7), dyslipidaemia (OR 1.8; 95% CI 1.6 to 2.1) and hypertension (OR 1.9; 95% CI 1.6 to 2.2). Surgical treatment failure at 5 years was predicted by combined demographic and anthropometric measures from baseline, 1 and 2 years postsurgery (area under the curve=0.874).

CONCLUSION

Laparoscopic RYGB leads to a marked and sustained weight loss with improvement of obesity-related comorbidity in most patients. However, 23% met at least one definition of surgical treatment failure, which was associated with a greater risk of relapse and a higher incidence of T2D, dyslipidaemia and hypertension 5 years after surgery. Poor initial weight loss and early weight regain are strong predictors of long-term treatment failure and may be used for early identification of patients who require additional weight loss support.

Earlier Provision of Gastric Bypass Surgery in Canada Enhances Surgical Benefit and Leads to Cost and Comorbidity Reduction

Background: Effective provision of bariatric surgery for patients with obesity may be impeded by concerns of payers regarding costs or perceptions of patients who drop out of surgical programs after referral. Estimates of the cost and comorbidity impact of these inefficiencies in gastric bypass surgery in Canada are lacking but would aid in informing healthcare investment and resource allocation.

Objectives: To estimate total and relative public payer costs for surgery and comorbidities (diabetes, hypertension, and dyslipidemia) in a bariatric surgery population.

Methods: A decision analytic model for a 100-patient cohort in Canada (91% female, mean body mass index 49.2 kg/m², 50% diabetes, 66% hypertension, 59% dyslipidemia). Costs include surgery, surgical complications, and comorbidities over the 10-year post-referral period. Results are calculated as medians and 95% credibility intervals (CrIs) for a pathway with surgery at 1 year (“improved”) compared with surgery at 3.5 years (“standard”). Sensitivity analyses were performed to test independent contributions to results of shorter wait time, better post-surgical weight loss, and randomly sampled cohort demographics.

Results: Compared to standard care, the improved path was associated with reduction in patient-years of treatment for each of the three comorbidities, corresponding to a reduction of $1.1 (0.68–1.6) million, or 34% (26-41%) of total costs. Comorbidity treatment costs were 9.0- and 4.7-fold greater than surgical costs for the standard and improved pathways, respectively. Relative to non-surgical bariatric care, earlier surgery was associated with earlier return on surgical investment and 2-fold reduction in risk of prevalence of each comorbidity compared to delayed surgery.

Conclusions: Comorbidity costs represent a greater burden to payers than the costs of gastric bypass surgery. Investments may be worthwhile to reduce wait times and dropout rates and improve post-surgical weight loss outcomes to save overall costs and reduce patient comorbidity prevalence.

Diabetes Remission and Relapse After Bariatric Surgery: a Nationwide Population-Based Study

PURPOSE

The long-term impact of bariatric surgery on the remission of type 2 diabetes (T2DM) remains to be clarified through large nationally representative cohorts. The objectives were to determine the incidence of T2DM remission and relapse after bariatric surgery, to determine the factors associated with remission and to establish a profile for patients at risk for relapse.

MATERIALS AND METHODS

We conducted a population-based cohort study using data from the French national health insurance database (Systeme national des données de santé [SNDS]). We had access to exhaustive regional data between 2013 and 2017 and to a national representative sample of the French population (EGB) from 2008 to 2018. Patients were included if they were adults and diabetics with incidental bariatric surgery.

RESULTS

This study shows that 50% of patients are in remission from diabetes after bariatric surgery within a median of 2 to 4 months. Diabetes relapse was observed in 13-20% within 10 years. The factors favouring remission already described were noted (non-insulin-dependent diabetes) and original factors were also identified, in particular the advantage of bypass surgery over sleeve gastrectomy, with more remissions and fewer relapses.

CONCLUSION

This study highlights a 50% prevalence of remission and a low prevalence of relapse. There are non-modifiable risk factors for remission and relapse (characteristics of diabetes, age, lipid-lowering therapy) and modifiable factors (type of surgery). Identifying these factors is essential for optimal management of patients. Additional data are essential to confirm the results of our analysis of the factors associated with relapse.

Impact of Metabolic Surgery on Type 2 Diabetes Mellitus, Cardiovascular Risk Factors, and Mortality: A Review

BACKGROUND

The association between obesity and a reduction in life expectancy is well established, and cardiovascular disease is a leading cause of mortality. Bariatric surgery has long been established as the most effective and durable intervention for obesity, and is the only intervention for obesity that consistently improves multiple comorbidities, reduces cardiovascular disease and long-term mortality. The purpose of this review is to describe the impact of metabolic/bariatric surgery on type 2 diabetes mellitus and cardiometabolic parameters, including cardiovascular mortality.

METHODS

A systematic literature search of Pubmed, MEDLINE, and Cochrane Central Register was performed. We included randomized controlled trials, meta-analysis, case-control trials, and cohort studies that contain data on reductions in cardiovascular risk factors and cardiovascular mortality in subjects who underwent metabolic/bariatric surgery from January 1, 2005 to June 1, 2020.

CONCLUSION

There is sufficient evidence from randomized controlled trials that metabolic/bariatric surgery is associated with a significant improvement of all cardiovascular risk factors. Although studies are showing a reduction of macrovascular events and cardiovascular mortality, these findings come from observational studies and should be confirmed in randomized clinical trials.

Can genetics help predict efficacy of bariatric surgery? An analysis of microRNA profiles

BACKGROUND

There is significant variability in weight loss after bariatric surgery. We hypothesize that part of this variability may be predetermined by genetic differences associated with metabolic homeostasis. MicroRNA (miRNA) are short pieces of RNA that regulate gene expression and are readily detectable in serum. They are implicated in numerous metabolic processes, including weight homeostasis. In this pilot study, we briefly review the role of miRNA, and assess the feasibility of using them in the clinical setting of obesity treatment.

OBJECTIVES

To evaluate the feasibility of using miRNA to predict weight loss after bariatric surgery.

SETTING

Academic medical center.

METHODS

Serum was collected from patients at the initial bariatric surgery consultation. Weight loss data were collected 6 to 12 months postoperatively. Individuals experiencing the least and the greatest amount of percentage of excess weight lost at 6 months were analyzed to assess for genetic differences in miRNA expression.

RESULTS

The median percentage of excess weight lost was 51% (range, 34%-63%) for those who lost the least and 87% (range, 82%-111%) for those who lost the most weight. Groups were similar in age, sex, diabetic status, and type of surgery. In total, of the 119 miRNA detected in the serum of the patients, 6 demonstrated potential for discriminating between the high and low weight loss groups. These miRNA have previously been implicated in regulation of fatty acid biosynthesis, adipocyte proliferation, type 2 diabetes, and obesity.

CONCLUSIONS

In this pilot study, we demonstrated the feasibility of identifying genetic differences between high and low weight loss groups by identifying distinct serum miRNA. In the near future, these biomarkers could facilitate informed decisions about surgery. In addition, these miRNA could open new genetic pathways that describe the pathophysiology of obesity, and provide targets for future treatment.

Comparison of Comorbidity Treatment and Costs Associated With Bariatric Surgery Among Adults With Obesity in Canada

IMPORTANCE

Information on the associations between barriers to delivery of bariatric surgery and poor weight trajectory afterward is lacking. Estimates are needed to inform decisions by administrators and clinicians to improve care.

OBJECTIVE

To estimate the difference in patient-years of treatment for diabetes, hypertension, and dyslipidemia and public-payer cost between the Canadian standard and an improved bariatric surgery care pathway.

DESIGN, SETTING, AND PARTICIPANTS

Economic evaluation of a decision analytic model comparing the outcomes of the standard care in Canada with an improved bariatric care pathway with earlier sleeve gastrectomy delivery and better postsurgical weight trajectory. The model was informed by published clinical data (101 studies) and meta-analyses (11 studies) between January and May 2019. Participants were a hypothetical 100-patient cohort with demographic characteristics derived from a Canadian study.

INTERVENTIONS

Reduction of Canadian mean bariatric surgery wait time by 2.5 years following referral and improvement of patient postsurgery weight trajectory to levels observed in other countries.

MAIN OUTCOMES AND MEASURES

Modeling weight trajectory after sleeve gastrectomy and resolution rates for comorbidities in Canada in comparison with an improved care pathway to estimate differences in patient-years of comorbidity treatment over 10 years following referral and the associated costs.

RESULTS

For the 100-patient cohort (mean [SD] 88.2% [1.4%] female; mean [SD] age, 43.6 [9.2] years; mean [SD] body mass index, 49.4 [8.2]; and mean [SD] comorbidity prevalence of 50.0% [4.1%], 66.0% [3.9%], and 59.3% [4.0%] for diabetes, hypertension, and dyslipidemia, respectively) over 10 years following referral, the improved vs standard care pathway was associated with median reduction in patient-years of treatment of 324 (95% credibility interval [CrI], 249-396) for diabetes, 245 (95% CrI, 163-356) for hypertension, and 255 (95% CrI, 169-352) for dyslipidemia, corresponding to total savings of $900 000 (95% CrI, $630 000 to $1.2 million) for public payers in the base case. Relative to standard of care, the associated reduction in costs was approximately 29% (95% CrI, 20%-42%) in the improved pathway. Sensitivity analyses demonstrated independent associations of earlier surgical delivery and various levels of postsurgical weight trajectory improvements with overall savings.

CONCLUSIONS AND RELEVANCE

This study suggests that health care burden may be decreased through improvements to delivery and management of patients undergoing sleeve gastrectomy. More data are needed on long-term patient experience with bariatric surgery in Canada to inform better estimates.

Conversion from Prediabetes to Diabetes in Individuals with Obesity, 5-Years Post-Band, Sleeve, and Gastric Bypass Surgeries

BACKGROUND

Identifying risk factors for conversion to diabetes among individuals with obesity and prediabetes is important for preventing diabetes.

PURPOSE

We assessed conversion rates to diabetes 5 years after three types of metabolic surgery and examined predictors of diabetes development.

METHODS

We accessed data of individuals with prediabetes, defined as fasting glucose (FG) 100-125 mg/dL (5.6-6.9 mmol/L) or HbA1c 5.7-6.4% at baseline (preoperatively), who underwent metabolic surgeries in Clalit Health Services during 2002-2011.

RESULTS

Of 1,756 individuals with prediabetes, 819 underwent gastric banding (GB), 845 sleeve gastrectomy (SG), and 92 Roux-en-Y gastric bypass (RYGB). Mean age was 41.6 years and 73.5% were women. Five years post-surgery, 177 (10.1%) had developed diabetes. Conversion rates by type of surgery were 14.4%, 6.3%, and 6.5% for GB, SG, and RYGB, respectively (p < 0.001). Conversion was more rapid following GB than SG or RYGB (χ²(2) = 29.67, p < 0.005). In a multiple-logistic-regression model, predictors of diabetes development 5 years postoperatively were (1) weight loss during the first postoperative year and (2) preoperative levels of both FG and HbA1c within the prediabetes range. Baseline weight, age, and sex, were not associated with conversion to diabetes. Conversion rates were lower (4.7%) five years postoperatively for patients who lost > 25% of their baseline weight, compared to those who lost less than 15% of their weight during the first postoperative year: (14.0% < 0.001).

CONCLUSIONS

Our findings emphasize the importance of preoperative glycemic control and weight loss during the first year postoperatively, for the long-term prevention of diabetes in patients with prediabetes undergoing metabolic surgery.