Baseline circulating ghrelin does not predict weight regain neither maintenance of weight loss after gastric bypass at long term

Prevalence and predictors of weight recurrence following bariatric surgery: A longitudinal prospective cohort study from Tehran Obesity Treatment Study (TOTS)

BACKGROUND

Considering the lack of a standardized definition for weight recurrence (WR), the prevalence and predictors of WR remain inconsistent.

METHODS

The prospective study was conducted on 1939 individuals who underwent bariatric surgery;66.8% underwent sleeve gastrectomy (SG), 33.2%, underwent gastric bypass (GB)[of them 87% one-anastomosis gastric bypass (OAGB), and 13% Rue and Y gastric bypass (RYGB)]. During a follow-up of 72 months, the prevalence of WR ranged from 13.5% to 35.5% according to five different definitions. The generalized estimated equation method was used to assess weight changes, excess weight loss (EWL%), and body composition (fat mass (FM), fat-free mass (FFM)and FFM loss/weight loss% (FFML/WL%)) by a bioelectrical impedance analyzer. Stepwise logistic regression models were applied to determine the independent predictors of WR.

RESULTS

Among 1939 participants followed up for 72 months, WR definitions were applied to 650 patients (75.4% females) with an average BMI of 44.3 ± 5.4 kg/m2,491 (75.5%) and 159 (24.5%) of whom underwent SG and GB, respectively. WR group had relatively higher weights and FM and lower EWL%. A WR turning point was observed at 24 months post-surgery (Ptime before & after 24 months<0.001). The most significant risk factors for WR included SG (in all WR definitions), a younger age (in four out of five definitions), and a higher baseline BMI (in three out of five definitions).

CONCLUSION

The prevalence and predictors of WR varied greatly depending on the definition applied. The prominent risk factors of WR included SG, younger age, and a higher baseline BMI.

Towards precision medicine in bariatric surgery prescription

Obesity is a complex, multifactorial and chronic disease. Bariatric surgery is a safe and effective treatment intervention for obesity and obesity-related diseases. However, weight loss after surgery can be highly heterogeneous and is not entirely predictable, particularly in the long-term after intervention. In this review, we present and discuss the available data on patient-related and procedure-related factors that were previously appointed as putative predictors of bariatric surgery outcomes. In addition, we present a critical appraisal of the available evidence on which factors could be taken into account when recommending and deciding which bariatric procedure to perform. Several patient-related features were identified as having a potential impact on weight loss after bariatric surgery, including age, gender, anthropometrics, obesity co-morbidities, eating behavior, genetic background, circulating biomarkers (microRNAs, metabolites and hormones), psychological and socioeconomic factors. However, none of these factors are sufficiently robust to be used as predictive factors. Overall, there is no doubt that before we long for precision medicine, there is the unmet need for a better understanding of the socio-biological drivers of weight gain, weight loss failure and weight-regain after bariatric interventions. Machine learning models targeting preoperative factors and effectiveness measurements of specific bariatric surgery interventions, would enable a more precise identification of the causal links between determinants of weight gain and weight loss. Artificial intelligence algorithms to be used in clinical practice to predict the response to bariatric surgery interventions could then be created, which would ultimately allow to move forward into precision medicine in bariatric surgery prescription.

What About My Weight? Insufficient Weight Loss or Weight Regain After Bariatric Metabolic Surgery

Context

This review study aimed to investigate the definition, etiology, risk factors (RFs), management strategy, and prevention of insufficient weight loss (IWL) and weight regain (WR) following bariatric metabolic surgery (BMS).

Evidence Acquisition

Electronic databases were searched to retrieve relevant articles. The inclusion criteria were English articles with adult participants assessing the definition, prevalence, etiology, RFs, management strategy, and prevention of IWL/WR.

Results

Definition: The preferred definition for post-BMS IWL/WR are the terms "Lack of maintenance of total weight loss (TWL)>20%" and "weight change in percentage compared to nadir weight or weight loss". Prevalence: The exact prevalence of IWL/WR is still being determined due to the type of BMS and various definitions. Etiology: Several mechanisms, including hormonal/metabolic, dietary non-adherence, physical inactivity, mental health, and anatomic surgical failure, are possible etiologies of post-BMS IWL/WR. Risk factors: Preoperative body mass index (BMI), male gender, psychiatric conditions, comorbidities, age, poor diet, eating disorders, poor follow-ups, insufficient physical activity, micronutrients, and genetic-epigenetic factors are the most important RFs. Management Strategy: The basis of treatment is lifestyle interventions, including dietary, physical activity, psychological, and behavioral therapy. Pharmacotherapy can be added. In the last treatment line, different techniques of endoscopic surgery and revisional surgery can be used. Prevention: Behavioral and psychotherapeutic interventions, dietary therapy, and physical activity therapy are the essential components of prevention.

Conclusions

Many definitions exist for WR, less so for IWL. Etiologies and RFs are complex and multifactorial; therefore, the management and prevention strategy is multidisciplinary. Some knowledge gaps, especially for IWL, exist, and these gaps must be filled to strengthen the evidence used to guide patient counseling, selection, and improved outcomes.

Factors associated with weight regain post-bariatric surgery: a systematic review

INTRODUCTION

To systematically review the literature to assess the incidence and risk factors of weight regain (WR) after bariatric surgery. Bariatric surgery is the most effective intervention for sustained weight loss of morbidly obese patients, but WR remains a concern.

MATERIALS AND METHODS

A PRISMA compliant systematic literature review was performed using the PubMed database, Embase and the Cochrane Library in July of 2019. Studies that reported ≥ 10% WR after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) were included. The Newcastle-Ottawa scale (NOS) was used for assessing study quality.

RESULTS

Out of 2915 retrieved abstracts, 272 full papers were reviewed, and 32 studies included (25 of high and 7 of fair quality) reporting weight outcomes on 7391 RYGB and 5872 SG patients. 17.6% (95% CI 16.9-18.3) had a WR ≥ 10%. Risk factors related with WR fell into 5 categories, namely anatomical, genetic, dietary, psychiatric, and temporal. Specifically, gastrojejunal stoma diameter, gastric volume following sleeve, anxiety, time after surgery, sweet consumption, emotional eating, portion size, food urges, binge eating, loss of control/disinhibition when eating, and genetics have been positively associated with WR while postprandial GLP-1, eagerness to change physical activity habits, self-esteem, social support, fruit and zinc consumption, HDL, quality of life have been negatively associated.

CONCLUSION

At least 1 in 6 patients after bariatric surgery had ≥ 10% WR. This review identified several factors related to WR that can be used to counsel patients preoperatively and direct postoperative strategies that minimize WR risk.

Pre-operative Predictors of Weight Loss and Weight Regain Following Roux-en-Y Gastric Bypass Surgery: a Prospective Human Study

BACKGROUND

There are currently few pre-operative predictors of initial and long-term weight loss following bariatric surgery.

OBJECTIVES

We evaluated the role of pre-operative patient characteristics and baseline gut and adipose-derived hormones in predicting maximal total body weight loss (WL_max) and risk of weight regain (WR) after Roux-en-Y gastric bypass (RYGB) surgery.

METHODS

One hundred five adult patients undergoing primary RYGB were prospectively recruited. Baseline demographics were recorded and fasting plasma glucose, glycosylated hemoglobin (A1C), insulin, glucagon, leptin, active ghrelin, glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) levels were measured on day of surgery.

RESULTS

Our cohort had a mean age of 44.4 ± 13.0 years, and initial BMI (body mass index) of 45.1 ± 6.7 kg/m² with mean post-operative follow-up of 40 months. Eighty patients were female and 26 had type 2 diabetes mellitus (T2D). Average WL_max was 35.3 ± 7.4%. On univariate analysis, higher baseline fasting ghrelin, lower age, lower CRP (C-reactive protein), lower A1C, and negative T2D status were associated with greater WL_max (p < 0.05). Controlling for these variables using stepwise multivariate regression, only higher fasting ghrelin and younger age were associated significantly with greater WL_max (p < 0.05). In subgroup multivariate regression analysis of T2D patients, higher ghrelin and glucagon were significantly associated with greater WL_max. Following stepwise multivariate regression, lower initial BMI and lower glucagon were associated with greater WR (p < 0.05).

CONCLUSIONS

Incorporation of baseline biological and hormonal markers may help in developing more accurate predictive models for weight loss following bariatric surgery that help inform patient counseling and decision-making.

Changes in metabolic hormones after bariatric surgery and their predictive impact on weight loss

BACKGROUND

Although various metabolic hormones have been implicated in bariatric-related weight loss, their use as predictors of weight loss is unknown. Our study evaluates changes in metabolic hormones after bariatric surgery, and their role as predictors of weight loss.

METHODS

This nonrandomized study included 51 patients, 21 underwent laporascopic adjustable gastric banding (LAGB), 15 laparoscopic sleeve gastrectomy (LSG) and 15 Roux-en Y gastric bypass (RYGB). Serum ghrelin, leptin, insulin, growth hormone, HOMA-IR and HOMA-β was recorded at baseline and 1, 3, 6 and 12 months, and correlated with weight loss. Successful weight loss was defined as excess weight loss >50% at 12 months for all groups.

RESULTS

Weight loss pattern was similar in all groups. Ghrelin increased only in the LAGB group (P = 0·016). However, baseline ghrelin concentrations >664·6 pg/mL in the LSG group predicted successful weight loss with 81·8% sensitivity and 100·0% specificity, and ghrelin >969·8 pg/mL in the 1st postoperative month predicted success with 83·3% sensitivity and 83·3% specificity in the LAGB group. Insulin and HOMA-IR decreased significantly in the LSG and RYGB group, HOMA-β increased in the LAGB and LSG group. Serum leptin decreased and GH increased in all groups (P < 0·001 for all changes). Changes in insulin, leptin and growth hormone were not predictors, but a consequence of weight loss.

CONCLUSIONS

LSG is the most effective procedure for improvement of beta-cell function. High baseline ghrelin in the LSG group and an adequate 1st month increase in the LAGB group are associated with greater weight loss. Validation studies are required to confirm the role of ghrelin in predicting weight loss after bariatric surgery, but also in selecting candidates for specific bariatric procedures.

The future of the Roux-en-Y gastric bypass

Archaic surgical procedures such as the jejunoileal bypass, vertical banded gastroplasty and duodenal switch have contributed to the current best practice of Roux-en-Y gastric bypass (RYGB) procedure for the treatment of obesity and its consequences. Despite this, RYGB has been blighted with late occurring adverse events such as severe malnutrition, marginal ulcer and reactive hypoglycemia. Despite this, RYGB has given us an opportunity to examine the effect of surgery on gut hormones and the impact on metabolic syndrome which in turn has allowed us to carry out a lower impact but equally, if not more effective, procedure - the vertical sleeve gastrectomy (VSG). We examine the benefits of sleeve gastrectomy from the less challenging technical aspect to the effect on obesity and its metabolic syndrome long-term and have concluded that sleeve gastrectomy is possibly the next current best practice.