Predictors of Success in Bariatric Surgery: the Role of BMI and Pre-operative Comorbidities

Stage of fibrosis is not a predictive determinant of weight loss in patients undergoing bariatric surgery

BACKGROUND

Obesity and nonalcoholic fatty liver disease (NAFLD) are an increasing health care burden worldwide. Weight loss is currently the best option to alleviate NAFLD and is efficiently achieved by bariatric surgery. Presence of NAFLD seems to be predictive for postoperative weight loss. To date, only few predictive factors for postbariatric weight loss (age, diabetes, psychiatric disorders) are established.

OBJECTIVES

Since liver fibrosis is the pathogenic driver for the progression of liver disease, we investigated its role in predicting postoperative weight loss. This study focuses on the correlation between fibrosis stage and weight loss.

SETTING

University and university-affiliated cooperation, Germany.

METHODS

We used a prospective, single-center cohort study including 164 patients who underwent bariatric surgery with simultaneous liver biopsies. Liver fibrosis was determined histologically according to Kleiner score and noninvasively by APRI and FIB-4 score. Percentage of total body weight loss was calculated at 1-year follow up visit.

RESULTS

Thirty-two patients were found without fibrosis, whereas 91 patients showed mild fibrosis (F1), 37 significant fibrosis (F2), and only 4 patients presented advanced fibrosis (F3) at the time of bariatric surgery. Weight loss was similar across different degrees of fibrosis stage. Accordingly, linear regression analysis did not identify predictors of weight loss among fibrosis scores. In multivariable analysis, age and presence of diabetes showed the strongest predictive value.

CONCLUSIONS

Baseline presence of fibrosis was not associated with postoperative weight loss, while age and diabetes were independent predictors of weight loss. Bariatric surgery should be applied independently of the fibrosis stage.

Changes in Cognitive Function Following Bariatric Surgery: An Updated Systematic Review

Since a previous systematic review published in 2016, there have been further studies investigating the association of changes in cognitive function following bariatric surgery. All studies since the original review that reported at least one element of cognitive function before and after bariatric surgery were eligible. A total of 137 additional studies were identified; 13 were included in addition to the 18 studies previously. Almost all studies reported improvements in at least one domain. Most revealed improvements were limited to a few domains and were not universal. Further findings investigated cognitive function improvement in relation to procedure choice, and mental health or quality of life post-surgery. Further high-powered studies are still necessary, but these findings support the impact of bariatric surgery on cognitive function in obesity.

Peripheral inflammation associated with depression and reduced weight loss: a longitudinal study of bariatric patients

BACKGROUND

Research implicates inflammation in the vicious cycle between depression and obesity, yet few longitudinal studies exist. The rapid weight loss induced by bariatric surgery is known to improve depressive symptoms dramatically, but preoperative depression diagnosis may also increase the risk for poor weight loss. Therefore, we investigated longitudinal associations between depression and inflammatory markers and their effect on weight loss and clinical outcomes in bariatric patients.

METHODS

This longitudinal observational study of 85 patients with obesity undergoing bariatric surgery included 41 cases with depression and 44 controls. Before and 6 months after surgery, we assessed depression by clinical interview and measured serum high-sensitivity C-reactive protein (hsCRP) and inflammatory cytokines, including interleukin (IL)-6 and IL-10.

RESULTS

Before surgery, depression diagnosis was associated with significantly higher serum hsCRP, IL-6, and IL-6/10 ratio levels after controlling for confounders. Six months after surgery, patients with pre-existing depression still had significantly higher inflammation despite demonstrating similar weight loss to controls. Hierarchical regression showed higher baseline hsCRP levels predicted poorer weight loss (β = -0.28, p = 0.01) but had no effect on depression severity at follow-up (β = -0.02, p = 0.9). Instead, more severe baseline depressive symptoms and childhood emotional abuse predicted greater depression severity after surgery (β = 0.81, p < 0.001; and β = 0.31, p = 0.001, respectively).

CONCLUSIONS

Depression was significantly associated with higher inflammation beyond the effect of obesity and other confounders. Higher inflammation at baseline predicted poorer weight loss 6 months after surgery, regardless of depression diagnosis. Increased inflammation, rather than depression, may drive poor weight loss outcomes among bariatric patients.

Revisional Bariatric Surgery due to Complications: Indications and Outcomes

BACKGROUND

The increasing prevalence of bariatric procedures has led to a surge in revisional surgeries. Failure of bariatric surgery can be attributed to inadequate weight loss or complications necessitating revisional surgery. In this study, we investigated the indications and outcomes of revisional surgery due to complications following primary bariatric surgery.

MATERIALS AND METHODS

A retrospective study was conducted using data from the Tehran Obesity Treatment Study, which included patients who underwent revisional bariatric surgery between March 2013 and September 2021 due to complications following primary bariatric surgery.

RESULTS

Of the 5382 patients who underwent primary bariatric surgery (sleeve gastrectomy, one-anastomosis gastric bypass, and Roux-en-Y gastric bypass), 203 (3.70%) required revisional surgery, with 37 cases performed due to surgical complications. The indications of revisional operations were gastroesophageal reflux disease (GERD) (n=17, 45.9%), protein-calorie malnutrition (PCM) (n=14, 37.8%), unexplained abdominal pain (n=5, 13.5%), and phytobezoar (n=1, 0.03%). In the postoperative follow-up, most patients exhibited improvement in signs and symptoms related to underlying causes. However, eight patients experienced early or late complications of grade III or higher according to the Clavien-Dindo classification, with one death resulting from liver failure.

CONCLUSION

Revisional bariatric surgery may effectively address complications from primary bariatric surgery, with the majority of patients experiencing improvements in symptoms. While the overall incidence of revisional surgery due to complications is relatively low, our findings suggest that GERD and PCM are the most common indications for revisional surgery.

Predicting Early Weight Loss Failure Using a Bariatric Surgery Outcomes Calculator and Weight Loss Curves

CONTEXT

Weight loss after bariatric surgery can be accurately predicted using an outcomes calculator; however, outliers exist that do not meet the 1 year post-surgery weight projections.

OBJECTIVE

Our goal was to determine how soon after surgery these outliers can be identified.

DESIGN

We conducted a retrospective cohort study.

SETTING, PATIENTS, AND INTERVENTION

Using a bariatric surgery outcomes calculator formulated by the Michigan Bariatric Surgery Collaborative (MBSC), predicted weight loss at 1 year post-surgery was calculated on all patients who underwent primary bariatric surgery at a single-center academic institution between 2006 and 2015 who also had a documented 1-year follow-up weight (n = 1050).

MAIN OUTCOME MEASURES

Weight loss curves were compared between high, low, and non-outliers as defined by their observed-to-expected (O:E) weight loss ratio based on total body weight loss (TBWL) %.

RESULTS

Mean predicted weight loss for the study group was 39.1 ± 9.9 kg, while mean actual weight loss was 39.7 ± 17.1 kg resulting in a mean O:E 1.01 (± 0.35). Based on analysis of the O:E ratios at 1 year post-surgery, the study group was sub-classified. Low outliers (n = 188, O:E 0.51) had significantly lower weight loss at 2 months (13.1% vs 15.6% and 16.5% TBWL, p < 0. 001) and at 6 months (19% vs 26% and 30% TBWL, p < 0.001) when compared to non-outliers (n = 638, O:E 1.00) and high outliers (n = 224, O:E 1.46), respectively.

CONCLUSIONS

Weight loss curves based on individually calculated outcomes can help identify low outliers for additional interventions as early as 2 months after bariatric surgery.

SCL-90 empirical factors predict post-surgery weight loss in bariatric patients over longer time periods

PURPOSE

This longitudinal study examined how pre-intervention psychological health helps predict bariatric surgery (BS) success as percentage of expected body mass index loss (%EBMIL) over shorter to longer periods.

METHODS

Adult candidates for BS (N = 334, 67.4% females) completed the Symptoms Checklist 90 (SCL-90) questionnaire; on average, 11 months occurred between the pre-surgery psychological evaluations and the bariatric intervention. We explored the factor structure of the SCL-90 items and inspected how SCL-90 empirical factors compared with SCL-90 scales and general indices predicted %EBMIL at 3-6-month, 1-year, and 2-year follow-up occasions, adjusting for gender, pre-intervention use of antidepressants and actual and ideal BMIs.

RESULTS

Factor analysis combined the 90 items into 8 factors, which partially replicated the expected item structure. The SCL-90 empirical factors (but not the SCL-90 scales and indices) contributed to predict BS success. In fact, the Relational Distress factor directly protected from weight regain at 1-year follow-up, indirectly via 1-year %EBMIL at the 2-year follow-up, when it further strengthened the impact of the empirical factor of Generalized Anxiety on the 2-year BS outcome. The results also evidenced a cascade effect of the pre-surgery actual BMI across time as well as unique and direct effects of pre-surgery use of antidepressants and perceived ideal BMI on the 2-year outcome.

CONCLUSIONS

SCL-90 empirical factor scores for obese patients are more efficient in anticipating BS success compared with original scale scores. They reveal that relational distress and anxiety are risk factors for postoperative weight loss, in addition to pre-intervention actual BMI, antidepressant therapy, and perceived ideal BMI.

LEVEL OF EVIDENCE

III, well-designed cohort.

Predicting satisfaction with outcome and follow-up care 5 years after bariatric surgery: A prospective evaluation

Objective

Patient satisfaction is viewed as essential for a successful outcome of bariatric surgery. Few studies have explored long-term satisfaction prospectively. This study aimed to examine pre- and post-surgery predictors for satisfaction with follow-up care, and change in outcome satisfaction from one to 5 years after bariatric surgery.

Methods

A sample of 210 participants was recruited from a single treatment center. Self-reported and medical record data regarding mental and somatic health, body image, follow-up attendance, and weight loss were obtained before, 1 year, and 5 years after surgery.

Results

Over 90% of the participants were satisfied with the results and treatment 1 year after surgery, while 69% had their outcome expectations fulfilled and 62% were satisfied with the follow-up 5 years after surgery. A shift from initial satisfaction to unfulfillment of expectations was predicted by baseline body dissatisfaction, greater percentage of weight regain after initial weight loss, and more discomfort from somatic symptoms 5 years after surgery. In addition to symptom discomfort, worry about surgery predicted satisfaction with follow-up care.

Conclusion

At 5 years, one-fifth of those initially satisfied reported that bariatric surgery had failed to meet their expectations. This suggests that outcome expectations related to weight loss, somatic symptoms, and body image need to be addressed both before and after bariatric surgery.

Weight Regain Outcomes After Bariatric Surgery in the Long-term Follow-up: Role of Preoperative Factors

PURPOSE

Weight regain (WR) compromises the effectiveness of bariatric surgery. The objective of this study was to determine differences in long-term WR prevalence using different definitions and analyze possible preoperative predictors involved.

METHODS

Single-center retrospective cohort study including 445 adults who underwent 3 modalities of bariatric surgery between 2009 and 2014.

EXPOSURE

age, gender, ethnicity, body mass index (BMI), type 2 diabetes (T2D), hypertension (HTN), and type of surgery.

MAIN OUTCOMES

WR at year 6 assessed by 4 definitions and 6 multivariate models based on common thresholds.

RESULTS

Our cohort (71.1% female) had a mean age of 44.78 ± 11.94 years, and mean presurgery BMI of 44.94 ± 6.88 kg/m², with a median follow-up of 6 years (IQR=5-8). The prevalences of T2D and HTN were 36.0% and 46.7% respectively. WR rates over thresholds ranged from 25.4 to 68.1%, with significant differences between groups in the WR measured as the percentage of maximum weight loss (MWL) and the increase in excess weight loss (EWL). Presurgery BMI was a significant predictor in 3 models; restrictive techniques were associated with WR in all the models except for those considering WR over 10 kg and WR over 15% from nadir as dependent variables.

CONCLUSIONS

In this long-term study, WR defined as percentage of MWL and increase in EWL from nadir had the greatest significance in logistic regression models with preoperative BMI and type of surgery as independent variables. These findings could serve to establish a standardized outcome reporting WR in other longitudinal studies.

KEY POINTS

• Lack of standardized outcome to measure weight regain after bariatric surgery. • Lowest rates of weight regain in malabsorptive techniques in all definitions applied. • Weight regain measured as percentage of maximum weight lost.

Cabral P, Guerreiro V, Lourenço R, Meira P, Salazar D, Ferreira MJ, Pedro J, Barkoudah E, Sande A, Lau E, B. Souto S, Preto J, Freitas P, Carvalho D. Beta Cell Function as a Baseline Predictor of Weight Loss After Bariatric Surgery

BACKGROUND

Obesity is a multifactorial disease, which is strongly associated to other metabolic disorders. Bariatric surgery is the most effective treatment of morbid obesity. The role of beta cell function in weight loss after bariatric surgery is uncertain.

AIM

To evaluate the association between beta cell function and percentage of total body weight loss (TBWL%) 1, 2, 3, and 4 years after bariatric surgery in patients with morbid obesity.

METHODS

Retrospective longitudinal study in patients with morbid obesity followed in our center between January 2010 and July 2018. Patients were excluded if they had diabetes at baseline or missing data on the needed parameters. We evaluated baseline Homeostatic Model Assessment of IR, Homeostatic Model Assessment of β-cell function (HOMA-beta), Quantitative Insulin Sensitivity Check Index, and Matsuda and DeFronzo index, and TBWL% at years 1 to 4. Linear regression models were used to evaluate the association of indexes of insulin resistance with TBWL% (unadjusted and adjusted for age, sex, BMI, and type of surgery).

RESULTS

There were 1,561 patients included in this analysis. HOMA-beta was negatively associated with TBWL% at second, third, and fourth years post-surgery (β = -1.04 [-1.82 to -0.26], p<0.01; β = -1.16 [-2.13 to -0.19], p=0.02; β = -1.29 [-2.64 to 0.06], p=0.061, respectively). This was not observed in the first year post-surgery nor for the other indexes. Glycemia at baseline was positively associated to EWL% at second and third years post-surgery.

CONCLUSION

β-cell function at baseline seems to be associated to long-term weight loss, explicitly after the first year post bariatric surgery. This might be a helpful predictor of weight loss in clinical practice.

Third bariatric procedure for insufficient weight loss or weight regain: how far should we go?

BACKGROUND

Revisional procedures in bariatric surgery are increasing with several debated failure risk factors, such as super obesity and old age. No study has yet evaluated the outcomes and risks of a third bariatric procedure indicated for weight loss failure or weight regain.

OBJECTIVES

To assess failure risks of a third bariatric procedure according to Reinhold's criteria (percentage excess weight loss [%EWL] ≤50% and/or body mass index [BMI] ≥35 kg/m²).

SETTING

A university-affiliated tertiary care center, France.

METHODS

From 2009 to 2019, clinical data and weight loss results of patients who benefited from 3 bariatric procedures for weight loss failure or weight regain were collected prospectively and analyzed using a binary logistic regression. Weight loss failure was defined according to Reinhold's criteria.

RESULTS

Among 1401 bariatric procedures performed, 336 patients benefited from 2 or more procedures, and 45 had a third surgery. Eleven patients that were reoperated on because of malnutrition or gastroesophageal reflux disease were excluded from the final analysis. Among 34 patients with 3 procedures because of weight loss failure or regain, mean BMI was 48.3 ± 8.3 kg/m², and mean age was 30 ± 10.7 years. Three out of 34 patients (9%) presented a severe complication (Dindo-Clavien IIIb) and 2 (6%) had a minor one. Achieving Reinhold's weight loss criteria after the second bariatric procedure was a significant predictor of success of the third procedure (β = 2.9 ± 1.3 S.E.).

CONCLUSION

Not reaching Reinhold's criteria after a second bariatric procedure was identified as a significant risk factor of failure of a third procedure. A third surgery should be carefully discussed especially in case of primary failure of previous procedures.

Overall Treatment Satisfaction 5 Years After Bariatric Surgery

INTRODUCTION

Up to 30 % of patients undergoing bariatric surgery are dissatisfied with treatment outcomes in the long term. The aim of this study was to examine overall satisfaction with treatment 5 years after bariatric surgery and its association with body mass index (BMI) and health-related quality of life (HRQOL).

METHODS

Patients were surveyed 5 years after bariatric surgery; 108 patients had duodenal switch (DS) and 153 patients had laparoscopic sleeve gastrectomy (LSG). The main outcome was overall treatment satisfaction, assessed by a single question, and analyzed by multiple logistic regression. Estimates for continuous independent variables represent the odds ratios (OR) for a 2-standard deviation difference.

RESULTS

Five years after surgery, 82.4 % of the patients were very satisfied or satisfied, whereas 17.6 % were unsure or dissatisfied. The following variables assessed at 5 years were associated with being dissatisfied/unsure: a higher BMI (OR = 6.1, 95 % CI = 2.7-14.0, p < 0.001), reduced obesity-specific HRQOL (OR = 3.0, 95 % CI = 1.1-7.8, p = 0.03), and reduced mental HRQOL (OR = 0.3, 95 % CI = 0.1-0.8, p = 0.02). We also found that a higher proportion of patients who underwent LSG, compared to DS, reported being dissatisfied/unsure (OR = 3.3, 95 % CI = 1.3-8.8, p = 0.01).

CONCLUSION

Reduced mental HRQOL and obesity-related HRQOL, as well as higher BMI, were associated with less satisfaction with overall treatment outcomes 5 years after bariatric surgery. Differences in overall treatment satisfaction by type of operation warrant further investigation.

Physical activity impacts insulin sensitivity post metabolic bariatric surgery in adolescents with severe obesity

BACKGROUND/OBJECTIVES

We hypothesized that physical activity (PA) improves insulin sensitivity in adolescents with severe obesity beyond that attributable to metabolic bariatric surgery (MBS).

SUBJECTS/METHODS

StepWatch^TM monitors objectively measured PA in 88 participants in the Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study. Primary outcomes included absolute change in fasting insulin, HOMA-IR, and fasting glucose from pre-surgery (baseline) to 6, 12, 24, and 36 months post-MBS. SAS PROC TRAJ generated activity trajectories based on probability and individual participant step count trajectories. Linear regression models were used, adjusted for baseline value, visit, surgical procedure, sex, and percent change in BMI. Additional models adjusted for percent change in iliac waist circumference (IWC) or percent body fat (BF), measured by bio-impedance.

RESULTS

Two activity trajectories were identified: more active (MA, n = 13) and less active (LA, n = 75). MA baseline mean daily step count was >6000, increasing to >9000 at 2 years. LA mean daily step count remained at ~4000. Few participants recorded moderate step activity (cadence >80 steps/minute). Still, fasting insulin and HOMA-IR differed in association with activity trajectoy. MA was associated with a greater absolute decrease in fasting insulin (-7.8 μU/ml [95% CI: (-11.8, -3.7)], p ≤ 0.001) and a greater decrease in HOMA-IR (-1.9 [95% CI: (-3.0, -0.7)], p = 0.001), when adjusted for percent change in BMI. The significant independent effect of MA remained when adjusted for percent change in IWC or percent BF. Clinically, 100% of MA trajectory participants normalized fasting insulin, HOMA-IR, and fasting glucose by 6 months and normalization remained throughout the 36 months follow up. In contrast, 76.3 and 65.8% of LA trajectory participants normalized fasting insulin and HOMA-IR, respectively, by 12 months with 28.6% of both remaining normalized at 36 months.

CONCLUSIONS

PA is independently associated with improved insulin sensitivity beyond that attributable to MBS in adolescents with severe obesity.

Seasonal variation of body weight loss after bariatric surgery

Seasonal variations have been described in humans in several variables such as sleep, mood, appetite, food preferences, or body weight. We hypothesized that these variations could also influence the decrease in body weight rate in patients submitted to body weight loss interventions. Thus, here we tested the variations of weight loss according to the time of the year the surgery took place in a group patients (n = 1322) submitted to bariatric surgery in the Hospital Universitari de la Vall d'Hebron in Barcelona (geographical coordinates: 41°25'41″N 2°8'32″E). For the analysis, the percentage of total body weight loss (%TWL), excess body weight loss (%EWL) and percentage of body mass index loss (%BMIL) were calculated at 3 (n = 1255), 6 (n = 1172), 9 (n = 1002), and 12 months (n = 1076) after surgery. For %EWL and %BMIL a statistically significant seasonal variation was detected when the variables were calculated at 3 months, but not at the other times, with more weight loss in summer-fall. However, seasonal variations were not detected for %TWL (p = 0.09). The mean amplitude of the seasonal rhythm for %EWL was of 1.8%, while for the rhythm of %BMIL was 0.7%. Moreover, a second peak was detected in January-February modulating the seasonal rhythm of the two variables. Results confirm seasonal variations in humans and indicate that short term responses to weight loss can be modulated by the time of year.