A total weight loss of 25% shows better predictivity in evaluating the efficiency of bariatric surgery

A New Nomogram for Predicting Early Weight Loss Outcomes in Patients with Obesity Following Laparoscopic Sleeve Gastrectomy

PURPOSE

Laparoscopic sleeve gastrectomy (LSG) is an effective treatment for obesity, but early weight loss outcomes vary owing to individual nutritional and metabolic differences. We developed a nomogram model to predict early weight loss after LSG, incorporating computed tomography (CT)-based body composition metrics and preoperative inflammatory-nutritional markers.

METHODS

We retrospectively analyzed 305 patients with obesity who underwent LSG at the Affiliated Hospital of Qingdao University between January 2016 and June 2023. An external validation cohort of 105 patients from a separate institution was also included. Patients were categorized into optimal remission (%total weight loss [%TWL] ≥ 25%) and suboptimal remission (%TWL < 25%) weight loss groups one year postoperatively. Predictive variables were identified using Least Absolute Shrinkage and Selection Operator (LASSO) regression and multivariate logistic regression. A nomogram was constructed based on the significant predictors. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration curves, decision curve analysis (DCA), and clinical impact curve (CIC).

RESULTS

Independent predictors of suboptimal remission included BMI > 40 kg/m2, elevated total cholesterol, high neutrophil-to-lymphocyte ratio, high cortisol, low skeletal muscle index, and elevated visceral-to-subcutaneous adipose tissue area ratio. The constructed nomogram demonstrated strong predictive performance, with AUCs of 0.864 and 0.842 in the training and external validation cohorts, respectively. Calibration curves indicated excellent agreement between predicted and observed outcomes. DCA and CIC confirmed the model's clinical utility in both cohorts.

CONCLUSION

The developed nomogram effectively predicts early weight loss outcomes after LSG, supporting targeted perioperative management and personalized nutritional interventions.

Differences in Weight Loss Postsleeve Gastrectomy Among Patients With Various Types of Obesity Based on Waist-To-Hip Ratio Classification

Background: In recent years, laparoscopic sleeve gastrectomy (LSG) has become the main surgical procedure for weight loss, and most clinical studies have focused on the postoperative complications and treatment of metabolic syndrome after LSG. However, it is not clear whether there is a difference in the postoperative weight loss effect between patients with central and noncentral obesity after LSG. Purpose: To investigate the effect of LSG on weight loss in patients with central obesity and relationship between preoperative waist-hip ratio and weight loss effect. Methods: We conducted a retrospective study comprising 360 patients who underwent LSG at the Qianfoshan Hospital, Jinan, Shandong Province, China, between 2019 and 2024. Based on the preoperative waist-to-hip ratio (WHR), the participants were divided into central and noncentral obesity groups, and various quantitative and preoperative biochemical indices were measured. Most patients were followed up for at least 6 months. Results: There were significant differences in weight loss outcomes between women in the central and noncentral obesity groups in the first and third months after surgery; however, no significant differences were observed in the sixth and twelfth months. No significant differences were observed in weight loss outcomes between men in the central and noncentral obesity groups. There were significant differences in the development of central obesity between the two sexes and between those with and without type 2 diabetes. There were significant differences in body mass index (BMI) and white blood cell counts between women in the central and noncentral obesity groups, with patients with central obesity having higher BMI values and white blood cell counts before surgery. There were significant differences in the platelet count (PLT), gamma-glutamyl transferase (GGT), glycosylated hemoglobin A1c (HbA1c), and fasting plasma glucose (FPG) levels between men in the central and noncentral obesity groups, with patients with central obesity having lower PLT, higher GGT, HbA1c, and FPG levels. There was a significant correlation between WHR and early weight loss outcomes after surgery.

Nomogram for Predicting Suboptimal Weight Loss at Three Years after Roux-en-Y Gastric Bypass Surgery in Chinese Patients with Obesity and Type 2 Diabetes

INTRODUCTION

Strategies to address suboptimal weight loss after Roux-en-Y gastric bypass (RYGB) can be developed if at-risk patients are identified in advance. This study aimed to build a pre-surgery prediction nomogram for early prediction of insufficient weight loss (IWL) or weight regain (WR) after bariatric surgery in Chinese patients.

METHODS

In this retrospective study, 187 patients with obesity and type 2 diabetes who underwent laparoscopic RYGB were followed yearly for 3 years. Suboptimal weight loss included IWL and WR. IWL was defined as a total weight loss percentage of <25% at 1 year postoperatively, and WR was defined as a maximum weight loss percentage of >20% at 3 years postoperatively. Multivariate logistic regression was performed to identify independent predictors and to establish a nomogram to predict the occurrence of suboptimal weight loss.

RESULTS

Multivariate logistic regression revealed that male sex (OR 4.268, 95% CI: 1.413-12.890), body mass index (OR 0.816, 95% CI: 0.705-0.946), and glycated hemoglobin (OR 1.493, 95% CI: 1.049-2.126) were independent predictors of IWL/WR. The AUC value of the nomogram constructed from the above three factors was 0.781. The Hosmer-Lemeshow test showed that the model had a good fit (p = 0.143). The calibration curve of the nomogram is close to an ideal diagonal line. Furthermore, the decision curve analysis demonstrated the good net benefits of the model.

CONCLUSIONS

A nomogram based on pre-surgery factors was developed to predict postoperative IWL/WR. This provides a convenient and useful tool for predicting suboptimal weight loss before surgery.

The Impact of Longer Biliopancreatic Limb Length on Weight Loss and Comorbidity Improvement at 5 Years After Primary Roux-en-Y Gastric Bypass Surgery: A Population-Based Matched Cohort Study

INTRODUCTION

Different limb lengths are used in Roux-en-Y gastric bypass (RYGB) surgery, as there is no consensus which limb length strategy has the best outcomes. The biliopancreatic limb (BPL) is thought to play an important role in achieving weight loss and associated comorbidity resolution. The objective of this study was to assess the impact of a longer BPL on weight loss and comorbidity improvement at 5 years after primary RYGB.

METHODS

All patients aged ≥ 18 years undergoing primary RYGB between 2014-2017 with registered follow-up 5 years after surgery were included. Long BPL was defined as BPL ≥ 100 cm and short BPL as BPL < 100 cm. The primary outcome was achieving at least 25% total weight loss (TWL) at 5 years. Secondary outcomes included absolute %TWL and improvement of comorbidities. A propensity score matched logistic and linear regression was used to estimate the difference in outcomes between patients with long and short BPL.

RESULTS

At 5 years, long BPL had higher odds to achieve ≥ 25% TWL (odds ratio (OR) 1.19, 95% confidence interval (CI) [1.01 - 1.41]) and was associated with 1.26% higher absolute TWL (β = 1.26, 95% CI [0.53 - 1.99]). Furthermore, long BPL was more likely to result in improved diabetes mellitus (OR = 2.17, 95% CI [1.31 - 3.60]) and hypertension (OR = 1.45, 95% CI [1.06 - 1.99]).

CONCLUSION

Patients undergoing RYGB with longer BPL achieved higher weight loss and were more likely to achieve improvement of comorbidities at 5 years.

Major dietary patterns and their associations with total weight loss and weight loss composition 2-4 years after sleeve gastrectomy

BACKGROUND

Food intakes 1-2 years following bariatric surgery depend more on patients than the surgery's gastrointestinal tract changes. This study aimed to determine the major dietary patterns of patients after the first two years of sleeve gastrectomy and to investigate their associations with total weight loss (TWL) and the proportion of TWL as fat mass (FM) and fat-free mass (FFM) loss.

METHODS

This cross-sectional study included 146 patients undergoing sleeve gastrectomy 2-4 years after surgery. Dietary patterns were determined using principal component analysis based on the 19 food groups. The percentage of FM loss relative to TWL (%FML) and FFM loss relative to TWL (%FFML) were calculated. A suboptimal clinical response was defined as a TWL of less than 25%. High FM loss and excessive FFM loss were defined based on the highest tertiles. Linear and logistic regression models were used to derive unstandardized (B) coefficients and odds ratios (OR), with dietary pattern scores serving as both a continuous and a binary variable (higher vs. lower adherence groups based on median).

RESULTS

Two predominant dietary patterns were retained. Each 1-unit increase in the first dietary pattern score characterized by high intakes of fast foods, soft drinks, processed meats, sugar confectionary, salty snacks, grains, and organ meats was associated with higher %FFML (B = 1.99; 95% confidence interval (CI) 0.34, 3.66), lower %FML (B = - 1.84; 95% CI - 3.49, - 0.20), and higher odds of excessive FFM loss (OR = 1.84; 95% CI 1.09, 3.11). Participants with higher adherence to the first dietary pattern had lower %TWL, and greater odds of suboptimal clinical response and excessive FFM loss than those with lower adherence. Each 1-unit increase in score for the second dietary pattern characterized by a high intake of fruits, dairy, vegetables, legumes, eggs, nuts, red meats, poultry, and fish was associated with lower odds of suboptimal clinical response (OR = 0.51; 95% CI 0.31, 0.86).

CONCLUSION

Patients should be encouraged to modify their diet by reducing the consumption of ultra-processed foods and increasing their intake of high-quality protein sources, fruits, and vegetables to achieve the best postoperative outcome.

Optimizing Hospital Performance Evaluation in Total Weight Loss Outcomes After Bariatric Surgery: A Retrospective Analysis to Guide Further Improvement in Dutch Hospitals

INTRODUCTION

Bariatric surgery aims for optimal patient outcomes, often evaluated through the percentage total weight loss (%TWL). Quality registries employ funnel plots for outcome comparisons between hospitals. However, funnel plots are traditionally used for dichotomous outcomes, requiring %TWL to be dichotomized, potentially limiting feedback quality. This study evaluates whether a funnel plot around the median %TWL has better discriminatory performance than binary funnel plots for achieving at least 20% and 25% TWL.

METHODS

All hospitals performing bariatric surgery were included from the Dutch Audit for Treatment of Obesity. A funnel plot around the median was constructed using 5-year %TWL data. Hospitals positioned above the 95% control limit were colored green and those below red. The same hospitals were plotted in the binary funnel plots for 20% and 25% TWL and colored according to their performance in the funnel plot around the median. We explored the hospital's procedural mix in relation to %TWL performance as possible explanatory factors.

RESULTS

The median-based funnel plot identified four underperforming and four outperforming hospitals, while only one underperforming and no outperforming hospitals were found with the binary funnel plot for 20% TWL. The 25% TWL binary funnel plot identified two underperforming and three outperforming hospitals. The proportion of sleeve gastrectomies performed per hospital may explain part of these results as it was negatively associated with median %TWL (β =  - 0.09, 95% confidence interval [- 0.13 to - 0.04]).

CONCLUSION

The funnel plot around the median discriminated better between hospitals with significantly worse and better performance than funnel plots for dichotomized %TWL outcomes.

Adherence to Dietary Behavior Recommendations Moderates the Effect Between Time Since Metabolic and Bariatric Surgery and Percentage Total Weight Loss

PURPOSE

Metabolic and bariatric surgery (MBS) is the gold standard in treating severe obesity. Previous research implies that different psychological and behavior-related factors might be critical for MBS' sustained success. Yet adherence to dietary behavior recommendations and its impact on weight development is rarely examined. This study investigated the relationship between adherence to dietary behavior recommendations and the percentage of total weight loss (%TWL) after MBS.

MATERIALS AND METHODS

This study is a cohort study (acquisition in Germany). N = 485 patients after MBS, being in grade III of obesity (body mass index (BMI) ≥ 40 kg/m2) pre-MBS, were included. Participants answered a standardized assessment on the relevant constructs, including adherence to dietary behavior recommendations, depression symptoms, weight, diet, and MBS characteristics.

RESULTS

BMI pre-MBS, type of MBS, age, regularity of physical activity, and depression symptoms were identified as significant covariates of %TWL and adherence. Within 6 months after MBS, adherence seems to peak, F(5,352) = 12.35, p < .001. Adherence and time since MBS predict %TWL. A higher adherence (moderator) is related to a higher %TWL, R2 = 52.65%, F(13,344) = 31.54, p < .001.

CONCLUSION

After MBS, adherence to dietary behavior recommendations seems crucial for maximizing its success. Implications for the optimization of MBS' success in aftercare management arise. In particular, behavior modification interventions should be routinely implemented.

Assessing the predictive value of the suppressed 1 mg overnight dexamethasone suppression test in success of bariatric surgery

Bariatric surgery has been proven to be a successful intervention for managing obesity. There are numerous studies in the literature aiming to predict the factors influencing the success of bariatric surgery. Our study aims to determine whether preoperative 1 mg overnight dexamethasone suppression test (1 mg-DST) serum cortisol levels can serve as predictors of the effectiveness of bariatric surgery in severe obese patients without Cushing syndrome. A total of 98 patients who underwent bariatric surgery were included in the study. The preoperative 1 mg-DST levels, insulin levels, thyroid function tests, and lipid profiles of the patients were recorded. The patients' preoperative, postoperative 3rd, and 6th month weights were recorded and the percent total weight loss (%TWL) is calculated. Patients were categorized into 2 groups based on their TWL at 6 months. The 1 mg-DST results were significantly lower in the high-TWL-6 group (0.93 ± 0.37 μg/dL) compared to the low-TWL-6 group (1.09 ± 0.36 μg/dL, P = .040). Similarly, Homeostatic Model Assessment for Insulin Resistance values were lower in the high-TWL-6 group (5.63 ± 2.21) compared to the low-TWL-6 group (6.63 ± 2.55, P = .047). The optimal cutoff value found for 1 mg-DST level was 0.97 µg/dL, providing 50% sensitivity and 70% specificity. This study is the first to examine the predictive role of suppressed 1 mg-DST levels on postoperative weight loss in nondiabetic patients. The most prominent result of this study was that we observed a negative correlation between 1 mg-DST levels and %TWL.

Associations of change in body fat percentage with baseline body composition and diabetes remission after bariatric surgery

OBJECTIVE

The objective of this study was to determine the role of body fat percentage (BFP) changes in diabetes remission (DR) and the association between baseline body composition and its changes after bariatric surgery.

METHODS

We analyzed 203 patients with type 2 diabetes who underwent Roux-en-Y gastric bypass. Body composition was measured using a gold-standard-derived predictive equation and magnetic resonance imaging. Body composition changes were calculated as 100 × (baseline value - follow-up value)/baseline value. We verified the results in a laparoscopic sleeve gastrectomy cohort with 311 patients.

RESULTS

Compared with non-remission patients in the Roux-en-Y gastric bypass cohort, those who achieved DR showed a higher baseline fat-free mass index (FFMI) and experienced the most significant changes in BFP (p < 0.001). In comparative analyses, BFP changes were significantly better than BMI changes in identifying short- and long-term DR. Linear regression analysis identified FFMI as the most significant baseline variable correlated with BFP changes (p < 0.001). Baseline BMI was positively correlated with changes in BFP but negatively correlated with changes in FFMI. These findings were replicated in the laparoscopic sleeve gastrectomy cohort.

CONCLUSIONS

BFP changes determine DR after bariatric surgery, and baseline FFMI is crucial for BFP changes. A low initial BMI is associated with a smaller BFP reduction and greater FFMI loss after bariatric surgery.

Association of postoperative dietary macronutrient content and quality with total weight loss and fat-free mass loss at midterm after sleeve gastrectomy

OBJECTIVES

This study aimed to investigate the associations of macronutrient quantities and qualities with percentage total weight loss and percentage of fat-free mass loss relative to total weight loss in adults undergoing sleeve gastrectomy.

METHODS

This cross-sectional study included 146 patients on postoperative time since sleeve gastrectomy of 2 to 4 y. Diet was assessed using a food frequency questionnaire. Macronutrient quality index, carbohydrate quality index, fat quality index, and healthy plate protein quality index were calculated. The associations of dietary variables with percentage total weight loss and percentage of fat-free mass loss relative to total weight loss were determined using linear regression. Logistic regression was used to estimate the odds of non-response (percentage total weight loss < 25%) and excessive fat-free mass loss (percentage of fat-free mass loss relative to total weight loss > 28%) based on dietary intakes.

RESULTS

Forty-six (31.5%) were non-responders, and 49 (33.6%) experienced excessive fat-free mass loss. The fully adjusted model showed a 0.75 decrease in percentage total weight loss per 5% carbohydrate increase (95% CI, -1.45 to -0.05). The odds of non-response were 53% lower per 5% increase in protein (95% CI, 0.23-0.94). Each 5-g higher intake of fat was associated with 0.29 higher percentage of fat-free mass loss relative to total weight loss (95% CI, 0.03-0.55). The odds of excessive fat-free mass loss were reduced by 5% per gram of fiber intake (95% CI, 0.90-0.99). Each 5% increment in energy intake from protein that was isocalorically substituted for either carbohydrate or fat was associated with lower odds of nonresponse. Macronutrient quality indices had no significant associations.

CONCLUSIONS

Adherence to a high-protein, high-fiber diet after sleeve gastrectomy may enhance surgical success by improving total weight loss and preventing excessive fat-free mass loss.

Plasma SHBG Levels as an Early Predictor of Response to Bariatric Surgery

BACKGROUND

Obesity is a growing global health problem, and currently, bariatric surgery (BS) is the best solution in terms of sustained total weight loss (TWL). However, a significant number of patients present weight regain (WR) in time. There is a lack of biomarkers predicting the response to BS and WR during the follow-up. Plasma SHBG levels, which are low in obesity, increase 1 month after BS but there is no data of plasma SHBG levels at long term. We performed the present study aimed at exploring the SHBG role in predicting TWL and WR after BS.

METHODS

Prospective study including 62 patients with obesity undergoing BS. Anthropometric and biochemical variables, including SHBG were analyzed at baseline, 1, 6, 12, and 24 months; TWL ≥ 25% was considered as good BS response.

RESULTS

Weight loss nadir was achieved at 12 months post-BS where maximum SHBG increase was reached. Greater than or equal to 25% TWL patients presented significantly higher SHBG increases at the first and sixth months of follow-up with respect to baseline (100% and 150% respectively, p = 0.025), than < 25% TWL patients (40% and 50% respectively, p = 0.03). Also, these presented 6.6% WR after 24 months. The first month SHBG increase predicted BS response at 24 months (OR = 2.71; 95%CI = [1.11-6.60]; p = 0.028) and TWL in the 12th month (r = 0.330, p = 0.012) and the WR in the 24th (r =  - 0.301, p = 0.028).

CONCLUSIONS

Our results showed for the first time that increase in plasma SHBG levels within the first month after BS is a good predictor of TWL and WR response after 2 years.

The Relationship between Depressive Symptoms, Quality of Life and miRNAs 8 Years after Bariatric Surgery

(1) Background: There are conflicting results on whether weight loss after bariatric surgery (BS) might be associated with quality of life (QoL)/depressive symptomatology. We aim to determine whether BS outcomes are associated with QoL/depressive symptomatology in studied patients at the 8-year follow-up after BS, as well as their relationship with different serum proteins and miRNAs. (2) Methods: A total of 53 patients with class III obesity who underwent BS, and then classified into "good responders" and "non-responders" depending on the percentage of excess weight lost (%EWL) 8 years after BS (%EWL ≥ 50% and %EWL < 50%, respectively), were included. Basal serum miRNAs and different proteins were analysed, and patients completed tests to evaluate QoL/depressive symptomatology at 8 years after BS. (3) Results: The good responders group showed higher scores on SF-36 scales of physical functioning, role functioning-physical, role functioning-emotional, body pain and global general health compared with the non-responders. The expression of hsa-miR-101-3p, hsa-miR-15a-5p, hsa-miR-29c-3p, hsa-miR-144-3p and hsa-miR-19b-3p were lower in non-responders. Hsa-miR-19b-3p was the variable associated with the response to BS in a logistic regression model. (4) Conclusions: The mental health of patients after BS is limited by the success of the intervention. In addition, the expression of basal serum miRNAs related to depression/anxiety could predict the success of BS.

Effect of regional body composition changes on bone density remodeling after sleeve gastrectomy

Background

Sleeve gastrectomy (SG) results in bone mineral density (BMD) loss and varying body composition parameters. However, the effects of body compositions on bone health are controversial. In order to accurately demonstrate their relationship and provide new insights into the causes of BMD loss after sleeve gastrectomy, this study is aimed to investigate the role of changes in body composition in BMD loss 12 months after SG.

Methods

41 Chinese individuals with obesity (25 women and 16 men) who underwent SG were prospectively examined for at least 12 months. Measurements of anthropometrics, body composition, BMD and blood samples were collected.

Results

For 12 months, the femoral neck (FN) BMD and total hip (TH) BMD decreased significantly compared with baseline in both sexes but not lumbar spine (LS) BMD. Greater TH BMD loss was observed in men than in women. For the first 6 months post-SG, the FN BMD loss was positively associated with the estimated fat free mass index (eFFMI) reduction in women (adjusted β = 0.77, P = 0.004) and positively associated with reduction of subcutaneous fat area (SFA) in men (r = 0.931, P = 0.007). For 12 months post-SG, the FN BMD loss was negatively associated with visceral fat area (VFA) reduction in women (adjusted β = -0.58, P = 0.027) and men (adjusted β = -0.68, P = 0.032). TH BMD loss was positively associated with waist circumference reduction in women (r = 0.448, P = 0.028).

Conclusion

FN and TH BMD decrease after SG in both women and men. The changes in body compositions are associated with BMD loss at different time points and bone sites. Our data emphasize the limitation of simply taking the total weight loss (% TWL) as an influencing factor of bone mineral density and the necessity of delineating body composition in relevant studies.

Constructing and Validating a Dynamic Nomogram to Predict Response to Bariatric Surgery: A Multicenter Retrospective Study

PURPOSE

Suboptimal response is one of the major problems for bariatric surgery, and constructing an individualized model for predicting outcomes of bariatric surgery is essential. Thus, the aim of this study is to develop a nomogram to predict the response to bariatric surgery.

MATERIALS AND METHODS

509 patients who underwent bariatric surgery between 2019 to 2020 from 6 centers were retrieved and assessed. Multiple Imputation was used to replace missing data. Patients with %TWL ≥ 20% 1 year after bariatric surgery were classified as patients with optimal response, while the others were patients with suboptimal response. A web-based nomogram was constructed and validated. ROC curve and calibration curve were used to determine the predictive ability of our model.

RESULTS

56 (11.0%) patients were classified as patients with suboptimal response, and they showed advanced age, lower pre-operative BMI, smaller waist circumference, higher fasting glucose, higher HbA1c and lower fasting insulin compared to patients with optimal response. A forward likelihood ratio logistic regression analysis indicated that age (OR = 0.943, 95% CI: 0.915-0.971, p < 0.001), pre-operative BMI (OR = 1.109, 95% CI: 1.002-1.228, p = 0.046) and waist circumference (OR = 1.043, 95% CI: 1.000-1.088, p = 0.048) were essential factors contributing to the response to bariatric surgery. Lastly, a web-based nomogram was constructed to predict the response to bariatric surgery and demonstrated an AUC of 0.829 and 0.798 upon internal and external validation.

CONCLUSION

Age, BMI and fasting glucose were proved to be essential factors influencing the response to bariatric surgery. The nomogram constructed in this study demonstrated good adaptivity.

Determination of weight loss effectiveness evaluation indexes and establishment of a nomogram for forecasting the probability of effectiveness of weight loss in bariatric surgery: a retrospective cohort

BACKGROUND

The purpose of this research was to determine the index that contributes the most to assessing the effectiveness of weight loss 1 year following bariatric surgery and to implement it as the clinical outcome to develop and confirm a nomogram to predict whether bariatric surgery would be effective.

METHODS

Patient information was extracted from the Chinese Obesity and Metabolic Surgery Database for this retrospective study. The most contributing weight loss effectiveness evaluation index was created using canonical correlation analysis (CCA), and the predictors were screened using logistic regression analysis. A nomogram for estimating the likelihood of effectiveness of weight loss was constructed, and its performance was further verified.

RESULTS

Information was obtained for 540 patients, including 30 variables. According to the CCA, ≥25 percentage total weight loss was found to be the most correlated with patient information and contribute the most as a weight loss effectiveness evaluation index. Logistic regression analysis and nomogram scores identified age, surgical strategy, abdominal circumference, weight loss history, and hyperlipidemia as predictors of effectiveness in weight loss. The prediction model's discrimination, accuracy, and clinical benefit were demonstrated by the consistency index, calibration curve, and decision curve analysis.

CONCLUSIONS

The authors determined a 25 percentage total weight loss as an index for weight loss effectiveness assessment by CCA and next established and validated a nomogram, which demonstrated promising performance in predicting the probability of effectiveness of weight loss in bariatric surgery. The nomogram might be a valuable tool in clinical practice.

Preoperative Serum Cortisol Level Is Predictive of Weight Loss After Laparoscopic Sleeve Gastrectomy in Men with Severe Obesity but Not Women

BACKGROUND

Bariatric surgery is an effective treatment for severe obesity and its associated medical problems. Preoperative factors that predict postoperative weight loss remain to be fully characterized, however.

METHODS

Anthropometric and laboratory data were collected retrospectively for severely obese patients who underwent laparoscopic sleeve gastrectomy (LSG) between April 2016 and July 2019 at our hospital. Preoperative factors that predicted weight loss at 1 year after LSG were investigated.

RESULTS

A total of 122 subjects (45 men and 77 women) underwent LSG. The mean ± SD age and body mass index at surgery were 44.4 ± 10.4 years and 40.7 ± 6.7 kg/m². The percent total weight loss (%TWL) was 27.0 ± 8.6 among all subjects, 26.4 ± 8.0 among men, and 27.4 ± 8.9 among women, with no significant difference between the sexes. The %TWL showed a significant inverse correlation with serum cortisol level in men and with age and the visceral/subcutaneous fat area ratio in women. Multivariable regression analysis revealed the presence of type 2 diabetes and the serum cortisol concentration to be negatively associated with %TWL among all subjects and men, respectively. Receiver operating characteristic curve analysis identified an optimal cutoff of 10 µg/dL for prediction of a %TWL of ≥ 25 in men by serum cortisol level.

CONCLUSIONS

Serum cortisol concentration was identified as a predictor for postoperative weight loss in men. Our results may thus help inform the decision to perform LSG or more effective surgical procedures in men with severe obesity.

Sex-specific differences in bone mineral density loss after sleeve gastrectomy

Background

Sleeve gastrectomy is an effective bariatric procedure; however, sleeve gastrectomy-related adverse skeletal outcomes have been increasingly reported. High levels of sex hormone-binding globulin (SHBG) have been documented to be a risk factor of bone mineral density (BMD) loss with different effects observed between sexes. The aim of this study was to identify sex-specific changes in BMD following sleeve gastrectomy and to evaluate the role of SHBG in this process.

Methods

This retrospective study included 19 middle-aged men and 30 non-menopausal women with obesity who underwent sleeve gastrectomy in China. Anthropometrics, bone turnover markers, calciotropic hormones, BMD, SHBG, and gonadal steroids were measured preoperatively and at 6 and 12 months postoperatively. Longitudinal changes in BMD, bone turnover markers and SHBG were compared between sexes by linear mixed models. Multiple stepwise regression analysis was used to identify the predictors of BMD loss at the investigated bone sites.

Results

Over the 12-month study period, total hip and femoral neck BMD decreased, while lumbar spine BMD remained largely unchanged in both sexes. Linear mixed models revealed significant sex × time interaction effects in total hip BMD and SHBG, showing that men had a significantly greater reduction in total hip BMD and less increase in SHBG after sleeve gastrectomy than women. In the multivariate model, SHBG was significantly associated with total hip BMD loss in men (adjusted β = −0.533, P = 0.019) but not women while total estrogen was significantly associated with total hip BMD loss in women (adjusted β = 0.508, P = 0.01) but not men.

Conclusion

Significant sex-specific BMD changes were observed after sleeve gastrectomy in the current study. Sleeve gastrectomy-related increase in SHBG may be a specific risk factor for total hip BMD loss in men. Our results indicate that sex-specific screening may be warranted to facilitate personalized postoperative bone care in this population.

Distal gastric bypass revision for weight recurrence or nonresponse to primary procedure: initial experience and outcomes in an academic practice

BACKGROUND

Considerable weight recurrence (WR) after Roux-en-Y gastric bypass (RYGB) may occur in nearly 20% of patients. While several nonoperative, endoscopic, and surgical interventions exist for this population, the optimal approach is unknown. This study reports our initial experience with distal bypass revision (DGB) and provides a comparison with patients after primary RYGB.

METHODS

Single-institution, retrospective review was conducted for patients who underwent DGB from 2018 to 2020. A Roux and common channel of 150 cm each were constructed (total alimentary limb 300 cm). A group of primary RYGB patients with similar demographics were selected as controls. Demographics, comorbidity resolution, surgical technique, complications, excess weight loss (EWL), total weight loss (TWL), BMI, and weight change data were compared. Patient postoperative weight loss (WL) was also compared after their primary and DGB operations.

RESULTS

Sixteen DGB patients, all female, were compared with 29 controls. DGB was performed on average 12.3 years after primary RYGB. In the DGB group, mean BMI was 53.7 before primary RYGB, 31.9 at nadir, and 44.1 prior to DGB. Post-DGB, mean BMI was 40.5, 37.4, 34.8, and 34.4, at 3-, 6-, 12-, and 24-months, respectively. Five patients (31.3%) experienced complications and were readmitted within 30 days, with two of them (12.5%) requiring reintervention and one (6.3%) undergoing reoperation. Mean EWL and TWL up to 2 years after DGB were lower than that after the patient's original RYGB (52.3 ± 18.6 vs. 67.2 ± 33.2; p = 0.126 and 19.6 ± 13.3 vs. 29.6 ± 11.8; p = 0.027, respectively).

CONCLUSIONS

DGB resulted in excellent WL up to 2 years after surgery but was associated with considerable postoperative complication rates. The magnitude of TWL was lower compared with the primary operation. Only a few patients experienced nutritional complications. Results of this study can help counsel patients pursuing DGB for WR or nonresponse to primary RYGB. The comparative effectiveness of this approach to other available options remains to be determined.

Hospital Variation in Preference for a Specific Bariatric Procedure and the Association with Weight Loss Performance: a Nationwide Analysis

PURPOSE

Hospitals performing a certain bariatric procedure in high volumes may have better outcomes. However, they could also have worse outcomes for some patients who are better off receiving another procedure. This study evaluates the effect of hospital preference for a specific type of bariatric procedure on their overall weight loss results.

METHODS

All hospitals performing bariatric surgery were included from the nationwide Dutch Audit for Treatment of Obesity. For each hospital, the expected (E) numbers of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one-anastomosis gastric bypass (OAGB) were calculated given their patient-mix. These were compared with the observed (O) numbers as the O/E ratio in a funnel plot. The 95% control intervals were used to identify outlier hospitals performing a certain procedure significantly more often than expected given their patient-mix (defined as hospital preference for that procedure). Similarly, funnel plots were created for the outcome of patients achieving ≥ 25% total weight loss (TWL) after 2 years, which was linked to each hospital's preference.

RESULTS

A total of 34,558 patients were included, with 23,154 patients completing a 2-year follow-up, of whom 79.6% achieved ≥ 25%TWL. Nine hospitals had a preference for RYGB (range O/E ratio [1.09-1.53]), with 1 having significantly more patients achieving ≥ 25%TWL (O/E ratio [1.06]). Of 6 hospitals with a preference for SG (range O/E ratio [1.10-2.71]), one hospital had significantly fewer patients achieving ≥ 25%TWL (O/E ratio [0.90]), and from two hospitals with a preference for OAGB (range O/E ratio [4.0-6.0]), one had significantly more patients achieving ≥ 25%TWL (O/E ratio [1.07]). One hospital had no preference for any procedure but did have significantly more patients achieving ≥ 25%TWL (O/E ratio [1.10]).

CONCLUSION

Hospital preference is not consistently associated with better overall weight loss results. This suggests that even though experience with a procedure may be slightly less in hospitals not having a preference, it is still sufficient to achieve similar weight loss outcomes when surgery is provided in centralized high-volume bariatric institutions.

Prevalence of sarcopenia in women at stable weight phase after Roux-en-Y gastric bypass

Objective

Evaluating the prevalence of sarcopenia in women submitted to bariatric surgery - Roux-en-Y gastric bypass. Design: Observational, cross-sectional study.

Subjects and methods

Women (18-65 years old) who underwent bariatric surgery (BG) ≥ 2 years and reached stable weight ≥ 6 months, were investigated. Control group (CG) comprised non-operated matched women with obesity. Body composition was determined through dual-energy X-ray absorptiometry. Low lean mass (LLM) was defined as appendicular lean mass index (ALM kg/height m2) < 5.5 kg/m2. Physical strength was assessed through dynamometer and sit-to-stand test (SST), whereas performance was assessed through 4-m gait speed and Short Physical Performance Battery Tests (SPPB). Sarcopenia was diagnosed in the presence of LLM and low strength.

Results

One-hundred and twenty women (60 in each group, 50 ± 9.7 years old) were investigated. All anthropometric and body composition parameters were lower in BG than in CG, whereas strength and performance were similar between groups. Women with reduced strength presented high total fat mass and low physical activity level (p < 0.005). LLM was observed in 35% of BG and in 18.3% of CG (p = 0.04), whereas sarcopenia was diagnosed in 28.3% of BG and in 16.6% of CG (p = 0.12). Sarcopenic women in BG had better performance both in SST (p = 0.001) and SPPB (p = 0.004). Total lean mass (OR:1.41, 95% CI [1.18; 1.69], p < 0.001) and obesity (OR: 38.2 [2.27; 644.12], p < 0.001) were associated with sarcopenia in the multivariate analysis.

Conclusion

Despite great weight loss, sarcopenia prevalence did not increase in BG and its presence was influenced by total lean mass and obesity.

Development of a New Index Based on Preoperative Serum Lipocalin 2 to Predict Post-LSG Weight Reduction

Background

Bariatric surgery is the most effective therapy for obesity, but targeted weight reduction is not always achieved. Serum lipocalin-2 (LCN2) is closely associated with obesity, but its impact on weight loss after surgery is unknown. We aimed to access the reliability of LCN2 levels and other parameters as effective predictors of excellent weight loss (≥ 75% excess weight loss (EWL)) 1 year after bariatric surgery.

Methods

This retrospective study evaluated 450 patients (aged 18–65 years) with obesity at 3 months and 1 year after laparoscopic sleeve gastrectomy (LSG) surgery. Seventy-four patients who underwent LSG surgery and met the inclusion and exclusion criteria were included in this study. Serum LCN2, thyroid function, and metabolic and anthropometric parameters were assessed. Weight reduction was expressed as %EWL and percent total weight loss (%TWL) at 3 months and 1 year post surgery. Multivariable logistic regression analysis and receiver operating characteristic (ROC) curve analysis were used to evaluate predictors of ≥ 75%EWL.

Results

In our cohort, %EWL and %TWL were both strongly associated with preoperative serum LCN2 levels. The binary logistic regression analysis showed that preoperative LCN2, waist circumference, and glycated hemoglobin were independent predictors of excellent weight loss.

Conclusions

Based on these results, we determined a new P index with better predictive value for excellent weight reduction (≥ 75%EWL) 1 year after LSG surgery.

Graphical abstract

Food Reward after Bariatric Surgery and Weight Loss Outcomes: An Exploratory Study

Changes in food preferences after bariatric surgery may alter its effectiveness as a treatment for obesity. We aimed to compare food reward for a comprehensive variety of food categories between patients who received a sleeve gastrectomy (SG) or a Roux-en-Y gastric bypass (RYGB) and to explore whether food reward differs according to weight loss. In this cross-sectional exploratory study, food reward was assessed using the Leeds Food Preference Questionnaire (LFPQ) in patients at 6, 12, or 24 months after SG or RYGB. We assessed the liking and wanting of 11 food categories. Comparisons were done regarding the type of surgery and total weight loss (TWL; based on tertile distribution). Fifty-six patients (30 SG and 26 RYGB) were included (women: 70%; age: 44.0 (11.1) y). Regarding the type of surgery, scores were not significantly different between SG and RYGB, except for ‘non-dairy products—without color’ explicit liking (p = 0.04). Regarding TWL outcomes, explicit liking, explicit wanting, and implicit wanting, scores were significantly higher for good responders than low responders for ‘No meat—High fat’ (post-hoc corrected p-value: 0.04, 0.03, and 0.04, respectively). Together, our results failed to identify major differences in liking and wanting between the types of surgery and tended to indicate that higher weight loss might be related to a higher reward for high protein-content food. Rather focus only on palatable foods, future studies should also consider a broader range of food items, including protein reward.

Minimum Threshold of Bariatric Surgical Weight Loss for Initial Diabetes Remission

OBJECTIVE

There are few studies testing the amount of weight loss necessary to achieve initial remission of type 2 diabetes mellitus (T2DM) following bariatric surgery and no published studies with use of weight loss to predict initial T2DM remission in sleeve gastrectomy (SG) patients.

RESEARCH DESIGN AND METHODS

With Cox proportional hazards models we examined the relationship between initial T2DM remission and percent total weight loss (%TWL) after bariatric surgery. Categories of %TWL were included in the model as time-varying covariates.

RESULTS

Of patients (N = 5,928), 73% were female; mean age was 49.8 ± 10.3 years and BMI 43.8 ± 6.92 kg/m2, and 57% had Roux-en-Y gastric bypass (RYGB). Over an average follow-up of 5.9 years, 71% of patients experienced initial remission of T2DM (mean time to remission 1.0 year). With 0-5% TWL used as the reference group in Cox proportional hazards models, patients were more likely to remit with each 5% increase in TWL until 20% TWL (hazard ratio range 1.97-2.92). When categories >25% TWL were examined, all patients had a likelihood of initial remission similar to that of 20-25% TWL. Patients who achieved >20% TWL were more likely to achieve initial T2DM remission than patients with 0-5% TWL, even if they were using insulin at the time of surgery.

CONCLUSIONS

Weight loss after bariatric surgery is strongly associated with initial T2DM remission; however, above a threshold of 20% TWL, rates of initial T2DM remission did not increase substantially. Achieving this threshold is also associated with initial remission even in patients who traditionally experience lower rates of remission, such as patients taking insulin.

Development and validation of a scoring system for pre-surgical and early post-surgical prediction of bariatric surgery unsuccess at 2 years

Bariatric surgery (BS) is an effective treatment for morbid obesity. However, a simple and easy-to-use tool for the prediction of BS unsuccess is still lacking. Baseline and follow-up data from 300 consecutive patients who underwent BS were retrospectively collected. Supervised regression and machine-learning techniques were used for model development, in which BS unsuccess at 2 years was defined as a percentage of excess-weight-loss (%EWL) < 50%. Model performances were also assessed considering the percentage of total-weight-loss (%TWL) as the reference parameter. Two scoring systems (NAG-score and ENAG-score) were developed. NAG-score, comprising only pre-surgical data, was structured on a 4.5-point-scale (2 points for neck circumference ≥ 44 cm, 1.5 for age ≥ 50 years, and 1 for fasting glucose ≥ 118 mg/dL). ENAG-score, including also early post-operative data, was structured on a 7-point-scale (3 points for %EWL at 6 months ≤ 45%, 1.5 for neck circumference ≥ 44 cm, 1 for age ≥ 50 years, and 1.5 for fasting glucose ≥ 118 mg/dL). A 3-class-clustering was proposed for clinical application. In conclusion, our study proposed two scoring systems for pre-surgical and early post-surgical prediction of 2-year BS weight-loss, which may be useful to guide the pre-operative assessment, the appropriate balance of patients' expectations, and the post-operative care.

Metabolic surgery in China: present and future

Obesity and its related complications comprise a serious public health problem worldwide, and obesity is increasing in China. Metabolic surgery is a new type of treatment with unique advantages in weight loss and obesity-related metabolic complications. The pathogenesis of obesity is complex and not yet fully understood. Here, we review the current efficacy and safety of metabolic surgery, as well as recent progress in mechanistic studies and surgical procedures in China. The exciting and rapid advances in this field provide new opportunities for patients with obesity and strike a balance between long-term effectiveness and safety.

Effect of postbariatric maternal weight loss and surgery to conception interval on perinatal outcomes of nulliparous women

BACKGROUND

Bariatric surgery is associated with an increased risk of delivering a small neonate. The role of maternal weight loss and surgery to conception interval is unclear.

OBJECTIVES

To investigate the effect of maternal weight loss, as a result of bariatric surgery, and surgery to conception interval on fetal growth and birthweight (BW).

SETTING

Inner London Teaching Hospital METHODS: We studied prospectively nulliparous women with previous bariatric surgery. Information on type, time, and presurgery weight was obtained. Surgery-to-conception interval was calculated as the time between surgery and conception, defined as the fourteenth day of the pregnancy dated by first trimester ultrasound scan. In the first trimester, maternal weight was measured. Assessment of maternal weight change between presurgery and first trimester of pregnancy was defined as total weight loss (TWL) (%). Fetal ultrasound scans were performed twice; 30-32 and 35-37 weeks' gestation and estimated fetal weight (EFW) was calculated. Fetal growth rate was calculated as the ratio of EFW increase (in grams) between 30-32 and 35-37 weeks divided by the time interval (in days) between the 2 examinations. BW was recorded.

RESULTS

The study included 54 pregnant women, 26 with a restrictive procedure (gastric band or vertical sleeve gastrectomy) and 28 with a gastric bypass. Surgery to conception interval was not a significant predictor of the offspring's growth. Maternal TWL was a significant predictor of fetal growth rate (P = .04) and predictor of BW (P = .005), even after adjustment for confounders.

CONCLUSIONS

Maternal weight loss, as a result of bariatric surgery, has an inverse correlation with fetal growth rate and BW.