A Comparison of the Effects of Roux-en-Y Gastric Bypass and Sleeve Gastrectomy on Body Mass Composition as Measured by Air Displacement Plethysmography

Effect of laparoscopic sleeve gastrectomy versus laparoscopic Roux-en-Y gastric bypass on body composition

BACKGROUND

There is limited data with respect to body composition changes for laparoscopic sleeve gastrectomy (SG) and laparoscopic Roux-en-Y gastric bypass (RYGB). The objective of this study was to analyse changes in body composition between these two procedures during the first year after bariatric surgery.

METHODS

A prospective study was performed in patients undergoing bariatric surgery at two tertiary hospitals between 2017 and 2023. Body composition was assessed with dual-energy x-ray absorptiometry immediately before surgery, and at 1-, 6-, 12-, 18- and 24-months post-operatively, with a subgroup analysis performed for patients who undertook a scan at 18- and 24-months. Total weight loss (TWL), body mass index (BMI), fat mass (FM), lean body mass (LBM) and bone mineral content (BMC) parameters were compared between SG and RYGB.

RESULTS

Forty-five patients were included in this series (SG n = 30, RYGB n = 15). There was a significant reduction in mean %TWL of 26.94 ± 8.86% and mean BMI of 11.12 ± 3.70 kg/m2 over 12-months. LBM accounted for 17.8% of TWL over 12-months, SG and RYGB did not differ in terms of loss of FM or LBM. For both procedures, the loss of LBM appeared to plateau at 6-months post-operatively. The only statistically significant finding between the two procedures was that RYGB resulted in an additional 0.06 kg loss compared with SG.

CONCLUSION

SG and RYGB have been shown to have comparable weight loss and body composition changes in the short-to-medium term following surgery. LBM reduction was most significant in the early post-operative period across the entire cohort.

Effect on Body Composition of a Meal-Replacement Progression Diet in Patients 1 Month after Bariatric Surgery

BACKGROUND

Progression diets after bariatric surgery (BS) are restricted in calories and protein, and they may induce a worsening of body composition. The aim of this study was to evaluate the effect of a modified diet with an oral nutritional supplement that is hyperproteic and normocaloric over the body composition.

METHODS

A two-arm ambispective observational cohort study was designed. Forty-four patients who underwent sleeve gastrectomy were included in the study. Thirty patients received a progression diet with a normocaloric, hyperproteic oral nutritional supplement during the first two weeks after surgery (820 kcal, 65.5 g protein). They were compared with a historical cohort of 14 patients treated with a standard progression diet (220 kcal, 11.5 g protein). Anthropometric and body composition (using electrical bioimpedanciometry) data were analyzed before BS and 1 month after the surgery.

RESULTS

The mean age was 47.35(10.22) years; 75% were women, and the average presurgical body mass index (BMI) was 45.98(6.13) kg/m2, with no differences between both arms of intervention. One month after surgery, no differences in the percentage of excess weight loss (%PEWL) were observed between patients in the high-protein-diet group (HP) and low-protein-diet group (LP) (HP: 21.86 (12.60)%; LP: 18.10 (13.49)%; p = 0.38). A lower loss of appendicular skeletal muscle mass index was observed in the HP (HP: -5.70 (8.79)%; LP: -10.54 (6.29)%; p < 0.05) and fat-free mass index (HP: 3.86 (8.50)%; LP:-9.44 (5.75)%; p = 0.03), while a higher loss of fat mass was observed in the HP (HP: -14.22 (10.09)%; LP: -5.26 (11.08)%; p < 0.01).

CONCLUSIONS

In patients undergoing gastric sleeve surgery, the addition of a normocaloric, hyperproteic formula managed to slow down the loss of muscle mass and increase the loss of fat mass with no differences on total weight loss.

Risedronate use may blunt appendicular lean mass loss secondary to sleeve gastrectomy: Results from a pilot randomized controlled trial

Background

Despite robust weight loss and cardiometabolic benefit, lean mass loss following sleeve gastrectomy (SG) confers health risk. Bisphosphonates are a potential therapeutic agent for lean mass maintenance. Thus, our objective was to explore the effect of six months of risedronate (vs placebo) on change in dual energy x-ray absorptiometry (DXA) and computed tomography (CT) derived lean mass metrics in the year following SG.

Methods

24 SG patients were randomized to six months of 150 mg oral risedronate or placebo capsules (NCT03411902). Body composition was assessed at baseline and six months with optional 12-month follow-up using whole-body DXA and CT at the lumbar spine and mid-thigh. Group treatment effects and 95% CIs were generated from a mixed model using contrast statements at six and 12 months, adjusted for baseline values.

Results

Of 24 participants enrolled [55.7±6.7 years (mean±SD), 79% Caucasian, 83% women, body mass index (BMI) 44.7±6.3kg/m2], 21 returned for six-month testing, and 14 returned for 12-month testing. Six-month weight loss was -16.3 kg (-20.0, -12.5) and -20.9 kg (-23.7, -18.1) in the risedronate and placebo groups, respectively (p=.057). Primary analysis at six-months revealed a non-significant sparing of appendicular lean mass in the risedronate group compared to placebo [-1.2 kg (-2.3, -0.1) vs -2.1 kg (-3.0, -1.2)]; p=.20. By 12-months, the risedronate group displayed no change in appendicular lean mass from baseline [-0.5 kg (-1.5, 0.6)]; however, the placebo group experienced significantly augmented loss [-2.9 kg (-3.6, -2.1)].

Conclusion

Pilot data indicate risedronate treatment may mitigate appendicular lean mass loss following SG. Further study is warranted.

Alterations in Fecal Short-Chain Fatty Acids after Bariatric Surgery: Relationship with Dietary Intake and Weight Loss

Bariatric surgery is associated with weight loss attributed to reduced caloric intake, mechanical changes, and alterations in gut hormones. However, some studies have suggested a heightened incidence of colorectal cancer (CRC) has been associated with bariatric surgery, emphasizing the importance of identifying mechanisms of risk. The objective of this study was to determine if bariatric surgery is associated with decreases in fecal short-chain fatty acids (SCFA), a group of bacterial metabolites of fiber. Fecal samples (n = 22) were collected pre- (~6 weeks) and post-bariatric surgery (~4 months) in patients undergoing Roux-en-Y gastric bypass and sleeve gastrectomy. SCFA levels were quantified using liquid chromatography/mass spectrometry. Dietary intake was quantified using 24-h dietary recalls. Using an aggregate variable, straight SCFAs significantly decreased by 27% from pre- to post-surgery, specifically acetate, propionate, butyrate, and valerate. Pre-surgery weight was inversely associated with butyrate, with no association remaining post-surgery. Multiple food groups were positively (sugars, milk, and red and orange vegetables) and inversely (animal protein) associated with SCFA levels. Our results suggest a potential mechanism linking dietary intake and SCFA levels with CRC risk post-bariatric surgery with implications for interventions to increase SCFA levels.

Excessive weight loss after bariatric surgery: a prediction model retrospective cohort study

Bariatric surgery has been recognized as the most effective long-term treatment for morbid obesity. Despite the considerable positive results, adverse consequence can develop. Excessive Weight Loss (EXWL), a rare consequence of bariatric surgery, can lead to a broad adverse consequence. The aim of this study was determining of prevalence and the predicting model of EXWL in patient underwent bariatric surgery until 24 months after surgery. Data have been extracted from the National Obesity Surgery Database in obesity clinic of Iran University of Medical Sciences. The subjects of this retrospective cohort study were morbid obese individuals who underwent three various types of bariatric surgery [One Anastomosis Gastric Bypass (OAGB), Roux-en-Y Gastric Bypass (RYGB), or Sleeve Gastrectomy (SG)] in period of 24 months ago. EXWL has been defined as reaching to less than or equal to BMI 18.5 at any time until 24 months after surgery. SPSS was used in data analysis. Among 4214 subjects of this study, most excess weight loss after surgery has taken place in 18 months after surgery. 11.4% (n = 495) of patients experienced EXWL with highest percentage among OAGB patients (15.1%) at time of 24 months after surgery. The females (20.4% vs.9.9%) and younger persons (35.45 ± 10.25 vs. 39.06 ± 10.76) were more susceptible to EXWL. Patients with EXWL had significantly lower BMI (body mass index) (41.11 ± 4.51 vs. 46.73 ± 6.26) (Kg/m2), and were less probable to had emotional eating. Visceral fat level, fat percentage, and BMI were the best predictor of EXWL (P value for all < 0.05). So that per level increase in visceral fat, decreases the probability of EXWL as 47% and 61% in SG and OAGB. Moreover, each unit lower BMI leads to 25% higher susceptibility to experience EXWL. Surgery should be adjusted in younger females with a lower BMI and healthy metabolic status who are more prone to EXWL. In such a way that minimize weight loss speed/value. It may be possible by selection of other surgery procedures, rather than OAGB, tighter follow-ups, and consultations of patients after surgery is emphasized for more EXWL vulnerable patients.

Surgical Treatment of Obesity. Special Mention to Roux-en-Y Gastric Bypass and Vertical Gastrectomy

INTRODUCTION

The prevalence of obesity has increased exponentially in recent decades, being one of the diseases that most affects global health. It is a chronic disease associated with multiple comorbidities, which lead to a decrease in life expectancy and quality of life. It requires a multidisciplinary approach by a specialized medical team. Obesity can be treated with conservative or with surgical treatments that will depend on the characteristics of the patient.

OBJECTIVE/METHODOLOGY

The referenced surgery can be performed using different surgical techniques that are analyzed in the present work through an exhaustive narrative bibliographic review in the PubMed and Cochrane databases, as well as in UpToDate.

RESULTS

Currently, those most used are restrictive techniques, specifically vertical gastrectomy and mixed techniques, with gastric bypass being the "gold standard".

CONCLUSIONS

In order to choose one technique or another, the characteristics of each patient and the experience of the surgical team must be taken into account.

The Effect of Protein Consumption on Fat-Free Mass, Fat Mass, and Weight Loss 1 Year After Sleeve Gastrectomy and Roux-en-Y Gastric Bypass

OBJECTIVE

Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) both limit protein and calorie intake and result in loss of fat-free mass (FFM), fat mass (FM), and weight. This study examined protein consumption and body composition changes after bariatric surgery.

METHODS

A prospective study of patients undergoing SG and RYGB between January 1 and December 31, 2016, with 1-year follow-up. Dietary, body composition, and physical activity data were collected at 3, 6, and 12 months post-operatively by bioelectric impedance and food records. Clinical laboratory data were obtained pre- and post-surgery.

RESULTS

One hundred and five patients (62 [59%] SG and 43 [41%] RYGB) were included in this study. Mean age was 31.8 ± 7.22 years. TWL% after 1 year in SG was 27.11% (p < 0.001) and that in RYGB was 30.41% (p < 0.0001). Reported protein consumptions after RYGB increased from 41.59 ± 22.86 g/day at 3 months (p = 0.004) to 57.90 ± 19.24 g/day at 12 months compared to 52.36 ± 25.04 g and 53.54 ± 29.75 g in SG. Similarly, energy intake after RYGB at 3 and 12 months increased from 895.9 ± 422.61 to 1188.15 ± 463.86 kcal/day compared to 1007.67 ± 422.62 to 1068 ± 575.89 kcal/day after SG (p = 0.009). There was a significant loss of fat-free mass and muscle mass in SG patients at 3 and 12 months from 61.58 ± 3.61 kg and 58.47 ± 3.09 kg to 54.18 ± 11.05 (p < 0.001) and 51.55 ± 10.62 (p = 0.004) but not in RYGB patients. Physical activity levels were similar in SG and RYGB patients.

CONCLUSION

There was a significant preservation of muscle mass after RYGB. Protein intake in majority of the patients was below 60 g/day during the first year after SG and RYGB.

The Influence of Laparoscopic Sleeve Gastrectomy on Body Composition and Fat Distribution in Obese Caucasian Men and Women

Background

The aim of the study was to assess changes in body composition in patients subjected to laparoscopic sleeve gastrectomy (LSG).

Methods

Changes in body composition following LSG were determined in a group of 155 patients with obesity (117 women and 38 men), with dual-energy X-ray absorptiometry (DXA). Whole body fat mass (FM) and lean body mass (LBM) were determined, and abdominal fat mass (AbdF) was assessed within the region extending from the top of the pubic bone up to the line between 12th thoracic and 1st lumbar vertebras.

Results

Over the period of 12 months following LSG, body mass index decreased by 28.2 ± 9.0% (p < 0.001). The reduction of body weight by 35.4 ± 12.6 kg (p < 0.001) was the result of a decrease in FM by 23.9 ± 8.9 kg (p < 0.001) and LBM by 10.5 ± 3.8 kg (p < 0.001). AbdF decreased from 13.2 ± 3.1 to 8.2 ± 2.7 kg (p < 0.001), but abdominal fat to total fat mass ratio increased from 24.9 ± 4.7 to 28.0 ± 5.8% (p < 0.001). The loss of AbdF was more pronounced in men than in women. The rate of FM loss was attenuated with patients’ age.

Conclusions

Over the period of 12 months following LSG, the reduction of FM was more than twice as much as decrease of LBM. The loss of AbdF was slower than a loss of peripheral subcutaneous fat.

Changes in serum albumin and liver enzymes following three different types of bariatric surgery: six-month follow-up. A retrospective cohort study

BACKGROUND

Few reports have examined the effects of Roux-en-Y gastric bypass (RYGB), one-anastomosis gastric bypass (OAGB) and sleeve gastrectomy (SG) on changes to serum albumin (Alb) and liver enzyme levels.

OBJECTIVE

To compare short-term post-surgery changes in serum Alb, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALKP) levels. Body composition changes were also measured and compared among three groups.

DESIGN AND SETTING

Retrospective cohort study conducted in Tehran, Iran.

METHODS

151 OAGB, RYGB and SG patients referred to the obesity clinic of Hazrat-e Rasool General Hospital, Tehran, Iran, were evaluated. Physical characteristics and biochemical parameters were measured pre-surgery and then after three and six months.

RESULTS

Through repeated measurements to determine intragroup changes, significant changes in serum AST (P = 0.003) and ALT (P < 0.001) were observed in follow-ups. However, Alb levels did not change (P = 0.413). Body fat, fat-free mass and muscle mass decreased significantly in each group (P < 0.05). In a univariate general linear model for determining intergroup changes, SG showed greater decreases in ALT and AST at three and six months (P < 0.05) and in ALKP at six months (P = 0.037), compared with OAGB. There were no significant differences in Alb levels. Also, RYGB had a greater effect on reducing fat percentage (three months, P = 0.011; six months, P = 0.059) and fat mass (three months, P = 0.042) than OAGB.

CONCLUSION

SG and RYGB may be superior to OAGB in reducing liver enzymes and body fat, respectively. However, Alb levels showed no significant differences.

Nonalcoholic Fatty Liver Disease Impairs the Liver-Alpha Cell Axis Independent of Hepatic Inflammation and Fibrosis

Nonalcoholic fatty liver disease (NAFLD) is associated with impaired hepatic actions of glucagon and insulin. Glucagon and amino acids are linked in an endocrine feedback circuit, the liver-alpha cell axis, that may be disrupted by NAFLD. We investigated how NAFLD severity affects glucagon and insulin resistance in individuals with obesity and whether bariatric surgery improves these parameters. Plasma and liver biopsies from 33 individuals with obesity (collectively, OBE) were obtained before and 12 months after bariatric surgery (Roux-en-Y gastric bypass [RYGB] or sleeve gastrectomy [SG]). Nine healthy control individuals (collectively, CON) undergoing cholecystectomy were used as a comparison group. The NAFLD activity score (NAS) was used to subdivide study participants into the following groups: OBE-no steatosis, OBE+steatosis, and nonalcoholic steatohepatitis (NASH) and/or grade 2 fibrosis (Fib) (OBE-NASH-Fib). Measurements of amino acids by targeted metabolomics and glucagon were performed. Glucagon, amino acids (P < 0.05), and the glucagon-alanine index, a validated surrogate marker of glucagon resistance, were increased in OBE by 60%, 56%, and 61%, respectively, when compared with CON but irrespective of NAFLD severity. In contrast, markers of hepatic insulin resistance increased concomitantly with NAS. Hyperglucagonemia resolved in OBE-no steatosis and OBE+steatosis but not in OBE-NASH-Fib (median, 7.0; interquartile range, 5.0-9.8 pmol/L), regardless of improvement in insulin resistance and NAS. The type of surgery that participants underwent had no effect on metabolic outcomes. Conclusion: Glucagon resistance to amino acid metabolism exists in individuals with NAFLD independent of NAS severity. Patients with NASH showed persistent hyperglucagonemia 12 months after bariatric surgery, indicating that a disrupted liver-alpha cell may remain in NAFLD despite major improvement in liver histology.

Missing Something? Comparisons of Effectiveness and Outcomes of Bariatric Surgery Procedures and Their Preferred Reporting: Refining the Evidence Base

Comparisons of effectiveness of bariatric surgery (BS) procedures encompass weight loss, metabolic/clinical outcomes, and improvements or worsening of comorbidities. Post-operative physical activity (PA) and diet influence such outcomes but are frequently not included in comparisons of effectiveness. We assessed the value and necessity of including post-operative PA/diet data when comparing effectiveness of BS. Including post-operative PA/diet data has significant benefits for BS and patients. The paper proposes an explicit preferred reporting system (Preferred REporting of post-operative PHYsical activity and Diet data in comparisons of BS effectiveness: PRE-PHYD Bariatric). Including post-operative PA/diet data could result in more accurate appraisals of effectiveness of BS procedures. This could translate into better 'individualized' BS by achieving a better 'fit' between patient and procedure.