Ghrelin, leptin, and glycemic control after sleeve gastrectomy versus Roux-en-Y gastric bypass-results of a randomized clinical trial. Impact of Bariatric Surgery on Ghrelin and Obestatin Levels in Obesity or Type 2 Diabetes Mellitus Rat Model Weight loss induced by Roux-en-Y gastric bypass but not laparoscopic adjustable gastric banding increases circulating bile acids. Weight Loss, Appetite Suppression, and Changes in Fasting and Postprandial Ghrelin and Peptide-YY Levels After Roux-en-Y Gastric Bypass and Sleeve Gastrectomy: A Prospective, Double Blind Study Cholesterol absorption decreases after Roux-en-Y gastric bypass but not after gastric banding. Roux-en-Y gastric bypass surgery of morbidly obese patients induces swift and persistent changes of the individual gut microbiota Improved acylated ghrelin suppression at 2 years in obese patients with type 2 diabetes: effects of bariatric surgery vs standard medical therapy Preserved Insulin Secretory Capacity and Weight Loss Are the Predominant Predictors of Glycemic Control in Patients With Type 2 Diabetes Randomized to Roux-en-Y Gastric Bypass
BACKGROUND Sleeve gastrectomy ( SG ) and Roux-en-Y gastric bypass ( RYGB ) cause weight loss and metabolic improvement , but results of published studies are contradictory . OBJECTIVES The aim of this study was to compare the effects of SG and RYGB on ghrelin , leptin , and glucose homeostasis in a r and omized controlled trial . SETTING University hospital , Pol and . METHODS Seventy-two morbidly obese patients were r and omly selected to undergo either SG ( n = 36 ) or RYGB ( n = 36 ) .  Fasting ghrelin , leptin , glucose , insulin , C-peptide , glucagon , glycated hemoglobin , and homeostasis model assessment of insulin resistance were assessed preoperatively and at 1 , 6 , and 12 months postoperatively . No differences were found in anthropometric and biochemical parameters between the study groups at baseline . RESULTS Sixty-nine ( 95.8 % ) patients completed the study .  Percentage of excess weight loss at 12 months was 67.6±19.3 % after SG and 64.2±18.5 % after RYGB ( P>.05 ) . Fasting ghrelin levels decreased 1 month after SG ( from 76.8 pmol/L to 35.3 pmol/L ; P<.05 ) and remained reduced until 12 months ( 41.6 pmol/L ; P<.05 ) but increased 12 months after RYGB from 74.6 pmol/L to 130.2 pmol/L ( P<.05 ) . Leptin , glucose , insulin , and C-peptide concentrations and glycated hemoglobin and homeostasis model assessment of insulin resistance values decreased significantly in both groups during 12 months . CONCLUSIONS RYGB and SG induce comparable weight loss and improvement in metabolism of glucose . Ghrelin levels decrease after SG and increase after RYGB , but this difference does not affect similar outcomes of these procedures during 1-year follow-up . The contribution of ghrelin to weight loss or metabolic benefits after bariatric surgery is not straightforward , but rather influenced by multiple factors We aim ed to evaluate the therapeutic efficacy on weight control by different bariatric surgeries and investigate the ghrelin and obestatin changes after these surgeries in obesity and nonobese type 2 diabetes mellitus ( T2DM ) rats . Obese rats were r and omly assigned to receive sleeve gastrectomy ( SG , n = 8) , minigastric bypass ( MGBP , n = 8) , roux-en-Y gastric bypass ( RYGBP , n = 8) , and sham operation ( SO , n = 4 ) . Another 4 rats served as control . Besides , Goto-Kakisaki ( GK ) rats were also r and omly divided into similar groups except for total gastrectomy ( TG , n = 8) group . The results showed that in obese rats , weigh loss in RYGBP group was similar to that in MGBP group but larger than that in SG group . Ghrelin significantly increased in RYGB group , but obestatin increased in MGBP group . Ghrelin/obestatin ratio significantly decreased in SG group . In GK rats , weight loss was most obvious in TG group . Postoperatively , ghrelin was significantly increased in MGBP and RYGB groups but decreased in TG group . Obestatin also showed an increase in MGBP and RYGB groups . Ghrelin/obestatin in TG group decreased significantly . In conclusion , RYGB and MGBP may be more suitable for obese rats , but TG may be the best strategy for T2DM rats to control weight with different mechanisms CONTEXT It has been hypothesized that increased plasma bile acids ( BAs ) contribute to metabolic improvements after Roux-en-Y gastric bypass ( RYGB ) surgery by the G protein-coupled receptor TGR5-mediated effects on glucagon-like peptide-1 secretion and thyroid hormones . OBJECTIVE The objective of this study was to evaluate the importance of bariatric surgery-induced alterations in BA physiology on factors that regulate glucose homeostasis ( insulin secretion and sensitivity ) and energy metabolism ( resting energy expenditure and thyroid hormone axis ) . DESIGN , PARTICIPANTS , INTERVENTION , AND MAIN OUTCOME MEASURE : Eighteen extremely obese subjects were studied before and after 20 % weight loss , induced by either laparoscopic adjustable gastric b and ing ( LAGB ) ( n = 10 ) or RYGB surgery ( n = 8) . RESULTS Plasma BAs more than doubled after RYGB [ fasting : 1.08 ( 0.26 - 1.42 ) to 2.28 ( 1.59 - 3.28 ) μmol/L , P = .03 ; postpr and ial : 2.46 ± 1.59 to 6.00 ± 2.75 μmol/L , P = .01 ] but were either lower or did not change after LAGB [ fasting : 1.80 ( 1.49 - 2.19 ) to 0.92 ( 0.73 - 1.15 ) μmol/L , P = .02 ; postpr and ial : 3.71 ± 2.61 to 2.82 ± 1.75 μmol/L , P = .14 ] . Skeletal muscle expression of TGR5 targets , Kir6.2 and cyclooxygenase IV , increased after RYGB but not LAGB . Surgery-induced changes in BAs were associated with increased peak postpr and ial plasma glucagon-like peptide-1 ( r(2 ) = 0.509 , P = .001 ) and decreased serum TSH ( r(2 ) = 0.562 , P < .001 ) but did not correlate with the change in insulin response to a meal ( r(2 ) = 0.013 , P = .658 ) , insulin sensitivity ( assessed as insulin stimulated glucose disposal during a hyperinsulinemic-euglycemic clamp procedure ) ( r(2 ) = 0.001 , P = .995 ) , or resting energy expenditure ( r(2 ) = 0.004 , P = .807 ) . CONCLUSIONS Compared with LAGB , RYGB increases circulating BAs and TGR5 signaling , but this increase in BAs is not a significant predictor of changes in glucose homeostasis or energy metabolism Background : Bariatric surgery is currently the most effective treatment in morbidly obese patients , leading to durable weight loss . Objective : In this prospect i ve double blind study , we aim to evaluate and compare the effects of  laparoscopic Roux-en-Y gastric bypass ( LRYGBP ) with laparoscopic sleeve gastrectomy ( LSG )  on body weight , appetite , fasting , and postpr and ial ghrelin and peptide-YY ( PYY ) levels . Methods : After r and omization , 16 patients were assigned to LRYGBP and 16 patients to LSG .  Patients were reevaluated on the 1st , 3rd , 6th , and 12th postoperative month . Blood sample s were collected after an overnight fast and in 6 patients in each group after a st and ard 420 kcal mixed meal . Results : Body weight and body mass index ( BMI ) decreased markedly ( P < 0.0001 ) and comparably after either procedure . Excess weight loss was greater after LSG at 6 months ( 55.5 % ± 7.6 % vs. 50.2 % ± 6.5 % , P = 0.04 ) and 12 months ( 69.7 % ± 14.6 % vs. 60.5 % ± 10.7 % , [ P = 0.05 ] ) . After LRYGBP fasting ghrelin levels did not change significantly compared with baseline ( P = 0.19 ) and did not decrease significantly after the test meal . On the other h and , LSG was followed by a marked reduction in fasting ghrelin levels ( P < 0.0001 ) and a significant suppression after the meal . Fasting PYY levels increased after either surgical procedure ( P ≤ 0.001 ) . Appetite decreased in both groups but to a greater extend after LSG . Conclusion : PYY levels increased similarly after either procedure . The markedly reduced ghrelin levels in addition to increased PYY levels after LSG , are associated with greater appetite suppression and excess weight loss compared with LRYGBP The differences in cholesterol metabolism after the 2 most common forms of obesity surgery , Roux-en-Y gastric bypass ( RYGB ) and gastric b and ing ( GB ) , have not been well characterized . In this study , effects of RYGB and GB on cholesterol absorption and synthesis were investigated . To this aim , 1-year follow-up of cholesterol metabolism in 2 nonr and omized cohorts undergoing either RYGB ( n = 29 ; age , 45.2 + /- 7.7 years ; body mass index [ BMI ] , 46.0 + /- 6.1 kg/m(2 ) ) or GB ( n = 26 ; age , 45.9 + /- 8.6 years ; BMI , 50.1 + /- 7.7 kg/m(2 ) ) was performed in a university hospital center specializing in the treatment of morbid obesity .  Serum markers of cholesterol synthesis ( cholestenol , desmosterol , and lathosterol ) and cholesterol absorption ( campesterol , sitosterol , avenasterol , and cholestanol ) were measured preoperatively and at follow-up and expressed as ratios to cholesterol . As expected based on observed weight loss ( 25 % after RYGB and 17 % after GB , P < .001 between groups ) , both operations decreased serum levels of cholesterol synthesis markers by 12 % to 28 % ( all Ps < .001 ) . A decrease in cholesterol absorption markers was only observed after RYGB ( -26 % for sitosterol ) and not after GB ( + 16 % , P = 2 x 10(-6 ) for difference between the groups ) . The difference in sitosterol ratio between the groups remained significant after adjustment for age , BMI , fasting insulin levels , and nutritional status ( P = 2 x 10(-4 ) ) , indicating a specific effect related to RYGB . We conclude that decrease in cholesterol absorption is a novel beneficial effect of RYGB . Together with an improved control of blood glucose , this may contribute to a better cardiovascular risk profile after RYGB Background Roux-en-Y gastric bypass ( RYGB ) is an effective means to achieve sustained weight loss for morbidly obese individuals . Besides rapid weight reduction , patients achieve major improvements of insulin sensitivity and glucose homeostasis . Dysbiosis of gut microbiota has been associated with obesity and some of its co-morbidities , like type 2 diabetes , and major changes of gut microbial communities have been hypothesized to mediate part of the beneficial metabolic effects observed after RYGB . Here we describe changes in gut microbial taxonomic composition and functional potential following RYGB . Methods We recruited 13 morbidly obese patients who underwent RYGB  , carefully phenotyped them , and had their gut microbiomes quantified before ( n = 13 ) and 3 months ( n = 12 ) and 12 months ( n = 8) after RYGB . Following shotgun metagenomic sequencing of the fecal microbial DNA purified from stools , we characterized the gut microbial composition at species and gene levels followed by functional annotation . Results In parallel with the weight loss and metabolic improvements , gut microbial diversity increased within the first 3 months after RYGB and remained high 1 year later . RYGB led to altered relative abundances of 31 species ( P < 0.05 , q < 0.15 ) within the first 3 months , including those of Escherichia coli , Klebsiella pneumoniae , Veillonella spp . , Streptococcus spp . , Alistipes spp . , and Akkermansia muciniphila . Sixteen of these species maintained their altered relative abundances during the following 9 months . Interestingly , Faecalibacterium prausnitzii was the only species that decreased in relative abundance . Fifty-three microbial functional modules increased their relative abundance between baseline and 3 months ( P < 0.05 , q < 0.17 ) . These functional changes included increased potential ( i ) to assimilate multiple energy sources using transporters and phosphotransferase systems , ( ii ) to use aerobic respiration , ( iii ) to shift from protein degradation to putrefaction , and ( iv ) to use amino acids and fatty acids as energy sources . Conclusions Within 3 months after morbidly obese individuals had undergone RYGB , their gut microbiota featured an increased diversity , an altered composition , an increased potential for oxygen tolerance , and an increased potential for microbial utilization of macro- and micro-nutrients . These changes were maintained for the first year post-RYGB.Trial registration Current controlled trials ( ID NCT00810823 , NCT01579981 , and NCT01993511 ) Objective : Roux-en-Y gastric bypass ( RYGB ) produces more durable glycemic control than sleeve gastrectomy ( SG ) or intensive medical therapy ( IMT ) . However , the contribution of acylated ghrelin ( AG ) , a gluco-regulatory/appetite hormone , to improve glucose metabolism and body composition in patients with type 2 diabetes ( T2D ) following RYGB is unknown . Design : STAMPEDE ( Surgical Treatment and Medication Potentially Eradicate Diabetes Efficiently ) was a prospect i ve , r and omized controlled trial . Subjects : Fifty-three ( body mass index : 36±3 kg m−2 , age : 49±9 years ) poorly controlled patients with T2D ( HbA1c ( glycated hemoglobin ) : 9.7±2 % ) were r and omized to IMT , IMT+RYGB or IMT+SG and underwent a mixed-meal tolerance test at baseline , 12 , and 24 months for evaluation of AG suppression ( postpr and ial minus fasting ) and beta-cell function ( oral disposition index ; glucose-stimulated insulin secretion × Matsuda index ) . Total/ and roid body fat ( dual-energy X-ray absorptiometry ) was also assessed . Results : RYGB and SG reduced body fat comparably ( 15–23 kg ) at 12 and 24 months , whereas IMT had no effect . Beta-cell function increased 5.8-fold in RYGB and was greater than IMT at 24 months ( P<0.001 ) . However , there was no difference in insulin secretion between SG vs IMT at 24 months ( P=0.32 ) . Fasting AG was reduced fourfold following SG ( P<0.01 ) and did not change with RYGB or IMT at 24 months . AG suppression improved more following RYGB than SG or IMT at 24 months ( P=0.01 vs SG , P=0.07 vs IMT ) . At 24 months , AG suppression was associated with increased postpr and ial glucagon-like peptide-1 ( r=−0.32 , P<0.02 ) and decreased and roid fat ( r=0.38 ; P<0.006 ) . Conclusions : Enhanced AG suppression persists for up to 2 years after RYGB , and this effect is associated with decreased and roid obesity and improved insulin secretion . Together , these findings suggest that AG suppression is partly responsible for the improved glucose control after RYGB surgery Improvement in  type 2 diabetes after Roux-en-Y gastric bypass ( RYGB )  has been attributed partly to weight loss , but mechanisms beyond weight loss remain unclear . We performed an ancillary study to the Diabetes Surgery Study to assess changes in incretins , insulin sensitivity , and secretion 1 year after r and omization to lifestyle modification and intensive medical management ( LS/IMM ) alone  ( n = 34 ) or in conjunction with RYGB  ( n = 34 ) . The RYGB group lost more weight and had greater improvement in HbA1c . Fasting glucose was lower after RYGB than after LS/IMM , although the glucose area under the curve decreased comparably for both groups . Insulin sensitivity increased in both groups . Insulin secretion was unchanged after LS/IMM but decreased after RYGB , except for a rapid increase during the first 30 min after meal ingestion . Glucagon-like peptide 1 ( GLP-1 ) was substantially increased after RYGB , while gastric inhibitory polypeptide and glucagon decreased . Lower HbA1c was most strongly correlated with the percentage of weight loss for both groups . At baseline , a greater C-peptide index and 90-min postpr and ial C-peptide level were predictive of lower HbA1c at 1 year after RYGB . β-Cell glucose sensitivity , which improved only after RYGB , and improved disposition index were associated with lower HbA1c in both groups , independent of weight loss . Weight loss and preserved β-cell function both predominantly determine the greatest glycemic benefit after RYGB
Meta-regression showed that gastric pouch volume , alimentary limb length and biliopancreatic limb length were not associated with changes in ghrelin levels .
Conclusion Fasting total ghrelin levels decreased in the short term ( ≤ 3 months ) and increased in the long term ( > 3 months ) after RYGB
Background Roux-en-Y gastric bypass ( RYGB ) is considered effective for weight loss and for treatment of many obesity-related metabolic diseases .
Ghrelin is an essential orexigenic peptide that plays an indispensable role in controlling body weight and energy homeostasis of post-operative patients .
This systematic review and meta- analysis aim ed to investigate changes in the level of fasting total ghrelin following RYGB .