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 .
Role of the foregut in the early improvement in glucose tolerance and insulin sensitivity following Roux-en-Y gastric bypass surgery.
Bypass of the foregut following Roux-en-Y gastric bypass ( RYGB ) surgery results in altered nutrient absorption , which is proposed to underlie the improvement in glucose tolerance and insulin sensitivity . We conducted a prospect i ve crossover study in which a mixed meal was delivered orally before RYGB ( gastric ) and both orally ( jejunal ) and by gastrostomy tube ( gastric ) postoperatively ( 1 and 6 wk ) in nine subjects .  Glucose , insulin , and incretin responses were measured , and whole-body insulin sensitivity was estimated with the insulin sensitivity index composite . RYGB result ed in an improved glucose , insulin , and glucagon-like peptide-1 ( GLP-1 ) area under the curve ( AUC ) in the first 6 wk postoperatively ( all P ≤ 0.018 ) ; there was no effect of delivery route ( all P ≥ 0.632 ) or route × time interaction ( all P ≥ 0.084 ) . The glucose-dependent insulinotropic polypeptide ( GIP ) AUC was unchanged after RYGB ( P = 0.819 ) ; however , GIP levels peaked earlier after RYGB with jejunal delivery . The ratio of insulin AUC to GLP-1 and GIP AUC decreased after surgery ( P = .001 and 0.061 , respectively ) without an effect of delivery route over time ( both P ≥ 0.646 ) . Insulin sensitivity improved post-RYGB ( P = 0.001 ) with no difference between the gastric and jejunal delivery of the mixed meal over time ( P = 0.819 ) . These data suggest that exclusion of nutrients from the foregut with RYGB does not improve glucose tolerance or insulin sensitivity . However , changes in the foregut response post-RYGB due to lack of nutrient exposure can not be excluded . Our findings suggest that foregut bypass may alter the incretin response by enhanced nutrient delivery to the hindgut
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 .