The Effect of Standard versus Longer Intestinal Bypass on GLP-1 Regulation and Glucose Metabolism in Patients with Type 2 Diabetes Undergoing Roux-en-Y Gastric Bypass. The Long-Limb study

Abstract

Objective <p>Roux-en-Y gastric bypass (RYGB) characteristically enhances post-prandial levels of Glucagon-like peptide 1 (GLP-1), a mechanism that contributes to its profound glucose-lowering effects. This enhancement is thought to be triggered by bypass of food to the distal small intestine with higher densities of neuroendocrine L-cells. We hypothesised that if this is the predominant mechanism behind the enhanced secretion of GLP-1, a longer intestinal bypass would potentiate the post-prandial peak in GLP-1, translating into higher insulin secretion and thus additional improvements in glucose tolerance. To investigate this, we conducted a mechanistic study comparing two variants of RYGB that differ in the length of intestinal bypass.</p> <p>Research Design and Methods</p> <p>Fifty-three patients with type 2 diabetes and obesity were randomised to either ‘standard limb’ RYGB (50cm biliopancreatic limb) or ‘long limb’ RYGB (150cm biliopancreatic limb). They underwent measurements of GLP-1 and insulin secretion following a mixed meal and insulin sensitivity using euglycaemic hyperinsulinaemic clamps at baseline, 2 weeks and at 20% weight loss after surgery.</p> <p>Results</p> <p>Both groups exhibited enhancement in post-prandial GLP-1 secretion and improvements in glycaemia compared to baseline. There were no significant differences in post-prandial peak concentrations of GLP-1, time to peak, insulin secretion, and insulin sensitivity. </p> <p>Conclusion</p> The findings of this study demonstrate that lengthening of the intestinal bypass in RYGB does not affect GLP-1 secretion. Thus, the characteristic enhancement of GLP-1 response after RYGB might not depend on delivery of nutrients to more distal intestinal segments.

The impact of bariatric surgery procedures on the modulation of cardiometabolic risk factors in patients with severe obesity: a 12-month follow-up

“…Indeed, postoperative changes in the gastrointestinal tract anatomy may reduce blood glucose by activating several gastrointestinal-dependent mechanisms. 33 Dyslipidemia is well-established as a common feature of patients with severe obesity, and is considered to be the main CMRF. 34 The results of the present study suggested that lipid profile levels improved significantly at 12 months after surgery.…”

“…Indeed, postoperative changes in the gastrointestinal tract anatomy may reduce blood glucose by activating several gastrointestinal-dependent mechanisms. 33…”

Length of biliopancreatic limb in Roux-en-Y gastric bypass and its impact on post-operative outcomes in metabolic and obesity surgery—systematic review and meta-analysis

“…All but one study concentrated on reporting clinical outcomes. Miras et al [34] conducted a mechanistic study investigating impact of the length of intestinal bypass in RYGB on GLP-1 and glucose homoeostasis, including insulin secretion and sensitivity. Findings of this study also disputed the benefit of elongating BP limb on a physiological level, with no evidence on beneficial impact of elongating BP limb on fasting and post-prandial gut hormones secretion and glucose homoeostasis over a standard RYGB.…”

Cirurgia Bariátrica Para Tratamento De Diabetes Tipo 2

“…Apesar de incorporar um membro biliopancreático três vezes mais longo (150cm), resultando na entrega de nutrientes a segmentos mais distais do intestino delgado em comparação com a técnica padrão, o bypass gástrico em Y de Roux de membro longo não produziu nenhuma diferença mensurável nas concentrações de GLP-1 em jejum ou pós-prandial em pacientes com DM2 e obesidade. (14) Katsogiannos P. demonstrou em seu estudo que há melhora rápida, em poucos dias, da resistência à insulina e controle glicêmico em pacientes obesos com diabetes tipo 2 ou pré-diabetes após bypass gástrico em Y de Roux. (15) Courcoulas A. P. chegou à conclusão de que os tratamentos cirúrgicos, incluindo by-pass gástrico em Y de Roux e banda gástrica ajustável laparoscópica, são seguros e mais eficazes do que a intervenção no estilo de vida isolada para remissão de diabetes a longo prazo e controle glicêmico em pessoas com obesidade.…”