CORRELATION BETWEEN PRE AND POSTOPERATIVE LEVELS OF GLP-1/GLP-2 AND WEIGHT LOSS AFTER ROUX-EN-Y GASTRIC BYPASS: A PROSPECTIVE STUDY

Peptide Tyrosine-Tyrosine Triggers GLP-2-Mediated Intestinal Hypertrophy After Roux-en-Y Gastric Bypass

Purpose 

Intestinal remodeling and adaptation of the alimentary limb after Roux-en-Y gastric bypass (RYGB) play an important role in the pathophysiological events that lead to type 2 diabetes mellitus (T2DM) improvement. Intestinal absorptive loop hypertrophy and growth following surgery have been related to GLP-2 secretion by ileal L-cells. The secretion of peptide tyrosine-tyrosine (PYY) enterohormone after a meal has been proposed as a trigger for ileal secretion of GLP-1. Our aim is to determine the role of PYY as a GLP-2 secretion modulator as an adaptation result in the alimentary limb after RYGB.

Method

We used a non-obese euglycemic rodent model. Circulating glucose, insulin, PYY, and GLP-2 were measured in the experimental and control groups. We used four groups: fasting control, Sham-operated, RYGB-operated (RYGB), and RYGB-operated and treated with BIIE0246 (RYGB + BII). BIIE0246 is a NPY2 receptor antagonist in L-cells. Intestinal glucose transporters and GLP-1 and PYY gut expression and hypertrophy were analyzed after 12 weeks of surgery.

Results

RYGB increased PYY3-36 plasma levels in rats with or without BII treatment. A high-insulin response was observed in the RYGB group but not in the control or RYGB + BII groups. BIIE0246 treatment limited plasma GLP-2 levels. In the alimentary intestinal limb, hypertrophy and SGLT1 and GLUT1 expression appeared to be reduced after RYGB compared to controls.

Conclusion

The postprandial ileal PYY secretion is enhanced after RYGB. This increase mediates GLP-2 release through its binding to the Y2 receptor on L-cells. This mechanism plays a role in alimentary limb hypertrophy after surgery.

Graphical abstract

SMALL INTESTINAL L CELL DENSITY IN PATIENTS WITH SEVERE OBESITY AFTER ROUX-EN-Y GASTRIC BYPASS

BACKGROUND:

Enteroendocrine L cells can be found in the entire gastrointestinal tract and their incretins act on glycemic control and metabolic homeostasis. Patients with severe obesity and type 2 diabetes mellitus may have lower density of L cells in the proximal intestine.

AIMS:

This study aimed to analyze the density of L cells in the segments of the small intestine in the late postoperative of Roux-en-Y gastric bypass in diabetic patients with standardization of 60 cm in both loops, alimentary and biliopancreatic.

METHODS:

Immunohistochemistry analysis assays were made from intestinal biopsies in three segments: gastrointestinal anastomosis (GIA= Point A), enteroenteral anastomosis (EEA= Point B= 60 cm distal to the GIA) and 60 cm distal to the enteroenteral anastomosis (Point C).

RESULTS:

A higher density of L cells immunostaining the glucagon-1 peptide was observed in the distal portion (Point C) when compared to the more proximal portions (Points A and B).

CONCLUSIONS:

The concentration of L cells is higher 60 cm distal to enteroenteral anastomosis when comparing to proximal segments and may explain the difference in intestinal lumen sensitization and enterohormonal response after Roux-en-Y gastric bypass.

DENTAL WEAR AND TOOTH LOSS IN MORBID OBESE PATIENTS AFTER BARIATRIC SURGERY

BACKGROUND

Obesity and its surgical treatment have been related with oral diseases. Aim: To evaluate and compare dental wear and dental loss in eutrophic and morbidly obese patients submitted to Roux-en-Y gastric bypass.

METHOD

Observational and analytical study with gender and age matching. The sample consisted of 240 patients, divided into four groups: eutrophic (GC=60), morbidly obese (GO=60), operated with up to 24 months (G24=60) and operated on for more than 36 months (G36=60). The following variables were analyzed: race, schooling, economic class, hypertension, diabetes, triglycerides, cholesterol, BMI, weight loss, waist-hip ratio, smoking, alcoholism, tooth loss and tooth wear.

RESULTS

GO presented lower economic class (p=0.012), hypertension (p<0.001), diabetes (p<0.001), cholesterol (p=0.001), BMI (p<0.001), waist-hip ratio (p<0.001) and percentage of weight loss percent (p<0.001) than groups G24 and G36. Dental wear was higher among the II and V sextants.

CONCLUSION

Individuals submitted to Roux-en-Y gastric bypass, regardless of the surgery period, presented more dental wear on the incisal/occlusal surfaces, and the anterior teeth were the most affected. Dental wear was associated with age and number of missing teeth.

Effect of different bariatric surgeries on dietary protein bioavailability in rats

Bariatric surgery may induce protein malabsorption, although data are scarce. This study aims at evaluating dietary protein bioavailability after different bariatric surgeries in rats. Diet-induced obese Wistar rats were operated for vertical sleeve gastrectomy (VSG) or Roux-en-Y gastric bypass (RYGB). The control group was composed of pair-fed, sham-operated rats (Sham). Two weeks after surgery, rats were fed a ¹⁵N protein meal. Protein bioavailability was assessed by determination of ¹⁵N recovery in the gastrointestinal tract and organs 6 h after the meal. Fractional protein synthesis rate (FSR) was assessed using a flooding dose of ¹³C valine. Weight loss was the highest in RYGB rats and the lowest in Sham rats. Surprisingly, RYGB (95.6 ± 0.7%) improved protein digestibility (P = 0.045) compared with Sham (93.5 ± 0.5%) and VSG (93.8 ± 0.6%). In contrast, ¹⁵N retained in the liver (P = 0.001) and plasma protein (P = 0.037) was lower than in Sham, with a similar trend in muscle (P = 0.052). FSR was little altered by bariatric surgery, except for a decrease in the kidney of RYGB (P = 0.02). The ¹⁵N distribution along the small intestinal tissue suggests that dietary nitrogen was considerably retained in the remodeled mucosa of RYGB compared with Sham. This study revealed that in contrast to VSG, RYGB slightly improved protein digestibility but altered peripheral protein bioavailability. This effect may be ascribed to a higher uptake of dietary amino acids by the remodeled intestine.NEW & NOTEWORTHY Using a sensitive ¹⁵N meal test, we found that gastric bypass slightly improved protein digestibility compared with sleeve gastrectomy or control but, in contrast, lowered protein retention in the liver and muscles. This paradox can be due to a higher uptake of dietary nitrogen by the intestinal mucosa that was hypertrophied. This study provides new insight on the digestive and metabolic fate of dietary protein in different models of bariatric surgery in rats.

IMPACT OF BARIATRIC SURGERY ON THE INFLAMMATORY STATE BASED ON CPR VALUE

BACKGROUND

PCR (C-reactive protein), produced in the liver after stimuli of inflammatory mediators, is determined as a marker of inflammatory activity (adipocytokines) and is present within adipocyte cells; besides being an inflammatory product, many studies have shown to be a predictor of complications.

AIM

To determine if the inflammatory state of the obese patient decreases after bariatric surgery, based on pre and post-operative PCR.

METHODS

A prospective, observational study in patients undergoing Roux-en-Y gastric by-pass surgery followed up for three months after surgery, with serum preoperative CRP in 30, 60 and 90 days after surgery.

RESULTS

A total of 19 patients, who had a mean CRP value before the surgical procedure of 0.80(±0.54) mg/dl, were followed, and when compared to the CRP with 30 days of surgery, they presented a significant increase to 2.68 mg/dl (p=0.012). When compared with the PCR of 60 days after the surgical procedure, it was also higher with the value of 3.32 mg/dl (p=0.27). However, at three months after surgery, the CRP showed a decrease when compared to the preoperative mark, with value of 0.45 mg/dl (p=0.0042).

CONCLUSION

Roux-en-Y gastric bypass was able to decrease the chronic inflammation status of these patients, based on the value of CRP, with three months of surgery.

MINI-GASTRIC BYPASS: DESCRIPTION OF THE TECHNIQUE AND PRELIMINARY RESULTS

Background:

In recent years, a surgical technique known as single-anastomosis gastric bypass or mini-gastric bypass has been developed. Its frequency of performance has increased considerably in the current decade.

Aim:

To describe the mini-gastric bypass technique, its implementation and preliminary results in a university hospital.

Methods:

This is an ongoing prospective trial to evaluate the long-term effects of mini-gastric bypass. The main features of the operation were: a gastric pouch with about 15-18 cm (50-150 ml) with a gastroenteric anastomosis in the pre-colic isoperistaltic loop 200 cm from the duodenojejunal angle (biliopancreatic loop).

Results:

Seventeen individuals have undergone surgery. No procedure needed to be converted to open approach. The overall 30-day morbidity was 5.9% (one individual had intestinal obstruction caused by adhesions). There was no mortality.

Conclusion:

Mini-gastric bypass is a feasible and safe bariatric surgical procedure.

COMPARISON OF THE LEVELS OF C-REACTIVE PROTEIN, GLP-1 AND GLP-2 AMONG INDIVIDUALS WITH DIABETES, MORBID OBESITY AND HEALTHY CONTROLS: AN EXPLORATORY STUDY

BACKGROUND

The glucagon-like peptides 1 and 2 (GLP-1/GLP-2) are gut hormones that may directly affect the glucose homeostasis and their activity seems to be significantly affected by chronic inflammation.

OBJECTIVE

To evaluate the postprandial levels of glucagon-like peptides 1 and 2 (GLP-1/GLP-2), C-reactive protein (CRP), and the postprandial glucose and insulin levels among individuals with obesity, type 2 diabetes, and healthy controls.

METHODS

An exploratory cross-sectional study, which involved individuals awaiting for bariatric/metabolic surgery and healthy controls. Postprandial levels of GLP-1, GLP-2, glucose, and insulin were obtained after a standard meal tolerance test. Inflammation was assessed by means of CRP.

RESULTS

There were 30 individuals enrolled in the study, divided into three groups: non-diabetic with morbid obesity (NDO; n=11 individuals), diabetic with mild obesity (T2D; n=12 individuals), and healthy controls (C; n=7 individuals). The mean CRP levels were significantly higher in the NDO group (6.6±4.7 mg/dL) than in the T2D (3.3±2.2 mg/dL) and C groups (2.5±3.2 mg/dL) (P=0.038). The GLP-1 levels following standard meal tolerance test and the area under the curve of GLP-1 did not differ among the three groups. The GLP-2 levels were significantly lower in the NDO and T2D than in the C group following standard meal tolerance test at all the times evaluated. The area under the curve of the GLP-2 was significantly lower in the NDO and T2D groups than in the C group (P=0.05 and P=0.01, respectively).

CONCLUSION

GLP-2 levels were impaired in the individuals with obesity and diabetes. This mechanism seems to be enrolled in preventing the worsening of the glucose homeostasis in these individuals.

QUALITY OF LIFE AFTER VERTICAL GASTRECTOMY EVALUATED BY THE BAROS QUESTIONNAIRE

Background

The satisfactory outcome in the surgical treatment of obesity must include, in addition to weight loss, a significant change in the pre-existing comorbidities and in the quality of life.

Aim

To evaluate the quality of life in the late postoperative period in patients that underwent videolaparoscopic sleeve gastrectomy.

Methods

It was applied the questionnaire "Bariatric Analysis and Reporting Outcome System" (BAROS) in patients that underwent videolaparoscopic sleeve gastrectomy.

Results

A total of 47 patients between 21-60 years old were evaluated. The total mean of BMI before surgery was 43.06±5.87 kg/m². The average percentage of the reduction of excess weight after surgery was 85.46±23.6%. The score obtained by patients in the questionnaire about the improvement in the quality of life showed excellent (36.17%), very good (40.43%), good (21.28%) and reasonable (2.13%) results. There was clinical improvement after surgery in all comorbidities investigated.

Conclusion

The weight loss was critical to improve the quality of life and offered the resolution or clinical improvement in all of the investigated comorbidities in patients submitted to sleeve gastrectomy.