Mucosal glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide cell numbers in the super-obese human foregut after gastric bypass

BACKGROUND

Super-obesity, a body mass index>50 kg/m(2), is difficult to treat. Many studies have focused on the anatomic changes of the intestines; the physiologic background is not clearly identified. It is established that Roux-en-Y gastric bypass (RYGB) augments secretion of glucagon-like peptide-1 (GLP-1), peptide tyrosine tyrosine (PYY), and insulin, but other aspects of gut hormone cell function in the alimentary limb are unknown.

OBJECTIVE

To study the effects of laparoscopic RYGB on enteroendocrine cells.

SETTING

University-affiliated, high-volume bariatric surgery center.

METHODS

Eighteen nondiabetic patients were drawn from the present study (NCT 01514799), randomizing between biliopancreatic (BP) limbs of either 60 cm (BP60) or 200 cm (BP200). Demographic characteristics did not differ at baseline or 12 months. Pouch and jejunal biopsies were obtained intraoperatively and using endoscopy at 12 months. Mucosal height and density of hormone-producing cell populations were assessed and mRNA expression measured with real-time polymerase chain reaction.

RESULTS

In perianastomotic jejunum, a 4.9-fold increase in GLP-1 cell density was evident 12 months after RYGB, most pronounced in the BP200-group. The densities of glucose-dependent insulinotropic polypeptide (GIP) cells and PYY immunoreactive cells were doubled after 12 months. GIP mRNA was unaffected, but GLP-1 and PYY mRNA were lower 12 months after RYGB. RYGB had no impact on villi length or density of ghrelin-, cholecystokinin-, neurotensin-, secretin-, or serotonin-producing cells after 12 months. Pouch mucosal height and cell densities of ghrelin-, histamine-, serotonin-, and somatostatin-producing cells remained unaffected by RYGB in both groups.

CONCLUSIONS

RYGB selectively increased the density of incretin-producing cell populations in the jejunum. This may provide anatomic explanation for the observed increased plasma levels of incretins.

Water with food intake does not influence caloric intake after gastric bypass (GBP): a cross-over trial

BACKGROUND

Bariatric patients seeking information meet very different recommendations on postoperative diet and eating behaviour. A reason for variability may be lack of hard evidence. A national survey on current dietary advice was conducted to serve as background for the present study on how drinking during a meal influenced caloric consumption.

METHODS

A standardised questionnaire was sent to all units in the Scandinavian Obesity surgery registry (SOReg) in order to obtain information regarding current diet advice after gastric bypass. Twenty-eight patients, 14 in each group, were studied either 2 months or 1 year after a standard gastric bypass (GBP). A standardised lunch was served on two separate days with or without water in randomised order. Meal and water weights were measured before and after. Hunger/satiety scores were obtained using visual analogue scales.

RESULTS

Response rate for surgeons was low, for dieticians 75 %. No clear consensus for liquid intake during meals was found; few surgeons advised patients whether or not to drink with meals. All patients ate to full satiety. Two months post-GBP, 7/14 patients consumed more solid food when allowed drinking water; the increase in caloric consumption was not significant. One year post-GBP, 5/14 patients consumed more solid food when allowed drinking water, the difference not reaching statistical significance.

CONCLUSION

Our study does not indicate that patients should refrain from drinking during meals the first year after a GBP, at least not from a caloric intake point of view.

Effects of prolonged increased intra-abdominal pressure on gastrointestinal blood flow in pigs

BACKGROUND

The aim of the study was to investigate the effects of prolonged intra-abdominal pressure on systemic hemodynamics and gastrointestinal blood circulation.

METHODS

The intra-abdominal pressure in anesthetized pigs was elevated to 20 mmHg (7 animals), 30 mmHg (7 animals), and 40 mmHg (4 animals), respectively. These pressures were maintained for 3 h by intra-abdominal infusion of Ringer's solution. A control group of seven animals had normal intra-abdominal pressure (IAP). Transit time flowmetry and colored microspheres were used to measure blood flow.

RESULTS

An IAP of 20 mmHg did not cause significant changes in systemic hemodynamics or tissue blood flow. An IAP of 30 mmHg caused reduced blood flow in the portal vein, gastric mucosa, small bowel mucosa, pancreas, spleen, and liver. Serum lactate increased in animals with an IAP of 30 mmHg, but microscopy did not disclose mucosal damage in the stomach or small bowel. An IAP of 40 mmHg was followed by severe circulatory changes.

CONCLUSIONS

Prolonged IAP at 20 mmHg did not cause changes in general hemodynamics or gastrointestinal blood flow. Prolonged IAP at 30 mmHg caused reduced portal venous blood flow and reduced tissue flow in various abdominal organs, but no mucosal injury. A prolonged IAP of 40 mmHg represented a dangerous trauma to the animals.