Post-prandial secretion of glucagon-like peptide-2 (GLP-2) after carbohydrate-, fat- or protein enriched meals in healthy subjects

Glucagon-like peptide 2 (GLP-2) is an important regulator of intestinal growth and function. In adherable mixed meals the macronutrient composition with the best potential for stimulating GLP-2 secretion is not known. We compared the effect of 3 iso-energetic meals, where approximately 60 % of the energy ratio was provided as either carbohydrate, fat, or protein, respectively, on the post-prandial endogenous GLP-2 secretion. The responses were compared to secretion profiles of peptide YY (PYY), and glucose-dependent insulinotropic peptide (GIP). Ten healthy subjects were admitted on three occasions, at least a week apart, after a night of fasting. In an open-label, crossover design, they were randomized to receive a high carbohydrate (HC), high fat (HF) or high protein (HP) meal. The meals were approximately ∼3.9 MJ. Venous blood was collected for 240 min, and plasma concentrations of GLP-2, GIP and PYY were measured with specific radioimmunoassays. Mean GLP-2 levels peaked already at 30 min for the HC meal, however the HP meal induced the highest mean GLP-2 peaking levels, resulting in significantly higher mean GLP-2 area under the curve (AUC) from baseline of 7279 pmol*min/L, 95 %-CI [6081;8477] compared to the HC meal: 4764 pmol*min/L, 95 %-CI [3498;6029], p = 0.020 and the HF meal: 4796 pmol*min/L, [3385;6207], p = 0.011. Findings were similar for the PYY. The HC meal provided a greater AUC for GIP compared to the HP- and HF meals. The HP meal was most effective with respect to stimulation of the postprandial GLP-2 and PYY secretion, whereas the HC meal was more effective for GIP.

Differences in methodology impact estimates of survival and dependence on home parenteral support of patients with nonmalignant short bowel syndrome

BACKGROUND

In patients with intestinal failure (IF), who are receiving home parenteral support (HPS), variations between centers in estimates of survival and HPS dependency often reflect differences in population characteristics. However, variations in methodology and adherence to model assumptions may further contribute.

OBJECTIVES

We investigated how differences in methodology affect estimates of outcomes in IF patients.

METHODS

We applied different model assumptions and statistical methods to real-life outcome data from a well-characterized cohort of nonmalignant short bowel syndrome (SBS) patients. This retrospective study was based on extracts from the Copenhagen IF database and from the Danish death registry.

RESULTS

Estimates of mortality varied substantially, depending on the study design and statistical method. The 5-y mortality rate obtained with the Kaplan-Meier (KM) method was estimated to be 10.1% higher if patients were only followed during HPS treatment, compared with follow-up regardless of HPS treatment. The 5-y cumulative incidence of weaning off HPS was overestimated by 4.4% when inappropriately using the KM method, instead of the cumulative incidence function. The 5-y survival rates in nonmalignant SBS-IF patients who initiated HPS were 89.1% for those aged younger than 40 y, 74.8% for patients aged 40-60 y, and 52.1% for those older than 60 y. A Cox regression analysis identified age and diagnoses other than inflammatory bowel disease as significant risk factors for mortality. For HPS dependency, bowel anatomy was significantly associated with the ability to wean off, and no patients without a colon and less than 100 cm remnant of the small bowel remained continuously weaned off and alive for one year.

CONCLUSIONS

The large variations in outcomes illustrated in this study emphasize the importance of the appropriate selection of statistical methods. A comparison between studies is problematic, due to differences in the methods employed.

Home Parenteral Nutrition in Adult Patients With Chronic Intestinal Failure: Catheter-Related Complications Over 4 Decades at the Main Danish Tertiary Referral Center

BACKGROUND/AIMS

Catheter-related complications (CRCs) cause mortality and morbidity in patients dependent on parenteral support at home (HPN) due to intestinal failure (IF). This study describes the incidences of CRCs in an adult IF cohort over 40 years. It illustrates the evolution and consequences of CRCs, their association to demographic characteristics, and potential risk factors in an effort to provide the rationale for preventive precautions to the relevant patients with IF at risk.

METHODS

All patients with IF discharged with HPN from 1970-2010 were included. Patient and treatment characteristics were extracted from the Copenhagen IF database. The incidences were given per 1000 central venous catheter (CVC) days.

RESULTS

The 1715 CRCs occurred in 70% of the 508 patients with IF (56% of the 2191 CVCs). The incidence of catheter-related bloodstream infections (CRBSIs) was 1.43. Higher age, HPN administration by community home nurses, and prior CRBSIs significantly raised the hazard for CRBSIs. In the 1970s, catheters were generally replaced following CRBSIs, whereas catheter salvage was the norm in the 2000s. The incidences of mechanical complications, tunnel infections, and catheter-related venous thromboses were 0.80, 0.25, and 0.11, respectively. The overall CRC incidence was 2.58, decreasing the first 3 decades but peaking in the last (2.84). The deaths related to CRCs were low (0.018).

CONCLUSION

Even in an experienced IF center of excellence, the incidence of CRCs increased over the 4 decades. This increase could be explained by the expansion of the indication of HPN to a more elderly and frail patient population.

Effect of Liraglutide Treatment on Jejunostomy Output in Patients With Short Bowel Syndrome: An Open-Label Pilot Study

BACKGROUND

An impaired hormonal "ileo-colonic brake" may contribute to rapid gastric emptying, gastric hypersecretion, high ostomy losses, and the need for parenteral support in end-jejunostomy short bowel syndrome (SBS) patients with intestinal failure (IF). Liraglutide, a glucagon-like peptide 1 receptor agonist, may reduce gastric hypersecretion and dampen gastric emptying, thereby improving conditions for intestinal absorption.

MATERIALS AND METHODS

In an 8-week, open-label pilot study, liraglutide was given subcutaneously once daily to 8 end-jejunostomy patients, aged 63.4 ± 10.9 years (mean ± SD) and with small bowel lengths of 110 ± 66 cm. The 72-hour metabolic balance studies were performed before and at the end of treatment. Food intake was unrestricted. Oral fluid intake and parenteral support volume were kept constant. The primary end point was change in the ostomy wet weight output.

RESULTS

Liraglutide reduced ostomy wet weight output by 474 ± 563 g/d from 3249 ± 1352 to 2775 ± 1187 g/d (P = .049, Student t test). Intestinal wet weight absorption tended to increase by 464 ± 557 g/d (P = .05), as did urine production by 765 ± 759 g/d (P = .02). Intestinal energy absorption improved by 902 ± 882 kJ/d (P = .02).

CONCLUSION

Liraglutide reduced ostomy wet weight output in end-jejunostomy patients with SBS-IF and increased their intestinal wet weight and energy absorption. If larger, randomized, placebo-controlled studies confirm these effects, it adds to the hypothesis that many ileo-colonic brake hormones in conjunction may be involved in the process of intestinal adaptation. By identification of key hormones and addressing their potential synergistic effects, better treatments may be provided to patients with SBS-IF. This trial was registered at clinicaltrialsregister.eu as 2013-005499-16.

Acute effects of continuous infusions of glucagon-like peptide (GLP)-1, GLP-2 and the combination (GLP-1+GLP-2) on intestinal absorption in short bowel syndrome (SBS) patients. A placebo-controlled study

BACKGROUND AND AIMS

The ileocolonic brake is impaired in short bowel syndrome (SBS) patients with distal bowel resections. An attenuated meal-stimulated hormone secretion may cause gastric hypersecretion, rapid gastric and intestinal transit and a poor adaptation. Attempting to restore this ileocolonic brake, this study evaluated the acute effects of continuous intravenous administration of glucagon-like peptide (GLP) 1 and 2, alone or in combination, on gastrointestinal function in SBS patients.

METHODS

SBS patients were admitted 4 times for identical 72-h balance studies, where infusions (1 pmol/kg/min) of GLP-1, placebo (saline), GLP-2 and GLP-1+2 (1 pmol/kg/min of each), were provided. Patients filled out a VAS questionnaire regarding subjective symptoms during treatments. Bone mineral content, body-weight and -composition were measured using DEXA scans. Blood glucose, insulin, pro insulin C-peptide and GLP concentrations were measured in relation to a standardized breakfast.

RESULTS

Nine SBS patients (5 women/4 men, aged 52±11) were enrolled and completed the study; 7 had end-jejunostomies, 2 had 50% of colon-in-continuity. All treatments significantly reduced the fecal wet weight, energy, nitrogen, sodium and potassium losses compared to placebo. However, only GLP-2 containing treatments increased absolute absorption of wet weight and sodium. Only GLP-1+2 improved the hydrational status evaluated by DEXA increases in the fat mass and calculated total body weight. GLP-1 and GLP-1+2 reduced the post-prandial blood glucose levels. A tendency of nausea and reduced appetite was seen in relation to GLP-1 treatment, but this was ameliorated by the co-administration of GLP-2.

CONCLUSION

GLP-1 decreased diarrhea and fecal excretions in SBS patients, but it seems less potent than GLP-2. The combination of GLP-1+2 numerically provided additive effects on intestinal absorption compared to either peptide given alone. Larger, long-term studies should further assess the potential of the glucagon-like peptides or analogs, alone or in combination, in the treatment of SBS patients.

Irreversibility of kindled alcohol-withdrawal behaviour in rats

In order to investigate whether alcohol-withdrawal kindling is an irreversible process, male Wistar rats were exposed to 12 episodes, each consisting of 2 days of severe alcohol intoxication and 5 days of alcohol withdrawal. Spontaneous withdrawal seizures were found in 15% of the animals during episodes 10-12. After an alcohol-free period of 26 days, the animals were subjected to three more episodes of alcohol dependence (i.e. episodes 13-15) in which 12% of the animals developed spontaneous withdrawal seizures. Based on several statistical tests, we concluded that there was no true difference between the seizure activity in episodes 10-12 and episodes 13-15, indicating that alcohol-withdrawal kindling is a long-lasting and perhaps irreversible process. In a second experiment, an alcohol-withdrawal kindled group was first exposed to seven episodes of alcohol dependence. A diazepam group went through the same alcohol regimen, but each withdrawal reaction was blocked by diazepam treatment. Finally, a single episode group was included which was fed isocalorically with the kindled animals. After an alcohol-free period of 11 days, all three groups were subjected to 4 days of severe alcohol intoxication. During the subsequent withdrawal reaction seizures were observed in 22-26% of the animals with no significant differences across the groups. These results call for a modification of the kindling hypothesis of alcohol withdrawal and suggest that kindling-induced alterations may be overlooked if convulsive behaviour is tested during a relatively strong withdrawal reaction.