Nutritional support for the patient with short-bowel syndrome

Identifying a subpopulation with higher likelihoods of early response to treatment in a heterogeneous rare disease: a post hoc study of response to teduglutide for short bowel syndrome

Purpose

Teduglutide, a glucagon-like peptide-2 analog, has demonstrated efficacy in reducing parenteral support (PS) among patients with short bowel syndrome with intestinal failure (SBS–IF). This study aims to identify a subpopulation of SBS–IF patients for whom teduglutide has an especially pronounced effect.

Patients and methods

Data were from a 24-week, Phase III trial (Study of Teduglutide Effectiveness in Parenteral Nutrition-Dependent SBS Subjects; NCT00798967) that randomized SBS–IF patients with PS dependency to receive teduglutide (n=43) or placebo (n=43). Two prediction models (1 for each arm) were developed for response, defined as 20% reduction in weekly PS at Weeks 20 and 24. Potential predictors included demographics, disease characteristics, and concomitant medications. Patients were then ranked based on the effect score, an individualized predicted response rate difference with teduglutide versus placebo. A subpopulation of patients with a pronounced benefit from teduglutide versus placebo was identified. Baseline characteristics and clinical outcomes were compared between patients included versus those not included in the subpopulation.

Results

Six predictors of response to teduglutide were selected: older age, volvulus as the cause of major intestinal resection, baseline PS volume >6 L per week, longer time since start of PS dependency, absence of ileocecal valve, and lower percentage of colon remaining. Higher percentage of colon remaining and volvulus were the selected predictors for response to placebo. A subpopulation of patients more likely to respond to teduglutide was identified as those with the top 60% effect scores. The difference in response rate between teduglutide and placebo was 62% in the subpopulation, which was substantially higher than the difference of 33% in the overall population. Mean PS day reduction was also significantly higher for teduglutide compared to placebo in the subpopulation.

Conclusion

Pretreatment characteristics as predictors of response to teduglutide versus placebo within 24 weeks were identifiable in the clinical trial population of SBS–IF patients.

Morphological adaptation with preserved proliferation/transporter content in the colon of patients with short bowel syndrome

In short bowel syndrome (SBS), although a remaining colon improves patient outcome, there is no direct evidence of a mucosal colonic adaptation in humans. This prospective study evaluates morphology, proliferation status, and transporter expression level in the epithelium of the remaining colon of adult patients compared with controls. The targeted transporters were Na+/H+ exchangers (NHE2 and 3) and oligopeptide transporter (PepT1). Twelve adult patients with a jejuno-colonic anastomosis were studied at least 2 yr after the last surgery and compared with 11 healthy controls. The depth of crypts and number of epithelial cells per crypt were quantified. The proliferating and apoptotic cell contents were evaluated by revealing Ki67, PCNA, and caspase-3. NHE2, NHE3, PepT1 mRNAs, and PepT1 protein were quantified by quantitative RT-PCR and Western blot, respectively. In patients with SBS compared with controls, 1) hyperphagia and severe malabsorption were documented, 2) crypt depth and number of cells per crypt were 35% and 22% higher, respectively (P < 0.005), whereas the proliferation and apoptotic levels per crypt were unchanged, and 3) NHE2 mRNA was unmodified; NHE3 mRNA was downregulated near the anastomosis and unmodified distally, and PepT1 mRNA and protein were unmodified. We concluded that, in hyperphagic patients with SBS with severe malabsorption, adaptive colonic changes include an increased absorptive surface with an unchanged proliferative/apoptotic ratio and well-preserved absorptive NHE2, NHE3, and PepT1 transporters. This is the first study showing a controlled nonpharmacological hyperplasia in the colon of patients with SBS.

Expression of growth hormone and its receptor in chronic atrophic gastritis and its clinical significance

AIM: To investigate the growth hormone (GH) and growth hormone receptor (GHR) expression of and its clinical significance in patients with chronic atrophic gastritis (CAG).

METHODS: A total of 90 cases were enrolled in the study. Thirty were healthy controls, the other 60 patients were divided into two groups according to the endoscopical and histological diagnosis. Blood samples were drawn in the morning (menarche did not occur during the blood extraction in female patients), gastric mucosa was obtained by endoscopy. Serum GH and gastrice mucosal GHR levels were measured using radioimmunoassay (RIA) and En Vinsion technique.

RESULTS: The average GH level was 1.021 ± 0.132 µg/L in CAG patients, in controls it was 2.869 ± 0.512 µg/L. There was a significant difference between these two groups (P < 0.01). The positive rate of GHR in CAG patients was 10%, in controls the rate was 100%. There was a significant difference (P < 0.01). There was no significant change of GH level (3.176 ± 0.421 µg/L) in patients with gastric carcinoma compared with controls (P > 0.05).

CONCLUSION: The study shows that levels of GH and GHR expression are low in CAG patients. CAG pathogenesis has a correlation with mucosal nutrient deficiency, decreased levels of GH and GHR have an adverse effect on the repair and regeneration of CAG. There is no significant change of GH in gastric carcinorma patients, GH dose not play a role in the pathogenesis of gastric cancer.

Nutritional management of short bowel syndrome in adults

Short bowel syndrome (SBS) comprises the sequelae of nutrient, fluid, and weight loss that occurs subsequent to greatly reduced functional surface area of the small intestine. Signs and symptoms of SBS include electrolyte disturbances; deficiencies of calcium, magnesium, zinc, iron, vitamin B12, or fat-soluble vitamin deficiency; malabsorption of carbohydrates, lactose, and protein; metabolic acidosis, gastric acid hypersecretion; formation of cholesterol biliary calculi and renal oxalate calculi; and dehydration, steatorrhea, diarrhea, and weight loss. Thorough nutritional management is the key factor in achieving an optimal outcome in SBS. Total parenteral nutrition is necessary in the early stages, as is replacement of excess fluid and electrolyte losses. Nutritional management of SBS has traditionally been divided into three phases: an acute phase when total parenteral nutrition is usually begun, an adaptation phase, and a maintenance phase. Recommendations regarding the need for parenteral nutrition vary depending on the presence or absence of certain factors: the ileocecal valve, jejunum, and functional colon. Patients with residual small bowel length of 100 cm or less usually require the administration of parenteral nutrition at home with good results. The total parenteral nutrition diet should consist of a majority of calories from fat, followed by protein, and the remaining as carbohydrates. Vitamins, minerals, and trace elements should also be added accordingly. Although total parenteral nutrition is initially necessary, treatment goals should focus on early transition to enteral nutrition followed by oral feeds. Other recent advances in the medical management of SBS include pharmacologic treatment and the use of specific nutrients and growth factors to stimulate intestinal absorption and adaptation. Both animal studies and clinical trials in humans have shown much promise in supplementation with growth factors and hormones. This strategy is likely to play a greater role in the treatment of SBS in the future.

Intestinal function and metabolism in the early adaptive phase after massive small bowel resection in the rat

PURPOSE

The aim of this study was to investigate the early adaptive responses in metabolism and gut function after massive small bowel resection.

METHODS

Male Wistar rats underwent an 80% small bowel resection (Ent group, n = 9) or a transection and reanastomozing (Sham group, n = 7). After 24 hours, substrate fluxes across the gut were determined together with intestinal protein synthesis, polyamine concentrations in gut tissue, and gut function by testing intestinal permeability using the urinary recovery of lactulose and rhamnose. To test for the effect of starvation, healthy starved rats were studied.

RESULTS

In the Ent group, intestinal uptake of glucose, lactate, glutamine, phenylalanine, branched chain amino acids, and total amino acids were equal to or higher than that in Sham rats. Intestinal protein synthesis increased, accompanied by an increase in spermidine to spermine polyamine ratios in the ileum and in the jejunal muscular layer. The urinary lactulose to rhamnose ratio also increased, suggesting increased intestinal permeability.

CONCLUSIONS

24 hours after massive small bowel resection, adaptive responses in metabolism and gut function already can be observed, as indicated by increased intestinal uptake of substrates and increased protein synthesis. This, however, is accompanied by an increase in intestinal permeability, which may indicate impaired intestinal barrier function. J Pediatr Surg 36:1746-1751.