Gastric emptying, glucose metabolism and gut hormones: Evaluation of a common preoperative carbohydrate beverage

Perioperative nutritional assessment and support in visceral surgery

Malnutrition in visceral surgery is frequent; it calls for screening prior to an operation, and its postoperative occurrence should be sought out and prevented, if possible. Organization of an individualized nutritional support strategy is based on systematic nutritional assessment and adapted to the type of surgery, the objectives being to forestall malnutrition and to reduce induced morbidity (immunosuppression, delayed wound healing, anastomotic fistulas…). Nutritional support is part and parcel of enhanced recovery after surgery (ERAS), and has shown effectiveness in the field of visceral surgery. Oral feeding should always be privileged to the greatest possible extent, complemented if necessary by nutritional supplements. If nutritional support is required, enteral nutrition should be favored over parenteral nutrition. As for the role of pharmaco-nutrition or immuno-nutrition, it remains ill-defined. Lastly, each type of visceral surgery entails specific modifications of the anatomy of the digestive system and is liable to have specific functional consequences, which should be known and taken into account in view of effectively tailoring nutritional support.

Therapeutic potential of non-starch polysaccharides on type 2 diabetes: from hypoglycemic mechanism to clinical trials

Non-starch polysaccharides (NSPs) have been reported to exert therapeutic potential on managing type 2 diabetes mellitus (T2DM). Various mechanisms have been proposed; however, several studies have not considered the correlations between the anti-T2DM activity of NSPs and their molecular structure. Moreover, the current understanding of the role of NSPs in T2DM treatment is mainly based on in vitro and in vivo data, and more human clinical trials are required to verify the actual efficacy in treating T2DM. The related anti-T2DM mechanisms of NSPs, including regulating insulin action, promoting glucose metabolism and regulating postprandial blood glucose level, anti-inflammatory and regulating gut microbiota (GM), are reviewed. The structure-function relationships are summarized, and the relationships between NSPs structure and anti-T2DM activity from clinical trials are highlighted. The development of anti-T2DM medication or dietary supplements of NSPs could be promoted with an in-depth understanding of the multiple regulatory effects in the treatment/intervention of T2DM.

Effect of Ingested Fluid Volume and Solution Osmolality on Intestinal Drug Absorption: Impact on Drug Interaction with Beverages

It was recently shown that osmolality-dependent fluid movement is a significant factor causing the clinically observed apple juice (AJ)-atenolol interaction. Here we examined whether osmolality-dependent fluid movement may also explain the AJ volume dependence of the AJ-atenolol interaction. In Wistar rats, the luminal fluid volume after administration of different volumes of purified water (0.5 and 1.0 mL) gradually reduced to a similar steady-state level, while that after administration of different volumes of AJ (0.5 and 1.0 mL) increased and attained different apparent steady-state levels. It was hypothesized that osmolality-dependent fluid secretion would account for the volume dependence of the apparent steady-state. Indeed, the luminal concentration of FD-4, a non-permeable compound, after administration in AJ was attenuated depending upon the ingested volume, whereas that after administration in purified water was independent of the ingested fluid volume. An in vivo pharmacokinetic study in rats showed that co-administration of AJ and hyperosmotic solution (adjusted to the osmolality of AJ) with atenolol volume-dependently reduced the AUC and C_max of atenolol significantly. These results show that osmolality-dependent variations in luminal fluid volume may indirectly influence the absorption characteristics of drugs, and can account for the observed volume dependence of beverage-drug interactions.

ESPEN practical guideline: Clinical nutrition in surgery

Early oral feeding is the preferred mode of nutrition for surgical patients. Avoidance of any nutritional therapy bears the risk of underfeeding during the postoperative course after major surgery. Considering that malnutrition and underfeeding are risk factors for postoperative complications, early enteral feeding is especially relevant for any surgical patient at nutritional risk, especially for those undergoing upper gastrointestinal surgery. The focus of this guideline is to cover both nutritional aspects of the Enhanced Recovery After Surgery (ERAS) concept and the special nutritional needs of patients undergoing major surgery, e.g. for cancer, and of those developing severe complications despite best perioperative care. From a metabolic and nutritional point of view, the key aspects of perioperative care include the integration of nutrition into the overall management of the patient, avoidance of long periods of preoperative fasting, re-establishment of oral feeding as early as possible after surgery, the start of nutritional therapy immediately if a nutritional risk becomes apparent, metabolic control e.g. of blood glucose, reduction of factors which exacerbate stress-related catabolism or impaired gastrointestinal function, minimized time on paralytic agents for ventilator management in the postoperative period, and early mobilization to facilitate protein synthesis and muscle function.

Impact of gastrointestinal tract variability on oral drug absorption and pharmacokinetics: An UNGAP review

The absorption of oral drugs is frequently plagued by significant variability with potentially serious therapeutic consequences. The source of variability can be traced back to interindividual variability in physiology, differences in special populations (age- and disease-dependent), drug and formulation properties, or food-drug interactions. Clinical evidence for the impact of some of these factors on drug pharmacokinetic variability is mounting: e.g. gastric pH and emptying time, small intestinal fluid properties, differences in pediatrics and the elderly, and surgical changes in gastrointestinal anatomy. However, the link of colonic factors variability (transit time, fluid composition, microbiome), sex differences (male vs. female) and gut-related diseases (chronic constipation, anorexia and cachexia) to drug absorption variability has not been firmly established yet. At the same time, a way to decrease oral drug pharmacokinetic variability is provided by the pharmaceutical industry: clinical evidence suggests that formulation approaches employed during drug development can decrease the variability in oral exposure. This review outlines the main drivers of oral drug exposure variability and potential approaches to overcome them, while highlighting existing knowledge gaps and guiding future studies in this area.

The Effect of Preoperative Carbohydrate Loading on Clinical and Biochemical Outcomes after Cardiac Surgery: A Systematic Review and Meta-Analysis of Randomized Trials

Background and aim: Preoperative fasting leads to metabolic stress and causes insulin resistance in patients undergoing cardiac surgery. The aim of this study was to assess the effect of preoperative oral carbohydrate loading (OCH) on outcome in patients undergoing planned cardiac surgery by systematically reviewing the literature and synthesizing evidence from randomized controlled trials (RCTs). Methods: Systematic search of PubMed/MEDLINE/Embase/Cinahl/Web of Science/ClinicalTrials databases was performed to identify relevant RCTs from databased inception until 05/03/2020. We included studies that compared outcome measures between OCH with control (placebo or standard starvation). We conducted a random-effect meta-analysis of clinical and biochemical parameters. Results: Nine studies (N = 9) were included with a total of 507 patients. OCH significantly decreased aortic clamping duration (n = 151, standardized mean difference (SMD) = −0.28, 95% confidence interval (CI) = −0.521 to −0.038, p = 0.023 and differences in means (DM) = −6.388, 95%CI = −11.246 to −1.529, p = 0.010). Patients from treatment groups had shorter intensive care unit (ICU) stay (n = 202, SMD = −0.542, 95%CI = −0.789 to −0.295, p < 0.001 and DM = −25.925, 95%CI = −44.568 to −7.283, p = 0.006) and required fewer units of insulin postoperatively (n = 85, SMD = −0.349, 95%CI = −0.653 to −0.044, p = 0.025 and DM = −4.523, 95%CI = −8.417 to −0.630, p = 0.023). The necessity to use inotropic drugs was significantly lower in the OCH group (risk ratio (RR) = 0.795, 95%CI = 0.689 to 0.919, p = 0.002). All other primary outcomes did not reveal a significant effect. Conclusions: Preoperative OCH in patients undergoing cardiac surgery demonstrated a 20% reduction in the use of inotropic drugs, a 50% reduction of the length of ICU stay, a 28% decrease in aortic clamping duration and a 35% decrease of postoperative insulin requirement.

Nutritional prehabilitation: physiological basis and clinical evidence

In this narrative review, we describe the physiological basis for nutritional prehabilitation and evaluate the clinical evidence for its current roles in the perioperative period. Surgical stress and fasting induce insulin resistance as a result of altered mitochondrial function. Insulin resistance in the perioperative period leads to increased morbidity in a dose-dependent fashion, while preoperative carbohydrate loading attenuates insulin resistance, minimises protein loss and improves postoperative muscle function. Carbohydrate loading is an established practice in many countries and a key component of enhanced recovery after surgery (ERAS) programs, yet its independent effects on clinical outcomes remain unclear. Amino acid supplements may confer additional positive effects on a number of markers of clinical outcomes in the perioperative period, but their current role is also poorly defined. Clinical studies evaluating nutritional interventions have been marred by conflicting data, which may be due to small sample sizes, as well as heterogeneity of patients and surgical procedures. At present, it is known that carbohydrate loading is safe and improves patients' wellbeing, but does not appear to influence length of hospital stay or rate of postoperative complications. This should be appreciated before its routine inclusion in ERAS programs.

Successful implementation of an Enhanced Recovery After Surgery program shortens length of stay and improves postoperative pain, and bowel and bladder function after colorectal surgery

Background

Despite international data indicating that Enhanced Recovery After Surgery (ERAS) programs, which combine evidence-based perioperative strategies, expedite recovery after surgery, few centers have successfully adopted this approach within the U.S. We describe the implementation and efficacy of an ERAS program for colorectal abdominal surgery in a tertiary teaching center in the U.S.

Methods

We used a multi-modal and continuously evolving approach to implement an ERAS program among all patients undergoing colorectal abdominal surgery at a single hospital at the University of California, San Francisco. 279 patients who participated in the Enhanced Recovery after Surgery program were compared to 245 previous patients who underwent surgery prior to implementation of the program. Primary end points were length of stay and readmission rates. Secondary end points included postoperative pain scores, opioid consumption, postoperative nausea and vomiting, length of urinary catheterization, and time to first solid meal.

Results

ERAS decreased both median total hospital length of stay (6.4 to 4.4 days) and post-procedure length of stay (6.0 to 4.1 days). 30-day all-cause readmission rates decreased from 21 to 9.4 %. Pain scores improved on postoperative day 0 (3.2 to 2.1) and day 1 (3.2 to 2.6) despite decreased opioid. Median time to first solid meal decreased from 4.7 to 2.7 days and duration of urinary catheterization decreased from 74 to 46 h. Similar improvements were observed in all other secondary end points.

Conclusions

These results confirm that a multidisciplinary, iterative, team-based approach is associated with a reduction in hospital stay and an acceleration in recovery without increasing readmission rates.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-016-0223-0) contains supplementary material, which is available to authorized users.

From endocrine to rheumatism: do gut hormones play roles in rheumatoid arthritis?

RA is characterized by chronic inflammation in the musculoskeletal system, in which TNF-α is the key cytokine trigger. TNF-α, previously known as cachectin, is implicated in the modulation of body composition and energy expenditure. Gut hormones, including acyl ghrelin, des-acyl ghrelin, GIP, GLP-1 and PYY, have been known to be the major regulators of appetite, nutrition, energy expenditure and body mass formation. Emerging evidence indicates that blockade of TNF-α by biologics not only ameliorates rheumatoid inflammation, but can affect the secretion and action of gut hormones on appetite, body composition, energy expenditure, muscle catabolism and bone remodelling. A link between the gastrointestinal endocrine axis and the immune system may be established through the interaction of proinflammatory cytokines, including TNF-α and these gut hormones. With the ever-increasing understanding of rheumatoid inflammation and the invention of more biologics to modulate the cytokine network, more attention should be given to the possible immunomodulatory roles of gut hormones in autoimmune inflammatory reactions.

Plasma ghrelin isoforms and gastric ghrelin O-acyltransferase expression are influenced by Helicobacter pylori status

OBJECTIVE

Helicobacter pylori is known to affect the host's nutritional status. This study was performed to elucidate the relationship between H. pylori status and the dynamics of the ghrelin system, in the context of ghrelin O-acyltransferase (GOAT) expression.

METHODS

We conducted a clinical study of 30 subjects focusing on the following points: 1) the effects of H. pylori infection on the concentrations of circulating ghrelin isoforms and on ghrelin and GOAT mRNA expression in the gastric mucosa, and 2) the effects of H. pylori eradication on the same parameters.

RESULTS

The plasma acyl-ghrelin and desacyl-ghrelin concentrations of 16 H. pylori positive participants were significantly lower than those of 14 H. pylori negative controls. The acyl-ghrelin/desacyl-ghrelin ratio was not significantly different between the H. pylori positive and H. pylori negative participants. The levels of ghrelin and GOAT mRNA in the gastric mucosa were significantly lower in the H. pylori positive participants than in the H. pylori negative controls. In 11 subjects in whom H. pylori eradication was successful, their plasma acyl-ghrelin levels tended to increase after H. pylori eradication, but the difference was not significant; however, their plasma desacyl-ghrelin levels were significantly reduced. Although gastric ghrelin mRNA expression increased significantly after H. pylori eradication, gastric GOAT mRNA expression tended to increase but was not significantly altered.

CONCLUSION

H. pylori status might affect the host's nutritional status through changes in the plasma levels of ghrelin isoforms and the gastric expression levels of ghrelin and GOAT mRNA.