Pancreatic polypeptide administration reduces insulin requirements of artificial pancreas in pancreatectomized dogs

Closed-loop artificial endocrine pancreas from Japan

The development of a closed-loop artificial pancreas (AP) in the Western countries and Japan is different. In Western countries, wearable AP with a closed-loop glycemic control system has been developed as a treatment for patients with type 1 and type 2 diabetes. On the contrary, in Japan, bedside closed-loop AP explored by a Japanese company (Nikkiso, Tokyo, Japan) has developed as perioperative glycemic control device in surgical patients and acute care patients with emergency. In this article, we reviewed the scientific evidence in the past and present and future prospects of perioperative glycemic control using bedside AP with a closed-loop system in Japan. Conventional perioperative strict glycemic controls have three major problems: hyperglycemia, hypoglycemia, and variability in blood glucose concentrations. In Japan, perioperative strict glycemic control using the current bedside AP STG-55 (Nikkiso, Tokyo, Japan) has been developed since 2010. This novel glycemic control method achieved not only stable glycemic control without hyperglycemia, hypoglycemia, and less variability of blood glucose concentrations but also reduced postoperative infectious complications in patients undergoing major surgeries. Among the rapidly increasing number of surgical or emergency patients with diabetes, frailty, and sarcopenia of intrinsic glucose intolerance, more sophisticated and smaller AP available easily in operating rooms and intensive care units will be warranted to promote improved therapeutic outcomes in such critically ill patients.

Alterations in Enteroendocrine Hormones After Total Pancreatectomy With Islet Autotransplantation

OBJECTIVE

When total pancreatectomy with islet autotransplantation (TPIAT) is performed for chronic pancreatitis, the pancreas and most of the duodenum are removed, with Roux-en-Y reconstruction of the gastrointestinal tract. Enteroendocrine cells in the intestines and pancreas secrete hormones coordinating digestion and motility, but anatomic reconstruction alters transit of nutrients to these cells. We hypothesized that TPIAT leads to changes in enteroendocrine hormones.

METHODS

Glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and pancreatic polypeptide (PP) were measured from mixed-meal tolerance tests of 34 clinical trial participants before and 18 months after TPIAT. Area under the curve of GLP-1 and PYY-stimulated responses were calculated by trapezoidal method, and the PP response was measured as the stimulated max minus baseline (ΔPP).

RESULTS

Area under the curve of GLP-1 and PYY increased significantly after TPIAT (GLP-1 average +553.1 pg/mL per minute, P = 0.004; PYY average +4647.9 pg/mL per minute, P = 0.02). ΔPP trended toward lower after TPIAT (average, -52.2 pg/mL, P = 0.06).

CONCLUSIONS

In this novel study of enteroendocrine hormones in TPIAT patients, stimulated levels of GLP-1 and PYY were significantly higher after versus before TPIAT. ΔPP was lower after TPIAT, but not significantly. These hormone changes have potential clinical implications that warrant further research.

Current status and issues of the artificial pancreas: abridged English translation of a special issue in Japanese

Surgical stress induces hyperglycemia and gives rise to glucose toxicity, which causes infectious diseases, resulting in unfavorable surgical outcomes. Intensive insulin treatment can control short- and long-term complications in patients with not only diabetes mellitus, but also surgical diabetes; however, it is associated with an increased risk of hypoglycemia. The wearable artificial pancreas was originally developed to control glucose levels in patients with type 1 diabetes, progressing to a device with enhanced stability and safety for these patients. Its usability has further progressed to include patients with type 2 diabetes. The bedside artificial pancreas is the only closed-loop-type artificial pancreas which can maintain stable glycemic control in accordance with a target blood glucose range, based on the patient's actual blood glucose levels. Moreover, this stable glycemic control with a low variation in blood glucose concentration within the target range is produced without any hypoglycemia. Significant advances of this device will now occur due to the approval of treatment for perioperative glycemic control by the Japanese Health Care Insurance System in 2016. Along with an increase in the number of mainly elderly patients with low glucose tolerance, it is expected that the role of the artificial pancreas will increase in the future. Considering the current state and expense of regenerative and transplant medicine, along with donor shortages, further development of the artificial pancreas and associated glycemic control can be expected.

Impact of newly developed, next-generation artificial endocrine pancreas

BACKGROUND

Recent studies have shown that strict perioperative blood glucose management may reduce mortality and morbidity in critically ill adult patients. The purpose of this study was to assess the accuracy and efficacy of the intraoperative application of a newly developed, next-generation artificial endocrine pancreas (STG-55, Nikkiso Co., Ltd., Tokyo, Japan).

METHODS

Twenty patients scheduled to undergo surgery were enrolled in this study. The STG-55 is designed to be more user-friendly than its conventional counterpart (STG-22) while maintaining the latter's fundamental functions, such as a closed-loop system using algorithms for insulin and glucose infusion. After anesthetic induction, a 20G intravenous catheter was inserted into a peripheral forearm vein and connected to a continuous blood glucose monitor. The resultant 105 scores for paired blood glucose values were compared by Bland-Altman analysis.

RESULTS

Stable blood glucose values were maintained automatically, and there were no complications related to use of the STG-55. A close correlation (r=0.96) was observed between continuous glucose measurements using the STG-55 and conventional intermittent glucose measurements. The difficulty of manipulation using this system was decreased by improved preparation procedures.

CONCLUSION

The glycemic control system using the STG-55 could provide an alternative way to achieve effective and safe perioperative glycemic control.

Perioperative intensive insulin therapy using an artificial endocrine pancreas with closed-loop glycemic control system: the effects of no hypoglycemia

BACKGROUND

We examined whether perioperative intensive insulin therapy (IIT) using an artificial pancreas (AP) with a closed-loop glycemic control system can be used to prevent hypoglycemia in surgical patients.

METHODS

Between 2006 and 2012, perioperative glycemic control using an AP was performed in 427 patients undergoing general surgery. A total of 305 patients undergoing IIT using an AP in the target blood glucose range of 80 to 110 mg/dL were enrolled in the study. Data were collected prospectively and were reviewed or analyzed retrospectively.

RESULTS

No patients had hypoglycemia. Perioperative mean blood glucose level and achievement rates in target blood glucose range of 80 to 110 mg/dL were 100.5 ± 11.9 mg/dL and 88.1% ± 16.0%, respectively. For the 3 primary operative methods, including hepatic, pancreatic, and esophageal resections, there were no significant differences in glycemic control stability between the types of surgery.

CONCLUSION

Perioperative IIT using an AP with a closed-loop glycemic control system can be used to prevent hypoglycemia and maintain stable glycemic control with less variability of blood glucose concentration.

A novel peptide nanomedicine for treatment of pancreatogenic diabetes

Pancreatogenic diabetes (PD) is a potentially fatal disease that occurs secondary to pancreatic disorders. The current anti-diabetic therapy for PD is fraught with adverse effects that can increase morbidity. Here we investigated the efficacy of novel peptide nanomedicine: pancreatic polypeptide (PP) in sterically stabilized micelles (SSM) for management of PD. PP exhibits significant anti-diabetic efficacy but its short plasma half-life curtails its therapeutic application. To prolong and improve activity of PP in vivo, we evaluated the delivery of PP in SSM. PP-SSM administered to rats with PD, significantly improved glucose tolerance, insulin sensitivity and hepatic glycogen content compared to peptide in buffer. The studies established the importance of micellar nanocarriers in protecting enzyme-labile peptides in vivo and delivering them to target site, thereby enhancing their therapeutic efficacy. In summary, this study demonstrated that PP-SSM is a promising novel anti-diabetic nanomedicine and therefore should be further developed for management of PD.

FROM THE CLINICAL EDITOR

Pancreatic peptide was earlier demonstrated to address pancreatogenic diabetes, but its short half-life represented major difficulties in further development for therapeutic use. PP-SSM (pancreatic polypeptide in sterically stabilized micelles) is a promising novel anti-diabetic nanomedicine that enables prolonged half-life and increased bioactivity of PP, as shown in this novel study, paving the way toward clinical studies in the near future.

Development of perioperative glycemic control using an artificial endocrine pancreas

It is well known that tight glycemic control (TGC) in patients with diabetes mellitus is the most important to reduce complications, such as nephropathy, neuropathy, and retinopathy. Also, surgical stress induced hyperglycemia leading to glucose toxicity is the main cause of infectious complications after surgery. Recently perioperative TGC has been proven an effective method to reduce postoperative infectious complications and accelerate enhanced recovery after surgery (ERAS), with the main purpose of short staying hospital. However, conventional TGC with open-loop glycemic control system is likely to induce not only occurrence of hypoglycemia but also unstable glycemic control. To solve these problems, we have involved introduction of novel glycemic control using an artificial pancreas (AP) with closed-loop glycemic control system since 2006. To date, this novel perioperative glycemic control was performed in more than 400 surgical patients. As a result, we established stable and safe TGC using an AP to improve surgical outcomes without hypoglycemia. In this paper, we report current scientific evidence focusing on perioperative glycemic control using an AP.

Technical challenges and clinical outcomes of using a closed-loop glycemic control system in the hospital

According to large randomized trials, results suggest that maintaining normoglycemia postoperatively through tight glycemic control (TGC) and intensive insulin therapy (IIT) can improve surgical outcomes as well as reduce mortality and morbidity in critically ill patients. However, trials examining the effects of TGC have had conflicting results. Systematic reviews and meta-analyses have also led to differing conclusions. The main reason these clinical trials and meta-analyses show negative results for TGC is the high incidence of hypoglycemia induced by IIT. This could not be prevented because there is no reliable technique that can avoid this condition during IIT. The development of accurate, continuous blood glucose monitoring devices and closed-loop systems for computer-assisted blood glucose control in the intensive care unit (ICU) will probably help avoid hypoglycemia in these situations. The STG closed-loop glycemic control system was introduced to our department to be used and evaluated for strict serum glucose control with no hypoglycemic episodes during IIT in the surgical ICU, to reduce the workload of ICU nurses, and to decrease incidents related to the management of blood glucose levels according to manual conventional venous infusion insulin therapy. The goal of our team was to use the STG closed-loop glycemic control system for perioperative TGC in surgical patients to solve the complications of IIT and reduce risk of hypoglycemia. The challenge at our hospital demonstrated that the STG closed-loop glycemic control system can be expected to achieve TGC with no occurrence of hypoglycemia induced by IIT after surgery.

Surgery for a gastroenteropancreatic neuroendocrine tumor (GEPNET) in multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominantly inherited endocrine tumor syndrome characterized by tumor development in various endocrine organs such as the parathyroid, endocrine pancreas, anterior pituitary and adrenal cortex. The first extensive database for Asian patients with MEN1 was established by the MEN Consortium of Japan. Although the clinical features of Japanese patients with MEN1 are similar to those from Western countries, there are several characteristic differences between them. In particular, gastroenteropancreatic neuroendocrine tumor (GEPNET) is seen in approximately 60 % of patients with MEN1 in Japan. Although its development is the strongest prognostic factor in patients with MEN1, the characteristics of MEN1-associated GEPNET still remain unclear. This is especially true for the differences in clinical features of GEPNET with and without MEN1. Improved long-term survival is obtained by curative surgery for patients with MEN1-associated GEPNET. The current surgical indications are expanding even in patients with hepatic metastases because of the improved surgical outcome. This article reviews the clinical characteristics in these patients with a particular focus on surgery, diagnosis, surgical indications, surgical method, and surgical outcome.

Tight glycemic control using an artificial endocrine pancreas may play an important role in preventing infection after pancreatic resection

It is well known that perioperative hyperglycemia is the main cause of infectious complications after surgery. To improve perioperative glycemic control, we wish to highlight and comment on an interesting paper published recently by the Annals of Surgery entitled: “Early postoperative hyperglycemia is associated with postoperative complications after pancreatoduodenectomy (PD)” by Eshuis et al. The authors concluded that early postoperative glucose levels more than 140 mg/dL was significantly associated with complications after PD. Since we recommend that perioperative tight glycemic control (TGC) is an effective method to prevent postoperative complications including surgical site infection after distal, proximal, and total pancreatic resection, we support strongly this conclusion drawn in this article. However, if early postoperative glucose control in patients undergoing PD was administrated by conventional method such as sliding scale approach as described in this article, it is difficult to maintain TGC. Therefore, we introduce a novel perioperative glycemic control using an artificial endocrine pancreas against pancreatogenic diabetes after pancreatic resection including PD.

Retrospective study on the effect of tight glucose control in postoperative sepsis patients using an artificial pancreas

Tight glucose control (TGC) using a sliding scale based on intermittent blood glucose measurements occasionally can have a fatal outcome as a result of insulin-induced hypoglycemia. The present study was undertaken to examine whether the use of an artificial pancreas to achieve TGC would be possible in postoperative patients with sepsis. The retrospective study was carried out as an exploratory study, focusing on the possibility of precise evaluation of the significance of TGC as a beneficial intervention by serological monitoring of various mediators. TGC was accomplished using an artificial pancreas (STG-22; (Nikkiso, Tokyo, Japan). The patients were divided into two groups: the TGC group (6 patients with sepsis in whom the target blood glucose level set at <150 mg/dl was attempted using the artificial pancreas), and the glucose control (GC) group (6 patients with sepsis in whom glucose control was attempted using a sliding scale; target blood glucose level was set at 200 mg/dl or lower). The mean blood glucose level was 129.7 ± 9.7 mg/dl in the TGC group and 200.9 ± 14.7 mg/dl in the GC group (P < 0.01, ANOVA). No hypoglycemia associated with the artificial pancreas was seen in any of the patients. The serum levels of S100A12 and HMGB-1 tended to decrease, and those of sRAGE tended to increase, in the TGC group. Further data collection from a larger number of cases would be expected to allow a precise assessment of TGC as a potentially beneficial intervention in sepsis patients.

Preliminary study on glucose control with an artificial pancreas in postoperative sepsis patients

BACKGROUND

Glucose control is essential to avoid hypoglycemia in postoperative patients.

AIM

To conduct a preliminary examination to evaluate the feasibility of the use of an artificial pancreas for glucose control as well as the accuracy of assessment by the artificial pancreas of the insulin dose required.

SUBJECTS AND METHODS

Glucose control using an artificial pancreas was undertaken in 8 postoperative sepsis patients. The blood glucose level was set at 80-150 mg/dl. Blood glucose levels over time, insulin dose requirements, and occurrence of hypoglycemia (≤40 mg/dl) were recorded for each patient. The patients were divided into 2 groups based on the total insulin dose they received over the 7 days (HG, n = 4: consisting of patients who required a higher insulin dose; LG, n = 4: patients who required a lower insulin dose). The data of the 2 groups were analyzed retrospectively.

RESULTS

The blood glucose level before glucose control was 203.3 ± 9.9 mg/dl and could be controlled in all patients to within the target range. No hypoglycemia events were recorded for any of the patients. The insulin dose in the HG and LG groups was 21,824.8 ± 6,030.4 and 6,254.5 ± 3,402.3 mU/kg (p < 0.05).

CONCLUSIONS

Accurate glucose control could be achieved with the artificial pancreas.

Gut peptide hormones and pediatric type 1 diabetes mellitus

The aims of our study were to evaluate plasma levels of gut hormones in children with Type 1 diabetes mellitus (T1DM) in comparison with healthy controls and to correlate plasma concentrations of gut hormones with blood biochemistry, markers of metabolic control and with anthropometric parameters. We measured postprandial levels of specific gut peptide hormones in T1DM children. Amylin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP-1), ghrelin, leptin, pancreatic polypeptide (PP), and polypeptide YY (PYY) were assessed in 19 T1DM children and 21 healthy reference controls. Multiplex assay kit (LINCOplex(®)) was used for determination of the defined plasma hormone levels. T1DM subjects had significantly reduced amylin (p<0.001) and ghrelin (p<0.05) levels, whereas GIP (p<0.05) was elevated when compared with healthy controls. Plasma levels of other measured hormones did not differ statistically between the studied groups. Further analysis of T1DM patients demonstrated an association between body mass index and GLP-1 (r=0.4642; p<0.05), leptin (r=0.5151; p<0.05), and amylin (r=0.5193; p<0.05). Ghrelin levels positively correlated with serum HDL cholesterol (r=0.4760; p<0.05). An inverse correlation was demonstrated with triglycerides (TG) (r= -0.5674; p<0.01), insulin dosage (r= -0.5366; p<0.05), and HbA1c% (r= -0.6864; p<0.01). Leptin was inversely correlated with TG (r= -0.6351; p<0.01). Stepwise regression analysis was performed to enlighten the predictive variables. Our study demonstrated an altered secretion pattern of gut peptide hormones in T1DM children. A close correlation was revealed between these peptides as well as with blood biochemistry, markers of metabolic control and with anthropometric parameters. Further studies are essential to explore this issue in T1DM children.

Intensive insulin therapy during cardiovascular surgery

Recent evidence in the fields of surgery, emergency and critical care medicine indicates that strict glycemic control results in lower mortality. Hyperglycemia occurs frequently in patients with and without diabetes during cardiovascular surgery, especially during cardiopulmonary bypass. However, strict glucose control is difficult to achieve during cardiovascular procedures. To establish effective intensive insulin therapy during cardiovascular surgery, we conduct continuous blood glucose monitoring and employ automatic control by using an artificial endocrine pancreas (the STG-22, Nikkiso, Tokyo, Japan). In this review, we will outline the present status and problems of conventional glycemic control for perioperative cardiovascular surgery and introduce the new perioperative blood glucose management method that we are testing now. We will also discuss the importance of perioperative glycemic control for cardiovascular surgery as well as future prospects.

Relationship between perioperative glycemic control and postoperative infections

Perioperative hyperglycemia in critically ill surgery patients increases the risk of postoperative infection (POI), which is a common, and often costly, surgical complication. Hyperglycemia is associated with abnormalities in leukocyte function, including granulocyte adherence, impaired phagocytosis, delayed chemotaxis, and depressed bactericidal capacity. These leukocyte deficiencies are the cause of infection and improve with tight glycemic control, which leads to fewer POIs in critically ill surgical patients. Tight glycemic control, such as intensive insulin therapy, has a risk of hypoglycemia. In addition, the optimal targeted blood glucose range to reduce POI remains unknown. Since 2006, we have investigated tight perioperative blood glucose control using a closed-loop artificial endocrine pancreas system, to reduce POI and to avoid hypoglycemia. In this Topic Highlight, we review the relationship between perioperative glycemic control and POI, including the use of the artificial pancreas.

Perioperative intensive insulin therapy using artificial endocrine pancreas in patients undergoing pancreatectomy

Perioperative glycemic control is important for reducing postoperative infectious complications. However, clinical trials have shown that efforts to maintain normoglycemia in intensive care unit patients result in deviation of glucose levels from the optimal range, and frequent attacks of hypoglycemia. Tight glycemic control is even more challenging in those undergoing pancreatic resection. Removal of lesions and surrounding normal pancreatic tissue often cause hormone deficiencies that lead to the destruction of glucose homeostasis, which is termed pancreatogenic diabetes. Pancreatogenic diabetes is characterized by the occurrence of hyperglycemia and iatrogenic severe hypoglycemia, which adversely effects patient recovery. Postoperatively, a variety of factors including surgical stress, inflammatory cytokines, sympathomimetic drug therapy, and aggressive nutritional support can also affect glycemic control. This review discusses the endocrine aspects of pancreatic resection and highlights postoperative glycemic control using a closed-loop system or artificial pancreas. In previous experiments, we have demonstrated the reliability of the artificial pancreas in dogs with total pancreatectomy, and its postoperative clinical use has been shown to be effective and safe, without the occurrence of hypoglycemic episodes, even in patients after total pancreatectomy. Considering the increasing requirement for tight perioperative glycemic control and the recognized risk of hypoglycemia, we propose the use of an artificial endocrine pancreas that is able to monitor continuously blood glucose concentrations with proven accuracy, and administer automatically substances to return blood glucose concentration to the optimal narrow range.

Problems associated with glucose toxicity: Role of hyperglycemia-induced oxidative stress

Glucose homeostasis deficiency leads to a chronic increase in blood glucose concentration. In contrast to physiological glucose concentration, chronic superphysiological glucose concentration negatively affects a large number of organs and tissues. Glucose toxicity means a decrease in insulin secretion and an increase in insulin resistance due to chronic hyperglycemia. It is now generally accepted that glucose toxicity is involved in the worsening of diabetes by affecting the secretion of β-cells. Several mechanisms have been proposed to explain the adverse effects of hyperglycemia. It was found that persistent hyperglycemia caused the functional decline of neutrophils. Infection is thus the main problem resulting from glucose toxicity in the acute phase. In other words, continued hyperglycemia is a life-threatening risk factor, not only in the chronic but also the acute phase, and it becomes a risk factor for infection, particularly in the perioperative period.

Accuracy and reliability of continuous blood glucose monitor in post-surgical patients

BACKGROUND

The STG-22 is the only continuous blood glucose monitoring system currently available. The aim of this study is to determine the accuracy and reliability of the STG-22 for continuously monitoring blood glucose level in post-surgical patients.

METHODS

Fifty patients scheduled for routine surgery were studied in surgical intensive care unit (ICU) of a university hospital. After admission to the ICU, the STG-22 was connected to the patients. An attending physician obtained blood samples from a radial arterial catheter. Blood glucose level was measured using the ABL800FLEX immediately after blood collection at 0, 4, 8, and 16 h post-admission to the ICU (total of 200 blood glucose values).

RESULTS

The correlation coefficient (R2) was 0.96. In the Clarke error grid, 100% of the paired measurements were in the clinically acceptable zone A and B. The Bland and Altman analysis showed that bias+/-limits of agreement (percent error) were 0.04(0.7)+/-0.35(6.3) mmol (mg/dl) (7%), -0.11(-2)+/-1.22(22) (15%) and -0.33(-6)+/-1.28(23) (10%) in hypoglycemia (<70(3.89) mmol (mg/dl), normoglycemia (3.89(70)-10(180) mmol (mg/dl), and hyperglycemia (>10(180) mmol (mg/dl), respectively.

CONCLUSIONS

The STG-22 can be used for measuring blood glucose level continuously and measurement results are consistent with intermittent measurement (percentage error within 15%). Therefore, the STG-22 is a useful device for monitoring in blood glucose level in the ICU for 16 h.

The accuracy of a continuous blood glucose monitor during surgery

BACKGROUND

Protocols for tight control of blood glucose can be difficult to achieve in the surgical setting, especially when relying upon intermittent blood glucose testing. A continuous blood glucose monitoring system can facilitate blood glucose management. In the present study, we compared blood glucose measured continuously (STG-22, Nikkiso, Tokyo, Japan), during surgery with coincident measurements obtained intermittently using a conventional laboratory glucometer (ABL 800FLEX (Radiometer Medical Aps, [symbol: see text], Denmark). The goal of the study was to determine the reliability and accuracy of the continuous method during surgery.

MATERIAL AND METHODS

Twenty-nine patients scheduled for routine surgery with general anesthesia were enrolled in this study. After anesthetic induction, a 20G IV catheter was inserted in a peripheral forearm vein and connected to the continuous blood glucose monitor. A radial arterial catheter was also inserted from which samples for blood glucose estimation were obtained by an anesthesiologist, following an established protocol of discarding 3 mL of blood before the actual blood sampling. Blood glucose was measured by ABL 800FLEX immediately after sampling. One hundred points of paired blood glucose values were obtained, which were compared using Bland and Altman analysis.

RESULTS

Bias and upper and lower limits of agreement were -2.6, 23, and -28, respectively. The percentage error of the lower/upper limits of agreement was 21% and 18%, respectively.

DISCUSSION AND CONCLUSIONS

The blood glucose measurements obtained continuously agreed with the coincident intermittent measurements within 21%. The STG-22 may still be useful for following changes continuously and reducing the frequency of intermittent measurement, but the need for testing samples with a reliable device is not eliminated.

Continuous post-operative blood glucose monitoring and control using a closed-loop system in patients undergoing hepatic resection

BACKGROUND AND AIMS

Hyperglycemia induced by surgical stress often causes the dysregulation of liver metabolism and immune function resulting in impaired post-operative recovery. The aim of this study was to evaluate the usefulness of a closed-loop system providing continuous monitoring and strict control of post-operative blood glucose in patients after hepatic resection.

PATIENTS AND METHODS

A total of 19 patients who underwent hepatic resection for primary liver tumor between August and December 2006 were enrolled in the study. Following surgery, blood glucose was continuously monitored by the STG-22 closed-loop system. Glucose levels were controlled using either a manual injection of insulin according to the commonly used sliding scale (manual insulin group, n = 9) or a programmed infusion of insulin determined by the control algorithm of the STG-22 (programmed insulin group, n = 10). The total amount of insulin used in the first 16 h following hepatic resection in the two groups was measured.

RESULTS

In the manual insulin group, post-operative blood glucose rose initially and reached a plateau of approximately 250 mg/dl between 4 h and 7 h post-hepatectomy and then returned towards normal levels by 16 h. In the programmed insulin group, blood glucose was steadily lowered, reaching the target zone (90-110 mg/dl) by 12 h post-surgery. The total amount of insulin administered per patient during the first 16 h post-surgery was significantly higher in the programmed insulin group (183 +/- 188 IU) than in the manual insulin group (8 +/- 7 IU; P < 0.001). No hypoglycemia was observed in either group.

CONCLUSIONS

Post-operative hyperglycemia was observed for up to 16 h in hepatectomized patients. In this post-operative hyperglycemic state, the STG-22 closed-loop system safely and quickly achieved glycemic control, indicating its clinical value in the post-operative management of hepatectomized patients.

News in gut-brain communication: a role of peptide YY (PYY) in human obesity and following bariatric surgery?

Recent advances in obesity research focused on neuroendocrine control of food intake, appetite and body weight balance. Gut hormones, which are sequentially released from different regions of the gut, send signals to the areas of appetite control in the central nervous system causing a release of counter-regulatory hormones also originating from the gastrointestinal system. Ghrelin, a peptide secreted from the gastric fundus is released just before meal intake and stimulates hunger and food intake. Recently, peptide YY has been suggested to counteract ghrelin by inducing satiety and reducing appetite and caloric intake. While the effects of PYY on various gastrointestinal functions are well described, its action on weight loss is less known. Controversial results on the effect of exogenous administration of PYY(3-36) opened the discussion on the respective roles of PYY and/or PYY(3-36) in body weight homeostasis in man.