A randomised trial of enteric-coated nutrient pellets to stimulate gastrointestinal peptide release and lower glycaemia in type 2 diabetes.

AIMS/HYPOTHESES: Glucagon-like peptide-1 (GLP-1), an important mediator of postprandial glycaemia, could potentially be stimulated by delivering small quantities of nutrient to a long length of distal gut. We aimed to determine whether enteric-coated pellets, releasing small amounts of lauric acid throughout the ileum and colon, could reduce glycaemic responses to meals in type 2 diabetes, associated with stimulation of GLP-1. METHODS: Eligible patients, who had type 2 diabetes controlled by diet or metformin, were each studied on two occasions in a hospital setting. After an overnight fast, patients consumed 5 g active pellets (47% lauric acid by weight) or placebo with breakfast (T = 0 min) and lunch (T = 240 min), in a crossover design with order randomised by the hospital pharmacy and allocation concealed by numbered containers. Patients and investigators making measurements were blinded to the intervention. Blood was sampled frequently for blood glucose (the primary outcome) and hormone assays. RESULTS: Eight patients were randomised (four to receive either intervention first), and all completed the study without adverse effects. Blood glucose was lower after breakfast (T = 0-240 min, area under the curve (AUC) 2,075 ± 368 vs 2,216 ± 163 mmol/l × min) and lunch (T = 240-480 min, AUC 1,916 ± 115 vs 2,088 ± 151 mmol/l × min) (p = 0.02 for each) after active pellets than after placebo. Plasma GLP-1 concentrations were higher after breakfast (p = 0.08) and lunch (p = 0.04) for active pellets. While there were no differences in insulin or glucose-dependent insulinotropic polypeptide concentrations, glucagon concentrations were higher after breakfast and lunch (p = 0.002 for each) for active pellets. CONCLUSIONS/INTERPRETATION: Delivering small amounts of nutrient to the ileum and colon can stimulate substantial endogenous GLP-1 release and attenuate postprandial glycaemia. This novel approach has therapeutic potential in type 2 diabetes. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12612000600842. FUNDING: The study was funded by Meyer Nutriceuticals.

The effects of sitagliptin on gastric emptying in healthy humans - a randomised, controlled study.

BACKGROUND: The rate of gastric emptying (GE) and subsequent release of the incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are critical determinants of postprandial glycaemia in health and type 2 diabetes. Slowing of GE may be the dominant mechanism by which exogenous GLP-1, and some GLP-1 analogues, improve postprandial glycaemia. AIM: To determine the effect of sitagliptin on GE in healthy subjects, and the relationships between GE with glycaemia and incretin hormone secretion. METHODS: Fifteen volunteers (22.8 ± 0.7 years) were studied on two occasions following 2 days dosing with sitagliptin (100 mg/day) or placebo. GE (scintigraphy), glycaemia and plasma GLP-1 and GIP (total and intact), insulin and glucagon were measured for 240 min following a mashed potato meal (1808 kJ). RESULTS: There was no difference in GE between sitgaliptin and placebo [50% emptying time (T50): P = 0.4]. Mean blood glucose was slightly less (P = 0.02) on sitagliptin. Sitagliptin reduced plasma glucagon between 75 and 120 min (P < 0.05), and increased intact GLP-1 (P = 0.0002) and intact GIP (P = 0.0001) by approximately twofold, but reduced total GIP (P = 0.0003) and had no effect on total GLP-1 (P = 0.16) or insulin (P = 0.75). On sitagliptin the initial rise in blood glucose (r = -0.66, P = 0.008) and the intact GIP response (r = -0.66, P = 0.007) were inversely related, whereas the intact GLP-1 response was related directly (r = 0.52, P = 0.05) to the T50. CONCLUSIONS: While the effects of sitagliptin on glycaemic control are unlikely to relate to slowing of GE in healthy humans, the rate of GE is a significant determinant of postprandial glycaemia on sitagliptin.

Constrictive pericarditis following myocardial revascularization. A case report.

The occurrence of constrictive pericarditis after coronary bypass surgery is rare and clinical manifestations may appear at variable intervals after surgery. Three possible causes have been postulated, all of which were probably involved in the case which we describe. The clinical diagnosis of postoperative constriction is difficult and not often considered. It is best confirmed by means of cardiac catheterization, which shows typical haemodynamic features. Surgical treatment is both difficult and a threat to the coronary bypass grafts, when present. Conservative management with diuretics is preferred unless constriction is severe.

Calcification of glutaraldehyde-preserved porcine xenografts in young patients.

In a series of 568 patients with glutaraldehyde-preserved porcine xenografts followed for up to 3 1/2 years, calcification and stenosis of the xenograft has proved to be an important cause of valve failure. We have seen this complication only in children and adolescents. Seven of 54 patients under 16 years of age at the time of initial operation have required reoperation for calcification and prosthetic stenosis. Three patients who died had calcified, stenosed prosthesis at autopsy. The calcification has involved all of the cusps of the affected prostheses, and the calcified area often was enclosed by a superficial layer of noncalcified cuspidal tissue. We no longer insert xenograft valves in young patients.