Incretin action maintains insulin secretion, but not hepatic insulin action, in people with impaired fasting glucose
To determine whether altered GLP-1 activity contributes to the abnormal endogenous glucose production (EGP) and insulin secretion characteristic of people with impaired fasting glucose (IFG). People with IFG (n=10) and normal glucose tolerance (NGT; n=13) underwent assessment of EGP (via [6,6-(2)H(2)]-glucose infusion). Parameters of whole body insulin action and secretion were estimated by IVGTT and OGTT. Measures of EGP and insulin secretion were made before and after sitagliptin administration. EGP was not different at baseline (glucose R(a); 1.47+/-0.08 vs. 1.46+/-0.05mg/kg/min, IFG vs. NGT, p=0.93). However, when differences in circulating insulin were accounted for (EGPXSSPI; 20.2+/-2.1 vs. 14.4+/-1.0AU, vs. NGT, p=0.03) the hepatic insulin resistance index was significantly higher in IFG. Baseline insulin action (S(i); 2.3+/-0.1x10(-4)/microU/ml vs. 3.5+/-0.4x10(-4)/microU/ml, p=0.01, IFG vs. NGT) and secretion (DI; 587+/-81x10(-4)/min vs. 1171+/-226x10(-4)/min, p=0.04, IFG vs. NGT) were impaired in IFG when evaluated by the IVGTT, but not by OGTT (insulin sensitivity 4.52+/-1.08x10(-4)dl/kg/min vs. 6.73+/-1.16x10(-4)dl/kg/min, IFG vs. NGT, p=0.16; indices of basal (Phi(b)), static (Phi(s)), dynamic (Phi(d)), and total (Phi(t)) insulin secretion, p>0.07). Sitagliptin did not change EGP or insulin secretion in either group. Incretin action maintained insulin secretion, but not hepatic insulin action, in people with IFG.
[Show abstract] [Hide abstract] ABSTRACT: Prediabetes, a high-risk state for future development of diabetes, is prevalent globally. Abnormalities in the incretin axis are important in the progression of B-cell failure in type 2 diabetes. Incretin based therapy was found to improve B cell mass and glycaemic control in addition to having multiple beneficial effects on the systolic and diastolic blood pressure, weight loss in addition to their other beneficial effects on the liver and cardiovascular system. In prediabetes, several well-designed preventive trials have shown that lifestyle and pharmacologic interventions such as metformin, thiazolidinediones (TZD), acarbose and, nateglinide and orlistat, are effective in reducing diabetes development. In recent small studies, incretin based therapy (DPP IV inhibitors and GLP-1 agonists) have also been extended to patients with prediabetes since it was shown to better preserve B-cell function and mass in animal studies and in clinical trials and it was also shown to help maintain good long term metabolic control. Because of the limited studies and clinical experience, their side effects and costs currently guidelines do not recommend incretin-based therapies as an option for treatment in patients with prediabetes. With future clinical trials and studies they may be recommended for patients with impaired fasting glucose or impaired glucose tolerance.0Comments 7Citations
- "...ut having an effect on the whole body or hepatic insulin sensitivity or indices of B cell function . The effects of liraglutide on obese patients with prediabetes have been evaluated where liraglutid..."A study using sitagliptin treatment for 8 weeks in patients with impaired fasting glucose was also found to be associated with modest improvements in B cell function according to the Disposition Index although neither fasting nor postprandial glucose levels were altered . In another study, 4 weeks of sitagliptin therapy was found to increase incretin concentrations and to decrease fasting glucose concentration in patients with impaired fasting glucose (IFG) who had normal glucose tolerance (NGT) without having an effect on the whole body or hepatic insulin sensitivity or indices of B cell function . The effects of liraglutide on obese patients with prediabetes have been evaluated where liraglutide (1.2, 1.8, 2.4, and 3.0 mg sc once daily) was compared with another anti-obesity medication , orlistat (120 mg po tid) or with placebo (subcutaneous daily) in 564 obese, non-diabetic individuals, 31% of whom had IGT, and it was associated with significantly greater weight loss when compared to placebo (p < 0.0001 at 1.8–3.0
[Show abstract] [Hide abstract] ABSTRACT: Increased insulin resistance is frequently associated with chronic liver disease and is a pathophysiological feature of hepatogenous diabetes. Distinctive factors including hepatic parenchymal cell damage, portal-systemic shunting and hepatitis C virus are responsible for the development of hepatogenous insulin resistance/diabetes. Although it remains unclear whether insulin secretion from pancreatic beta cells is impaired as it is in type 2 diabetes, retinopathic and cardiovascular risk is low and major causes of death in cirrhotic patients with diabetes are liver failure, hepatocellular carcinoma and gastrointestinal hemorrhage. Hemoglobin A1c is an inaccurate marker for the assessment and management of hepatogenous diabetes. Moreover, exogenous insulin or sulfonylureas may be harmful because these agents may promote hepatocarcinogenesis. Thus, pathogenesis, cause of death, assessment and therapeutic strategy for hepatogenous insulin resistance/diabetes differ from those for lifestyle-related type 2 diabetes. In this article, we review features of insulin resistance in relationship to chronic liver disease. We also discuss the impact of anti-diabetic agents on interferon treatment and hepatocarcinogenesis.0Comments 20Citations
- "...with a regular coffee consumption show a lower rate of disease progression such as hepatic fibrosis131132133 and HCC134135136137138 . Recently, it was also reported that more than 3 cups per day coffee ..."In various studies including a large prospective study, patients with HCV-related liver disease with a regular coffee consumption show a lower rate of disease progression such as hepatic fibrosis131132133 and HCC134135136137138 . Recently, it was also reported that more than 3 cups per day coffee drinkers are three times more likely to have a virological response to peginterferon plus ribavirin treatment than non-drinkers  .
- [Show abstract] [Hide abstract] ABSTRACT: We hypothesize that type 2 diabetic patients with different phenotypes may show different response to incretin-based therapies. Therefore, we tested whether the presence of metabolic syndrome (MS) influences glycemic response to these drugs. We prospectively followed 211 patients, treated with the GLP-1 analog exenatide (n = 102) or a DPP-4 inhibitor (n = 109) for at least 4 months. Treatment was decided on clinical grounds. We collected baseline data (age, sex, BMI, waist, systolic and diastolic blood pressure, lipid profile, data on diabetic complications and concomitant treatment) and HbA1c at subsequent visits. Patients were divided into groups according to the presence/absence of MS. Compared to patients on exenatide, patients on DPP-4 inhibitors were older and had lower BMI, waist, diastolic blood pressure, fasting plasma glucose, and HbA1c. At means of baseline values, HbA1c reduction was similar in patients treated with exenatide or DPP-4 inhibitors. Patients on exenatide showed significantly higher HbA1c reduction if they had MS (-1.55 ± 0.22%; n = 88) than if they had not (-0.34 ± 0.18%; P = 0.002). Conversely, patients on DPP-4 inhibitors showed significantly lower HbA1c reduction if they had MS (-0.60 ± 0.12%; n = 73) than if they had not (-1.50 ± 0.24%; P < 0.001). Type of MS definition (ATP-III, IDF or WHO) poorly influenced these trends. The interaction between type of therapy (exenatide vs. DPP-4 inhibitors) and MS remained significant after adjusting for age, baseline HbA1c, BMI, and concomitant medications. In conclusion, the presence of MS appears to modify the response to incretin-based therapies. Given the non-randomized nature of this study, these data need to be replicated.0Comments 12Citations