Fixed-ratio combination therapy for type 2 diabetes: the top ten things you should know about insulin and glucagon-like peptide-1 receptor agonist combinations

Many individuals with type 2 diabetes (T2D) will eventually require insulin therapy to help achieve and maintain adequate glycemic control. However, the use of insulin can be associated with adverse effects such as hypoglycemia and weight gain, and in some patients the addition of insulin to treatment regimens is often still insufficient to achieve target glycemic control. Combining basal insulin with a glucagon-like peptide-1 receptor agonist (GLP-1 RA) for the treatment of patients with T2D has been demonstrated to be effective and well tolerated, while mitigating many of the adverse events associated with giving either of these drug classes alone. Two titratable, fixed-ratio combination therapies, iGlarLixi and IDegLira, that combine basal insulin and a GLP-1 RA in a once-daily subcutaneous injection are currently approved by the US Food and Drug Administration (FDA) for the treatment of patients with T2D. The fixed-ratio combination iGlarLixi combines insulin glargine 100 Units/mL with lixisenatide, while IDegLira combines insulin degludec 100 Units/mL with liraglutide. While these new fixed-ratio combinations contain antihyperglycemic medications that are familiar to most health care providers, there are many questions relating to their use when formulated as a fixed-ratio combination therapy. This article discusses the ‘top 10’ considerations that health care providers should know about these novel combination therapies as these agents begin to gain an increasing presence in clinical practice.     

GLP-1 receptor agonists for prevention of cardiorenal outcomes in type 2 diabetes: An updated meta-analysis including the REWIND and PIONEER 6 trials

A meta-analysis of cardiovascular outcome trials (CVOTs) comparing glucagon-like peptide-1 receptor agonists (GLP-1RAs) and placebo concerning cardiorenal outcomes in patients with type 2 diabetes (T2D) is presented. An electronic search without language restrictions up to June 15, 2019 was conducted to determine eligible trials. A meta-analysis of available trial data was undertaken, using a random-effects model to calculate overall hazard ratios (HRs) and 95% confidence intervals (CIs). Data from seven CVOTs, comprising 56 004 patients (68.9% with established cardiovascular disease) were included. GLP-1RA reduced major cardiovascular events (MACE) by 13% (HR, 0.87; 95% CI, 0.80–0.96; P = 0.011) with a non-significant heterogeneity between subgroups of patients with and without cardiovascular disease (CVD) (P = 0.220). GLP-1RA also reduced the risk of cardiovascular death by 12%, of non-fatal stroke by 16%, of hospitalization for heart failure by 9%, of all-cause mortality by 11%, and the broad composite kidney outcome by 17%; the latter appeared to be driven only by a reduction in macroalbuminuria (HR, 0.76 [0.68–0.86]; P = 0.003). GLP-1RAs have moderate benefits concerning MACE, and also reduce hospitalization for heart failure and all-cause mortality; they also robustly reduce the incidence of macroalbuminuria, without affecting the progression of diabetic renal disease.     

Overview of new antiobesity drugs

A short overview of new drugs approved for the treatment of obesity (lorcaserin, phentermine/topiramate combination) as well as those with a perspective for approval as antiobesity drugs (cetilistat, naltrexone/bupropion combination, liraglutide) is presented. All these drugs produce significant weight loss accompanied by reductions in cardiometabolic health risks. Although the adverse events were rather rare and tended to decrease with the duration of treatment with most of these medications, the drug-specific safety concerns should be seriously considered. In order to ensure an appropriate, efficient and safe implementation of novel antiobesity drugs into the comprehensive treatment of obesity, it will be necessary to establish a network of physicians and other health-care providers well educated in obesity management.     

Effects of liraglutide on postprandial insulin and glucagon responses in Japanese patients with type 2 diabetes

This study assessed the endocrine pancreatic responses to liraglutide (0.9 mg once a day) during normal living conditions in Japanese patients with type 2 diabetes. The study included 14 hospitalized patients with type 2 diabetes. Meal tests were performed after improvement of glycemic control achieved by two weeks of multiple insulin injection therapy and after approximately two weeks of liraglutide treatment. Continuous glucose monitoring was performed to compare daily variation in glycemic control between multiple insulin injection therapy and liraglutide treatment. Liraglutide reduced plasma glucose levels after the test meals (60–180 min; p<0.05), as a result of significant increases in insulin secretion (0–180 min; p<0.05) and decreases in the incremental ratio of plasma glucagon (15–60 min; p<0.05). Continuous glucose monitoring showed that liraglutide treatment was also associated with a decrease in glucose variability. We also demonstrated that optimal glycemic control seen as a reduction in 24-h mean glucose levels and variability was obtained only with liraglutide monotherapy. In conclusion, liraglutide treatment increases insulin secretion and suppresses glucagon secretion in Japanese patients with type 2 diabetes under normal living conditions. The main therapeutic advantages of liraglutide are its use as monotherapy and its ability to decrease glucose variability.     

Fixed combination of insulin and a glucagon-like peptide-1 analog for the treatment of type 2 diabetes,exemplified by insulin degludec and liraglutide

Insulin therapy in the management of Type 2 diabetes is often postponed and/or not adequately intensified to maintain glycemic control because of the risk of weight gain and hypoglycemia. A fixed combination of the long-acting insulin degludec and liraglutide has recently been accepted by the EMA for the management of Type 2 diabetes. The incentive for this combination is to exploit the advantages of each of the drugs while counterbalancing the side effects. Insulin degludec effectively reduces fasting plasma glucose, but carries the risk of hypoglycemia and body weight gain. Liraglutide, on the other hand, exerts glycemic control with a minimal risk of hypoglycemia and, at the same time, reduces appetite and body weight.     

Liraglutide prevents high glucose level induced insulinoma cells apoptosis by targeting autophagy

Background  The pathophysiology of type 2 diabetes is progressive pancreatic beta cell failure with consequential reduced insulin secretion. Glucotoxicity results in the reduction of beta cell mass in type 2 diabetes by inducing apoptosis. Autophagy is essential for the maintenance of normal islet architecture and plays a crucial role in maintaining the intracellular insulin content by accelerating the insulin degradation rate in beta cells. Recently more attention has been paid to the effect of autophagy in type 2 diabetes. The regulatory pathway of autophagy in controlling pancreatic beta cells is still not clear. The aim of our study was to evaluate whether liraglutide can inhibit apoptosis and modulate autophagy in vitro in insulinoma cells (INS-1 cells).

Methods  INS-1 cells were incubated for 24 hours in the presence or absence of high levels of glucose, liraglutide (a long-acting human glucagon-like peptide-1 analogue), or 3-methyadenine (3-MA). Cell viability was measured using the Cell Counting Kit-8 (CCK8) viability assay. Autophagy of INS-1 cells was tested by monodansylcadaverine (MDC) staining, an autophagy fluorescent compound used for the labeling of autophagic vacuoles, and by Western blotting of microtubule-associated protein I light chain 3 (LC3), a biochemical markers of autophagic initiation.

Results  The viability of INS-1 cells was reduced after treatment with high levels of glucose. The viability of INS-1 cells was reduced and apoptosis was increased when autophagy was inhibited. The viability of INS-1 cells was significantly increased by adding liraglutide to supplement high glucose level medium compared with the cells treated with high glucose levels alone. 

Conclusions  Apoptosis and autophagy were increased in rat INS-1 cells when treated with high level of glucose, and the viability of INS-1 cells was significantly reduced by inhibiting autophagy. Liraglutide protected INS-1 cells from high glucose level-induced apoptosis that is accompanied by a significant increase of autophagy, suggesting that liraglutide plays a role in beta cell apoptosis by targeting autophagy. Thus, autophagy may be a new target for the prevention or treatment of diabetes.

     

Liraglutide changes postprandial responses of gut hormones involved in the regulation of gallbladder motility

Aim

Liraglutide treatment is associated with gallbladder-related disorders and has been shown to delay postprandial gallbladder refilling. The gut hormones cholecystokinin (CCK), fibroblast growth factor 19 (FGF19) and glucagon-like peptide 2 (GLP-2), are known to regulate gallbladder motility and may be implicated in gallbladder-related disorders associated with liraglutide treatment.

Materials and Methods

In a double-blind, 12-week trial, 52 participants [50% male, age 47.6 ± 10.0 years, body mass index 32.6 ± 3.4 kg/m² (mean ± standard deviation)] with obesity were randomized 1:1 to once-daily subcutaneous liraglutide (escalated from 0.6 mg to 3.0 mg once-daily) or placebo. During liquid meal tests performed at baseline, after the first dose and following 12 weeks of treatment, we evaluated postprandial gallbladder dynamics and plasma responses of CCK, FGF19 and GLP-2.

Results

Liraglutide reduced postprandial FGF19 after the first dose [area under the curve (AUC)_{0-240 min} 24.8 vs. 48.0 min × ng/ml, treatment ratio (TR) (95% confidence interval) 0.52 (0.39; 0.69)] and following 12 weeks of treatment [AUC_{0-240 min} 33.7 vs. 48.5 ng/ml × min, TR 0.69 (0.52; 0.93)]. Liraglutide also reduced postprandial GLP-2 responses (AUC_{0-240 min} 3650 vs. 4894 min × pmol/L, TR 0.75 (0.62; 0.90)] following the first dose as well as after 12 weeks [AUC_{0-240 min} 3760 vs. 4882 min × pmol/L, TR 0.77 (0.60; 0.99)]. Liraglutide increased postprandial responses of CCK after the first dose [AUC_{0-240 min} 762 vs. 670 min × pmol/L; TR 1.14 (0.97; 1.33)] and following 12 weeks of treatment [AUC_{0-240 min} 873 vs. 628 min × pmol/L; TR 1.39 (1.12; 1.73)].

Conclusion

Compared with placebo, treatment with liraglutide decreased postprandial FGF19 and GLP-2 concentrations and increased postprandial CCK concentrations, which may explain the delayed postprandial gallbladder refilling observed in individuals with obesity treated with liraglutide.