When Intensive Insulin Therapy (MDI) Fails in Patients With Type 2 Diabetes: Switching to GLP-1 Receptor Agonist Versus Insulin Pump

Saxagliptin combined with additional oral antihyperglycaemic agents in drug-naive diabetic patients with high glycosylated haemoglobin: A 24-week, multicentre, randomized, open-label, active parallel-controlled group clinical trial in China (SUCCESS)

AIM

To assess the efficacy and safety of a dipeptidyl peptidase-4 (DPP-4) inhibitor combined respectively with three oral antihyperglycaemic agents in Chinese patients with newly diagnosed type 2 diabetes mellitus (T2DM) with high levels of glycated haemoglobin (HbA1c).

MATERIALS AND METHODS

Between 30 December 2014 and 1 November 2017, a 24-week, multicentre, parallel-controlled study was performed on drug-naive T2DM patients. In total, 648 patients with 8.0% ≤ HbA1c ≤ 11.0%, aged 18-80 years and body mass index (BMI) 19-40 kg/m² were randomly assigned 1:1:1 to receive saxagliptin (Saxa) combined with metformin (Met), acarbose (Aca) or gliclazide (Gli) modified release (MR) tablets (Saxa + Met, Saxa + Aca and Saxa + Gli). The primary outcome was the absolute change in HbA1c from baseline; secondary outcome was the percentage of patients achieving HbA1c <7.0% and ≤6.5%.

RESULTS

Each treatment arm contained 216 patients; overall, 583 completed the 24-week trial. At 24 weeks, the mean (95% confidence interval) change in HbA1c from baseline in Saxa + Met, Saxa + Aca and Saxa + Gli were, respectively: -2.9% [-3.1, -2.8]; -2.6% [-2.8, -2.5]; and -2.8% [-2.9, -2.6] (overall p = .04, Saxa + Aca vs. Saxa + Met, p = .010, Saxa + Gli vs. Saxa + Met, p = 0.18). At 24 weeks, 84.9%, 74.7% and 80.3% of participants were at HbA1c <7.0% (overall p = .05); and 72.6%, 59.8% and 63.3% were HbA1c ≤6.5% (overall p = 0.10). The rates of minor or symptomatic hypoglycaemia were very low.

CONCLUSIONS

Initial treatment with a DPP-4 inhibitor combined with Metform, alpha-glycosidase inhibitor or sulphonylurea was safe and effective for patients with newly diagnosed T2DM and high HbA1c. DPP-4 inhibitor combined with Met showed the best efficacy for this population.

Islet Encapsulation: New Developments for the Treatment of Type 1 Diabetes

Islet transplantation is a promising approach for the treatment of type 1 diabetes (T1D). Currently, clinical islet transplantation is limited by allo - and autoimmunity that may cause partial or complete loss of islet function within a short period of time, and long-term immunosuppression is required to prevent rejection. Encapsulation into semipermeable biomaterials provides a strategy that allows nutrients, oxygen and secreted hormones to diffuse through the membrane while blocking immune cells and the like out of the capsule, allowing long-term graft survival and avoiding long-term use of immunosuppression. In recent years, a variety of engineering strategies have been developed to improve the composition and properties of encapsulation materials and to explore the clinical practicality of islet cell transplantation from different sources. In particular, the encapsulation of porcine islet and the co-encapsulation of islet cells with other by-standing cells or active ingredients for promoting long-term functionality, attracted significant research efforts. Hydrogels have been widely used for cell encapsulation as well as other therapeutic applications including tissue engineering, cell carriers or drug delivery. Here, we review the current status of various hydrogel biomaterials, natural and synthetic, with particular focus on islet transplantation applications. Natural hydrophilic polymers include polysaccharides (starch, cellulose, alginic acid, hyaluronic acid, chitosan) and peptides (collagen, poly-L-lysine, poly-L-glutamic acid). Synthetic hydrophilic polymers include alcohol, acrylic acid and their derivatives [poly (acrylic acid), poly (methacrylic acid), poly(acrylamide)]. By understanding the advantages and disadvantages of materials from different sources and types, appropriate materials and encapsuling methods can be designed and selected as needed to improve the efficacy and duration of islet. Islet capsule transplantation is emerging as a promising future treatment for T1D.

Effect of kolaviron on islet dynamics in diabetic rats

Kolaviron, a biflavonoid isolated from the edible seeds of Garcinia kola, lowers blood glucose in experimental models of diabetes; however, the underlying mechanisms are not yet fully elucidated. The objective of the current study was to assess the effects of kolaviron on islet dynamics in streptozotocin-induced diabetic rats. Using double immunolabeling of glucagon and insulin, we identified insulin-producing β- and glucagon-producing α-cells in the islets of diabetic and control rats and determined the fractional β-cell area, α-cell area and islet number. STZ challenged rats presented with islet hypoplasia and reduced β-cell area concomitant with an increase in α-cell area. Kolaviron restored some islet architecture in diabetic rats through the increased β-cell area. Overall, kolaviron-treated diabetic rats presented a significant (p < 0.05) increase in the number of large and very large islets compared to diabetic control but no difference in islet number and α-cell area. The β-cell replenishment potential of kolaviron and its overall positive effects on glycemic control suggest that it may be a viable target for diabetes treatment.

Tolerability and Effectiveness of Switching to Dulaglutide in Patients With Type 2 Diabetes Inadequately Controlled With Insulin Therapy

AIMS

Glucagon-like peptide 1 (GLP-1) receptor agonists have demonstrated strong glycemic control. However, few studies have investigated the effects of switching from insulin to GLP-1 receptor agonists. We aimed to investigate, using real-world data, whether switching to dulaglutide improves glycemic control in patients with type 2 diabetes mellitus (T2D) inadequately controlled with conventional insulin treatment.

MATERIALS AND METHODS

We retrospectively evaluated 138 patients with T2D who were switched from insulin to dulaglutide therapy. We excluded 20 patients who dropped out during the follow-up period. The participants were divided into two groups according to whether they resumed insulin treatment at 6 months after switching to a GLP-1 receptor agonist (group I) or not (group II). A multiple logistic regression analysis was performed to evaluate the parameters associated with the risk of resuming insulin after replacement with dulaglutide.

RESULTS

Of 118 patients initiated on the GLP-1 receptor agonist, 62 (53%) resumed insulin treatment (group I), and 53 (47%) continued with GLP-1 receptor agonists or switched to oral anti-hypoglycemic agents (group II). Older age, a higher insulin dose, and lower postprandial glucose levels while switching to the GLP-1 receptor agonist were associated with failure to switch to the GLP-1 receptor agonist from insulin.

CONCLUSIONS

A considerable proportion of patients with T2D inadequately controlled with insulin treatment successfully switched to the GLP-1 receptor agonist. Younger age, a lower dose of insulin, and a higher baseline postprandial glucose level may be significant predictors of successful switching from insulin to GLP-1 receptor agonist therapy.

The burden of type 2 diabetes in Europe: Current and future aspects of insulin treatment from patient and healthcare spending perspectives

Due to the progressive nature of type 2 diabetes (T2DM), initiation of insulin therapy is very likely in the disease continuum. This article aims at highlighting the current situation with regard to insulin therapy in people with T2DM in Europe and at presenting the associated unmet need. Challenges for both people with T2DM and healthcare professionals include clinical inertia also derived from fear of hypoglycaemia, weight gain and injections as well as increased need for a comprehensive diabetes management. We compare national and international guidelines and recommendations for the initiation and intensification of insulin therapy with the real-world situation in six European countries, demonstrating that glycaemic targets are only met in a minority of people with T2DM on insulin therapy. Furthermore, this work evaluates currently recorded numbers of people with T2DM treated with insulin in Europe, the proportion not achieving the stated glycaemic targets and thus in need to enhance insulin therapy e.g. by a change in means of insulin delivery including, but not limited to, insulin pens, wearable mealtime insulin delivery patches, patch pumps, and conventional insulin pumps with continuous subcutaneous insulin infusion.

Therapies for Type 1 Diabetes: Current Scenario and Future Perspectives

Type 1 diabetes (T1D) is caused by autoimmune destruction of insulin-producing β cells located in the endocrine pancreas in areas known as islets of Langerhans. The current standard-of-care for T1D is exogenous insulin replacement therapy. Recent developments in this field include the hybrid closed-loop system for regulated insulin delivery and long-acting insulins. Clinical studies on prediction and prevention of diabetes-associated complications have demonstrated the importance of early treatment and glucose control for reducing the risk of developing diabetic complications. Transplantation of primary islets offers an effective approach for treating patients with T1D. However, this strategy is hampered by challenges such as the limited availability of islets, extensive death of islet cells, and poor vascular engraftment of islets post-transplantation. Accordingly, there are considerable efforts currently underway for enhancing islet transplantation efficiency by harnessing the beneficial actions of stem cells. This review will provide an overview of currently available therapeutic options for T1D, and discuss the growing evidence that supports the use of stem cell approaches to enhance therapeutic outcomes.

Characterization of the Molecular Mechanisms Underlying Glucose Stimulated Insulin Secretion from Isolated Pancreatic β-cells Using Post-translational Modification Specific Proteomics (PTMomics)

Normal pancreatic islet β-cells (PBCs) abundantly secrete insulin in response to elevated blood glucose levels, in order to maintain an adequate control of energy balance and glucose homeostasis. However, the molecular mechanisms underlying the insulin secretion are unclear. Improving our understanding of glucose-stimulated insulin secretion (GSIS) mechanisms under normal conditions is a prerequisite for developing better interventions against diabetes. Here, we aimed at identifying novel signaling pathways involved in the initial release of insulin from PBCs after glucose stimulation using quantitative strategies for the assessment of phosphorylated proteins and sialylated N-linked (SA) glycoproteins.Islets of Langerhans derived from newborn rats with a subsequent 9-10 days of maturation in vitro were stimulated with 20 mm glucose for 0 min (control), 5 min, 10 min, and 15 min. The isolated islets were subjected to time-resolved quantitative phosphoproteomics and sialiomics using iTRAQ-labeling combined with enrichment of phosphorylated peptides and formerly SA glycopeptides and high-accuracy LC-MS/MS. Using bioinformatics we analyzed the functional signaling pathways during GSIS, including well-known insulin secretion pathways. Furthermore, we identified six novel activated signaling pathways (e.g. agrin interactions and prolactin signaling) at 15 min GSIS, which may increase our understanding of the molecular mechanism underlying GSIS. Moreover, we validated some of the regulated phosphosites by parallel reaction monitoring, which resulted in the validation of eleven new phosphosites significantly regulated on GSIS. Besides protein phosphorylation, alteration in SA glycosylation was observed on several surface proteins on brief GSIS. Interestingly, proteins important for cell-cell interaction, cell movement, cell-ECM interaction and Focal Adhesion (e.g. integrins, semaphorins, and plexins) were found regulated at the level of sialylation, but not in protein expression. Collectively, we believe that this comprehensive Proteomics and PTMomics survey of signaling pathways taking place during brief GSIS of primary PBCs is contributing to understanding the complex signaling underlying GSIS.

Impact of improving postprandial glycemic control with intensifying insulin therapy in type 2 diabetes

Worldwide, many people with type 2 diabetes are not at recommended glycemic targets and remain at increased risk of microvascular and macrovascular complications. Reaching recommended glycemic targets requires normalizing both fasting and postprandial glucose (PPG). For some patients, this will require addition of a prandial insulin delivered by injection to control PPG excursions. Evidence from epidemiological studies suggests an association between postprandial hyperglycemia and cardiovascular disease, and thus, expert guidelines recommend that treatment for elevated PPG not be delayed. Indeed, studies have demonstrated that PPG makes the greatest contribution to HbA_1c in patients who are approaching, but have not yet reached HbA_1c <7.0%. Appropriately timed exposure of the liver to insulin is critical in suppressing hepatic glucose output (and therefore PPG levels) after a meal. Rapid-acting insulin analogs, with their faster onset and shorter duration of action, offer advantages over regular human insulin. Unfortunately, even with improved pharmacokinetic/pharmacodynamic characteristics, rapid-acting insulin analogs are still unable to fully reproduce the rapid release of insulin into the portal circulation and suppression of hepatic glucose output that occurs in the individual without diabetes after starting a meal. The next generation of rapid-acting insulin analogs will have an even more favorable pharmacokinetic profile that should allow patients to further improve glycemic control. Continuous subcutaneous insulin infusion (CSII) represents another option for intensifying therapy and improving postprandial control in some patients, and studies have shown that the benefits are sustainable long-term. However, it is currently unclear which patients stand to benefit the most from the extra expense and complexity of a CSII regimen, and further studies are needed.

Intensive insulin therapy combined with metformin is associated with reduction in both glucose variability and nocturnal hypoglycaemia in patients with type 2 diabetes

BACKGROUND

The effect on glucose variability in patients with intensive insulin therapy has not been fully understood. This observational study investigated the different glucose variability and hypoglycaemia patterns in type 2 diabetes patients treated with continuous subcutaneous insulin infusion (CSII) or multiple daily injections (MDI) with or without metformin administration.

METHODS

During hospitalization, a total of 501 patients with poor glycaemic control and in initial treatment with either CSII alone (n = 187), CSII + Metformin (n = 81), MDI alone (n = 146), or MDI + Metformin (n = 87) were involved in the final analysis. Data obtained from continuous glucose monitoring were used to assess blood glucose fluctuation and nocturnal hypoglycaemia.

RESULTS

Among the 4 groups, no difference was found in mean blood glucose levels. Results in parameters reflecting glucose fluctuation: continuous overlapping net glycaemic action in CSII + Metformin and mean amplitude of glycaemic excursions in MDI + Metformin were significantly lower than those in either CSII alone or MDI alone, respectively, even after adjustment (P = .031 and .006). Frequency of nocturnal hypoglycaemia was significantly decreased in CSII + Metformin as compared with CSII alone (0.6% vs 1.8%) and in MDI + Metformin as compared with MDI alone (1.6% vs 2.3%), with the highest frequency observed in MDI alone and the lowest in CSII + Metformin (all between group P < .001). Consistent results were obtained in between-group comparisons for hypoglycaemia duration. Subgroup analysis matched with baseline body mass index, and glycated haemoglobin and fasting blood glucose further confirmed these findings.

CONCLUSION

Metformin added to initial CSII or MDI therapy is associated with a reduction in both glucose fluctuation and nocturnal hypoglycaemic risk in patients with type 2 diabetes.