Addition of Liraglutide to Insulin in Patients With Type 1 Diabetes: A Randomized Placebo-Controlled Clinical Trial of 12 Weeks

Glucagon-like peptide-1 receptor agonists modestly reduced blood pressure among patients with and without diabetes mellitus: A meta-analysis and meta-regression

AIM

The cardiovascular benefits provided by glucagon-like peptide-1 receptor agonists (GLP-1RAs) extend beyond weight reduction and glycaemic control. One possible mechanism may relate to blood pressure (BP) reduction. We aim to quantify the BP-lowering effects of GLP1-RAs.

METHODS

A comprehensive database search for placebo-controlled randomized controlled trials on GLP-1RA treatment was conducted until December 2023. Data extraction and quality assessment were carried out, employing a robust statistical analysis using a random effects model to determine outcomes with a mean difference (MD) in mmHg and 95% confidence intervals (CIs). The primary endpoint was the mean difference in systolic BP (SBP) and diastolic BP. Subgroup analyses and meta-regressions were done to account for covariates.

RESULTS

Compared with placebo, GLP-1RAs modestly reduced SBP [semaglutide: MD -3.40 (95% CI -4.22 to -2.59, p < .001); liraglutide: MD -2.61 (95% CI -3.48 to -1.74, p < .001); dulaglutide: MD -1.46 (95% CI -2.20 to -0.72, p < .001); and exenatide: MD -3.36 (95% CI -3.63 to -3.10, p < .001)]. This benefit consistently increased with longer treatment durations. Diastolic BP reduction was only significant in the exenatide group [MD -0.94 (95% CI -1.78 to -0.1), p = .03]. Among semaglutide cohorts, mean changes in glycated haemoglobin and mean changes in body mass index were directly associated with SBP reduction.

CONCLUSION

Patients on GLP-1RA experienced modest SBP lowering compared with placebo. This observed effect was associated with weight/body mass index reduction and better glycaemic control, which suggests that BP-lowering is an indirect effect of GLP-1RA and unlikely to be responsible for the benefits.

Can Unmet Needs Be Addressed by Adjunctive Therapies? Findings from a Patient Perspectives Survey in Adults with Type 1 Diabetes

Many individuals with type 1 diabetes (T1D) do not achieve their management goals. The patient perspective on unmet needs in T1D may guide the role of adjunctive therapies, including glucagon like peptide-1 receptor agonists (GLP-1RAs). A quantitative online survey (n = 133) assessed (1) self-reported demographic and management data, (2) management priorities, satisfaction, and willingness to use adjunctive therapies and (3) conducted a risk-benefit analysis using three masked drug profiles (1.8 mg vs 0.6 mg liraglutide vs placebo). A subgroup of respondents (n = 20) participated in semi-structured interviews to extend upon survey insights. Needs were unmet by current treatment in 28% of surveyed individuals. The greatest unmet needs included (1) glycemia, (2) management-related fatigue, and (3) weight management. Most respondents (94%) indicated that they would use adjunctive therapies. The preferred administration route was daily tablets (66%) followed by weekly injections (32%). Metabolic improvements were most valued (reduction in hypoglycemia, hyperglycemia). Most respondents (94%) preferred the liraglutide risk-benefit profile (1.8 mg, then 0.6 mg) over placebo. Individuals with T1D self-report many unmet needs. While not currently approved in T1D, GLP-1RA properties align with many management priorities reported by individuals with T1D.

Optimization of guideline-directed medical therapies in patients with diabetes and chronic kidney disease

Diabetes is the leading cause of chronic kidney disease (CKD) and kidney failure worldwide. CKD frequently coexists with heart failure and atherosclerotic cardiovascular disease in the broader context of cardio-kidney-metabolic syndrome. Diabetes and CKD are associated with increased risk of all-cause and cardiovascular death as well as decreased quality of life. The role of metabolic and hemodynamic abnormalities has long been recognized as an important contributor to the pathogenesis and progression of CKD in diabetes, while a more recent and growing body of evidence supports activation of both systemic and local inflammation as important contributors. Current guidelines recommend therapies targeting pathomechanisms of CKD in addition to management of traditional risk factors such as hyperglycemia and hypertension. Sodium-glucose cotransporter-2 inhibitors are recommended for treatment of patients with CKD and type 2 diabetes (T2D) if eGFR is ≥20 ml/min/173 m2 on a background of renin-angiotensin system inhibition. For patients with T2D, CKD, and atherosclerotic cardiovascular disease, a glucagon-like peptide-1 receptor agonist is recommended as additional risk-based therapy. A non-steroidal mineralocorticoid receptor antagonist is also recommended as additional risk-based therapy for persistent albuminuria in patients with T2D already treated with renin-angiotensin system inhibition. Implementation of guideline-directed medical therapies is challenging in the face of rapidly accumulating knowledge, high cost of medications, and lack of infrastructure for optimal healthcare delivery. Furthermore, studies of new therapies have focused on T2D and CKD. Clinical trials are now planned to inform the role of these therapies in people with type 1 diabetes (T1D) and CKD.

Glucagon-Like Peptide 1 Analogues as Adjunctive Therapy for Patients With Type 1 Diabetes: An Updated Systematic Review and Meta-analysis

CONTEXT

Concomitant obesity is common among patients with type 1 diabetes mellitus (T1DM), yet adjunctive therapy options are scarce.

OBJECTIVE

We assess the efficacy and adverse outcomes of glucagon-like peptide 1 (GLP-1) analogues when used as adjunctive therapy for T1DM.

METHOD

PubMed, EMBASE, Cochrane Central, and Scopus databases were searched for randomized controlled trials up to December 2022. Efficacy outcomes were A1c level, body weight, and total daily insulin (TDI) after ≥12 weeks of GLP-1 therapy. We also assessed 12 different adverse outcomes. Subgroup analysis was done for newly diagnosed or C-peptide positive (C-pos) patients. We report the certainty of evidence based on the GRADE assessment tool.

RESULTS

A total of 24 studies using 4 different GLP-1 analogues with a total of 3377 patients were included. Liraglutide had the most substantial evidence with effect sizes on A1c (-0.09%/mg), weight (-2.2 kg/mg), and TDI (-4.32 IU/mg). Liraglutide dose was the greatest predictor of greater average weight loss and TDI decrease but was associated with higher odds of nausea (OR 6.5; 95% CI, 5.0-8.4) and ketosis (OR 1.8; 95% CI, 1.1-2.8). Odds of severe (OR 0.67; 95% CI, 0.43-1.04) or symptomatic hypoglycemia (OR 0.89; 95% CI, 0.53-1.51) were not significantly elevated. Among C-pos patients, greater A1c decrease (-0.51% vs -0.28%) but similar weight loss and TDI were seen. Effect sizes for exenatide were similar, but studies had higher risk of bias and safety data were sparse.

CONCLUSION

Our meta-analysis supports therapeutic benefits of liraglutide for patients with T1DM mainly for weight loss and insulin dose reduction. Newly diagnosed or C-pos patients do not appear to experience greater weight loss benefits.

Incretins beyond type 2 diabetes

Incretin-based therapies, in particular glucagon-like peptide-1 (GLP-1) receptor agonists, have been evaluated in other forms of diabetes, but randomised controlled trials are mainly limited to people living with type 1 diabetes. In this review we present the evidence issuing from these trials and discuss their clinical implications as well as the difficulties in interpreting the data. In type 1 diabetes, the addition of GLP-1 receptor agonists to intensive insulin therapy lowers weight and required insulin doses compared with placebo, but the effects on glucose control (HbA1c, risk of hypoglycaemia) are dependent on the different study protocols. Side effects are limited to the gastrointestinal complaints of nausea, vomiting and diarrhoea. We briefly discuss the potential for using GLP-1 receptor agonists as (adjunct) therapies in other forms of diabetes, where the evidence to date is scarce.

GLP-1RAs caused gastrointestinal adverse reactions of drug withdrawal: a system review and network meta-analysis

Background

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) significantly reduce postprandial blood glucose, inhibit appetite, and delay gastrointestinal emptying. However, it is controversial that some patients are intolerant to GLP-1RAs.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched for randomized controlled trials (RCTs) using GLP-1RAs with documented withdrawal due to gastrointestinal adverse reactions (GI AEs) from their inception to September 28, 2022. After extracting the information incorporated into the studies, a random-effects network meta-analysis was performed within a frequentist framework.

Results

64 RCTs were finally enrolled, which included six major categories of the GLP-1RA. The sample size of the GLP-1RAs treatment group was 16,783 cases. The risk of intolerable gastrointestinal adverse reactions of Liraglutide and Semaglutide was higher than that of Dulaglutide. Meanwhile, the higher the dose of the same GLP-1RA preparation, the more likely to cause these adverse reactions. These intolerable GI AEs were not significantly related to drug homology or formulations and may be related to the degree of suppression of the appetite center.

Conclusion

Dulaglutide caused the lowest intolerable GI AEs, while Liraglutide and Semaglutide were the highest. For Semaglutide, the higher the dose, the more likely it is to drive GI AEs. Meanwhile, the risk of these GI AEs is independent of the different formulations of the drug. All these findings can effectively guide individualized treatment.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022359346, identifier CRD42022359346.

Clinical and Safety Outcomes With GLP-1 Receptor Agonists and SGLT2 Inhibitors in Type 1 Diabetes: A Real-World Study

CONTEXT

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) are used off-label in the management of type 1 diabetes mellitus (T1DM) in real-world practice as adjuvant therapies to insulin. There are few real-world data regarding efficacy and safety of this practice.

OBJECTIVE

This work aimed to determine the efficacy and safety of GLP-1RAs and sodium-glucose SGLT2is in the management of T1DM in real-world practice.

METHODS

A retrospective chart review was performed of all instances of GLP-1RA and/or SGLT2i use greater than 90 days in adult patients with T1DM at a single academic center. We report the clinical and safety outcomes over the duration of use.

RESULTS

We identified 104 patients with T1DM who ever used a GLP-1RA (76 patients) or SGLT2i (39 patients) for more than 90 days. After 1 year of therapy, GLP-1RA users had statistically significant reductions in weight (90.5 kg to 85.4 kg; P < .001), glycated hemoglobin A1c (HbA1c) (7.7% to 7.3%; P = .007), and total daily dose of insulin (61.8 units to 41.9 units; P < .001). SGLT2i users had statistically significant reductions in HbA1c (7.9% to 7.3%; P < .001) and basal insulin (31.3 units to 25.6 units; P = .003). GLP-1RA users compared to SGLT2i users had greater reduction in weight (P = .027) while HbA1c reduction was comparable between the groups. Over a mean total duration of use of 29.5 months/patient for both groups, more SGLT2i users experienced diabetic ketoacidosis (DKA) (12.8% vs 3.9%). Therapy was discontinued because of adverse events 26.9% of the time for GLP-1RA users vs 27.7% for SGLT2i users.

CONCLUSION

GLP-1RA and SGLT2i use in T1DM is associated with clinically relevant benefits. DKA remains a clinical concern with SGLT2i use, requiring careful patient selection and monitoring, with the risk to benefit ratio of treatment evaluated at an individual level.

Glucagon-like peptide-1 agonists combined with sodium-glucose cotransporter-2 inhibitors reduce weight in type 1 diabetes

OBJECTIVE

This study evaluated whether adding sodium-glucose cotransporter-2 inhibitors (SGLT2i) and/or glucagon-like peptide-1 receptor agonists (GLP1-RA) to insulin reduced weight and glycemia in people with type 1 diabetes.

METHODS

This retrospective analysis of electronic health records evaluated 296 people with type 1 diabetes over 12 months after medications were first prescribed. Four groups were defined: control n = 80, SGLT2i n = 94, GLP1-RA n = 82, and combination of drugs (Combo) n = 40. We measured changes at 1 year in weight and glycated hemoglobin (HbA1c).

RESULTS

The control group did not have changes in weight or glycemic control. The mean (SD) percentage weight loss after 12 months was 4.4% (6.0%), 8.2%  (8.5%), and 9.0% (8.4%) in the SGLT2i, GLP1-RA, and Combo groups, respectively (p < 0.001). The Combo group lost the most weight (p < 0.001). The HbA1c reduction was 0.4%  (0.7%), 0.3% (0.7%), and 0.6% (0.8%) in the SGLT2i, GLP1-RA, and Combo groups, respectively (p < 0.001). The Combo group had the biggest improvements in glycemic control and total and low-density lipoprotein cholesterol compared with baseline (all p < 0.01). Severe adverse events were similar between all the groups, with no increased risk of diabetic ketoacidosis.

CONCLUSIONS

The SGLT2i and GLP1-RA agents on their own improved body weight and glycemia, but combining the medications resulted in more weight loss. Treatment intensification appears to result in benefits with no difference in severe adverse events.

Medicines for Obesity: Appraisal of Clinical Studies with Grading of Recommendations, Assessment, Development, and Evaluation Tool

We evaluated the quality of evidence from phase III/IV clinical trials of drugs against obesity using the principles of Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool. Our systematic review evaluates the quality of clinical evidence from existing clinical trials and not the pharmacological efficacy of anti-obesity therapies. A literature search using select keywords in separate was performed in PubMed and ClinicalTrials.gov databases for phase III/IV clinical trials during the last ten years. Our findings indicate that the quality of existing clinical evidence from anti-obesity trials generally ranges from low to moderate. Most trials suffered from publication bias. Less frequently, trials suffered from the risk of bias mainly due to lack of blindness in the treatment. Our work indicates that additional higher-quality clinical trials are needed to gain more confidence in the estimate of the effect of currently used anti-obesity medicines, to allow more informed clinical decisions, thus reducing the risk of implementing potentially ineffective or even harmful therapeutic strategies.

Effect of glucagon-like peptide-1 receptor agonists on glycemic control, and weight reduction in adults: A multivariate meta-analysis

AIMS

To explore the effect of glucagon-like peptide-1 receptor agonist (GLP-1 RAs) on glycemic control and weight reduction in adults.

METHODS

Databases were searched from August 2021 to March 2022. Data were analyzed using mean difference (MD) values with 95% confidence intervals (CIs). Both random-and fixed-effect models were employed. Heterogeneity was explored using pre-specified subgroup analyses and meta-regression. Structural equation modeling fitting was used for the multivariate meta-analysis.

RESULTS

A total of 31 double-blind randomized controlled trials with 22,948 participants were included in the meta-analysis. The MD and 95% CI of the pooled GLP1-RA-induced change in the glycated hemoglobin level was -0.78% (-0.97%, -0.60%) in the random-effects model and -0.45% (-0.47%, -0.44%) in the fixed-effect model, with a high heterogeneity (I2 = 97%). The pooled body weight reduction was -4.05 kg (-5.02 kg, -3.09 kg) in the random-effects model and -2.04 kg (-2.16 kg, -1.92 kg) in the fixed-effect model (I2 = 98%). The standardized pooled correlation coefficient between HbA1c levels and body weight was -0.42. A negative correlation between glycemic control and weight reduction was obtained.

CONCLUSION

Long-acting GLP-1 RAs significantly reduced the glycated hemoglobin level and body weight in adults.

Recent developments in adjunct therapies for type 1 diabetes

INTRODUCTION

There have been many recent advances in the treatment of type 1 diabetes (T1D) including in insulin formulations, continuous glucose monitoring (CGM) technology and automated insulin delivery. However, long-term optimal glycemic control is still only achieved in a minority.

AREAS COVERED

Adjunct therapy - the use of therapeutic agents other than insulin - is one strategy aimed at improving outcomes. An ideal adjunct agent would improve glycemic control, reduce weight (or weight gain), reduce insulin requirement and prevent complications (e.g. cardiorenal) without increasing hypoglycemia. The amylin analogue pramlintide has been licensed in the USA, while the sodium glucose co-transporter-2 inhibitor (SGLT2i) dapagliflozin, was briefly (2019 - 2021) licensed for type 1 diabetes in Europe and the UK. However, other agents from the type 2 diabetes (T2D) arena including metformin, other SGLT2is, glucagon-like peptide-1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-IV (DPP-4) inhibitors have been investigated.

EXPERT OPINION

As evidence emerges for cardiorenal protection by SGLT2is and GLP-1RAs in T2D, it has become increasingly important to know whether people with T1D can also benefit. Here, we review recent trials of adjunct agents in T1D and discuss the efficacy and safety of these agents (alone and in combination) in an era in which continuous glucose monitoring is becoming standard of care.

Liraglutide treatment attenuates inflammation markers in the cardiac, cerebral and renal microvasculature in streptozotocin-induced diabetic rats

BACKGROUND

Diabetes mellitus (DM) induces cardiac and cerebral microvascular dysfunction via increased glycation, oxidative stress and endothelial activation. Liraglutide, a glucagon-like peptide-1 analogue, inhibited NOX2 and adhesion molecules in isolated endothelial cells. Here, we have studied how Liraglutide affects advanced glycation, NOX expression and inflammation of the cardiac, cerebral and renal microvasculature in diabetic rats.

METHODS

DM was induced in Sprague-Dawley rats (n = 15) via intraperitoneal streptozotocin (STZ) injection (60 mg/kg bodyweight). Ten control rats remained nondiabetic. From day 9 post-STZ injection, Liraglutide (200 μg/kg bodyweight; n = 7) or vehicle (n = 8) was injected subcutaneously daily until termination on day 29. The advanced glycation endproduct N-ε-(carboxymethyl)lysine (CML), NOX2, NOX4, ICAM-1 and VCAM-1 were subsequently immunohistochemically analysed and quantified to compare Liraglutide treatment with placebo.

RESULTS

In the heart, Liraglutide treatment significantly reduced the DM-increased scores/cm² for CML in both ventricles (from 253 ± 53 to 72 ± 12; p = .003) and atria (343 ± 29 to 122 ± 8; p = .0001) and for NOX2, ICAM-1 and VCAM-1, but not for NOX4. Also in the cerebrum and cerebellum of the brain, Liraglutide significantly reduced the scores/cm² for CML (to 60 ± 7 (p = .0005) and 47 ± 13 (p = .02), respectively), and for NOX2 and NOX4. In the kidney, the DM-induced expression of ICAM-1 and VCAM-1 was decreased in the blood vessels and glomeruli by Liraglutide treatment. Liraglutide did not affect blood glucose levels or bodyweight.

CONCLUSIONS

Our study implies that Liraglutide protects the cardiac, cerebral and renal microvasculature against diabetes-induced dysfunction, independent of lowering blood glucose in a type 1 diabetes rat model.

Effect of Liraglutide Treatment on Whole-body Glucose Fluxes in C-peptide-Positive Type 1 Diabetes During Hypoglycemia

CONTEXT

The effect of liraglutide in C-peptide-positive (C-pos) type 1 diabetes (T1D) patients during hypoglycemia remains unclear.

OBJECTIVE

To investigate the effect of a 12-week liraglutide treatment on the body glucose fluxes during a hypoglycemic clamp in C-pos T1D patients and its impact on the alpha- and beta-cell responses during hypoglycemia.

DESIGN

This was a randomized, double-blind, crossover study. Each C-pos T1D patient was allocated to the treatment sequence liraglutide/placebo or placebo/liraglutide with daily injections for 12 weeks adjunct to insulin treatment, separated by a 4-week washout period.

SETTING AND PARTICIPANTS

Fourteen T1D patients with fasting C-peptide ≥ 0.1 nmol/L.

INTERVENTION(S)

All patients underwent a hyperinsulinemic-stepwise-hypoglycemic clamp with isotope tracer [plasma glucose (PG) plateaus: 5.5, 3.5, 2.5, and 3.9 mmol/L] after a 3-month liraglutide (1.2 mg) or placebo treatment.

MAIN OUTCOME MEASURE(S)

The responses of endogenous glucose production (EGP) and rate of peripheral glucose disposal (Rd) were similar for liraglutide and placebo treatment during the clamp.

RESULTS

The numbers of hypoglycemic events were similar in both groups. At the clamp, mean glucagon levels were significantly lower at PG plateau 5.5 mmol/L in the liraglutide than in the placebo group but showed similar responses to hypoglycemia in both groups. Mean C-peptide levels were significantly higher at PG-plateaus 5.5 and 3.5 mmol/L after liraglutide treatment, but this effect was not reflected in EGP and Rd. Hemoglobin A1c and body weight were lower, and a trend for reduced insulin was seen after liraglutide treatment.

CONCLUSIONS

The results indicate that 3 months of liraglutide treatment does not promote or prolong hypoglycemia in C-pos T1D patients.

Glucose-Lowering Therapy beyond Insulin in Type 1 Diabetes: A Narrative Review on Existing Evidence from Randomized Controlled Trials and Clinical Perspective

Background: In Type 1 diabetes (T1D), according to the most recent guidelines, the everyday glucose-lowering treatment is still restricted to the use of subcutaneous insulin, while multiple therapeutic options exist for Type 2 diabetes (T2D). Methods: For this narrative review we unsystematically screened PubMed and Embase to identify clinical trials which investigated glucose-lowering agents as an adjunct to insulin treatment in people with T1D. Published studies up to March 2022 were included. We discuss the safety and efficacy in modifying cardiovascular risk factors for each drug, the current status of research, and provide a clinical perspective. Results: For several adjunct agents, in T1D, the scientific evidence demonstrates improvements in HbA1c, reductions in the risk of hypoglycemia, and achievements of lower insulin requirements, as well as positive effects on cardiovascular risk factors, such as blood lipids, blood pressure, and weight. As the prevalence of obesity, the major driver for double diabetes, is rising, weight and cardiovascular risk factor management is becoming increasingly important in people with T1D. Conclusions: Adjunct glucose-lowering agents, intended to be used in T2D, bear the potential to beneficially impact on cardiovascular risk factors when investigated in the T1D population and are suggested to be more extensively considered as potentially disease-modifying drugs in the future and should be investigated for hard cardiovascular endpoints.

Glucagon-like peptide-1 receptor agonists as adjunctive treatment for type 1 diabetes: Renewed opportunities through tailored approaches?

Exogenous insulin has been the mainstay treatment for individuals living with type 1 diabetes (T1D). Although there has been tremendous growth in both pharmacological and technological advancements, insulin monotherapy has proven to be insufficient for maintaining optimal glycaemic targets for most adults with T1D. At present, there is still no breakthrough for the treatment of T1D. Adjunctive pharmacotherapies might therefore complement insulin management to achieve better glycaemic control, while possibly offering additional benefits. Recent interest in re-purposing glucagon-like peptide-1 receptor agonists (GLP-1RAs), a leading antihyperglycaemic medication class approved for type 2 diabetes, has prompted the field to seek extended potential for the T1D population. The adjunctive use of GLP-1RAs has been at the forefront of T1D research, albeit with some conflicting trial findings to date. However, the potential of GLP-1 agonism for T1D may have been underestimated, possibly from missed opportunities or categorized effects. Moreover, some GLP-1RAs have demonstrated extra-pancreatic potential with emerging multi-organ protection involving the heart, kidneys, liver and brain in varied cohorts, which may bode well for the growing T1D profile of comorbid complications. This narrative review aims to summarize and critically appraise the current evidence-based literature from large-scale randomized controlled trials and closed-loop system pilot studies that examined GLP-1RAs as adjunctive therapy for T1D. Furthermore, we outline uncharted opportunities with GLP-1 agonism using versatile approaches in selected T1D populations that may inspire and re-direct future research in this field.

Liraglutide changes body composition and lowers added sugar intake in overweight persons with insulin pump-treated type 1 diabetes

AIMS

To present secondary outcome analyses of liraglutide treatment in overweight adults with insulin pump-treated type 1 diabetes (T1D), focusing on changes in body composition and dimensions, and to evaluate changes in food intake to identify potential dietary drivers of liraglutide-associated weight loss.

MATERIALS AND METHODS

A 26-week randomized placebo-controlled study was conducted to investigate the efficacy and safety of liraglutide 1.8 mg daily in 44 overweight adults with insulin pump-treated T1D and glucose levels above target, and demonstrated significant glycated haemoglobin (HbA1c)- and body weight-reducing effects. For secondary outcome analysis, dual X-ray absorptiometry scans were completed at Weeks 0 and 26, and questionnaire-based food frequency recordings were obtained at Weeks 0, 13 and 26 to characterize liraglutide-induced changes in body composition and food intake.

RESULTS

Total fat and lean body mass decreased in liraglutide-treated participants (fat mass -4.6 kg [95% confidence interval {CI} -5.7; -3.5], P < 0.001; lean mass -2.5 kg [95% CI -3.2;-1.7], P < 0.001), but remained stable in placebo-treated participants (fat mass -0.3 kg [95% CI -1.3;0.8], P = 0.604; lean mass 0.0 kg [95% CI -0.7;0.7]; P = 0.965 [between-group P values <0.001]). Participants reduced their energy intake numerically more in the liraglutide arm (-1.1 MJ [95% CI -2.0;-0.02], P = 0.02) than in the placebo arm (-0.9 MJ [95% CI -2.0;0.1], P = 0.22), but the between-group difference was statistically insignificant (P = 0.42). However, energy derived from added sugars decreased by 27% in the liraglutide arm compared with an increase of 14% in the placebo arm (P = 0.004).

CONCLUSIONS

Liraglutide lowered fat and lean body mass compared with placebo. Further, liraglutide reduced intake of added sugars. However, no significant difference in total daily energy intake was detected between liraglutide- and placebo-treated participants.

The Role of the α Cell in the Pathogenesis of Diabetes: A World beyond the Mirror

Type 2 Diabetes Mellitus (T2DM) is one of the most prevalent chronic metabolic disorders, and insulin has been placed at the epicentre of its pathophysiological basis. However, the involvement of impaired alpha (α) cell function has been recognized as playing an essential role in several diseases, since hyperglucagonemia has been evidenced in both Type 1 and T2DM. This phenomenon has been attributed to intra-islet defects, like modifications in pancreatic α cell mass or dysfunction in glucagon's secretion. Emerging evidence has shown that chronic hyperglycaemia provokes changes in the Langerhans' islets cytoarchitecture, including α cell hyperplasia, pancreatic beta (β) cell dedifferentiation into glucagon-positive producing cells, and loss of paracrine and endocrine regulation due to β cell mass loss. Other abnormalities like α cell insulin resistance, sensor machinery dysfunction, or paradoxical ATP-sensitive potassium channels (KATP) opening have also been linked to glucagon hypersecretion. Recent clinical trials in phases 1 or 2 have shown new molecules with glucagon-antagonist properties with considerable effectiveness and acceptable safety profiles. Glucagon-like peptide-1 (GLP-1) agonists and Dipeptidyl Peptidase-4 inhibitors (DPP-4 inhibitors) have been shown to decrease glucagon secretion in T2DM, and their possible therapeutic role in T1DM means they are attractive as an insulin-adjuvant therapy.

Double Diabetes: A Growing Problem Requiring Solutions

The growing proportion of type 1 diabetes mellitus (T1DM) patients with clinical features of insulin resistance (IR) has led to the description of a distinctive T1DM subgroup, still unrecognised by current guidelines, called double diabetes, assumingly associated with poorer metabolic phenotype and increased risk of micro- and macrovascular complications. The main goal of identifying double diabetes, estimated to be present in up to half of T1DM patients, is timely implementation of appropriate therapeutic interventions to reduce the increased risk of chronic complications and other adverse metabolic traits associated with this condition. Proposed diagnostic criteria are largely divided into three different groups: family history of type 2 diabetes mellitus (T2DM), obesity/metabolic syndrome, and IR. Estimated glucose disposal rate may prove the most reliable marker of double diabetes. In addition to general measures (diet, physical activity, antihypertensive, and lipid-lowering medications, etc.) and development of new insulin preparations with more hepatic action, double diabetes patients may derive more benefit from agents developed for T2DM. Indeed, such potentially promising agents include glucagon-like peptide-1 receptor agonists, sodium-glucose contrasporter-2 inhibitors, and their combination. We are now awaiting long-term trials assessing metabolic and vascular benefits of these medications in double diabetes.

The impact of pharmacological and lifestyle interventions on body weight in people with type 1 diabetes: A systematic review and meta-analysis

AIM

To systematically review the effects of pharmacological and lifestyle interventions on body weight as a secondary outcome in people with type 1 diabetes.

METHODS

The Ovid Medline, Embase and Cochrane Library databases were searched for relevant pharmacological (glucagon-like peptide-1 [GLP-1] receptor agonist, sodium-glucose co-transporter-2 [SGLT-2] inhibitor, dipeptidyl peptidase-4 [DPP-4] inhibitor and metformin) and lifestyle intervention studies (diet and exercise) for adults with type 1 diabetes reporting body weight change and HbA1c published from January 2000 to May 2020. Meta-analyses were performed for 16 randomized controlled trials (RCTs).

RESULTS

Thirty-three RCTs (n = 9344 participants), 26 pharmacological (on average 43.9 years, 83.1 kg, HbA1c 8.1%; 55.8% male) and seven lifestyle-based interventions (on average 37.0 years, 85.0 kg, HbA1c 8.1%; 84.6% male), were analysed. The GLP-1 receptor agonist liraglutide 0.6 mg (mean difference [MD]: -2.22 kg [95% CI: -2.55 to -1.90]), 1.2 mg (MD: -3.74 kg [95% CI: -4.16 to -3.33]) and 1.8 mg (MD: -4.85 kg [95% CI: -5.29 to -4.41]), and the SGLT-2 inhibitors empagliflozin 2.5 mg (MD: -1.47 kg [95% CI: -2.23 to -0.71]), 10 mg (MD: -2.77 kg [95% CI: -3.24 to -2.31]) and 25 mg (MD: -3.06 kg [95% CI: -3.57 to -2.55]) and sotagliflozin 200 mg (MD: -2.40 kg [95% CI: -2.87 to -1.94]) and 400 mg (MD: -3.23 [95% CI: -3.73 to -2.72]) were associated with significant reductions in body weight. No significant effect on body weight was found for DPP-4 inhibitors, other GLP-1-receptor agonists, metformin, or for lifestyle interventions (i.e. exercise and diet).

CONCLUSIONS

In people with type 1 diabetes, several adjuvant pharmacological interventions showed weight reduction as a secondary outcome. Future studies in overweight people with type 1 diabetes are needed to establish whether the lifestyle and pharmacological interventions reviewed here have potential as components of complex interventions aimed at body weight reduction as a primary outcome.

A systematic review and dose-response meta-analysis on the efficacy of dapagliflozin in patients with type 1 diabetes mellitus

Formulation of insulin analogs and its delivery are developed in over recent years but glycemic control in most patients with type-1 diabetes mellitus (DM) is not adequate yet. The aim of this meta-analysis is to evaluate the efficacy of dapagliflozin in patients with type-1 DM. The MEDLINE/PubMed, Scopus, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases were searched up to Aug 2020 to identify the potential literature. Random-effects model (DerSimonian and Laird method) was used to estimate the pooled effect size as weighted mean difference (WMD) with 95 % confidence interval (CI). Five randomized placebo-controlled trials with 11 arms were included in the quantitative analysis. The pooled results suggested a significant reduction in glycated hemoglobin A1C (HbA1C; WMD: -0.36 %, 95 % CI: -0.55, -0.18), body weight (WMD: -4.02 kg, 95 % CI: -4.78, -3.25), and total daily insulin dose (TDID; WMD: -10.36 %, 95 % CI: -13.42, -7.29), as well as an increase in 24-h urinary glucose excretion (24-h UGE; WMD: 90.02 g/24-h, 95 % CI: 72.96, 107.09) in dapagliflozin group compared to control group. Dose of dapagliflozin had a significant effect on body weight reduction (Coef = -3.7, p = 0.01) and 24-h UGE (coef = 0.85, p = 0.005). Pooled results of this meta-analysis identified a significant reduction in HbA1c levels, body weight, and TDID, and a substantial increase in 24-h UGE in patients who received dapagliflozin versus placebo.

Nutrition and Obesity in the Pathogenesis of Youth-Onset Type 1 Diabetes and Its Complications

Since the 1980s, there has been a dramatic rise in the prevalence of overweight and obesity in pediatric populations, in large part driven by sedentary lifestyles and changing dietary patterns with more processed foods. In parallel with the rise in pediatric obesity in the general population, the prevalence of overweight and obesity has increased among children and adolescents with type 1 diabetes. Adiposity has been implicated in a variety of mechanisms both potentiating the risk for type 1 diabetes as well as exacerbating long-term complications, particularly cardiovascular disease. Treatment options targeting the unique needs of obese pediatric patients, both before and after diagnosis of type 1 diabetes, are limited. In this review, we discuss the history of the epidemiology of the obesity epidemic in the context of pediatric type 1 diabetes, highlight the possible role of obesity in type 1 diabetes pathogenesis and review the concept of "double diabetes". The impact of obesity at and after diagnosis will be discussed, including noted differences in clinical and biochemical markers, lipid abnormalities, and long-term cardiovascular complications. Finally, we will review the existing literature on pharmacologic and nutritional interventions as potential treatment strategies for youth with coexisting type 1 diabetes and obesity.

Age, sex, disease severity, and disease duration difference in placebo response: implications from a meta-analysis of diabetes mellitus

BACKGROUND

The placebo response in patients with diabetes mellitus is very common. A systematic evaluation needs to be updated with the current evidence about the placebo response in diabetes mellitus and the associated factors in clinical trials of anti-diabetic medicine.

METHODS

Literature research was conducted in Medline, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for studies published between the date of inception and June 2019. Randomized placebo-controlled trials conducted in type 1and type 2 diabetes mellitus (T1DM/T2DM) were included. Random-effects model and meta-regression analysis were accordingly used. This meta-analysis was registered in PROSPERO as CRD42014009373.

RESULTS

Significantly weight elevation (effect size (ES) = 0.33 kg, 95% CI, 0.03 to 0.61 kg) was observed in patients with placebo treatments in T1DM subgroup while significantly HbA1c reduction (ES = - 0.12%, 95% CI, - 0.16 to - 0.07%) and weight reduction (ES = - 0.40 kg, 95% CI, - 0.50 to - 0.29 kg) were observed in patients with placebo treatments in T2DM subgroup. Greater HbA1c reduction was observed in patients with injectable placebo treatments (ES = - 0.22%, 95% CI, - 0.32 to - 0.11%) versus oral types (ES = - 0.09%, 95% CI, - 0.14 to - 0.04%) in T2DM (P = 0.03). Older age (β = - 0.01, 95% CI, - 0.02 to - 0.01, P < 0.01) and longer diabetes duration (β = - 0.02, 95% CI, - 0.03 to - 0.21 × 10^-2, P = 0.03) was significantly associated with more HbA1c reduction by placebo in T1DM. However, younger age (β = 0.02, 95% CI, 0.01 to 0.03, P = 0.01), lower male percentage (β = 0.01, 95% CI, 0.22 × 10^-2, 0.01, P < 0.01), higher baseline BMI (β = - 0.02, 95% CI, - 0.04 to - 0.26 × 10^-2, P = 0.02), and higher baseline HbA1c (β = - 0.09, 95% CI, - 0.16 to - 0.01, P = 0.02) were significantly associated with more HbA1c reduction by placebo in T2DM. Shorter diabetes duration (β = 0.06, 95% CI, 0.06 to 0.10, P < 0.01) was significantly associated with more weight reduction by placebo in T2DM. However, the associations between baseline BMI, baseline HbA1c, and placebo response were insignificant after the adjusted analyses.

CONCLUSION

The placebo response in diabetes mellitus was systematically outlined. Age, sex, disease severity (indirectly reflected by baseline BMI and baseline HbA1c), and disease duration were associated with placebo response in diabetes mellitus. The association between baseline BMI, baseline HbA1c, and placebo response may be the result of regression to the mean.

Liraglutide treatment in overweight and obese patients with type 1 diabetes: A 26-week randomized controlled trial; mechanisms of weight loss

AIM

To investigate the effects of liraglutide treatment on glycaemic control and adipose tissue metabolism in overweight and obese people with type 1 diabetes (T1DM).

RESEARCH DESIGN AND METHODS

A total of 84 adult overweight and obese patients with T1DM, with no detectable C-peptide, were randomized (1:1) to either placebo or 1.8 mg/d liraglutide for 6 months. Blood samples were collected at 0, 12 and 26 weeks. Subcutaneous adipose tissue biopsies, a high-calorie high-fat meal challenge test, continuous glucose monitoring, dual-energy X-ray absorptiometry and MRI were performed before and at the end of treatment.

RESULTS

In all, 37 and 27 patients who received liraglutide and placebo, respectively, completed the study. Glycated haemoglobin fell by 0.41 ± 0.18% (4.5±1.4 mmol/mol) from baseline after liraglutide treatment (P = 0.001), and by 0.29 ± 0.19% (3.1±2.0 mmol/mol) compared to placebo (P = 0.1). There was no increase in hypoglycaemia, while the time spent in normal glycaemia increased (P = 0.015) and time spent in hyperglycaemia decreased (P = 0.019). Body weight fell significantly in the liraglutide group, mostly in the form of fat mass loss (including visceral fat), with no change in lean mass. Systolic blood pressure (SBP) also fell after liraglutide treatment. Liraglutide also caused a significant increase in the expression of adipose tissue triglyceride lipase, carnitine palmitoyl transferase-1, peroxisome proliferator-activated receptor (PPAR)α, PPARδ, uncoupling protein-2 and type 2 iodothyronine deiodinase in the adipose tissue.

CONCLUSIONS

Liraglutide improves glycaemia, reduces adiposity and SBP. Liraglutide also stimulates mechanisms involved with an increase in lipid oxidation and thermogenesis, while conserving lean body mass.

Adjunct therapies in treatment of type 1 diabetes

In spite of developments with novel insulin preparations, novel modes of insulin delivery with insulin infusion pumps, and the facility of continuous glucose monitoring, only 20% of patients with type 1 diabetes are under adequate control. The need for innovation is clear, and, therefore, the use of adjunct therapies with other pharmacological agents currently in use for type 2 diabetes, has been tried. Currently, pramlintide is the only agent licensed for use in this condition in addition to insulin. Global trials have been conducted with liraglutide, a glucagon-like peptide 1 receptor agonist (GLP-1RA), dapagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, and sotagliflozin, an inhibitor of both SGLT1 and SGLT2 transporters. While dapagliflozin and sotagliflozin have now been licensed for clinical use in this condition in Europe and Japan, they have hitherto not been licensed in the United States due to a small increase in the risk of diabetic ketoacidosis. However, these agents reduce glycosylated hemoglobin (HbA1c) by 0.4%, reduce glycemic oscillations, and do not increase the risk of hypoglycemia. Liraglutide, on the other hand, induced a smaller reduction in HbA1c and thus was not considered for a license. However, further trials are currently being conducted with a combination of semaglutide, the most potent GLP-1RA, and dapagliflozin to determine whether this approach would yield better outcomes.

Liraglutide reduces systolic blood pressure in patients with type 2 diabetes mellitus: A meta-analysis of randomized trials

The antidiabetic effect of liraglutide in patients with type 2 diabetes mellitus has been explored in several trials. We performed this meta-analysis determining the effects of liraglutide on blood pressure in these patients. Three electronic databases (Pubmed, Web of Science, and Cochrane Central) were searched for all published articles evaluating the effects of liraglutide on blood pressure in subjects with type 2 diabetes mellitus. Total 968 patients were included in 10 randomized, double-blind, placebo-controlled trials with a follow-up of 16 ± 9 weeks. Liraglutide 1.8 mg/day reduced systolic blood pressure (weighted mean differences -5.39 (95% confidence interval, -7.26, -3.51) mm Hg, p < .001) and body weight (weighted mean differences -2.07 (95% confidence interval, -2.62, -1.51) kg, p < .001) in patients with type 2 diabetes mellitus. There was no significant difference for changes of diastolic blood pressure between liraglutide 1.8 mg/day and placebo in these patients (weighted mean differences -0.53 (95% confidence interval, -1.96, 0.89) mm Hg, p > .05). The increases of heart rate were greater than placebo in patients treated with liraglutide 1.8 mg/day (weighted mean differences 6.03 (95% confidence interval, 4.78, 7.29) kg, p < .001). There was no significant correlation between reduction of systolic blood pressure and weight loss in patients treated with liraglutide 1.8 mg/day (p = .24). In conclusion, liraglutide reduces systolic blood pressure and body weight in patients with type 2 diabetes mellitus. These data suggest the beneficial effects of liraglutide on cardiovascular protection and may improve prognosis in these patients.

Lixisenatide in type 1 diabetes: A randomised control trial of the effect of lixisenatide on post-meal glucose excursions and glucagon in type 1 diabetes patients

AIMS

The GLP1 agonist lixisenatide is glucagonostatic and reduces post-prandial blood glucose (PPBG) in type 2 diabetes. This study investigates its impact in type 1 diabetes (T1D).

METHODS

In a blinded, crossover trial, 25 patients with T1D were randomised to 4 weeks adjunctive treatment with lixisenatide (L) or placebo (P), with a 4-week washout period. The primary outcome was percentage of 3 hours PPBG in target (4-10 mmol/L) assessed by CGM before and after treatment. Participants also underwent post-treatment standardised mixed meal test (MMT, n = 25) and hyperinsulinaemic hypoglycaemic clamp (n = 15).

RESULTS

PPBG CGM readings in target were similar between L vs P (Mean % ± SE, breakfast 45.4 ± 6.0 vs 44.3 ± 6.0, P = .48, lunch 45.5 ± 5.8 vs 50.6 ± 5.3, P = .27 and dinner 43.0 ± 6.7 vs 47.7 ± 5.6, P = .30). HbA1C was similar between L vs P (64.7 ± 1.6 vs 64.1 ± 1.6 mmol/mol, P = .30). Prandial insulin fell after lixisenatide (dose change -0.7 ± 0.6 vs +2.4 ± 0.7 units/d, P = .004), but basal insulin dose was similar between groups. The post-MMT glucose area under the curve (AUC) was lower with L than P (392.0 ± 167.7 vs 628.1 ± 132.5 mmol/L × min, P < .001), as was the corresponding glucagon AUC (140.0 ± 110.0 vs 304.2 ± 148.2 nmol/L × min, P < .001). Glucagon and counter-regulatory hormone values at a blood glucose of 2.4 mmol/L during the hypoglycaemic clamp were similar between L and P.

CONCLUSION

In T1D, PPBG values were not altered by adjunctive lixisenatide although prandial insulin dose fell. Glucose and glucagon level during an MMT were significantly lower after lixisenatide, without affecting counter-regulatory response during hypoglycaemia.

Liraglutide reduces hyperglycaemia and body weight in overweight, dysregulated insulin-pump-treated patients with type 1 diabetes: The Lira Pump trial-a randomized, double-blinded, placebo-controlled trial

AIM

To investigate the efficacy of adding the glucagon-like peptide-1 receptor agonist liraglutide to continuous subcutaneous insulin infusion (CSII) in overweight or obese persons with type 1 diabetes and non-optimal glycaemic control.

MATERIALS AND METHODS

A 26-week, randomized, double-blind, placebo-controlled trial including 44 overweight or obese adults with type 1 diabetes randomized 1:1 to liraglutide 1.8 mg once daily (QD) or placebo added to CSII treatment. The primary endpoint was change in haemoglobin A1c (HbA1c). Secondary endpoints included change in insulin dose, CSII settings, glycaemic variability, body weight and patient-reported outcome measures. Finally, adverse effects including hypoglycaemic events were registered.

RESULTS

HbA1c was reduced by 5 mmol/mol (0.5%) from a baseline of 66 mmol/mol (8.2%) in patients treated with liraglutide compared with a non-significant change of +2.3 mmol/mol (0.2%) from a baseline of 66 mmol/mol (8.1%) in patients treated with placebo (between-group difference 7 mmol/mol [0.7%], P < 0.001). Liraglutide reduced total insulin dose by 8 units/day or 16% of total insulin dose (P = 0.008). Mean body weight was reduced by 6.3 kg (P < 0.001) compared with placebo. Concomitantly, time spent in glycaemic target range 4-10 mmol/L (71-180 mg/dL) increased while the risk of hypoglycaemia did not differ between groups at the end of treatment.

CONCLUSION

Liraglutide treatment reduced HbA1c, total daily insulin dose and body weight without increasing the risk of hypoglycaemia in CSII-treated patients with type 1 diabetes and insufficient glycaemic control. Liraglutide may be considered a potential add-on therapy to insulin in this subgroup of patients.

Treatment strategies for hypertension in patients with type 1 diabetes

INTRODUCTION

Type 1 diabetes mellitus (T1DM) is a chronic, autoimmune disease that is characterized by total absence of insulin production. Hypertension is a common comorbidity in T1DM with complex pathophysiology, while it is also a well-recognized risk factor for the development of cardiovascular disease (CVD), as well as other microvascular diabetic complications.

AREAS COVERED

The purpose of this review is to present the current definitions, epidemiological data and prevalence rates of hypertension in T1DM, as well as to describe current therapeutic options.

EXPERT OPINION

Hypertension affects around a third of the type 1 diabetic population, with higher prevalence rates in older individuals with longer disease duration. Although hypertension affects a substantial proportion of T1DM individuals, blood pressure control rates are disappointingly low. Alongside lifestyle modification, antihypertensive treatment should be initiated in those with blood pressure above 140/90 mmHg, with a systolic blood pressure target of 130 mmHg and lower, if tolerated. In those with established CVD or diabetic nephropathy, systolic blood pressure targets below 130 mmHg should be pursued. Initial pharmacotherapy should consist of a renin-angiotensin-aldosterone system inhibitor. There is an urgent need for good quality data regarding proper antihypertensive treatment initiation, optimal BP targets and optimal antihypertensive treatment for better clinical outcomes.

New Frontiers in the Treatment of Type 1 Diabetes

Type 1 diabetes is an autoimmune disease caused by the immune-mediated destruction of pancreatic β cells that results in lifelong absolute insulin deficiency. For nearly a century, insulin replacement has been the only therapy for most people living with this disease. Recent advances in technology and our understanding of β cell development, glucose metabolism, and the underlying immune pathogenesis of the disease have led to innovative therapeutic and preventative approaches. A paradigm shift in immunotherapy development toward the targeting of islet-specific immune pathways involved in tolerance has driven the development of therapies that may allow for the prevention or reversal of this disease while avoiding toxicities associated with historical approaches that were broadly immunosuppressive. In this review, we discuss successes, failures, and emerging pharmacological therapies for type 1 diabetes that are changing how we approach this disease, from improving glycemic control to developing the "holy grail" of disease prevention.

Liraglutide as Adjunct to Insulin Treatment in Patients with Type 1 Diabetes: A Systematic Review and Meta-analysis

BACKGROUND

A few Randomized Controlled Trials (RCTs) have evaluated the use of liraglutide in Type 1 Diabetes (T1D). Through the present systematic review and meta-analysis, we aim at critically appraising and summarizing those RCTs, providing precise effect estimates.

METHODS

We searched major databases and grey literature from their inception to October 2018, for RCTs with a duration ≥ 12 weeks, comparing liraglutide with placebo or any other comparator as adjunct to insulin in patients with T1D, investigating major efficacy and safety endpoints. This review is reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement.

RESULTS

We included 5 trials with 2,445 randomized participants. Liraglutide provided modest reductions in HbA1c, with liraglutide 1.8 mg producing the greatest decrease (MD = -0.24%, 95% CI -0.32 to -0.16, I2=0%). Significant weight reduction, up to 4.87 kg with liraglutide 1.8 mg was also observed (95% CI -5.31 to -4.43, I2=0%). Decrease in total daily insulin dose, primarily driven by a decrease in bolus insulin requirements, was demonstrated. Liraglutide decreased non-significantly the odds for severe hypoglycemia (OR=0.80, 95% CI 0.57-1.14, I2=0%), while it increased significantly the odds for gastrointestinal adverse events (for nausea, OR=4.70, 95% CI 3.68-6.00, I2=37%, and for vomiting, OR=2.50, 95% CI 1.54-4.72, I2=27%). A significant increase in heart rate was also demonstrated. No association with diabetic ketoacidosis or malignancies was identified.

CONCLUSION

In patients with T1D, liraglutide might prove be an adjunct to insulin, improving glycemic control, inducing body weight loss and decreasing exogenous insulin requirements and severe hypoglycemia.

Effects of Sodium-Glucose Cotransporter Inhibitor/Glucagon-Like Peptide-1 Receptor Agonist Add-On to Insulin Therapy on Glucose Homeostasis and Body Weight in Patients With Type 1 Diabetes: A Network Meta-Analysis

Many patients with type 1 diabetes (T1D) do not achieve the glycemic target goal with insulin treatment. In this study, we aimed to evaluate the efficacy and safety of add-on to insulin therapy in patients with T1D. We conducted direct and indirect network meta-analyses using Bayesian models and ranked hypoglycemic agents via mixed treatment comparison, using data from the CENTRAL, MEDLINE, EMBASE, and Science Citation Index Expanded databases. Randomized controlled trials (RCTs) involving patients with T1D treated with insulin and add-on metformin or sodium-glucose cotransporter inhibitors or glucagon-like peptide-1 receptor agonists from January 1970 to September 2019 were included in this study. Twenty-three RCTs with 5,151 subjects were divided into the following groups: insulin alone, insulin+metformin, insulin+canagliflozin, insulin+dapagliflozin, insulin+empagliflozin, insulin+sotagliflozin, insulin+liraglutide, and insulin+exenatide. HbA1c level in the insulin+sotagliflozin group was significantly lower than that in the insulin alone group (mean difference: -0.43, 95% credible interval: -0.62 to -0.23). Total daily insulin dose in the insulin+sotagliflozin group was significantly lower than that in the insulin alone group. Compared with that in the insulin alone group, body weight in the groups treated with insulin+add-on canagliflozin, sotagliflozin, and exenatide was significantly decreased by 4.5, 2.8, and 5.1 kg, respectively. Hypoglycemic episodes did not differ among the groups. In patients with T1D, insulin+sotagliflozin decreased the HbA1c level, daily insulin dose, and body weight without hypoglycemia compared with insulin monotherapy. Insulin+canagliflozin or insulin+exenatide was effective in reducing body weight compared with insulin alone. In conclusion, sotagliflozin treatment decreased not only the HbA1c levels and insulin dose but also the body weight without causing hypoglycemia in patients with T1D. Treatment with canagliflozin and exenatide effectively reduced body weight in patients with T1D. However, ketoacidosis associated with the use of SGLT inhibitors should be considered in these patients. Thus, our results suggest that sotagliflozin has a high probability of being ranked first as an adjunctive therapy to insulin in patients with T1D.

Glucagon-like peptide 1 receptor agonists in type 1 diabetes mellitus

PURPOSE

The role of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) in the treatment of type 1 diabetes mellitus (T1DM), including efficacy and safety evidence, is reviewed.

SUMMARY

Currently approved treatment options for glycemic control in T1DM include insulin, which combats insulin deficiency but does not effectively target disease progression or alpha cell dysfunction; and pramlintide, whose use requires multiple daily doses and involves a high likelihood of gastrointestinal side effects. GLP-1 RAs have a unique mechanism of action in T1DM, addressing alpha cell dysfunction and thereby suppressing inappropriate glucagon secretion. GLP-1 RA dosing varies from once weekly to twice daily, and the class is well tolerated in patients with type 2 diabetes. Among the GLP-1 RAs, exenatide and liraglutide have been studied in patients with T1DM, with published evidence consistently demonstrating weight loss, decreases in total daily insulin requirements, and modest improvements in glycemic control. GLP-1 RA therapy appears to be well tolerated in patients with T1DM and is associated with nonsignificant increases in hypoglycemia risk.

CONCLUSION

GLP-1 RA therapy represents an important add-on therapy option for achieving decreased insulin doses, weight loss, and modest improvements in HbA1c levels without significantly increasing hypoglycemia risk in patients with T1DM. Patients who have detectable C-peptide and/or are overweight or cannot achieve glycemic goals without hypoglycemia have been found to benefit the most from GLP-1 RA therapy. Further studies are warranted to evaluate these agents' potential impact on clinical outcomes such as microvascular and macrovascular complications.

Effect of the GLP-1 receptor agonist exenatide on impaired awareness of hypoglycemia in type 1 diabetes; a randomized controlled trial

CONTEXT

Impaired awareness of hypoglycemia (IAH), resulting from habituation to recurrent hypoglycemia, can be reversed by strict avoidance of hypoglycemia. Adjunctive treatment with glucagon-like peptide-1 (GLP-1) receptor agonists may reduce glucose variability, hence lower the risk of hypoglycemia and improve awareness. The aim of our study was to investigate the effect of exenatide on awareness of hypoglycemia in people with type 1 diabetes and IAH.

METHODS

This was a randomized double-blind, placebo-controlled cross-over trial. Ten patients with type 1 diabetes and IAH were included (age 38.5±4.4 years, 40% males, HbA1c 7.2±0.4 % (55.2±4.8 mmol/mol)). Patients were treated with exenatide 5µg twice daily (first 2 weeks), followed by 10µg twice daily (remaining 4 weeks) or matching placebo, with a 4-week washout period. Patients wore blinded glucose sensors in the final weeks and modified hyperinsulinemic normoglycemic-hypoglycemic glucose clamps (nadir 2.5 mmol/l) were performed at the end of each treatment period.

RESULTS

Treatment with exenatide caused body weight to fall as compared to placebo (-3.9±0.9 vs. 0.6±1.2 kg, p=0.047). Exenatide did not change mean 24-hour glucose levels (8.3±0.4 vs. 8.5±0.3 mmol/l, exenatide vs. placebo, p=0.64), median (interquartile range) percentage of time spent in hypoglycemia (15.5 [4.5, 25.5] vs. 7.8 [4.4, 17.1]%, p=0.11) and frequency of hypoglycemia (15.8±3.7 vs. 12.1±3.5, p=0.19). Symptom scores in response to clamped hypoglycemia were similar between exenatide (median change 1.0 [-1.5, 7.0]) and placebo (4.5 [1.5, 5.8], p=0.08).

CONCLUSIONS

Six weeks treatment with exenatide did not improve awareness of hypoglycemia in patients with type 1 diabetes and IAH.

Addition of glucagon-like peptide-1 receptor agonist therapy to insulin in C-peptide-positive patients with type 1 diabetes

We aimed to test the hypothesis that addition of glucagon-like peptide-1 receptor agonists (GLP-1RAs) to insulin in C-peptide-positive patients with type 1 diabetes (T1D) will result in a reduction in glycated haemoglobin (HbA1c) with reduced insulin requirements and a rise in C-peptide concentrations. We conducted a retrospective analysis of 11 normal-weight patients with T1D consecutively treated with a GLP-1RA in addition to insulin. Paired t tests were used to compare the changes in HbA1c, insulin doses, body weight, body mass index, and C-peptide concentrations prior to and 12 ± 1 weeks after GLP-1RA therapy. At the end of 12 ± 1 weeks of GLP-1RA therapy, HbA1c fell from 10.74 ± 0.96% (95 ± 10.5 mmol/mol) to 7.4 ± 0.58% (58 ± 6.3mmol/mol) (P < 0.01), body weight fell from 71 ± 2.0 to 69 ± 2 kg (P = 0.06), and total insulin dose was reduced by 64% from 33 ± 6 to 11 ± 5 units (P < 0.01). Five out of 10 patients did not require any insulin. C-peptide concentrations increased significantly from 0.43 ± 0.09 ng/ml (0.14 ± 0.02 nmol/L) to 1.42 ± 0.42ng/ml (0.47 ± 0.13 nmol/L) (P = 0.01). Addition of GLP-1RA therapy to insulin in normal-weight patients with T1D led to a reduction in HbA1c with reduced insulin requirements, a 3.5-fold increase in C-peptide concentrations and freedom from insulin therapy in 50% of patients who tolerated the GLP-1RA therapy over a period of 12 ± 1 weeks.

Incretin-based therapies for patients with type 1 diabetes: a meta-analysis

OBJECTIVE

Combined treatment with an incretin-based drug, such as a glucagon-like peptide 1 receptor agonist (GLP-1 RA) or a dipeptidyl peptidase-4 (DPP-4) inhibitor, and basal insulin is a new strategy for improving glucose control in type 1 diabetes mellitus (T1DM). We performed a meta-analysis to assess the effect of this combined treatment on glycaemic control, insulin dose, severe hypoglycaemia, weight gain and gastrointestinal side effects in T1DM patients.

METHODS

We searched PubMed, EMBASE and the Cochrane Library for relevant studies published before July 16, 2018. The primary outcome was glycosylated haemoglobin (HbA1c). Secondary outcomes included total daily insulin dose, body weight, severe hypoglycaemia and gastrointestinal side effects.

RESULTS

Nine randomized controlled trials (RCTs) involving 2389 patients were ultimately included in the meta-analysis. The pooled data suggested that incretin-based therapy was associated with a reduction in HbA1c levels (weighted mean difference (WMD) -0.17%, 95% confidence interval (CI) -0.24 to -0.11, P < 0.001), total daily insulin dose (WMD -5.53 IU/day, 95% CI -8.89 to -2.17, P = 0.001) and body weight (WMD -3.24 kg, 95% CI -4.43 to -2.04, P < 0.001). Incretins did not increase the risk of severe hypoglycaemia (odds ratio (OR) 0.83, 95% CI 0.60-1.16, P = 0.287) but increased the occurrence of gastrointestinal side effects (OR 3.46, 95% CI 2.20-5.45, P < 0.001).

CONCLUSIONS

In T1DM patients, GLP-1 RAs, but not DPP-4 inhibitors, combined with insulin appear to be an effective therapy but may increase the occurrence of gastrointestinal side effects.

The impact of the glucagon-like peptide 1 receptor agonist liraglutide on the streptozotocin-induced diabetic mouse kidney proteome

In diabetes mellitus (DM), the kidneys are exposed to increased levels of hyperglycemia-induced oxidative stress. Elevated amounts of reactive oxygen species (ROS) are believed to provoke ultrastructural changes in kidney tissue and can eventually result in DM late complications such as diabetic nephropathy. While it is reported that glucagon-like peptide 1 receptors (GLP-1R) are present in the kidney vasculature, the effects of GLP-1 on the kidney proteome in DM is not well described. Thus, we set out to investigate potential effects on the proteomic level. Here the effects of GLP-1R agonism using the GLP-1 analogue liraglutide are studied in the kidneys of streptozotocin (STZ)-treated mice (n = 6/group) by label-free shotgun mass spectrometry (MS) and targeted MS. Unsupervised and supervised multivariate analyses are followed by one-way ANOVA. Shotgun MS data of vehicle and liraglutide-treated mouse groups are separated in the supervised multivariate analysis and separation is also achieved in the subsequent unsupervised multivariate analysis using targeted MS data. The mouse group receiving the GLP-1R agonist liraglutide has increased protein abundances of glutathione peroxidase-3 (GPX3) and catalase (CATA) while the abundances of neuroplastin (NPTN) and bifunctional glutamate/proline-tRNA ligase (SYEP) are decreased compared to the STZ vehicle mice. The data suggest that GLP-1R agonism mainly influences abundances of structurally involved proteins and proteins involved in oxidative stress responses in the STZ mouse kidney. The changes could be direct effects of GLP-1R agonism in the kidneys or indirectly caused by a systemic response to GLP-1R activation.

Adjunct Antihyperglycemic Agents in Overweight and Obese Adults With Type 1 Diabetes

OBJECTIVE

People with type 1 diabetes often have suboptimal glycemic control. The gold standard of treatment is basal-bolus insulin or subcutaneous insulin infusion via insulin pump. Although insulin therapy improves glycemic control, weight gain and hypoglycemia often limit achievement of hemoglobin A_1C (A1C) goals. The number of people with type 1 diabetes who are overweight or obese is increasing, and there are many similarities between what was historically called type 1 and type 2 diabetes. Therefore, there is rationale for using antihyperglycemic agents that target other pathophysiological abnormalities to facilitate weight loss and improve glycemic control.

DATA SOURCES

We performed a MEDLINE search from 1975 through October 2018 to identify articles that studied noninsulin agents in adults with type 1 diabetes and body mass index (BMI) ≥25 kg/m².

STUDY SELECTION AND DATA EXTRACTION

Identified articles were included if the study duration was ≥4 weeks, included ≥20 patients, and set mean baseline BMI ⩾25kg/m².

DATA SYNTHESIS

This review summarizes 32 clinical trials. Amylin mimetics, sodium-glucose-like transporter-2 inhibitors, and glucagon-like-peptide-1 receptor agonists demonstrate the greatest improvements in body weight and A1C. The most common adverse effects are hypoglycemia and ketosis. Relevance to Patient Care and Clinical Practice: Patients with type 1 diabetes may have interest in starting noninsulin agents. Clinicians need to be knowledgeable in the efficacy and adverse effect profile of these agents, specifically in people with type 1 diabetes.

CONCLUSIONS

Adding noninsulin antihyperglycemic agents may benefit select overweight or obese adults with type 1 diabetes. These agents are off-label, and if used, close monitoring is essential.

Do glucagon-like peptide-1 receptor (GLP-1R) agonists have potential as adjuncts in the treatment of type 1 diabetes?

INTRODUCTION

Glucagon-like peptide-1 (GLP-1) is produced by the gut, stimulates insulin secretion from the pancreatic β-cells, and inhibits glucagon secretion from the α-cells. The GLP-1 receptor (GLP-1R) agonists are used in the treatment of type 2 diabetes (T2DM).

AREAS COVERED

This review covers the clinical trials of the GLP-1R agonists (exenatide and liraglutide) and their potential as adjunct treatment in type 1 diabetes mellitus (T1DM).

EXPERT OPINION

GLP-1R agonists are unable to increase insulin secretion, in subjects with T1DM, who are C-peptide negative. Also, the GLP-1R agonists either have no effect or cause a small inhibition of glucagon secretion in subjects with T1DM. There is no evidence that the GLP-1R agonists cause a major reduction in HbA1c, or have a major effect on hypo- or hyperglycemia in subjects with TD1M. The main beneficial effect of the GLP-1R agonists is probably the modest weight loss, which may underlie the reduction in dose of insulin used. Given that the GLP-1R agonists cause gastrointestinal adverse effects, and with reduced insulin doses, increase the risk of ketosis, it seems to me that the risk with these agents may outweigh any benefit in T1DM, and that they have little potential as adjuncts in the treatment of T1DM.

Non-insulin pharmacological therapies for treating type 1 diabetes

INTRODUCTION

Despite intensified insulin treatment, many persons with type 1 diabetes (T1D) do not achieve glycemic and metabolic targets. Consequently, non-insulin chemical therapies that improve glycemic control and metabolic parameters without increasing the risk of adverse events (including hypoglycemia) are of interest as adjunct therapies to insulin.

AREAS COVERED

In this review, the authors discuss the efficacy and safety of non-insulin therapies, including pramlintide, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 inhibitors (DPP-4), sodium-glucose cotransporter (SGLT1 and SGLT2) inhibitors, metformin, sulfonylureas, and thiazolidinediones as add-on therapies to insulin in T1D.

EXPERT OPINION

The current evidence shows that the efficacy of non-insulin therapies as add-on therapies to insulin is minimal or modest with an average HbA1c reduction of 0.2-0.5% (2-6 mmol/mol). Indeed, the current focus is on the development of SGLT inhibitors as adjuncts to insulin in type 1 diabetes. Studies of subgroups with obesity, residual beta-cell function (including newly diagnosed patients) and patients prone to hypoglycemia could be areas of future research.

Adjuvant Pharmacotherapies to Insulin for the Treatment of Type 1 Diabetes

PURPOSE OF REVIEW

Insulin therapy alone fails to achieve target glycemic control in the majority of individuals with type 1 diabetes (T1D), motivating the investigation of additive medications. This review focuses on the recent findings on the use of adjunctive pharmacotherapy in T1D.

RECENT FINDINGS

Metformin and glucagon-like peptide-1 receptor agonists have been associated with weight reduction and decrease in daily insulin requirements without sustainable improvement in glycemic control. Sodium-glucose cotransporter (SGLT)-2 inhibitors, dual SGLT-1/2 inhibitors, and pramlintide have been shown to reduce hemoglobin A1c, induce weight loss, and lower insulin dose. The benefits of dipeptidyl peptidase-4 inhibitors, thiazolidinediones, and alpha glucosidase inhibitors appear to be more limited. Gastrointestinal symptoms and increased hypoglycemia are adverse effects of certain classes. Although not devoid of side effects, additive pharmacotherapies in T1D can improve glycemic control and lower body weight and insulin requirement. Longer studies are needed before consideration for widespread clinical care.

Pramlintide but Not Liraglutide Suppresses Meal-Stimulated Glucagon Responses in Type 1 Diabetes

CONTEXT

Postprandial hyperglycemia remains a challenge in type 1 diabetes (T1D) due, in part, to dysregulated increases in plasma glucagon levels after meals.

OBJECTIVE

This study was undertaken to examine whether 3 to 4 weeks of therapy with pramlintide or liraglutide might help to blunt postprandial hyperglycemia in T1D by suppressing plasma glucagon responses to mixed-meal feedings.

DESIGN

Two parallel studies were conducted in which participants underwent mixed-meal tolerance tests (MMTTs) without premeal bolus insulin administration before and after 3 to 4 weeks of treatment with either pramlintide (8 participants aged 20 ± 3 years, hemoglobin A1c 6.9 ± 0.5%) or liraglutide (10 participants aged 22 ± 3 years, hemoglobin A1c 7.6 ± 0.9%).

RESULTS

Compared with pretreatment responses to the MMTT, treatment with pramlintide reduced the peak increment in glucagon from 32 ± 16 to 23 ± 12 pg/mL (P < 0.02). In addition, the incremental area under the plasma glucagon curve from 0 to 120 minutes dropped from 1988 ± 590 to 737 ± 577 pg/mL/min (P < 0.001), which was accompanied by a similar reduction in the meal-stimulated increase in the plasma glucose curve from 11,963 ± 1424 mg/dL/min pretreatment vs 2493 ± 1854 mg/dL/min after treatment (P < 0.01). In contrast, treatment with liraglutide had no effect on plasma glucagon and glucose responses during the MMTT.

CONCLUSIONS

Adjunctive treatment with pramlintide may provide an effective means to blunt postmeal hyperglycemia in T1D by suppressing dysregulated plasma glucagon responses. In contrast, plasma glucose and glucagon responses were unchanged after 3 to 4 weeks of treatment with liraglutide.

Exenatide Increases IL-1RA Concentration and Induces Nrf-2‒Keap-1‒Regulated Antioxidant Enzymes: Relevance to β-Cell Function

PURPOSE

We previously demonstrated the anti-inflammatory and antioxidant effects of exenatide. We now hypothesized that exenatide also increases the plasma concentration of interleukin-1 receptor antagonist (IL-1RA), an endogenous anti-inflammatory protein, and modulates the nuclear factor erythroid 2‒related factor‒Kelchlike ECH-associated protein 1‒antioxidant response element (Nrf-2‒Keap-1‒ARE) system to induce key antioxidant enzymes to suppress inflammatory and oxidative stress.

METHODS

Twenty-four patients with obesity and type 2 diabetes receiving combined oral and insulin therapy were randomly assigned to receive either exenatide 10 μg or placebo twice a day for 12 weeks.

RESULTS

Exenatide increased IL-1RA concentration by 61% (from 318 ± 53 to 456 ± 88 pg/mL; P < 0.05). Exenatide treatment also suppressed Keap-1 protein (P < 0.05) and increased messenger RNA expression of NQO-1, glutathione S-transferase PI, heme oxygenase-1, and p21 and increased NAD(P)H dehydrogenase [quinone] 1 protein (P < 0.05) in mononuclear cells.

CONCLUSIONS

Because IL-1RA protects, maintains, and stimulates β-cell function in humans and Nrf-2‒Keap-1‒ARE protects β cells in animals with experimental diabetes, these actions of exenatide may contribute to a potential protective effect on β cells in diabetes.

Incretins: Beyond type 2 diabetes

While the use of incretins, including GLP-1 receptor agonists and PDD-IV inhibitors, is well established in the treatment of type 2 diabetes, many other aspects of these agents are yet to be discovered and utilized for their potential clinical benefit. These include the potential role of GLP-1 receptor agonists in the induction of weight loss, blood pressure reduction, anti-inflammatory and nephro- and cardio-protective actions. Their potential benefit in type 1 diabetes is also being investigated. This review will attempt to comprehensively describe novel discoveries in the field of incretin pathophysiology and pharmacology beyond their classical role in the treatment of type 2 diabetes.