Durable efficacy of liraglutide in patients with type 2 diabetes and pronounced insulin-associated weight gain: 52-week results from the Effect of Liraglutide on insulin-associated wEight GAiN in patients with Type 2 diabetes' (ELEGANT) randomized controlled trial

Efficacy and Safety of Tirzepatide Compared with GLP-1 RAs in Patients with Type 2 Diabetes Treated with Basal Insulin: A Network Meta-analysis

INTRODUCTION

The relative efficacy and safety of tirzepatide was compared with glucagon-like peptide 1 receptor agonists (GLP-1 RAs) in patients with type 2 diabetes mellitus (T2DM) treated with basal insulin using a network meta-analysis (NMA).

METHODS

A systematic literature review was performed to identify randomized controlled trials of GLP-1 RAs in patients with T2DM treated with insulin and an antihyperglycaemic drug. For the NMA, studies included trials with 100% of patients treated with basal insulin background therapy with a titration scheme comparable to the SURPASS-5 trial. The following data were extracted for efficacy and safety assessment at the primary endpoint of each study: changes from baseline in glycated haemoglobin (HbA1c) and body weight and the incidence of nausea, vomiting or diarrhoea, hypoglycaemia, and patients discontinuing treatment because of adverse events. In this study, a comparative analysis of tirzepatide was performed with the GLP-1 RAs dulaglutide, exenatide, and lixisenatide in addition to placebo.

RESULTS

A total of six studies were included across the analyses. Tirzepatide 5, 10, and 15 mg showed statistically significant, greater reductions in HbA1c and body weight at the primary endpoint versus all GLP-1 RA comparators and placebo. Tirzepatide 5, 10, and 15 mg showed a statistically significant, higher likelihood of experiencing nausea compared with those who received placebo or exenatide 2 mg; no statistically significant differences were observed when compared with all other GLP-1 RA comparators. No statistically significant differences were observed in the proportions of patients who discontinued treatment because of adverse events when tirzepatide 5, 10, and 15 mg were compared with GLP-1 RA comparators, apart from tirzepatide 10 and 15 mg versus placebo.

CONCLUSION

Tirzepatide demonstrated statistically significantly greater reductions in HbA1c and body weight when compared with selected GLP-1 RAs and placebo in patients with T2DM treated with basal insulin. Overall, the safety profile of tirzepatide was similar to that of GLP-1RAs.

Is the steady-state concentration, duration of action, or molecular weight of GLP-1RA associated with cardiovascular and renal outcomes in type 2 diabetes?

IMPORTANCE

Disparities were found in the cardiovascular and renal outcomes among different glucagon-like peptide 1 receptor agonist (GLP-1RA) subtypes. However, whether the characteristics of GLP-1RA itself are associated with these disparities remains unclear.

OBJECTIVE

To assess the association between the steady-state concentration, duration of action, or molecular weight of GLP-1RA and the risks of cardiovascular and renal outcomes in patients with type 2 diabetes (T2D).

DATA SOURCES

PubMed, MEDLINE, EMBASE, Cochrane and Clinicaltrial.gov from inception to April 2022.

STUDY SELECTION

Randomized controlled trials (RCTs) investigating GLP-1RAs in patients with T2D were included.

DATA EXTRACTION AND SYNTHESIS

Literature screening and data extraction were performed independently by 2 researchers. The outcomes were computed as odds ratio (OR) and its 95% confidence interval (CI). Subgroup analyses were conducted according to steady-state concentration, duration of action and molecular weight of GLP-1RAs.

MAIN OUTCOMES AND MEASURES

Primary outcomes were major adverse cardiovascular events (MACE), composite renal outcome and all-cause mortality.

RESULTS

In all, 61 RCTs were included. When compared with non-GLP-1RA agents, GLP-1RAs with high steady-state concentration were associated with greater risk reduction in MACE (p for subgroup difference = 0.01) and the composite renal outcome (p for subgroup difference = 0.008) in patients with T2D. Greater risk reductions in MACE between GLP-1RA users versus non-GLP-RA users were observed in long acting stratum when compared with short acting stratum (p for subgroup difference = 0.04) in patients with T2D. The molecular weight of GLP-1RAs was not associated with the risk of cardiovascular and renal outcomes.

CONCLUSIONS AND RELEVANCE

GLP-1RAs with high steady-state concentrations might be associated with greater risk reductions in cardiovascular and renal outcomes in patients with T2D. Long acting GLP-1RAs might outperform short acting ones in reducing the risk of cardiovascular outcomes. These findings provided new insights for guiding the clinical applications of GLP-1RAs in patients with T2D.

Decreased Risk of Anxiety in Diabetic Patients Receiving Glucagon-like Peptide-1 Receptor Agonist: A Nationwide, Population-Based Cohort Study

Background: Previous findings on using Glucagon-like peptide-1 receptor agonist (GLP1-RA) as an antidepressant were conflicting, lacking large-scale studies. We used population-based data to investigate depression and anxiety risk in diabetic patients receiving the medication.

Methods: From claims records of the National Health Insurance Research Database (NHIRD) of Taiwan, we identified cohorts of 10,690 GLP1-RA users and 42,766 propensity score-matched patients without GLP1-RA use from patients with diabetes mellitus (DM) diagnosed in 2011–2017, matched by age, gender, index year, occupation, urbanization, comorbidities, and medications. Incidence, hazard ratios (HR) and 95% confidence interval (CI) of depression and/or anxiety were estimated by the end of 2017.

Results: The overall combined incidence of anxiety and/or depression was lower in GLP1-RA users than in non-users (6.80 versus 9.36 per 1,000 person-years), with an adjusted HR adjusted hazard ratio (aHR) of 0.8 (95% CI: 0.67–0.95) after controlling for covariates. The absolute incidence reduction was greater in anxiety (2.13 per 1,000 person-years) than in depression (0.41 per 1,000 person-years). The treatment effectiveness was significant for women. Patients taking GLP1-RA for longer than 180 days had the incidence of anxiety reduced to 2.93 per 1,000 person-years, with an aHR of 0.41 (95%CI: 0.27–0.61), compared to non-users. Dulaglutide could significantly decrease risks of both anxiety and depression.

Conclusion: Patients with DM receiving GLP1-RA therapy have a greater reduction of the risk of anxiety than that of depression. Our findings strengthen previous research that advocated possible anti-depressant or anxiolytic effects of GLP1-RA and may lead to improved treatment adherence among patients with DM.

Diabetic diarrhoea: A study on gastrointestinal motility, pH levels and autonomic function

BACKGROUND

Chronic diarrhoea is a common, but poorly investigated diabetes complication. Autonomic neuropathy is a leading pathophysiological theory founded on old, small studies. Studies of gastrointestinal motility and pH levels are lacking.

OBJECTIVES

Using new diagnostic methods, we aimed to find out if diabetic diarrhoea was associated with alterations in gastrointestinal motility, pH levels and autonomic function.

METHODS

Fifty-seven patients (42 women, 46 with type 1 diabetes) were prospectively included. Symptoms were evaluated with the gastrointestinal symptom rating scale, defining ≥4 points as cases with diarrhoea. Patients scoring <4 were used as controls. We used the wireless motility capsule to measure gastrointestinal transit times, pH levels and contractility parameters. Autonomic function was assessed by measuring heart rate variability, baroreflex sensitivity and orthostatic hypotension.

RESULTS

Seventeen patients (30%) had diarrhoea. Compared with controls, cases had slower gastric emptying (21:46 vs. 4:14, h:min, p = 0.03) and faster colonic transit (18:37 vs. 54:25, p < 0.001). Cases had increased intraluminal pH in the antrum (2.4 vs. 1.2, p = 0.009), caecum (7.3 vs. 6.4, p = 0.008) and entire colon (7.1 vs. 6.7, p = 0.05). They also had a decreased pH difference across the pylorus (3.3 vs. 4.9, p = 0.004) and ileocaecal junction (0.6 vs 1.0, p = 0.009). The groups did not differ in autonomic function, but diastolic blood pressure drop correlated r_s = -0.34 (p = 0.04) with colonic transit time.

CONCLUSIONS

Patients with diabetic diarrhoea had altered gastrointestinal transit and intraluminal pH levels, but minimal changes in autonomic function. Our results suggest that tests of gastrointestinal function are clinically useful in diabetic diarrhoea.

Effect of Exenatide Use on Cognitive and Affective Functioning in Obese Patients With Type 2 Diabetes Mellitus: Exenatide Use Mediates Depressive Scores Through Increased Perceived Stress Levels

PURPOSE/BACKGROUND

Glucagon-like peptide-1 (GLP-1) is a molecule used to treat type 2 diabetes mellitus (T2DM). Given their widespread expression in the nervous system, GLP-1 receptors also play a role in regulating mood and cognitive function. Here, we aimed to compare obese patients with T2DM, with or without exenatide (a GLP-1R agonist) use on cognitive and affective functioning.

METHODS/PROCEDURES

A total of 43 patients with T2DM (23 on exenatide and 20 without exenatide) were evaluated with the Snaith-Hamilton Pleasure Scale, Cognitive Failures Questionnaire, Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7, Childhood Trauma Questionnaire, Perceived Stress Scale (PSS), and Chronic Stress Scale, in addition to laboratory-based measures of reward learning (the probabilistic reward task) and working memory (Letter-N-Back task).

FINDINGS/RESULTS

Patients on exenatide had higher body mass index (BMI) (37.88 ± 5.44 vs 35.29 ± 6.30; P = 0.015), PHQ-9 (9.70 ± 4.92 vs 6.70 ± 4.66; P = 0.026), and PSS (29.39 ± 6.70 vs 23.35 ± 7.69; P = 0.015) scores. Other stress scales (Childhood Trauma Questionnaire and Chronic Stress Scale), Generalized Anxiety Disorder-7 scores, response bias, or discriminability as assessed by probabilistic reward task and self-report (Cognitive Failures Questionnaire) and laboratory-based (Letter-N-Back) cognitive measures were not significantly different between groups (both Ps > 0.05). Multivariate linear regression analyses adding BMI and PSS as covariates revealed that although BMI had no effect (P = 0.5), PSS significantly predicted PHQ-9 scores (P = 0.004). Mediation analysis showed that exenatide users reported higher PSS, with greater PSS associated with higher PHQ-9 levels (b = 0.236). There was no evidence on exenatide directly influencing PHQ-9 independent of PSS (c' = 1.573; P = 0.305; 95% bootstrap confidence interval, -1.487 to 4.634).

IMPLICATIONS/CONCLUSIONS

Based on previous research and our findings, exenatide use might be mediating depression scores through disrupting stress responses.

Efficacy and Safety of the New Appetite Suppressant, Liraglutide: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Obesity is a chronic disease associated with metabolic diseases such as diabetes and cardiovascular disease. Since the U.S. Food and Drug Administration approved liraglutide as an anti-obesity drug for nondiabetic patients in 2014, it has been widely used for weight control in overweight and obese people. This study aimed to systematically analyze the effects of liraglutide on body weight and other cardiometabolic parameters.

METHODS

We investigated articles from PubMed, EMBASE, and the Cochrane Library to search randomized clinical trials that examined body weight changes with liraglutide treatment.

RESULTS

We included 31 studies with 8,060 participants for this meta-analysis. The mean difference (MD) between the liraglutide group and the placebo group was -4.19 kg (95% confidence interval [CI], -4.84 to -3.55), with a -4.16% change from the baseline (95% CI, -4.90 to -3.43). Liraglutide treatment correlated with a significantly reduced body mass index (MD: -1.55; 95% CI, -1.76 to -1.34) and waist circumference (MD: -3.11 cm; 95% CI, -3.59 to -2.62) and significantly decreased blood pressure (systolic blood pressure, MD: -2.85 mm Hg; 95% CI, -3.36 to -2.35; diastolic blood pressure, MD: -0.66 mm Hg; 95% CI, -1.02 to -0.30), glycated hemoglobin (MD: -0.40%; 95% CI, -0.49 to -0.31), and low-density lipoprotein cholesterol (MD: -2.91 mg/dL; 95% CI, -5.28 to -0.53; MD: -0.87% change from baseline; 95% CI, -1.17 to -0.56).

CONCLUSION

Liraglutide is effective for weight control and can be a promising drug for cardiovascular protection in overweight and obese people.

Long-term efficacy and safety of combined insulin and glucagon-like peptide-1 therapy: Evidence from the LEADER trial

AIM

Glucagon-like peptide-1 receptor agonist (GLP-1RA) and insulin combination therapy is an effective treatment option for type 2 diabetes, but long-term data are lacking. The aim was to assess the long-term efficacy of the GLP-1RA liraglutide in subgroups by insulin use in the LEADER trial.

MATERIALS AND METHODS

LEADER assessed cardiovascular (CV) safety and efficacy of liraglutide (1.8 mg) versus placebo (plus standard of care therapy) in 9340 patients with type 2 diabetes and high risk of CV disease, for up to 5 years. We analyzed CV events, metabolic parameters and hypoglycaemia post hoc in three subgroups by baseline insulin use (basal-only insulin, other insulin or no insulin). Insulin was a non-random treatment allocation as part of standard of care therapy.

RESULTS

At baseline, 5171 (55%) patients were not receiving insulin, 3159 (34%) were receiving basal-only insulin and 1010 (11%) other insulins. Insulin users had a longer diabetes duration and slightly worse glycaemic control (HbA1c) than the no-insulin subgroup. Liraglutide reduced HbA1c and weight versus placebo in all three subgroups (P < .001), and severe hypoglycaemia rate in the basal-only insulin subgroup. The need for insulin was less with liraglutide. CV risk reduction with liraglutide was similar to the main trial results in the basal-only and no-insulin subgroups.

CONCLUSIONS

In patients on insulin, liraglutide improved glycaemic control, weight and need for insulin versus placebo, for at least 36 months with no increased risk of severe hypoglycaemia, while maintaining CV safety/efficacy, supporting the combination of liraglutide and insulin for management of type 2 diabetes.

A systematic review of the antidepressant effects of glucagon-like peptide 1 (GLP-1) functional agonists: Further link between metabolism and psychopathology: Special Section on "Translational and Neuroscience Studies in Affective Disorders". Section Editor, Maria Nobile MD, PhD. This Section of JAD focuses on the relevance of translational and neuroscience studies in providing a better understanding of the neural basis of affective disorders. The main aim is to briefly summaries relevant research findings in clinical neuroscience with particular regards to specific innovative topics in mood and anxiety disorders

INTRODUCTION

An increasing amount of preclinical and clinical evidence links together metabolic regulations and psychopathological mechanisms, in particular linking mood disorders with changes in Glycogen Synthase Kinase 3 beta and 5'Adenosine Monophosphate-activated Protein Kinase expression and activity. New hypoglycemic drugs, including thiazolidinediones and glucagon-like peptide 1 (GLP-1) functional agonists, which work by these mechanisms, have also been described as potential antidepressants. The putative role of thiazolidinediones in depression has been already supported, but no clear evidence exists yet for GLP-1 functional agonists. We conducted a systematic review and meta-analysis of the literature to describe the effect of GLP-1 functional agonists on depression rating scales and either support or confute a potential antidepressant role.

METHODS

We searched the PubMed and Scopus databases for terms related to DPP-4 inhibitors and GLP-1 receptor agonists, and depression, including symptoms and rating scales with acronyms and full names. We included longitudinal interventional and observational studies on GLP-1 functional agonists used for depression symptoms. We applied a random effects meta-analysis on standardized mean differences before-after treatment, comparing GLP-1 functional agonists versus control treatments.

RESULTS

Literature searches found 815 papers, 8 of which were eligible for meta-analysis. Both control treatments (-0.67, 95%C.I. -0.99 - -0.36, Z = 4.24, p < 0.0001) and GLP-1 functional agonists (-1.28, 95%C.I. -2.34 - -0.21, Z = 2.35, p = 0.02) resulted in a significant reduction of depression rating scores, although GLP-1 functional agonists tended to be superior. When a selection was made, including only studies conducted on diabetic patients that did not exclude depressed patients, the effect of GLP-1 functional agonists (-2.09, 95%C.I. -2.28 - -1.91, Z = 22.5, p < 0.00001) was significantly superior to that of control treatments (-0.57, 95%C.I. -0.66 - -0.49, Z = 13.6, p < 0.00001).

DISCUSSION

Results of this meta-analysis must be carefully considered, since the amount of studies available was low and heterogeneity was high. If further trials will confirm this hypothesis, GLP-1 functional agonists may be considered as antidepressants, either as adjuncts or in mono-therapy, with a peculiar value for preventing the adverse metabolic effects of long-term antipsychotic therapies used in rehabilitation.

Cost-benefit comparison of liraglutide and sitagliptin in the treatment of type 2 diabetes in Thailand

Aim

Liraglutide, a once-daily subcutaneous glucagon-like peptide-1 (GLP-1) agonist, is approved for treatment of hyperglycemia in patients with type 2 diabetes mellitus (T2DM). For patients with established cardiovascular diseases, liraglutide has also been shown to reduce major cardiovascular events. However, its cost is relatively higher than other oral antidiabetic drugs. This study aims to compare the costs and benefits of liraglutide vs sitagliptin, in treating T2DM in Thailand.

Methods

This study consists of two parts. In part 1, the cost of keeping T2DM under control per patient (HbA1c<7.0% with no reported hypoglycemia and no body weight gain) with liraglutide (1.2 and 1.8 mg daily) was compared with using sitagliptin (100 mg daily). Costs were based on Thai local data. Clinical outcomes were based on head-to-head randomized controlled trials. Part 2 estimated the cost-per-controlled patient, based on major cardiovascular outcomes (cardiovascular death, nonfatal myocardial infarction, non-fatal stroke). Economic benefit was calculated as the reduction in cardiovascular outcomes.

Results

In Thailand, liraglutide (1.8 mg daily) costs 7.37-times more than sitagliptin 100 mg. The cost per patient achieving a composite clinical endpoint (HbA1c<7.0%, with no weight gain and no hypoglycemic events) in patients with T2DM receiving liraglutide 1.8 mg is 2.80-times higher than patients receiving sitagliptin 100 mg. When cardiovascular benefits (reduced composite endpoint of major cardiovascular events, ie, cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke) were taken into account, it was found that liraglutide had lower cost than sitagliptin, resulting in estimated savings of 20,085 THB (620 USD) per patient per year.

Conclusion

The clinical benefits of liraglutide (HbA1c<7.0%, no hypoglycemia, no weight gain, reduced cardiovascular outcomes) partly offset its high price. Therefore, liraglutide should be considered as an appropriate treatment alternative to sitagliptin, particularly for T2DM patients with high cardiovascular risks.

Use of glucagon-like peptide-1 receptor agonists among individuals on basal insulin requiring treatment intensification

As Type 2 diabetes progresses, treatment is intensified with additional therapies in an effort to manage hyperglycaemia effectively and therefore avoid complications. When greater efficacy is required, options for injectable treatments include glucagon-like peptide-1 receptor agonists and insulin, which may be added on to oral glucose-lowering treatments. Among individuals receiving long-acting basal insulin as their first injectable treatment, ~40-60% are unable to achieve or maintain their target HbA_1c goals. For these people, treatment intensification options are relatively limited and include the addition of short-acting prandial insulin or a glucagon-like peptide-1 receptor agonist. Glucagon-like peptide-1 receptor agonists vary in their effects, with short- and long-acting agents having a greater impact on postprandial and fasting hyperglycaemia, respectively. Studies comparing treatment intensification options have found both glucagon-like peptide-1 receptor agonists and prandial insulin to be effective in reducing HbA_1c concentrations; however, recipients of glucagon-like peptide-1 receptor agonists lost weight and had a greater frequency of gastrointestinal adverse events, whereas those receiving prandial insulin gained weight and had a greater incidence of hypoglycaemia. In addition to the separate administration of a glucagon-like peptide-1 receptor agonist and basal insulin, fixed-ratio combinations of a glucagon-like peptide-1 receptor agonist and basal insulin offer a single administration for both treatments but have less flexibility in dose titration than treatment with their individual components. For individuals who require treatment intensification beyond basal insulin, use of these various options allows physicians to target the individual needs of their patients for the achievement of optimal long-term glycaemic control.

Short-term intensive insulin therapy could be the preferred option for new onset Type 2 diabetes mellitus patients with HbA1c > 9

Type 2 diabetes mellitus (T2DM) is a heterogeneous disease. Currently, the typical clinical therapeutic pathway for the disease consists of the stepwise addition of antihyperglycemic preparations over time, followed lastly by insulin therapy when functional β-cell capacity is severely deteriorated. Recognizing the complexity of disease management, personalized (precision) medicine approaches may enable the physician to tailor diabetes treatment based on HbA1c levels, body mass index (BMI), efficacy, risk of hypoglycemia, risk of weight gain, age, safety, cost, and even genetic characteristics. Although insulin therapy has traditionally been recommended as the last option in the sequential treatment algorithm of T2DM, it is notable that several guidelines and consensus statements suggest consideration of insulin as part of a first-line regimen. In the American Association of Clinical Endocrinologists (AACE)/American College of Endocrinology (ACE) comprehensive T2DM 2017 management algorithm, insulin is recommended for T2DM patients presenting with symptoms and an HbA1c >9.0%. In addition, the American Diabetes Association (ADA)/European Association for the Study of Diabetes (EASD) consensus statement recommends initial insulin therapy as an option when HbA1c ≥9%, and definite consideration with HbA1c ≥10-12%, and mentions that it may be possible to taper off insulin once initial glucotoxicity is reversed and to consider transfer to other types of non-insulin therapies. Based on accumulating evidence, an expert group has endorsed the concept of short-term intensive insulin (STII) therapy as an option for some patients with T2DM at the time of diagnosis. Notably, the latest Israeli guidelines suggest considering immediate, sometimes short-term, insulin treatment for patients with HbA1c >9% or with symptoms. It has been reported that nearly one-quarter (23%) of newly diagnosed T2DM patients in the US had an HbA1c ≥9.0% prior to initiation of treatment. For such patients, initiating insulin is difficult, although it has been almost 10 years since the ACE/AACE Diabetes Road Map suggested insulin therapy for treatment-naïve patients with high HbA1c. Lack of patient education resources in primary care and of provider knowledge as to approaches to insulin treatment (insulin initiation dosage, multiple daily injection or basal insulin supplement, insulin treatment duration) are major obstacles to selecting appropriately intensive but also timely therapy for newly diagnosed T2DM patients in clinical practice so as to minimize avoidable glycemic exposure. Treatment with STII early in the course of T2DM is of considerable interest. There is a wide range of evidence currently available supporting the use of STII therapy in newly diagnosed T2DM. For example, STII can quickly normalize glycemic control, improve β-cell function, restore first-phase insulin secretion, and even reduce glucagonemia in newly diagnosed T2DM, suggesting that it may provide unique capacity for modification of the natural process of diabetes. The largest and most robust clinical trial of STII therapy enrolled 382 newly diagnosed people with T2DM at nine centers in China and randomized them to either insulin (short-term continuous subcutaneous insulin infusion [CSII] or multiple daily injections [MDI]) or oral anti-hyperglycemic therapy. First-phase insulin secretion was increased in all three groups after 2 weeks of normoglycemia. Remission rates at 1 year were higher in the two insulin-treated groups (51.1% in the CSII group, 44.9% in the MDI group) than in the oral therapy group (26.7%). Furthermore, the increase in first-phase insulin response was maintained at 1 year in the two insulin-treated groups, but declined in the group allocated to oral medication (Fig. ). A beneficial effect of insulin therapy over oral anti-diabetic agents was also observed by Chen et al. [Figure: see text] A meta-analysis, including seven studies and 839 participants, further underscored the robustness of the evidence supporting STII therapy by showing that the proportion of patients in drug-free remission was 66.2% at 3 months, 58.9% at 6 months, 46.3% at 12 months, and 42.1% at 24 months. All but one study showed an improvement in β-cell function, as assessed by homeostatic model assessment of β-cell function (HOMA-B), and all but one study showed a decrease in insulin resistance, as assessed by homeostasis model assessment of insulin resistance (HOMA-IR). Therefore, STII has beneficial effects on both the fundamental pathophysiological mechanisms of T2DM (β-cell dysfunction and insulin resistance). Recent animal studies suggest a potential mechanism for such clinical benefits: β-cells dedifferentiate to endocrine progenitor-like cells during stress-induced hyperglycemia, and strictly normalizing blood glucose by insulin therapy could induce dedifferentiated cell redifferentiation to mature β-cells, and hence restoration of drug responsivity. In addition to its glucose-lowering activity, insulin may contribute to improved β-cell function by its antilipolytic, anti-inflammatory, and antiapoptotic effects. We recognized that not all newly diagnosed people with T2DM would experience improved β-cell function or achieve long-term remission following cessation of STII. It would be worthwhile to precisely identify the subpopulation more likely to benefit from this strategy. Previous studies have suggested that lower baseline fasting glucose, higher BMI, better early phase insulin secretion, and lower exogenous insulin requirements may be predictors of diabetes remission in newly diagnosed patients treated with STII therapy. A recent study demonstrated that a shorter duration of diabetes supplanted baseline HbA1c and β-cell function as an independent predictor of remission. In particular, diabetes duration <2 years predicted sustained remission, suggesting that the key determinant of inducing persistent drug-free diabetes remission with STII is early intervention. Although reluctance to initiate insulin treatment in T2DM is well described, it is interesting to see that when introduced early in the course of the disease as a short-term treatment, STII resulted in significant improvement in patient-reported quality of life and treatment satisfaction, demonstrating the patient acceptability of early insulin therapy. In our clinical experience, patients often request insulin resumption after a trial has ended because of the good clinical outcomes and the recognition that such treatment is much easier and better tolerated than expected. The pros and cons of STII therapy for new-onset T2DM patients with HbA1c >9%, based on current evidence and our understanding, are listed in Table . It is important that STII be considered an option at this early stage of the disease. Existing studies and clinical experience do indicate that this concept is very well received by patients and clinicians alike, especially when they realize that insulin only needs to be used for a few weeks, and that STII at that point in time does not necessarily require continuing long-term insulin therapy. Numerous public health, clinical efficacy and effectiveness, and cost-effectiveness questions need to be better understood before widespread adoption of this novel treatment regimen can be more endorsed. [Table: see text].

Is insulin the preferred treatment for HbA1c >9%?

The algorithms and guidelines of the American Association of Clinical Endocrinologists and the American Diabetes Association recommend that insulin administration be strongly considered for people with type 2 diabetes (T2D) with HbA1c levels exceeding 9.0% and 10%, respectively. Although the caveat is given in both sets of recommendations that this is particularly appropriate when patients are "symptomatic," referring to urinary frequency with increased thirst and appetite, weight loss, and ketosis, the clinical definition of such presentations may be ill-defined, and it is noteworthy that both documents consider insulin to offer particular benefit under such circumstances. However, with multiple options for glycemic treatment, it is of interest to reconsider this argument for insulin use. It should be recalled that in the UK Prospective Diabetes Study, diet alone was associated with a reduction in HbA1c from 9% to 7%. Drug-naïve people with T2D do often show surprisingly strong reductions in HbA1c with metformin-based dual-agent oral treatment approaches; a recent report showed that even with baseline HbA1c >11%, the combination of metformin with a sulfonylurea, pioglitazone, or sitagliptin was associated with reduction in HbA1c from 11.6% to 6.0%. A 32-week study of the combination of rosiglitazone with metformin in patients with mean baseline HbA1c 8.9% showed a mean HbA1c reduction of 2.3%, and an open-label cohort with baseline HbA1c 11.8% had a reduction in HbA1c to 7.8%. With metformin plus sitagliptin, a mean placebo-adjusted HbA1c reduction of 2.1% from a baseline of 8.8% was reported, with those patients with baseline HbA1c >9% having a 2.6% reduction in HbA1c, and an open-label cohort with baseline HbA1c 11.2% having a 2.9% reduction in HbA1c. Similar 2% HbA1c reductions from baseline levels of 9.1% were seen with metformin in initial combination with the sodium-glucose cotransporter 2 (SGLT2) inhibitor dapagliflozin. Although such dual oral agent approaches are more effective than monotherapy, with a combination regimen the HbA1c reduction will not be directly additive, because the expected reduction decreases at lower baseline HbA1c levels. As an example of this, administration of canagliflozin 300 mg daily to patients with baseline HbA1c >9% reduced levels from 9.6% by 1.8%, whereas at a baseline HbA1c of 10% either canagliflozin 300 mg or metformin 2 g/day reduced HbA1c by 2%; the addition of both agents led to an HbA1c reduction by somewhat less than 3%, which appears concordant with a reduction by the second agent from approximately 8% (10% to 2%). Similar less-than-additive effects of the addition of exenatide QW to dapagliflozin have been reported, with HbA1c reduction from a baseline of 10.0%-10.1% of 1.9% and 1.6% with the individual agents, respectively, and a reduction of 2.2% with their combination. However, one may consider these approaches inferior to the expected HbA1c reduction with insulin, suggesting that insulin should, indeed, be the preferred treatment for people with T2D and HbA1c >9%. Rather, studies comparing basal insulin directly with glucagon-like peptide-1 (GLP-1) receptor agonists (RA) suggest that the latter agents may offer superior benefit. The Diabetes Therapy Utilization: Researching Changes in HBA1C, Weight, and Other Factors Through Intervention with Exenatide Once Weekly (DURATION)-3 and Liraglutide Effect and Action in Diabetes (LEAD)-5 studies compared exenatide QW and liraglutide, respectively, with insulin glargine. Those study participants in the highest quartile of baseline HbA1c had levels ≥9.0% and ≥8.9%, with the GLP-1RA leading to 0.3% and 0.2% greater reductions in HbA1c, respectively, than insulin glargine. Another study comparing T2D patients receiving oral agents given liraglutide with those given insulin glargine showed that those in the highest baseline HbA1c quartile (mean 10.6%) had an HbA1c reduction of 3.1% with either agent. In the exenatide QW study, the reduction in HbA1c with this agent exceeded that with insulin glargine for those groups of study participants with HbA1c 9.0%-9.4%, 9.5%-9.9%, 10.0%-10.4%, 10.5%-10.9%, and even ≥11.0%. Similar superiority of the HbA1c-lowering effect of exenatide QW compared with that of insulin glargine was reported in a study with baseline HbA1c 8.5%. An individual-patient meta-analysis of six studies of another weekly GLP-1RA, namely dulaglutide, showed that at a baseline HbA1c of 10% the expected HbA1c reduction would be nearly 2.5%, and a study directly comparing dulaglutide with insulin glargine also showed a superior HbA1c-lowering effect of the former. Another advantage of the GLP-1RAs is their association with weight loss, rather than the weight gain associated with insulin treatment. An interesting potential combination is that of a GLP-1RA with a thiazolidinedione. In a study comparing the addition of exenatide QW and pioglitazone with the addition of basal-bolus insulin in 101 people receiving sulfonylureas and metformin with baseline HbA1c >10%, HbA1c fell from >11% by >4% compared with <4%, respectively, and the GLP-1RA plus thiazolidinedione treatment was associated with less weight gain and hypoglycemia. What can we conclude? Should HbA1c 11% be the new "use insulin" point? Insulin is an important part of our armamentarium for T2D, and is certainly needed for many patients, but with current therapeutic approaches including metformin, incretin-based treatments, SGLT2 inhibitors, and, possibly, thiazolidinediones, we can reconsider its use in many instances. Although there is no doubt that insulin is necessary for truly uncontrolled diabetes, we may wish to better define its correct indications.

Efficacy and safety of insulin-GLP-1 receptor agonists combination in type 2 diabetes mellitus: a systematic review

INTRODUCTION

Attaining optimal glycemic targets in patients with type 2 diabetes is often hard and compromised by the shortcomings of the several treatments. Areas covered: When glycemic levels are not adequately controlled, an association of GLP-1 receptor agonists and insulin therapy can be adopted. In order to assess the benefit/risk profile of this combination therapy, a literature search of randomized clinical trials was performed.Eighteen trials matched the inclusion criteria. In 10 studies, GLP-1 receptor agonists were added on to an existing regimen, whereas insulin added to an existing GLP-1 receptor agonists regimen occurred in 2 studies. Six studies compared GLP-1 receptor agonists with short acting insulin as a treatment strategy to intensify basal insulin therapy. Expert opinion: Clinical trials herein reviewed demonstrated the safety and the efficacy of combining GLP-1 receptor agonists with basal insulin, with most studies showing equal or slightly superior efficacy, as compared with the addition of prandial insulin, associated with weight loss and less hypoglycemia.