A Methodological Framework for Meta-analysis and Clinical Interpretation of Subgroup Data: The Case of Major Adverse Cardiovascular Events With GLP-1 Receptor Agonists and SGLT2 Inhibitors in Type 2 Diabetes

We present a methodological framework for conducting and interpreting subgroup meta-analyses. Methodological steps comprised evaluation of clinical heterogeneity regarding the definition of subpopulations, credibility assessment of subgroup meta-analysis, and translation of relative into absolute treatment effects. We used subgroup data from type 2 diabetes cardiovascular outcomes trials (CVOTs) with glucagon-like peptide 1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors for patients with established cardiovascular disease and those at high cardiovascular risk without manifest cardiovascular disease. First, we evaluated the variability in definitions of the subpopulations across CVOTs using major adverse cardiovascular events (MACE) incidence in the placebo arm as a proxy for baseline cardiovascular risk. As baseline risk did not differ considerably across CVOTs, we conducted subgroup meta-analyses of hazard ratios (HRs) for MACE and assessed the credibility of a potential effect modification. Results suggested using the same overall relative effect for each of the two subpopulations (HR 0.85, 95% CI 0.80-0.90, for GLP-1 receptor agonists and HR 0.91, 95% CI 0.85-0.97, for SGLT2 inhibitors). Finally, we calculated 5-year absolute treatment effects (number of fewer patients with event per 1,000 patients). Treatment with GLP-1 receptor agonists resulted in 30 fewer patients with event in the subpopulation with established cardiovascular disease and 14 fewer patients with event in patients without manifest cardiovascular disease. For SGLT2 inhibitors, the respective absolute effects were 18 and 8 fewer patients with event per 1,000 patients. This framework can be applied to subgroup meta-analyses regardless of outcomes or modification variables.

Comparison of tirzepatide and dulaglutide on major adverse cardiovascular events in participants with type 2 diabetes and atherosclerotic cardiovascular disease: SURPASS-CVOT design and baseline characteristics

BACKGROUND

Tirzepatide, a once-weekly GIP/GLP-1 receptor agonist, reduces blood glucose and body weight in people with type 2 diabetes. The cardiovascular (CV) safety and efficacy of tirzepatide have not been definitively assessed in a cardiovascular outcomes trial.

METHODS

Tirzepatide is being studied in a randomized, double-blind, active-controlled CV outcomes trial. People with type 2 diabetes aged ≥40 years, with established atherosclerotic CV disease, HbA1c ≥7% to ≤10.5%, and body mass index ≥25 kg/m2 were randomized 1:1 to once weekly subcutaneous injection of either tirzepatide up to 15 mg or dulaglutide 1.5 mg. The primary outcome is time to first occurrence of any major adverse cardiovascular event (MACE), defined as CV death, myocardial infarction, or stroke. The trial is event-driven and planned to continue until ≥1,615 participants experience an adjudication-confirmed component of MACE. The primary analysis is noninferiority for time to first MACE of tirzepatide vs dulaglutide by demonstrating an upper confidence limit <1.05, which will also confirm superiority vs a putative placebo, and also to determine whether tirzepatide produces a greater CV benefit than dulaglutide (superiority analysis).

RESULTS

Over 2 years, 13,299 people at 640 sites in 30 countries across all world regions were randomized. The mean age of randomized participants at baseline was 64.1 years, diabetes duration 14.7 years, HbA1c 8.4%, and BMI 32.6 kg/m2. Overall, 65.0% had coronary disease, of whom 47.3% reported prior myocardial infarction and 57.4% had prior coronary revascularization. 19.1% of participants had a prior stroke and 25.3% had peripheral artery disease. The trial is fully recruited and ongoing.

CONCLUSION

SURPASS-CVOT will provide definitive evidence as to the CV safety and efficacy of tirzepatide as compared with dulaglutide, a GLP-1 receptor agonist with established CV benefit.

Prospective External Validation of an Algorithm Predicting Hourly Basal Insulin Infusion Rates from Characteristics of Patients with Type 1 Diabetes Treated with Insulin Pumps

BACKGROUND

We previously published an algorithm predicting 24 h basal insulin infusion profiles in insulin pump-treated subjects with type 1 diabetes profiles from six subject characteristics. This algorithm was to be externally validated in an independent environment and patient population.

METHODS

Thirty-two patients with pump-treated type diabetes were switched to their individually algorithm-derived basal insulin infusion profile, and the appropriateness of fasting glycemic control was scrutinized by means of a supervised 24 h fast. Primary endpoint was appropriate fasting glycemic control according to pre-defined criteria in at least 80% of the cohort.

RESULTS

In 24 out of 32 patients switching to the algorithm-derived basal insulin infusion rate and undergoing a 24-h fasting period, appropriate glycemic control was achieved (=75%, lower than the pre-defined threshold of 80%), two patients discontinued the fast due to hyperglycemia, and six finished the fasting period, however, with inappropriate fasting glycemic control (entirely due to hyperglycemic episodes). There were no obvious differences in baseline characteristics between those with appropriate vs. inappropriate fasting glycemic control on the basal insulin infusion rate provided by the algorithm.

CONCLUSION

In conclusion, when testing fasting glycemic control with an algorithm-derived individual basal insulin infusion profile during a 24 h fasting period in a cohort unrelated in terms of the hospital environment and catchment area, the success rate was lower than a pre-defined threshold for concluding utility of this algorithm. Therefore, applying this algorithm in order to initiate or optimize basal insulin infusion profiles in type 1 diabetes cannot be generally recommended.

Incretin hormones and type 2 diabetes

Incretin hormones (glucose-dependent insulinotropic polypeptide [GIP] and glucagon-like peptide-1 [GLP-1]) play a role in the pathophysiology of type 2 diabetes. Along with their derivatives they have shown therapeutic success in type 2 diabetes, with the potential for further improvements in glycaemic, cardiorenal and body weight-related outcomes. In type 2 diabetes, the incretin effect (greater insulin secretory response after oral glucose than with 'isoglycaemic' i.v. glucose, i.e. with an identical glycaemic stimulus) is markedly reduced or absent. This appears to be because of a reduced ability of GIP to stimulate insulin secretion, related either to an overall impairment of beta cell function or to specific defects in the GIP signalling pathway. It is likely that a reduced incretin effect impacts on postprandial glycaemic excursions and, thus, may play a role in the deterioration of glycaemic control. In contrast, the insulinotropic potency of GLP-1 appears to be much less impaired, such that exogenous GLP-1 can stimulate insulin secretion, suppress glucagon secretion and reduce plasma glucose concentrations in the fasting and postprandial states. This has led to the development of incretin-based glucose-lowering medications (selective GLP-1 receptor agonists or, more recently, co-agonists, e.g. that stimulate GIP and GLP-1 receptors). Tirzepatide (a GIP/GLP-1 receptor co-agonist), for example, reduces HbA1c and body weight in individuals with type 2 diabetes more effectively than selective GLP-1 receptor agonists (e.g. semaglutide). The mechanisms by which GIP receptor agonism may contribute to better glycaemic control and weight loss after long-term exposure to tirzepatide are a matter of active research and may change the pessimistic view that developed after the disappointing lack of insulinotropic activity in people with type 2 diabetes when exposed to GIP in short-term experiments. Future medications that stimulate incretin hormone and other receptors simultaneously may have the potential to further increase the ability to control plasma glucose concentrations and induce weight loss.

Impact of concomitant oral glucose-lowering medications on the success of basal insulin titration in insulin-naïve patients with type 2 diabetes: a systematic analysis

Basal insulin treatment for type 2 diabetes is usually initiated on a background of oral glucose-lowering medications (OGLM). We wanted to examine the influence of various OGLMs on fasting plasma glucose (FPG) and hemoglobin A_1c (HbA_1c) values achieved after titration. A PubMed literature search retrieved 42 publications (clinical trials introducing basal insulin in 17 433 insulin-naïve patients with type 2 diabetes on a defined background of OGLM) and reporting FPG, HbA_1c, target achievement, hypoglycemic events, and insulin doses. 60 individual study arms were grouped by OGLM (combinations) allowed during the titration process: (a) metformin only; (b) sulfonylureas only; (c) metformin and sulfonylureas; or (d) metformin and dipeptidyl peptidase-4 (DPP-4) inhibitors. For all OGLM categories, weighted means and SD were calculated for baseline and end-of-treatment FPG, HbA_1c, target achievement, incidence of hypoglycemic events, and insulin doses. Primary end point was a difference in FPG after titration between OGLM categories. Statistics: analysis of variance and post hoc comparisons. Sulfonylureas, alone or in combination with metformin, impair the titration of basal insulin (insulin doses 30%-40% lower, more hypoglycemic episodes), thus leading to poorer final glycemic control (p<0.05 for FPG and HbA_1c after titration). Conversely, adding a DPP-4 inhibitor to metformin is superior to metformin alone (p<0.05 for FPG and HbA_1c achieved) in patients with type 2 diabetes initiating basal insulin therapy. In conclusion, OGLM are a major determinant of the success of basal insulin therapy. Sulfonylureas impair, while DPP-4 inhibitors (added to metformin) may facilitate the achievement of ambitious fasting glucose targets. PROSPERO registration number CRD42019134821.

Characteristics predicting the efficacy of SGLT-2 inhibitors versus GLP-1 receptor agonists on major adverse cardiovascular events in type 2 diabetes mellitus: a meta-analysis study

BACKGROUND

Recent large clinical trials have demonstrated cardiovascular benefits of similar overall magnitude for sodium-glucose cotransporter-2 inhibitor (SGLT-2i) and glucagon-like peptide-1 receptor agonist (GLP-1RA) therapy in subjects with type 2 diabetes. We sought to identify subgroups based on baseline characteristics with a differential response to either SGLT-2i or GLP-1RA.

METHODS

PubMed, Cochrane CENTRAL, and EMBASE were searched from 2008 to 2022 for SGLT-2i or GLP-1RA randomized trials that reported 3-point major adverse cardiovascular events (3P-MACE). Baseline clinical and biochemical characteristics included age, sex, body mass index (BMI), HbA1c, estimated glomerular filtration rate (eGFR), albuminuria, preexisting cardiovascular disease (CVD), and heart failure (HF). Absolute and relative risk reductions (ARR and RRR) regarding incidence rates for 3P-MACE with a 95% confidence interval were calculated. The association of average baseline characteristics in each study with the ARR and RRR for 3P-MACE was investigated by meta-regression analyses (random-effects model, assuming inter-study heterogeneity). Meta-analysis was also conducted to investigate whether the efficacy of SGLT-2i or GLP-1RA on 3P-MACE reduction could differ according to the patient's characteristics (e.g., HbA1c above/below cutoff).

RESULTS

After a critical assessment of 1,172 articles, 13 cardiovascular outcome trials with a total of 111,565 participants were selected. In meta-regression analysis, the more patients with reduced eGFR in the studies, the greater ARR by SGLT-2i or GLP-1RA therapy. Similarly, in the meta-analysis, SGLT-2i therapy tended to be more effective in reducing 3P-MACE in people with eGFR < 60 ml/min/1.73 m² than in those with normal renal function (ARR - 0.90 [-1.44 to - 0.37] vs. - 0.17 [-0.34 to - 0.01] events/100 person-years). Furthermore, people with albuminuria tended to respond better to SGLT-2i therapy than those with normoalbuminuria. However, this was not the case for the GLP-1RA treatment. Other factors including age, sex, BMI, HbA1c, and preexisting CVD or HF did not affect the efficacy of either SGLT-2i or GLP-1RA treatment on the ARR or RRR of 3P-MACE.

CONCLUSIONS

Because decreased eGFR [significant] and albuminuria [trend] were found to predict a better efficacy for SGLT-2i in 3P-MACE reduction, this class of drug should be preferred in such patients. However, GLP-1RA may be considered for patients with normal eGFR because it showed better efficacy than SGLT-2i in this subgroup [trend].

Gut hormone co-agonists for the treatment of obesity: from bench to bedside

The discovery and development of so-called gut hormone co-agonists as a new class of drugs for the treatment of diabetes and obesity is considered a transformative breakthrough in the field. Combining action profiles of multiple gastrointestinal hormones within a single molecule, these novel therapeutics achieve synergistic metabolic benefits. The first such compound, reported in 2009, was based on balanced co-agonism at glucagon and glucagon-like peptide-1 (GLP-1) receptors. Today, several classes of gut hormone co-agonists are in development and advancing through clinical trials, including dual GLP-1-glucose-dependent insulinotropic polypeptide (GIP) co-agonists (first described in 2013), and triple GIP-GLP-1-glucagon co-agonists (initially designed in 2015). The GLP-1-GIP co-agonist tirzepatide was approved in 2022 by the US Food and Drug Administration for the treatment of type 2 diabetes, providing superior HbA1c reductions compared to basal insulin or selective GLP-1 receptor agonists. Tirzepatide also achieved unprecedented weight loss of up to 22.5%-similar to results achieved with some types of bariatric surgery-in non-diabetic individuals with obesity. In this Perspective, we summarize the discovery, development, mechanisms of action and clinical efficacy of the different types of gut hormone co-agonists, and discuss potential challenges, limitations and future developments.

Meta-analysis of head-to-head clinical trials comparing incretin-based glucose-lowering medications and basal insulin: An update including recently developed glucagon-like peptide-1 (GLP-1) receptor agonists and the glucose-dependent insulinotropic polypeptide/GLP-1 receptor co-agonist tirzepatide

OBJECTIVE

To assess comparative efficacy, safety and tolerability of injectable incretin-based glucose-lowering medications (IBGLMs) versus basal insulin treatment in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We performed an updated meta-analysis of randomized clinical trials of head-to-head comparisons of IBGLMs (short- and long-acting glucagon-like peptide-1 [GLP-1] receptor agonists [GLP-1RAs] and glucose-dependent insulinotropic polypeptide [GIP]/GLP-1 receptor co-agonist tirzepatide) versus basal insulin using a PubMed database search (April 2022). The primary endpoint was difference in reduction of glycated haemoglobin (HbA_1c ) versus baseline between pooled IBGLMs (fixed-effects meta-analysis) and their subgroups (random-effects meta-analysis) versus basal insulin treatment (mean differences). Secondary endpoints were fasting plasma glucose, body weight, HbA_1c target achievement, hypoglycaemia, blood pressure and lipids. Risk of bias assessment was performed using Jadad scores and the Risk of Bias tool 2.0.

RESULTS

In all, 20 studies, representing 47 study arms and 11 843 patients, were eligible. Compared with basal insulin, IGBLMs lowered HbA_1c by 0.48 (0.45-0.52)% more than did basal insulin treatment. This effect was driven by pooled long-acting GLP-1RAs (ΔHbA_1c -0.25 [-0.38; -0.11]%) and the only GIP/GLP-1 receptor co-agonist, tirzepatide (pooled doses; ΔHbA_1c -0.90 [-1.06; -0.75]%), while short-acting GLP-1RAs were equally effective compared with basal insulin (P = 0.90). All IBGLM subgroups achieved significantly lower body weight versus insulin treatment (-4.6 [-4.7; -4.4] kg), in particular tirzepatide (-12.0 [-13.8; -10.1] kg). IBGLMs significantly reduced hypoglycaemia and blood pressure and improved lipid variables. Risk of bias was low. IBGLM treatment was associated with more nausea, vomiting and diarrhoea and study medication discontinuation.

CONCLUSIONS

Recently introduced, highly effective IBGLMs were superior to basal insulin treatment, reinforcing the recommendation that IBGLMs should be considered as the first injectable treatment for most patients with type 2 diabetes.

Comparison of Insulin-Treated Patients with Ambiguous Diabetes Type with Definite Type 1 and Type 2 Diabetes Mellitus Subjects: A Clinical Perspective

In clinical practice, the distinction between type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) can be challenging, leaving patients with "ambiguous" diabetes type. Insulin-treated patients (n=115) previously diagnosed with T2DM had to be re-classified based on clinical phenotype and laboratory results, and were operationally defined as having an ambiguous diabetes type. They were compared against patients with definite T1DM and T2DM regarding 12 clinical and laboratory features typically different between diabetes types. Characteristics of patients with ambiguous diabetes type, representing approximately 6% of all patients with T1DM or T2DM seen at our specialized clinic, fell in between those of patients with definite T1DM and T2DM, both regarding individual features and with respect to a novel classification based on multi-variable regression analysis (P<0.0001). In conclusion, a substantial proportion of diabetes patients in a tertiary care centre presented with an "ambiguous" diabetes type. Their clinical characteristics fall in between those of definite T1DM or T2DM patients.

Statistical power for MACE and individual secondary endpoints in cardiovascular outcomes trials for type 2 diabetes: a systematic review

Cardiovascular outcomes trials (CVOTs) with novel drugs to treat type 2 diabetes have uniformly chosen the composite "major adverse cardiovascular events (MACE)" as their primary endpoint, but they also report hazard ratios for individual cardiovascular outcomes (myocardial infarction, stroke, cardiovascular death, all-cause death, hospitalization for heart failure). We wanted to scrutinize the power to identify significant differences with respect to individual as compared to composite outcomes. We estimated post hoc the statistical power to detect significant differences of 10-25% for published studies, comparing the proportions of patients with an event (two-sided log-rank tests). For MACE, the power to detect a 15% difference ranged from 82.3 to 100.0% for larger trials, but was only 69.1 and 50.5 for smaller, preliminary trials (SUSTAIN-6 and PIONEER-6). For individual endpoints, the power, as a rule, was substantially lower. In conclusion, cardiovascular outcomes trials had appropriate power to detect significant reductions in hazard ratios with respect to the primary endpoint, but not for individual cardiovascular outcomes. This was particularly the case for small, preliminary studies. Our results call for caution when comparing results regarding individual endpoints between CVOTs, if the aim is to identify heterogeneity within or between medication classes.

Measurement of Gastric Emptying Using a 13C-octanoic Acid Breath Test with Wagner-Nelson Analysis and Scintigraphy in Type 2 Diabetes

INTRODUCTION

Breath tests utilising ¹³C-labelled substrates for the assessment of gastric emptying have been applied widely. Wagner-Nelson analysis is a pharmacokinetic model that can be utilised to generate a gastric emptying curve from the % ¹³CO₂ measured in breath samples. We compared Wagner-Nelson analysis with (i) scintigraphy and (ii) conventional breath test modelling to quantify gastric emptying in type 2 diabetes.

METHODS

Thirteen patients (age 68.1±1.5 years, body mass index 31.0±0.9 kg/m², HbA1c 6.3±0.2%) consumed a mashed potato meal comprising 65 g powdered potato, 20 g glucose, 250 ml water, an egg yolk labelled with 100 μL ¹³C-octanoic acid and 20MBq ^99mTc-calcium phytate. Scintigraphic data were acquired and breath samples collected for 4 hours after the meal. Gastric emptying curves were derived based on each technique; the 50% emptying time and intragastric retention at 60 min were also calculated.

RESULTS

With Wagner-Nelson analysis, a K_el=0.60 (the elimination constant) best approximated the scintigraphic gastric emptying curve. There was a relationship between the T50 calculated with scintigraphy and by both Wagner-Nelson K_el=0.60 (r²=0.45, P<0.05) and conventional analysis (r²=0.44, P<0.05). There was no significant difference in the 50% gastric emptying time for scintigraphy (68.5±4.8 min) and Wagner-Nelson K_el=0.60 (71.3±4.5 min), however, the 50% gastric emptying time calculated by conventional analysis was much greater at 164.7±6.0 min (P<0.001).

CONCLUSION

In type 2 diabetes, gastric emptying of a mashed potato meal measured using a ¹³C-octanoic acid breath test analysed with Wagner-Nelson K_el=0.60 closely reflects measurements obtained with scintigraphy, whereas, in absolute terms, the conventional breath test analysis does not.

Tirzepatide, a dual GIP/GLP-1 receptor co-agonist for the treatment of type 2 diabetes with unmatched effectiveness regrading glycaemic control and body weight reduction

Tirzepatide is the first dual GIP/GLP-1 receptor co-agonist approved for the treatment of type 2 diabetes in the USA, Europe, and the UAE. Tirzepatide is an acylated peptide engineered to activate the GIP and GLP-1 receptors, key mediators of insulin secretion that are also expressed in regions of the brain that regulate food intake. Five clinical trials in type 2-diabetic subjects (SURPASS 1–5) have shown that tirzepatide at 5–15 mg per week reduces both HbA_1c (1.24 to 2.58%) and body weight (5.4–11.7 kg) by amounts unprecedented for a single agent. A sizable proportion of patients (23.0 to 62.4%) reached an HbA_1c of < 5.7% (which is the upper limit of the normal range indicating normoglycaemia), and 20.7 to 68.4% lost more than 10% of their baseline body weight. Tirzepatide was significantly more effective in reducing HbA_1c and body weight than the selective GLP-1 RA semaglutide (1.0 mg per week), and titrated basal insulin. Adverse events related to tirzepatide were similar to what has been reported for selective GLP-1RA, mainly nausea, vomiting, diarrhoea, and constipation, that were more common at higher doses. Cardiovascular events have been adjudicated across the whole study program, and MACE-4 (nonfatal myocardial infarction, non-fatal stroke, cardiovascular death and hospital admission for angina) events tended to be reduced over up to a 2 year-period, albeit with low numbers of events. For none of the cardiovascular events analysed (MACE-4, or its components) was a hazard ratio > 1.0 vs. pooled comparators found in a meta-analysis covering the whole clinical trial program, and the upper bounds of the confidence intervals for MACE were < 1.3, fulfilling conventional definitions of cardiovascular safety. Tirzepatide was found to improve insulin sensitivity and insulin secretory responses to a greater extent than semaglutide, and this was associated with lower prandial insulin and glucagon concentrations. Both drugs caused similar reductions in appetite, although tirzepatide caused greater weight loss. While the clinical effects of tirzepatide have been very encouraging, important questions remain as to the mechanism of action. While GIP reduces food intake and body weight in rodents, these effects have not been demonstrated in humans. Moreover, it remains to be shown that GIPR agonism can improve insulin secretion in type 2 diabetic patients who have been noted in previous studies to be unresponsive to GIP. Certainly, the apparent advantage of tirzepatide, a dual incretin agonist, over GLP-1RA will spark renewed interest in the therapeutic potential of GIP in type 2 diabetes, obesity and related co-morbidities.

SGLT-2 inhibitors and GLP-1 receptor agonists in metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a chronic condition that affects nearly one billion people globally, characterized by triacylglycerol accumulation in the liver as a consequence of metabolic abnormalities (obesity and impaired glucose regulation). Low-grade inflammation, oxidative stress, mitochondrial dysfunction, and dysbiosis in gut microbiota are involved in the etiology of MAFLD, and both cardiovascular events and hepatic complications are the long-term consequences. In the absence of approved therapies for this condition, sodium-glucose cotransporter 2 inhibitors (SGLT-2 Is) and glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have the specific advantage of lowering body weight and providing cardiovascular benefits. Here, we discuss potential roles for SGLT-2 Is and GLP-1 RAs in the prevention and treatment of intrahepatic triacylglycerol accumulation and associated inflammation and/or fibrosis.

Acute effects of linagliptin on intact and total glucagon-like peptide-1 and gastric inhibitory polypeptide levels in insulin-dependent type 2 diabetes patients with and without moderate renal impairment

AIMS

To investigate the effect of renal impairment on incretin metabolism in patients with type 2 diabetes mellitus (T2DM) before and after treatment with the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin.

MATERIALS AND METHODS

Long-standing T2DM patients with normal (estimated glomerular filtration rate [eGFR] >90 mL/min/1.73m² ) and impaired (eGFR <60 mL/min/1.73m² ) renal function on stable treatment with insulin were included. Before and after 8 days of treatment with 5 mg linagliptin once daily, patients underwent a 75-g oral glucose tolerance test (OGTT) and total and intact glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP), glucose, insulin, C-peptide and glucagon concentrations were measured. The primary outcome was the difference between the study groups in change of intact GLP-1 concentrations.

RESULTS

Of 115 patients screened, 29 were analysed (15 [51.7%] with and 14 [48.3%] without renal impairment). Renal function differed significantly between the groups (101 ± 11 vs. 47 ± 13 mL/min/1.73m² ; P < 0.0001), while glycaemic control was similar (glycated haemoglobin 68 ±  5 vs. 66 ± 5 mmol/mol; P = 0.45). Baseline GLP-1 and GIP levels were comparable. Glucose concentrations during the OGTT were significantly lowered by linagliptin treatment in patients with renal impairment (P = 0.017), but not in those with normal renal function (P = 0.17). Treatment with linagliptin resulted in a significant increase in intact GLP-1 and GIP levels in patients with normal (P = 0.048 and P = 0.0001, respectively) and impaired (P = 0.040 and P = 0.0011, respectively) renal function during the OGTT. However, the primary outcome (difference between the groups in change of intact GLP-1 concentrations) was not significant (P = 0.22). Overall, linagliptin was well tolerated.

CONCLUSIONS

Treatment with linagliptin increases intact incretin levels in patients with T2DM. Impaired renal function does not compromise the effects of linagliptin on active or total incretin levels as well as on glucagon secretion. Thus, treatment with linagliptin is suitable for patients with T2DM, independently of renal function.

Consensus report: Definition and interpretation of remission in type 2 diabetes

Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks versus benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed "remission" as the most appropriate descriptive term, and HbA1c <6.5% (48 mmol/mol) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.

Impact of the Fasting Plasma Glucose Titration Target on the Success of Basal Insulin Titration in Insulin-Naïve Patients with Type 2 Diabetes: A Systematic Analysis

BACKGROUND/AIM

We aimed to examine beneficial and adverse outcomes of basal insulin titration performed with different fasting plasma glucose (FPG) titration targets (TT).

METHODS

A PubMed literature search retrieved 43 reported prospective clinical trials introducing basal insulin in 17643 insulin-naïve patients with type 2 diabetes reporting fasting plasma glucose (FPG), HbA_1c, target achievement, hypoglycemic events, and insulin doses. 61 individual study arms were grouped by fasting plasma glucose titration target (TT; 1: ≤5.0 mmol/l/90 mg/dl; 2: 5.01-5.6 mmol/l/90-100 mg/dl; and 3: ≥5.61 mmol/l/101 mg/dl). Weighted means and their standard deviations were calculated for baseline and end-of-treatment FPG (primary endpoint), HbA_1c, target achievement, hypoglycemic events, insulin doses, and body weight gain and compared over a duration of 31 ± 10 weeks.

RESULTS

Achieved FPG and HbA_1c at the end of the study were significantly lower (by up to 0.8 mmol/l or 0.23%, respectively) with more ambitious TTs (p < 0.0001), leading to better HbA_1c target achievement with more ambitious TTs (by up to 14.6% for HbA_1c ≤ 6.5%), without increasing the risk for hypoglycemic episodes.

CONCLUSIONS

Aiming for a lower FPG TT improves glycemic control without increasing the risk for hypoglycemia.

Consensus Report: Definition and Interpretation of Remission in Type 2 Diabetes

Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks versus benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed "remission" as the most appropriate descriptive term, and HbA1c < 6.5% (48 mmol/mol) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.

Effect of the Glucagon-like Peptide-1 Receptor Agonists Semaglutide and Liraglutide on Kidney Outcomes in Patients With Type 2 Diabetes: a Pooled Analysis of SUSTAIN 6 and LEADER Trials

Background: We assessed the effect of once-weekly semaglutide and once-daily liraglutide on kidney outcomes in type 2 diabetes (T2D). Methods: Pooled (N=12,637) and by-trial data from SUSTAIN 6 (N=3297) and LEADER (N=9340) were assessed for albuminuria change, annual slope of estimated glomerular filtration rate (eGFR) change, and time to persistent eGFR reduction (30%, 40%, 50%, and 57%) from baseline. Results: The median follow-up durations were 2.1 and 3.8 years for SUSTAIN 6 and LEADER, respectively. In the pooled analysis, semaglutide/liraglutide lowered albuminuria from baseline to 2 years post-randomization by 24% versus placebo (95% confidence interval [CI] [20%,27% ], p<0.001). Significant reductions were also observed in by-trial data analyses (p<0.001 for all), the largest being with semaglutide 1.0 mg: 33% (95% CI [24%,40% ], p<0.001) at 2 years. With semaglutide 1.0 mg and liraglutide, eGFR slope decline was significantly slowed by 0.87 and 0.26 mL/min/1.73 m²/year (p<0.0001 and p<0.001), respectively, versus placebo. Effects appeared larger in those with baseline eGFR <60 versus ≥60 mL/min/1.73m² (p_interaction=0.06 and 0.008 for semaglutide 1.0 mg and liraglutide, respectively). Semaglutide/liraglutide significantly lowered risk of persistent 40% and 50% eGFR reductions versus placebo (hazard ratio [HR] 0.86, 95% CI [0.75,0.99], p=0.039, and HR 0.80, 95% CI [0.66,0.97], p=0.023, respectively). Similar, non-significant, directional results were observed for 30% and 57% eGFR reductions (HR 0.92, 95% CI [0.84, 1.02], p=0.10, and HR 0.89, 95% CI [0.69, 1.13], p=0.34). In those with baseline eGFR 30-<60mL/min/1.73m², the likelihood of persistent reduction for all thresholds was increased, ranging from a HR 0.71 for 30% reduction (95% CI [0.59,0.85], p=0.0003, pinteraction=0.017) to 0.54 for 57% reduction (95% CI [0.36,0.81], p=0.003, pinteraction=0.035). Conclusions: In patients with T2D, semaglutide/liraglutide offered kidney-protective effects, which appeared more pronounced in those with pre-existing chronic kidney disease.

Patients with Type 1 Diabetes Treated with Insulin Pumps Need Widely Heterogeneous Basal Rate Profiles Ranging from Negligible to Pronounced Diurnal Variability

BACKGROUND

Pump-treated patients with type 1 diabetes have widely differing basal insulin infusion profiles. We analyzed consequences of such heterogeneity for glycemic control under fasting conditions.

METHODS

Data from 339 adult patients with type 1 diabetes on insulin pump therapy undergoing a 24-hour fast (basal rate test) were retrospectively analyzed. Hourly programmed basal insulin infusion rates and plasma glucose concentrations as well as their proportions within, below, or above arbitrarily defined target ranges were assessed for specific periods of the day (eg, 1-7 hours, "dawn" period, 16-19 hours, "dusk" period, reference period 20-1 hours/10-14 hours), by tertiles of a predefined "dawn" index (mean basal insulin infusion rate during the "dawn" divided by the reference periods).

RESULTS

The "dawn" index varied interindividually from 0.7 to 4.4. Basal insulin infusion profiles exhibited substantial differences (P = .011), especially overnight. Despite higher insulin infusion rates at 4 and 6.45 hours, patients with the most pronounced "dawn" phenomenon exhibited higher plasma glucose concentrations at those time points (P < .012). Patients with a marked "dawn" phenomenon exhibited a lower probability for low (<4.4 mmol/L) and a higher probability of high values (>7.2 mmol/L) during the dawn period (all P values <.01).

CONCLUSIONS

We observe substantial interindividual heterogeneity in the "dawn" phenomenon. However, widely different empirically derived basal insulin infusion profiles appear appropriate for individual patients, as indicated by similar plasma glucose concentrations, mainly in the target range, during a 24-hour fasting period.

Consensus report: definition and interpretation of remission in type 2 diabetes

Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks vs benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed 'remission' as the most appropriate descriptive term, and HbA_1c <48 mmol/mol (6.5%) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.

Prediction of Individual Basal Rate Profiles From Patient Characteristics in Type 1 Diabetes on Insulin Pump Therapy

BACKGROUND

Basal rate profiles in patients with type 1 diabetes on insulin pump therapy are subject to enormous inter-individual heterogeneity. Tools to predict basal rates based on clinical characteristics may facilitate insulin pump therapy.

METHODS

Data from 339 consecutive in-patients with adult type 1 diabetes on insulin pump therapy were collected. Basal rate tests were performed over 24 hours. A mathematical algorithm to predict individual basal rate profiles was generated by relating the individual insulin demand to selected clinical characteristics in an exploratory cohort of 170 patients. The predicted insulin pump profiles were validated in a confirmatory cohort of 169 patients.

FINDINGS

Basal rates (0.27 ± 0.01 IU.d^-1.kg^-1) showed circadian variations with peaks corresponding to the "dawn" and "dusk" phenomena. Age, gender, duration of pump treatment, body-mass-index, HbA_1c, and triacylglycerol concentrations largely predicted the individual basal insulin demand per day (IU/d; exploratory vs prospective cohorts: r² = 0.518, P < .0001). Model-predicted and actual basal insulin rates were not different (exploratory cohort: Δ 0.1 (95% CI -0.9; 1.0 U/d; P = .95; prospective cohort: Δ -0.5 (95% CI -1.5; 0.6 IU/d; P = .46). Similarly, precise predictions were possible for each hour of the day. Actual and predicted "dawn" index correlated significantly in the exploratory but not in the confirmatory cohort.

INTERPRETATION

Clinical characteristics predict 52% of the variation in individual basal rate profiles, including their diurnal fluctuations. The multivariate regression model can be used to initiate or optimize insulin pump treatment in patients with type 1 diabetes.

Macronutrient intake, appetite, food preferences and exocrine pancreas function after treatment with short- and long-acting glucagon-like peptide-1 receptor agonists in type 2 diabetes

AIM

To clarify the distinct effects of a long-acting (liraglutide) and a short-acting (lixisenatide) glucagon-like peptide-1 receptor agonist (GLP-1 RA) on macronutrient intake, gastrointestinal side effects and pancreas function.

MATERIALS AND METHODS

Fifty participants were randomized to either lixisenatide or liraglutide for a treatment period of 10 weeks. Appetite, satiety, macronutrient intake, gastrointestinal symptoms and variables related to pancreatic function and gastric emptying were assessed at baseline and after treatment.

RESULTS

Both GLP-1 RAs reduced macronutrient intake similarly. Weight loss and appetite reduction were not related to the delay in gastric emptying or gastrointestinal side effects (P > .05). Lipase increased significantly with liraglutide treatment (by 18.3 ± 4.1 U/L; P = .0001), but not with lixisenatide (-1.8 ± 2.4 U/L; P = .46). Faecal elastase and serum ß-carotin levels (indicators for exocrine pancreas function) improved in both groups (P < .05). Changes in lipase activities did not correlate with gastrointestinal symptoms (P > .05 for each variable).

CONCLUSIONS

Both GLP-1 RAs comparably affected body weight, energy and macronutrient intake. Both treatments were associated with indicators of improved exocrine pancreas function. Reductions in appetite and body weight as a result of treatment with short- or long-acting GLP-1 RAs are not driven by changes in gastric emptying or gastrointestinal side effects.

The evolving story of incretins (GIP and GLP-1) in metabolic and cardiovascular disease: A pathophysiological update

The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) have their main physiological role in augmenting insulin secretion after their nutrient-induced secretion from the gut. A functioning entero-insular (gut-endocrine pancreas) axis is essential for the maintenance of a normal glucose tolerance. This is exemplified by the incretin effect (greater insulin secretory response to oral as compared to "isoglycaemic" intravenous glucose administration due to the secretion and action of incretin hormones). GIP and GLP-1 have additive effects on insulin secretion. Local production of GIP and/or GLP-1 in islet α-cells (instead of enteroendocrine K and L cells) has been observed, and its significance is still unclear. GLP-1 suppresses, and GIP increases glucagon secretion, both in a glucose-dependent manner. GIP plays a greater physiological role as an incretin. In type 2-diabetic patients, the incretin effect is reduced despite more or less normal secretion of GIP and GLP-1. While insulinotropic effects of GLP-1 are only slightly impaired in type 2 diabetes, GIP has lost much of its acute insulinotropic activity in type 2 diabetes, for largely unknown reasons. Besides their role in glucose homoeostasis, the incretin hormones GIP and GLP-1 have additional biological functions: GLP-1 at pharmacological concentrations reduces appetite, food intake, and-in the long run-body weight, and a similar role is evolving for GIP, at least in animal studies. Human studies, however, do not confirm these findings. GIP, but not GLP-1 increases triglyceride storage in white adipose tissue not only through stimulating insulin secretion, but also by interacting with regional blood vessels and GIP receptors. GIP, and to a lesser degree GLP-1, play a role in bone remodelling. GLP-1, but not GIP slows gastric emptying, which reduces post-meal glycaemic increments. For both GIP and GLP-1, beneficial effects on cardiovascular complications and neurodegenerative central nervous system (CNS) disorders have been observed, pointing to therapeutic potential over and above improving diabetes complications. The recent finding that GIP/GLP-1 receptor co-agonists like tirzepatide have superior efficacy compared to selective GLP-1 receptor agonists with respect to glycaemic control as well as body weight has renewed interest in GIP, which previously was thought to be without any therapeutic potential. One focus of this research is into the long-term interaction of GIP and GLP-1 receptor signalling. A GLP-1 receptor antagonist (exendin [9-39]) and, more recently, a GIP receptor agonist (GIP [3-30] NH₂ ) and, hopefully, longer-acting GIP receptor agonists for human use will be helpful tools to shed light on the open questions. A detailed knowledge of incretin physiology and pathophysiology will be a prerequisite for designing more effective incretin-based diabetes drugs.

Consensus Report: Definition and Interpretation of Remission in Type 2 Diabetes

Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks versus benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed "remission" as the most appropriate descriptive term, and HbA1c <6.5% (48 mmol/mol) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.

Treatment of type 2 diabetes: challenges, hopes, and anticipated successes

Despite the successful development of new therapies for the treatment of type 2 diabetes, such as glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose cotransporter-2 inhibitors, the search for novel treatment options that can provide better glycaemic control and at reduce complications is a continuous effort. The present Review aims to present an overview of novel targets and mechanisms and focuses on glucose-lowering effects guiding this search and developments. We discuss not only novel developments of insulin therapy (eg, so-called smart insulin preparation with a glucose-dependent mode of action), but also a group of drug classes for which extensive research efforts have not been rewarded with obvious clinical impact. We discuss the potential clinical use of the salutary adipokine adiponectin and the hepatokine fibroblast growth factor (FGF) 21, among others. A GLP-1 peptide receptor agonist (semaglutide) is now available for oral absorption, and small molecules activating GLP-1 receptors appear on the horizon. Bariatric surgery and its accompanying changes in the gut hormonal milieu offer a background for unimolecular peptides interacting with two or more receptors (for GLP-1, glucose-dependent insulinotropic polypeptide, glucagon, and peptide YY) and provide more substantial glycaemic control and bodyweight reduction compared with selective GLP-1 receptor agonists. These and additional approaches will help expand the toolbox of effective medications needed for optimising the treatment of well delineated subgroups of type 2 diabetes or help develop personalised approaches for glucose-lowering drugs based on individual characteristics of our patients.

Long COVID - metabolic risk factors and novel therapeutic management

Cardiometabolic conditions, including type 1 and type 2 diabetes mellitus, are associated with severe COVID-19 and long COVID. Interventions to target multiple risk factors, combined with use of novel glucose-lowering agents that improve metabolic function and the key processes that are impaired in COVID-19, should be the preferred therapeutic options for management of people with long COVID.

Unklare Lymphadenopathie mit Panzytopenie bei einer Patientin mit rezidivierenden Hypoglykämien

Eine Patientin wurde aufgrund rezidivierender postprandialer Hypoglykämien nach Roux-en-Y-Magenbypass mit Diazoxid behandelt, nachdem eine Ernährungsumstellung keine Symptomlinderung erzielt hatte. Nach Eindosierung von Diazoxid mit guter Akutverträglichkeit wurde die Patientin entlassen. Eine Woche nach Therapieeinleitung kam es zu einer Lymphadenopathie und Panzytopenie. Es fanden sich keine Hinweise auf das Vorliegen eines Infekts. Nach Absetzen von Diazoxid sistierten die Beschwerden. Unser Fallbericht weist auf seltene unerwünschte hämatologische Arzneimittelwirkungen unter Diazoxid hin.

Voices: Insulin and beyond

Marking insulin's centennial, we share stories of researchers and clinicians whose seminal work has advanced our understanding of insulin, islet biology, insulin resistance, and diabetes. The past century of pursuing the "hormone of hormones" and advancing diabetes therapies is replete with stories of collaboration, perseverance, and triumph.

GLP-1 receptor agonists in the treatment of type 2 diabetes - state-of-the-art

BACKGROUND

GLP-1 receptor agonists (GLP-1 RAs) with exenatide b.i.d. first approved to treat type 2 diabetes in 2005 have been further developed to yield effective compounds/preparations that have overcome the original problem of rapid elimination (short half-life), initially necessitating short intervals between injections (twice daily for exenatide b.i.d.).

SCOPE OF REVIEW

To summarize current knowledge about GLP-1 receptor agonist.

MAJOR CONCLUSIONS

At present, GLP-1 RAs are injected twice daily (exenatide b.i.d.), once daily (lixisenatide and liraglutide), or once weekly (exenatide once weekly, dulaglutide, albiglutide, and semaglutide). A daily oral preparation of semaglutide, which has demonstrated clinical effectiveness close to the once-weekly subcutaneous preparation, was recently approved. All GLP-1 RAs share common mechanisms of action: augmentation of hyperglycemia-induced insulin secretion, suppression of glucagon secretion at hyper- or euglycemia, deceleration of gastric emptying preventing large post-meal glycemic increments, and a reduction in calorie intake and body weight. Short-acting agents (exenatide b.i.d., lixisenatide) have reduced effectiveness on overnight and fasting plasma glucose, but maintain their effect on gastric emptying during long-term treatment. Long-acting GLP-1 RAs (liraglutide, once-weekly exenatide, dulaglutide, albiglutide, and semaglutide) have more profound effects on overnight and fasting plasma glucose and HbA1c, both on a background of oral glucose-lowering agents and in combination with basal insulin. Effects on gastric emptying decrease over time (tachyphylaxis). Given a similar, if not superior, effectiveness for HbA1c reduction with additional weight reduction and no intrinsic risk of hypoglycemic episodes, GLP-1RAs are recommended as the preferred first injectable glucose-lowering therapy for type 2 diabetes, even before insulin treatment. However, GLP-1 RAs can be combined with (basal) insulin in either free- or fixed-dose preparations. More recently developed agents, in particular semaglutide, are characterized by greater efficacy with respect to lowering plasma glucose as well as body weight. Since 2016, several cardiovascular (CV) outcome studies have shown that GLP-1 RAs can effectively prevent CV events such as acute myocardial infarction or stroke and associated mortality. Therefore, guidelines particularly recommend treatment with GLP-1 RAs in patients with pre-existing atherosclerotic vascular disease (for example, previous CV events). The evidence of similar effects in lower-risk subjects is not quite as strong. Since sodium/glucose cotransporter-2 (SGLT-2) inhibitor treatment reduces CV events as well (with the effect mainly driven by a reduction in heart failure complications), the individual risk of ischemic or heart failure complications should guide the choice of treatment. GLP-1 RAs may also help prevent renal complications of type 2 diabetes. Other active research areas in the field of GLP-1 RAs are the definition of subgroups within the type 2 diabetes population who particularly benefit from treatment with GLP-1 RAs. These include pharmacogenomic approaches and the characterization of non-responders. Novel indications for GLP-1 RAs outside type 2 diabetes, such as type 1 diabetes, neurodegenerative diseases, and psoriasis, are being explored. Thus, within 15 years of their initial introduction, GLP-1 RAs have become a well-established class of glucose-lowering agents that has the potential for further development and growing impact for treating type 2 diabetes and potentially other diseases.

Twenty-Four Hour Fasting (Basal Rate) Tests to Achieve Custom-Tailored, Hour-by-Hour Basal Insulin Infusion Rates in Patients With Type 1 Diabetes Using Insulin Pumps (CSII)

BACKGROUND

Twenty-four hour fasting periods are being used to scrutinize basal insulin infusion rates for pump-treated patients with type 1 diabetes.

METHODS

Data from 339 consecutive in-patients with adult type 1 diabetes on insulin pump therapy undergoing a 24-hour fast as a basal rate test were retrospectively analyzed. Hourly programmed basal insulin infusion rates and plasma glucose concentrations within, below, or above arbitrarily defined target ranges were assessed for periods of the day of special interest (eg, 01:00-07:00 am, "dawn" period, 04:00-07:00 pm, and "dusk" period). Statistics: χ²-tests, paired t-tests were used.

RESULTS

Basal rates (mean: 0.90 ± 0.02 IU/h) showed circadian variations with peaks corresponding to "dawn" (1.07 ± 0.02 IU/h from 01:00 to 07:00 am) and, less prominently, "dusk" (0.95 ± 0.02 IU/h from 03:00 to 07:00 pm). Individual mean plasma glucose concentrations averaged 6.6 ± 0.1 mmol/L, with 53.1% in the predefined "strict" (4.4-7.2 mmol/L) target range. Interestingly, during the "dawn" period, plasma glucose was significantly higher (by 0.5 ± 0.1 mmol/L [95% confidence interval: 0.3-0.8 mmol/L; P < .0001]) and the odds ratio for hypoglycemia was significantly lower compared to the reference period.

INTERPRETATION

Twenty-four hour fasting periods as basal rate tests frequently unravel periods with inappropriate basal insulin infusion rates potentially responsible for fasting hyper- or hypoglycemia. Notably, the higher basal insulin infusion rate found during the "dawn" period seems to be justified and may need to be accentuated.

Day-to-Day Variations in Fasting Plasma Glucose Do Not Influence Gastric Emptying in Subjects With Type 1 Diabetes

OBJECTIVE

Acute experimental variations in glycemia decelerate (hyperglycemia) or accelerate (hypoglycemia) gastric emptying. Whether spontaneous variations in fasting plasma glucose (FPG) have a similar influence on gastric emptying is yet unclear.

RESEARCH DESIGN AND METHODS

Gastric emptying of a mixed meal was prospectively studied three times in 20 patients with type 1 diabetes and 10 healthy subjects with normal glucose tolerance using a ¹³C-CO₂ octanoate breath test with Wagner-Nelson analysis. The velocity of gastric emptying was related to FPG measured before the test (grouped as low, intermediate, or high). In addition, gastric emptying data from 255 patients with type 1 diabetes studied for clinical indications were compared by tertiles of baseline FPG.

RESULTS

Despite marked variations in FPG (by 4.8 [95% CI 3.4; 6.2] mmol/L), gastric emptying did not differ among the three prospective examinations in patients with type 1 diabetes (Δ T_1/2 between highest and lowest FPG: 1 [95% CI -35; 37] min; P = 0.90). The coefficient of variation for T_1/2 determined three times was 21.0%. Similar results at much lower variations in FPG were found in healthy subjects. In the cross-sectional analysis, gastric emptying did not differ between the tertiles of FPG (Δ T_1/2 between highest and lowest FPG: 7 [95% CI -10; 23] min; P = 0.66), when FPG varied by 7.2 (6.7; 7.8) mmol/L. However, higher HbA_1c was significantly related to slower gastric emptying.

CONCLUSIONS

Day-to-day variations in FPG not induced by therapeutic measures do not influence gastric emptying significantly. These findings are in contrast with those obtained after rapidly clamping plasma glucose in the hyper- or hypoglycemic concentrations range and challenge the clinical importance of short-term glucose fluctuations for gastric emptying in patients with type 1 diabetes. Rather, chronic hyperglycemia is associated with slowed gastric emptying.

Cardiovascular Safety and Benefits of Semaglutide in Patients With Type 2 Diabetes: Findings From SUSTAIN 6 and PIONEER 6

To exclude an excess risk of cardiovascular (CV) events, CV outcomes trials (CVOTs) have assessed the effects of new glucose-lowering therapies, including glucagon-like peptide-1 receptor agonists (GLP-1RAs), in patients with type 2 diabetes and established CV disease or CV risk factors. The CV safety of semaglutide vs. placebo, when added to standard care, was evaluated in the SUSTAIN 6 trial for the formulation administered once-weekly subcutaneously and in PIONEER 6 for the new once-daily oral formulation. In SUSTAIN 6 and PIONEER 6, both powered to demonstrate noninferiority (upper 95% confidence interval [CI] of the hazard ratio [HR] <1.8), there were fewer first major adverse CV events with semaglutide vs. placebo, with HRs of 0.74 (95% CI 0.58-0.95) and 0.79 (0.57-1.11), respectively. In SUSTAIN 6, the results were significant for noninferiority and superiority, although the latter was not prespecified. Surprisingly, CV and all-cause mortality were significantly reduced by oral semaglutide in PIONEER 6. The ongoing SOUL CVOT will further inform about CV outcomes with oral semaglutide vs. placebo (NCT03914326). Findings from SUSTAIN 6 and PIONEER 6 fall within the spectrum reported with other GLP-1RA CVOTs: noninferiority vs. placebo for major CV events was seen with lixisenatide and exenatide extended-release, while superiority was demonstrated with liraglutide, albiglutide, and dulaglutide. Beneficial outcomes have been recognized in international guidelines, which recommend subcutaneous liraglutide, semaglutide, and dulaglutide to reduce the risk of CV events in high-risk patients. Both indirect mechanisms via risk factor modification and direct effects via GLP-1 receptors in the CV system have been proposed to be responsible for CV event reductions. The exact mechanism(s) remains to be characterized, but appears to be mainly linked to anti-atherosclerotic effects. Further research is needed to elucidate the relevant mechanisms for CV benefits of GLP-1RAs.

COVID-19 and diabetes mellitus: from pathophysiology to clinical management

Initial studies found increased severity of coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in patients with diabetes mellitus. Furthermore, COVID-19 might also predispose infected individuals to hyperglycaemia. Interacting with other risk factors, hyperglycaemia might modulate immune and inflammatory responses, thus predisposing patients to severe COVID-19 and possible lethal outcomes. Angiotensin-converting enzyme 2 (ACE2), which is part of the renin-angiotensin-aldosterone system (RAAS), is the main entry receptor for SARS-CoV-2; although dipeptidyl peptidase 4 (DPP4) might also act as a binding target. Preliminary data, however, do not suggest a notable effect of glucose-lowering DPP4 inhibitors on SARS-CoV-2 susceptibility. Owing to their pharmacological characteristics, sodium-glucose cotransporter 2 (SGLT2) inhibitors might cause adverse effects in patients with COVID-19 and so cannot be recommended. Currently, insulin should be the main approach to the control of acute glycaemia. Most available evidence does not distinguish between the major types of diabetes mellitus and is related to type 2 diabetes mellitus owing to its high prevalence. However, some limited evidence is now available on type 1 diabetes mellitus and COVID-19. Most of these conclusions are preliminary, and further investigation of the optimal management in patients with diabetes mellitus is warranted.

Effects of Liraglutide on Cardiovascular Outcomes in Patients With Diabetes With or Without Heart Failure

BACKGROUND

More data regarding effects of glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes (T2D) and heart failure (HF) are required.

OBJECTIVES

The purpose of this study was to investigate the effects of liraglutide on cardiovascular events and mortality in LEADER (Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results) participants, by HF history.

METHODS

In the multinational, double-blind, randomized LEADER trial, 9,340 patients with T2D and high cardiovascular risk were assigned 1:1 to liraglutide (1.8 mg daily or maximum tolerated dose up to 1.8 mg daily) or placebo plus standard care, and followed for 3.5 to 5 years. New York Heart Association (NYHA) functional class IV HF was an exclusion criterion. The primary composite major adverse cardiovascular events outcome was time to first occurrence of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. Post hoc Cox regression analyses of outcomes by baseline HF history were conducted.

RESULTS

At baseline, 18% of patients had a history of NYHA functional class I to III HF (liraglutide: n = 835 of 4,668; placebo: n = 832 of 4,672). Effects of liraglutide versus placebo on major adverse cardiovascular events were consistent in patients with (hazard ratio [HR]: 0.81 [95% confidence interval (CI): 0.65 to 1.02]) and without (HR: 0.88 [95% CI: 0.78 to 1.00]) a history of HF (p interaction = 0.53). In both subgroups, fewer deaths were observed with liraglutide (HR: 0.89 [95% CI: 0.70 to 1.14] with HF; HR: 0.83 [95% CI: 0.70 to 0.97] without HF; p interaction = 0.63) versus placebo. No increased risk of HF hospitalization was observed with liraglutide, regardless of HF history (HR: 0.98 [95% CI: 0.75 to 1.28] with HF; HR: 0.78 [95% CI: 0.61 to 1.00] without HF; p interaction = 0.22). Effects of liraglutide on the composite of HF hospitalization or cardiovascular death were consistent in patients with (HR: 0.92 [95% CI: 0.74 to 1.15]) and without (HR: 0.77 [95% CI: 0.65 to 0.91]) a history of HF (p interaction = 0.19).

CONCLUSIONS

Based on these findings, liraglutide should be considered suitable for patients with T2D with or without a history of NYHA functional class I to III HF. (Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results [LEADER]; NCT01179048).

Impact of microvascular disease on cardiovascular outcomes in type 2 diabetes: Results from the LEADER and SUSTAIN 6 clinical trials

The randomized, double-blind, cardiovascular outcomes trials LEADER (NCT01179048) and SUSTAIN 6 (NCT01720446) showed cardiovascular risk reduction in patients with type 2 diabetes treated with liraglutide and semaglutide, respectively, compared with placebo. This post hoc analysis examined the impact of microvascular disease at baseline on cardiovascular outcomes in these trials, and the efficacy of liraglutide (1.8 mg) and once-weekly semaglutide (0.5-1.0 mg) in patients with and without microvascular disease. In total, 9340 patients from LEADER and 3297 patients from SUSTAIN 6 were included in this analysis; of these, 5761 and 2356 had a history of microvascular disease at baseline and 3835 and 1640 had a history of both microvascular and macrovascular disease, respectively. Patients with microvascular disease were shown to have an increased risk of major adverse cardiovascular events compared with patients without microvascular disease (hazard ratio [95% confidence interval] in LEADER: 1.15 [1.03; 1.29], P = .0136; SUSTAIN 6: 1.56 [1.14; 2.17], P = .0064). Liraglutide and semaglutide consistently reduced cardiovascular risk in patients with and without microvascular disease.

Superior weight loss with once-weekly semaglutide versus other glucagon-like peptide-1 receptor agonists is independent of gastrointestinal adverse events

INTRODUCTION

Gastrointestinal (GI) adverse events (AEs) are the most common AEs with glucagon-like peptide-1 receptor agonists (GLP-1RAs). Weight loss (WL) is slightly greater in people who experience GI AEs than those who do not. A previous mediation analysis of the SUSTAIN 1-5 trials indicated minor contribution of nausea/vomiting to the greater WL with once-weekly semaglutide versus comparators. Semaglutide demonstrated superior glycated hemoglobin and body weight (BW) reductions versus other GLP-1RAs in SUSTAIN 3 (versus exenatide extended release 2.0 mg), SUSTAIN 7 (versus dulaglutide) and SUSTAIN 10 (liraglutide 1.2 mg). The objective of this analysis was to assess if significantly greater WL with semaglutide versus other GLP-1RAs is mediated by nausea/vomiting and other GI AEs (diarrhea, constipation, dyspepsia) during dose escalation (baseline to week 12, when GI AEs are generally most prevalent) and from baseline to end of treatment (EOT: week 56 (SUSTAIN 3), 40 (SUSTAIN 7) or 30 (SUSTAIN 10)).

RESEARCH DESIGN AND METHODS

Subjects within trials were subdivided into those who reported (yes/no) nausea/vomiting or any other GI AE. Change from baseline in BW was assessed within each trial and subgroup. A mediation analysis separated WL into direct or indirect (mediated by GI AEs) effects.

RESULTS

From baseline to week 12 or EOT, the nausea/vomiting-mediated difference in WL was, respectively: 0.05 or 0.09 kg of 3.78 kg at EOT (SUSTAIN 3); 0.06 or 0.03 kg of 2.26 kg at EOT (low-dose comparison) and 0.08 or 0.04 kg of 3.55 kg at EOT (high-dose comparison) (SUSTAIN 7) and 0.05 or 0.09 kg of 3.82 kg at EOT (SUSTAIN 10).

CONCLUSIONS

In SUSTAIN 3, 7 and 10, nausea/vomiting by week 12 (end of dose escalation) or throughout treatment contributed minimally (<0.1 kg) to the superior WL with semaglutide versus GLP-1RA comparators at EOT.

The novel dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 (GLP-1) receptor agonist tirzepatide transiently delays gastric emptying similarly to selective long-acting GLP-1 receptor agonists

The effect of dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist (RA) tirzepatide on gastric emptying (GE) was compared to that of GLP-1RAs in non-clinical and clinical studies. GE was assessed following acute and chronic treatment with tirzepatide in diet-induced obese mice versus semaglutide or long-acting GIP analogue alone. Participants [with and without type 2 diabetes (T2DM)] from a phase 1, 4-week multiple dose study received tirzepatide, dulaglutide or placebo. GE was assessed by acetaminophen absorption. In mice, tirzepatide delayed GE to a similar degree to that achieved with semaglutide; however, these acute inhibitory effects were abolished after 2 weeks of treatment. GIP analogue alone had no effect on GE or on GLP-1's effect on GE. In participants with and without T2DM, once-weekly tirzepatide (≥5 and ≥4.5 mg, respectively) delayed GE after a single dose. This effect diminished after multiple doses of tirzepatide or dulaglutide in healthy participants. In participants with T2DM treated with an escalation schedule of tirzepatide 5/5/10/10 or 5/5/10/15 mg, a residual GE delay was still observed after multiple doses. These data suggest that tirzepatide's activity on GE is comparable to that of selective GLP-1RAs.

Validation of distinct type 2 diabetes clusters and their association with diabetes complications in the DEVOTE, LEADER and SUSTAIN-6 cardiovascular outcomes trials

AIMS

To validate the clusters of Swedish individuals with recent-onset diabetes at differential risk of complications, which were identified in a previous study, in three global populations with long-standing type 2 diabetes (T2D) who were at high cardiovascular risk, and to test for differences in the risk of major diabetes complications and survival endpoints.

MATERIALS AND METHODS

We assigned participants from recent global outcomes trials (DEVOTE [n = 7637], LEADER [n = 9340] and SUSTAIN-6 [n = 3297]) to the previously defined clusters according to age at diabetes diagnosis, baseline glycated haemoglobin (HbA1c) and body mass index (BMI). Outcomes were assessed using Kaplan-Meier analysis and log-rank tests.

RESULTS

The T2D clusters were consistently replicated across the three trial cohorts. The risk of major adverse cardiovascular events and cardiovascular death differed significantly, in all trials, across clusters over a median follow-up duration of 2.0, 3.8 and 2.1 years, respectively, and was highest for the cluster of participants with high HbA1c and low BMI (P < 0.05 in DEVOTE and LEADER). In LEADER and SUSTAIN-6, the risk of nephropathy differed across clusters (P < 0.0001 and P = 0.003, respectively). The risk of severe hypoglycaemia differed in DEVOTE (P = 0.006).

CONCLUSIONS

Previously identified clusters can be replicated in three geographically diverse cohorts of long-standing T2D and are associated with cluster-specific risk profiles for additional clinical and survival outcomes, providing further validation of the clustering methodology. The external validity and stability of clusters across cohorts provides a premise for future work to optimize the clustering approach to yield T2D subgroups with maximum predictive validity who may benefit from subtype-specific treatment paradigms.