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 polype

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. 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 (HbA1c ) 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, HbA1c target achievement, hypoglycaemia, blood pressure and lipids. Risk of bias assessment was performed using Jadad scores and the Risk of Bias tool 2.0. In all, 20 studies, representing 47 study arms and 11 843 patients, were eligible. Compared with basal insulin, IGBLMs lowered HbA1c by 0.48 (0.45-0.52)% more than did basal insulin treatment. This effect was driven by pooled long-acting GLP-1RAs (ΔHbA1c -0.25 [-0.38; -0.11]%) and the only GIP/GLP-1 receptor co-agonist, tirzepatide (pooled doses; ΔHbA1c -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. 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.

Nauck MA ，Mirna AEA ，Quast DR 《-》

Management of type 2 diabetes with the dual GIP/GLP-1 receptor agonist tirzepatide: a systematic review and meta-analysis.

Tirzepatide is a novel dual glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 receptor agonist (GLP-1 RA) currently under review for marketing approval. Individual trials have assessed the clinical profile of tirzepatide vs different comparators. We conducted a systematic review and meta-analysis to assess the efficacy and safety of tirzepatide for type 2 diabetes. We searched PubMed, Embase, Cochrane and ClinicalTrials.gov up until 27 October 2021 for randomised controlled trials with a duration of at least 12 weeks that compared once-weekly tirzepatide 5, 10 or 15 mg with placebo or other glucose-lowering drugs in adults with type 2 diabetes irrespective of their background glucose-lowering treatment. The primary outcome was change in HbA1c from baseline. Secondary efficacy outcomes included change in body weight, proportion of individuals reaching the HbA1c target of <53 mmol/mol (<7.0%), ≤48 mmol/mol (≤6.5%) or <39 mmol/mol (<5.7%), and proportion of individuals with body weight loss of at least 5%, 10% or 15%. Safety outcomes included hypoglycaemia, gastrointestinal adverse events, treatment discontinuation due to adverse events, serious adverse events, and mortality. We used version 2 of the Cochrane risk-of-bias tool for randomised trials to assess risk of bias for the primary outcome. Seven trials (6609 participants) were included. A dose-dependent superiority in lowering HbA1c was evident with all three tirzepatide doses vs all comparators, with mean differences ranging from -17.71 mmol/mol (-1.62%) to -22.35 mmol/mol (-2.06%) vs placebo, -3.22 mmol/mol (-0.29%) to -10.06 mmol/mol (-0.92%) vs GLP-1 RAs, and -7.66 mmol/mol (-0.70%) to -12.02 mmol/mol (-1.09%) vs basal insulin regimens. Tirzepatide was more efficacious in reducing body weight; reductions vs GLP-1 RAs ranged from 1.68 kg with tirzepatide 5 mg to 7.16 kg with tirzepatide 15 mg. Incidence of hypoglycaemia with tirzepatide was similar vs placebo and lower vs basal insulin. Nausea was more frequent with tirzepatide vs placebo, especially with tirzepatide 15 mg (OR 5.60 [95% CI 3.12, 10.06]), associated with higher incidence of vomiting (OR 5.50 [95% CI 2.40, 12.59]) and diarrhoea (OR 3.31 [95% CI 1.40, 7.85]). Odds of gastrointestinal events were similar between tirzepatide and GLP-1 RAs, except for diarrhoea with tirzepatide 10 mg (OR 1.51 [95% CI 1.07, 2.15]). Tirzepatide 15 mg led to higher discontinuation rate of study medication due to adverse events regardless of comparator, while all tirzepatide doses were safe in terms of serious adverse events and mortality. A dose-dependent superiority on glycaemic efficacy and body weight reduction was evident with tirzepatide vs placebo, GLP-1 RAs and basal insulin. Tirzepatide did not increase the odds of hypoglycaemia but was associated with increased incidence of gastrointestinal adverse events. Study limitations include presence of statistical heterogeneity in the meta-analyses for change in HbA1c and body weight, assessment of risk of bias solely for the primary outcome, and generalisation of findings mainly to individuals who are overweight or obese and already on metformin-based background therapy. PROSPERO registration no. CRD42021283449.

Karagiannis T ，Avgerinos I ，Liakos A ，Del Prato S ，Matthews DR ，Tsapas A ，Bekiari E ... -  《-》

Basal insulin intensification with GLP-1RA and dual GIP and GLP-1RA in patients with uncontrolled type 2 diabetes mellitus: A rapid review of randomized controlled trials and meta-analysis.

Tirzepatide, a dual agonist of Glucose-Dependent Insulinotropic Polypeptide (GIP) and Glucagon-Like Peptide 1 (GLP-1) receptors, improved glucose control and reduced body weight in different therapeutic approaches. Herein, we overviewed the role of GIP and GLP-1 in the pathophysiology of type 2 diabetes and systematically reviewed the efficacy and safety of injectable incretin-based therapy added to basal insulin in light of the results of the SURPASS-5 trial. We identified eleven randomized clinical trials. GLP-1 receptor agonists (GLP-1RAs) or Tirzepatide added to basal insulin than rigorously titrated basal insulin significantly ameliorates glucose control (Δ HbA1c = -1%, 95% CI -1.25; -0.74, I2 94%; Δ FPG = -14.6 mg/dL, 95% CI -21.6-; -7.6, I2 90%; chance to achieve HbA1c <7% = RR 2.62, 95% CI 2.10; 3.26, I2 89%), reduces body weight (Δ = -3.95 kg, 95% CI -5.1, -2.79, I2 96%) without increasing the risk of hypoglycemia (RR = 1.01, 95% CI 0.86; 1.18, I2 7.7%). Tirzepatide provides an impressive weight loss exceeding that observed with GLP-1RAs. Injectable incretin-based therapy plus basal insulin remains a potent and safe therapeutic approach in uncontrolled type 2 diabetes patients previously treated with basal insulin alone. Tirzepatide is expected to ameliorate the management of "diabesity" in this usually difficult-to-treat cluster of patients.

Lisco G ，De Tullio A ，Disoteo O ，De Geronimo V ，Piazzolla G ，De Pergola G ，Giagulli VA ，Jirillo E ，Guastamacchia E ，Sabbà C ，Triggiani V ... -  《Frontiers in Endocrinology》

Incretin hormones and type 2 diabetes.

Nauck MA ，Müller TD 《-》

The dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist tirzepatide: a novel cardiometabolic therapeutic prospect.

Incretin hormones are peptides released in the intestine in response to the presence of nutrients in its lumen. The main incretins are glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). GLP-1 stimulates insulin secretion, inhibits glucagon secretion at pancreatic α cells and has also extrapancreatic influences as slowing of gastric emptying which increases the feeling of satiety. GIP is the main incretin hormone in healthy people, causative of most the incretin effects, but the insulin response after GIP secretion in type 2 diabetes mellitus (T2DM) is strongly reduced. Therefore, in the past GIP has been considered an unappealing therapeutic target for T2DM. This conception has been changing during recent years, since it has been reported that resistance to GIP can be reversed and its effectiveness restored by improving glycemic control. This fact paved the way for the development of a GIP receptor agonist-based therapy for T2DM, looking also for the possibility of finding a combined GLP-1/GIP receptor agonist. In this framework, the novel dual GIP and GLP-1 receptor agonist tirzepatide seems to be not just a new antidiabetic medication. Administered as a subcutaneous weekly injection, it is a manifold single pharmacological agent that has the ability to significantly lower glucose levels, as well as improve insulin sensitivity, reduce weight and amend dyslipidemia favorably modifying the lipid profile. Tirzepatide and additional dual GLP-1/GIP receptor agonists that could eventually be developed in the future seem to be a promising furthest advance for the management of several cardiometabolic settings. Obviously, it is too early to be overly hopeful since it is still necessary to determine the long-term effects of these compounds and properly verify the potential cardiovascular benefits. Anyway, we are currently facing a novel and very appealing therapeutic option.

Fisman EZ ，Tenenbaum A 《Cardiovascular Diabetology》