Efficacy and Safety of Dulaglutide Monotherapy Compared to Glimepiride in Oral Antihyperglycemic Medication-Naïve Chinese patients with Type 2 Diabetes: A Post Hoc Analysis of AWARD-CHN1

Effects of once-weekly glucagon-like peptide-1 receptor agonists on type 2 diabetes mellitus complicated with coronary artery disease: Potential role of the renin-angiotensin system

AIM

To investigate the potential mechanism of once-weekly glucagon-like peptide-1 receptor agonists (GLP-1 RA) in the treatment of type 2 diabetes mellitus (T2DM) complicated with coronary artery disease (CAD).

METHODS

We searched both Chinese and English databases for randomized controlled trials related to once-weekly GLP-1 RA for T2DM complicated with CAD to verify the safety and efficacy of GLP-1 RA. The underlying mechanism was analysed by network pharmacology.

RESULTS

In total, 13 studies with 35 563 participants were included in the analysis. The pooled analysis found that dulaglutide, exenatide and semaglutide outperformed placebo in cardiovascular outcomes in patients with T2DM, with a significant reduction in the incidence of non-fatal stroke (p < .00). Levels of cardiovascular risk factors were significantly reduced in the once-weekly GLP-1 RA group compared with the conventional treatment group (glycated haemoglobin: p < .00; fasting blood glucose: p < .00; weight: p < .00; systolic blood pressure: p < .00; total cholesterol: p < .00; low-density lipoprotein cholesterol: p < .00). Network pharmacology results were enriched to the renin-angiotensin system, and matrix metalloproteinase 2 and renin (REN) may be the key targets. In addition, four key targets of dulaglutide, five key targets of exenatide and two key targets of semaglutide were enriched.

CONCLUSIONS

Our study suggests that once-weekly GLP-1 RA may have a potential protective effect on cardiovascular events in patients with T2DM combined with CAD, possibly through the renin-angiotensin system. However, further research is needed to confirm these findings and determine cause and effect.

Association of Dulaglutide Initiation Timing With Treatment Patterns and Clinical Outcomes in Patients With Type 2 Diabetes Mellitus in the United States

PURPOSE

To describe clinical characteristics and treatment outcomes for early or late initiation of dulaglutide therapy in patients with type 2 diabetes.

METHODS

This retrospective, claims-based analysis evaluated adults with type 2 diabetes, ≥1 claim for dulaglutide 0.75 mg or 1.5 mg once-weekly injection (between November 2014 and August 2019), and no prior use of glucagon-like peptide 1 receptor agonists or insulin. Cohorts were defined based on the number of oral antidiabetic drug (OAD) classes used within the 24-month baseline period before dulaglutide therapy initiation: 1 OAD, 2 OADs, or ≥3 OADs. The number of OAD classes used before dulaglutide therapy initiation served as a proxy for timing of initiation, with a higher number of OAD classes indicating a longer duration of T2D. Baseline demographic and clinical characteristics were compared across each cohort. Six-month follow-up outcomes, including change in glycosylated hemoglobin (HbA_1c) and treatment patterns, were descriptively assessed within each cohort.

FINDINGS

The study population consisted of 18,121 patients across the 1 OAD (n = 4822), 2 OADs (n = 6293), and ≥3 OADs (n = 7006) cohorts. Mean age at baseline was 54.7 years. Males were more prevalent in the ≥3 OADs cohort. Most patients (67%-70%) initiated treatment with dulaglutide 0.75 mg. Dose escalation to 1.5 mg was uncommon (15%-20%) but trended higher in the ≥3 OAD cohort. Adherence to dulaglutide at 6-month follow-up (61%-67%) increased with higher baseline OAD use. The HbA_1c assessment (n = 3178) included 761 patients in the 1 OAD cohort, 1088 patients in the 2 OADs cohort, and 1329 patients in the ≥3 OADs cohort. Baseline mean [SD] HbA_1c level increased with number of OAD classes (1 OAD: 8.18% [1.80]; 2 OADs: 8.56% [1.66]; and ≥3 OADs: 8.73% [1.51]). Patients in the early dulaglutide therapy initiator group experienced larger reductions in HbA_1c levels (1 OAD: -1.39%; 95% CI, -1.50 to -1.27; 2 OADs: -1.30%; 95% CI, -1.39 to -1.20; and ≥3 OADs: -1.01%; 95% CI, -1.09 to -0.93) versus the patients in the delayed initiator group. Patients in the early dulaglutide therapy initiator group also achieved HbA_1c <7% at 6-month follow-up more frequently than those in the later initiator group (1 OAD: 68%; 2 OADs: 51%; and ≥3 OADs: 33%).

IMPLICATIONS

Cohorts of dulaglutide therapy initiators, defined by prior OAD use as a proxy of timing of initiation, differed in their baseline characteristics and short-term follow-up outcomes. Earlier dulaglutide therapy initiation was associated with lower mean HbA_1c levels and increased probability of achievement of HbA_1c <7% during the 6-month follow-up period.

GLP-1 RA Improves Diabetic Retinopathy by Protecting the Blood-Retinal Barrier through GLP-1R-ROCK-p-MLC Signaling Pathway

BACKGROUND

GLP-1 receptor agonists (GLP-1RA) are common clinical agents that are clinically protective against diabetic complications, such as diabetic retinopathy (DR). Previous studies have shown that the RhoA/ROCK pathway plays an important role in the development of DR. However, the specific mechanism of action between GLP-1RA and DR remains unclear. The aim of this study was thus to investigate the main mechanism involved in the protective effect of GLP-1RA on DR.

METHODS

Type 2 diabetic mice were fed a high-sugar, high-fat diet. Changes in the retinal structure were observed via HE staining and transmission electron microscopy. The expression of retinal GLP-1R, blood-retinal barrier- (BRB-) related proteins, inflammatory factors, and related pathway proteins were studied via Western blot or immunohistochemistry/immunofluorescence analysis.

RESULTS

GLP-1RA treatment reduced the blood glucose and lipid levels as well as the body weight of the diabetic mice while also improving retinal thickness, morphology, and vascular ultrastructure. Moreover, restored GLP-1R expression, increased Occludin and ZO-1 levels, and decreased albumin expression led to reduced retinal leakage and improved the BRB by inhibiting the RhoA/ROCK pathway.

CONCLUSIONS

We found that the protective effect of GLP-1RA on the retina may be realized through the GLP-1R-ROCK-p-MLC signaling pathway.