Is polyethylene glycol loxenatide 100 μg the preferred glucagon-like peptide-1 receptor agonist for type 2 diabetes mellitus? A meta-analysis and trial sequential analysis

OBJECTIVE

This study aimed to systematically evaluate the efficacy, safety and optimal dose of polyethylene glycol loxenatide (PEX168) for treating type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Clinical trials of PEX168 for T2DM were identified in 8 databases, with a build time limit of January 2023. Included studies were subjected to meta-analysis and trial sequential analysis (TSA).

RESULTS

On the efficacy endpoint, the meta-analysis showed that PEX168 100 μg significantly reduced 0.86% glycated hemoglobin type A1c (HbA1c) (MD -0.86, 95% CI -1.02 - -0.70,  p<0.00001), 1.11 mmol/L fasting plasma glucose (FPG) (MD -1.11, 95% CI -1.49 - -0.74, p<0.00001) and 1.91 mmol/L 2h postprandial glucose (PPG) (MD -1.91, 95% CI -3.35 - -0.46, p=0.01) compared with placebo. The TSA showed that all these benefits were conclusive. On safety endpoints, total adverse events (AEs), gastrointestinal (GI) AEs, serious AEs, and hypoglycemia were comparable to placebo for PEX168 100 μg (p>0.05). In the dose comparison, the HbA1c, FPG, and 2h PPG of PEX168 200 μg were comparable to 100 μg (p>0.05), while GI AEs were significantly higher than 100 μg (RR=2.84, 95% CI 1.64-4.93,  p=0.0002).

CONCLUSIONS

PEX168 100 μg can significantly lower blood glucose and does not increase the risk of total AEs, GI AEs, and hypoglycemia, which may be a preferred glucagon-like peptide-1 receptor agonist for type 2 diabetes mellitus.

Effects of calcitonin gene-related peptide on apoptosis of peripheral blood mononuclear cells from patients with systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease with abnormal apoptosis and autoantibody production. Calcitonin gene-related peptide (CGRP) is a neuropeptide produced by the central and peripheral nervous systems and by endocrine cells. It can influence cell death in thymocytes and cultured smooth muscle cells, and inhibits the production of interleukin (IL)-2, which inhibits apoptosis.

AIMS

To investigate the effects of calcitonin gene-related peptide (CGRP) on apoptosis of peripheral blood mononuclear cells (PBMCs) from patients with SLE.

METHODS

The percentage of apoptosis of PBMCs from patients with SLE and healthy blood donors were examined using annexin-V/propidine iodide staining 48 h after culturing with CGRP and/or its receptor antagonist CGRP(8-37) at various concentrations. IL-2 activity in culture supernatants was determined using the incorporation of 3H-TdR by the IL-2-dependent cell line CTLL and evaluated by ELISA.

RESULTS

The percentage of spontaneous apoptosis of PBMCs from patients with SLE was higher than that of healthy blood donors (34.18 +/- 2.86 vs. 18.23 +/- 0.81, P < 0.001). CGRP, at all tested concentrations, had no effect on apoptosis of PBMCs from healthy blood donors, but significantly inhibited apoptosis of PBMCs from patients with SLE at concentrations of >or= 0.5 x 10(-8) mol/L (0.5 x 10(-8) mol/L: 32.01 +/- 3.98 vs. 34.18 +/- 2.86, P < 0.05; 1.0 x 0(-8) mol/L: 26.76 +/- 2.69 vs. 34.18 +/- 2.86, P < 0.001; 1.5 x 10(-8) mol/L: 25.97 +/- 2.65 vs. 34.18 +/- 2.86, P < 0.001), and the effect plateaued at 1.0 x 10(-8) mol/L, at which level inhibition was not significantly increased with increasing concentration. However, CGRP, at any concentration tested, could not reduce the rate of apoptosis of PBMCs from patients with SLE to the normal range. There were significant positive relationships between the effect of CGRP, on apoptosis of PBMCs and SLE Disease Activity Index (0.5 x 10(-8) mol/L: r(s) = 0.328, P < 0.05; 1.0 x 10(-8) mol/L: r(s) = 0.431, P < 0.01; 1.5 x 10(-8) mol/L: r(s) = 0.419, P < 0.01). CGRP(8-37) itself had no effect on apoptosis, but was able to block the effects of CGRP on PBMCs (0.5 x 10(-8) mol/L: 32.01 +/- 3.98 vs. 33.12 +/- 2.37, P < 0.05; 1.0 x 10(-8) mol/L: 26.76 +/- 2.69 vs. 34.73 +/- 2.32, P < 0.001; 1.5 x 10(-8) mol/L: 25.97 +/- 2.65 vs. 35.25 +/- 3.37, P < 0.001). There was no effect of CGRP on IL-2 production.

CONCLUSIONS

These results indicate that CGRP plays an important role in the apoptosis of PBMCs from patients with SLE via its receptor; low plasma levels of CGRP may cause accelerated apoptosis. This regulation does not seem to be related to IL-2.