As the first line of defense against risk factors, the nasal epithelial barrier maintains homeostasis in nasal mucosa. The composition of the epithelial barrier contains physical, chemical, immune, and microbiological barriers. Together, these barriers form the nasal defense against irritations. Risk factors from both internal and external environments can disrupt them. External risk factors contain allergens containing proteases, bacteria, virus, particulate matter, diesel exhaust particles, and cigarette smoke. In the meantime, inflammatory cytokines also increase the load on the barrier. Taking into account the role of the epithelial barrier in the nasal mucosa, some studies focus on the treatment of allergic rhinitis (AR) and chronic rhinosinusitis (CRS) by restoring the epithelial barrier, and some progress has been made. Among the therapeutic approaches, histone deacetylase (HDAC) inhibitor and steroid corticosteroids are considered two of the more studied categories, and their roles in repairing barriers have been demonstrated in AR and CRS. The underlying mechanism of HDAC inhibitor may be related to the transcription factor p63. And the protection of corticosteroids may be associated with the allergic disease susceptibility gene, protocadherin-1. Notably, manipulation of the microbiological barrier also has a positive effect on AR and CRS. Lactococcus and probiotics are two categories that are worth being explored continuously. We here review and discuss the compositions and risk factors of the nasal epithelial barrier. Furthermore, some novel and promising approaches to restore the defective barrier in nasal allergic diseases were mentioned.

Background: Changes in vascular function are closely associated with the development of cardiovascular disease (CVD). Pulse wave velocity (PWV) is a potential indicator of vascular dysfunction; it allows noninvasive assessment of arterial stiffness. Currently, evidence for the effects of different classes of antidiabetic drugs on arterial stiffness remains limited. In this study, a network meta‐analysis (NMA) was performed to explore the associations between changes in arterial stiffness and first‐line antidiabetic drugs by evaluating PWV in patients with different metabolic abnormalities.Methods: We systematically searched several electronic databases for randomized controlled trials (RCTs) published from inception until 25 August 2022, without language restrictions. The primary outcome was the change in PWV (ΔPWV) in all included studies; subgroup analysis was performed for patients with abnormal glucose metabolism, including prediabetes and diabetes mellitus. NMA was performed to calculate the mean differences (MDs) with 95% confidence intervals (CIs) as effect sizes to evaluate the ΔPWV.Results: Among the 2257 candidate articles identified in the initial search, 18 RCTs were eventually included in the analysis. In all studies, two classes of new antidiabetic drugs, glucagon‐like peptide‐1 receptor (GLP‐1R) agonists and sSodium‐glucose co‐transporter 2 (SGLT‐2) inhibitors, improved arterial stiffness by decreasing PWV compared with placebo (MD = −1.11, 95% CI: −1.94 to 0.28) and (MD = −0.76, 95% CI: −1.45 to −0.08). A conventional antidiabetic drug, metformin, also showed similar efficacy compared with placebo (MD = −0.73, 95% CI: −1.33 to −0.12). Finally, in subgroup studies of patients with abnormal glucose metabolism diseases, GLP‐1R agonists (MD = −1.06, 95% CI: −2.05 to −0.10) significantly decreased PWV compared with placebo.Conclusion: Three classes of antidiabetic drugs—GLP‐1R agonists, SGLT‐2 inhibitors, and metformin—have the potential to improve arterial stiffness. Among the six classes of antidiabetic drugs analyzed, GLP‐1R agonists constitute the only class of drugs that improves arterial stiffness in patients with abnormal glucose metabolism diseases.

Background: Hyaluronic acid (HA), the main component of the extracellular matrix, has the ability to promote tissue repair and regulate inflammation. It is used in otolaryngology as an adjuvant treatment to alleviate postoperative nasal symptoms. However, there is currently insufficient evidence demonstrating the therapeutic efficacy of HA for patients with nasal inflammatory diseases (NIDs). Therefore, this study aimed to evaluate the efficacy and safety of topical HA in the treatment of NID patients without receiving surgery.Methods: In this meta-analysis, comprehensive searches were conducted in PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science. Keywords searched included “hyaluronic acid,” “sinusitis,” “allergic rhinitis,” “rhinitis,” and “randomized controlled trials (RCTs).” The Cochrane Collaboration’s “Risk of Bias Assessment” tool was used to assess the quality of the included trials, and the meta-analysis was performed using the RevMan 5.3 and STATA 15 statistical software.Results: A total of 11 articles and 825 participants were enrolled. For the primary outcomes, the pooled results revealed that HA significantly improves nasal obstruction (SMD, −0.53; 95% CI, −0.92 to −0.14; p = 0.008; and I² = 79%) and rhinorrhea (SMD, −0.71; 95% CI, −1.27 to −0.15; p = 0.01; and I² = 90%) in patients with NIDs. As for the secondary outcomes, the pooled results demonstrated that when compared with the control group, HA could significantly improve nasal endoscopic scores (p < 0.05), rhinitis scores (p < 0.05), rhinomanometry (p < 0.05), nasal neutrophils (p < 0.05), and mucociliary clearance (p < 0.05). However, no significant differences were observed between the two groups regarding nasal itching, sneezing, hyposmia, quality-of-life scores, and nasal eosinophils. For the risk of bias, 54.5% and 45.5% of trials had a low risk of bias in the randomization process and deviation of the intended intervention, respectively.Conclusion: In the present study, the results reveal that HA might ameliorate symptoms of patients with NIDs. However, more clinical trials with larger participant cohorts are required to confirm this result.Systematic review registration number:clinicaltrials.gov, identifier CRD42023414539.

Background: Loratadine and montelukast are clinical first-line drugs in the treatment of allergic rhinitis (AR). However, there is no clear evidence of the efficacy of loratadine combined with montelukast in the treatment of AR. This study aimed to evaluate the efficacy and safety of the loratadine-montelukast combination on AR.Methods: In this meta-analysis, searches were conducted on PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and China National Knowledge Infrastructure (CNKI). The search terms included loratadine, montelukast, allergic rhinitis, and clinical trials. Meta-analyses were conducted using Rev Man 5.3 and Stata 15 statistical software.Results: A total of 23 studies with 4,902 participants were enrolled. For the primary outcome, pooled results showed that loratadine-montelukast can significantly reduce total nasal symptom scores (TNSS), when compared with loratadine (SMD, −1.00; 95% CI, −1.35 to −0.65, p < 0.00001), montelukast (SMD, −0.46; 95% CI, −0.68 to −0.25, p < 0.0001), or placebo (SMD, −0.93; 95% CI, −1.37 to −0.49, p < 0.00001). For secondary outcomes, pooled results showed that compared with loratadine, loratadine-montelukast can significantly improve nasal congestion, nasal itching, nasal sneezing, nasal rhinorrhea, and rhinoconjunctivitis quality of life questionnaires (RQLQ). Compared with montelukast, loratadine-montelukast can significantly improve nasal itching, and nasal sneezing. Compared with placebo, loratadine-montelukast can significantly improve nasal congestion, and RQLQ.Conclusion: Loratadine-montelukast combination is superior to loratadine monotherapy, montelukast monotherapy, or placebo in improving AR symptoms. Therefore, loratadine-montelukast combination can be an option for patients with moderate-severe AR or poorly response to monotherapy.Systematic review registration number: clinicaltrials.gov, identifier CRD42023397519.