Meta-Analysis of 11 Heterogeneous Studies regarding Dipeptidyl Peptidase 4 Inhibitor Add-On Therapy for Type 2 Diabetes Mellitus Patients Treated with Insulin

Reporting and methodological quality of systematic reviews of DPP-4 inhibitors for patients with type 2 diabetes mellitus: an evidence-based mapping

AIMS

To evaluate the reporting and methodological quality of relevant systematic reviews (SRs) and meta-analyses (MAs) on Dipeptidyl peptidase-4 inhibitors (DPP-4I) for Type 2 diabetes mellitus (T2DM).

METHODS

Relevant SRs and MAs on T2DM and DPP-4I published between 2017 and November 2021 were retrieved from PubMed, Embase, Cochrane Library, Web of Science, VIP, CNKI, CBM, and WanFang databases. Two independent reviewers performed the search, selection, and data extraction. The reporting and methodological quality of the reviewers was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Assessing the Methodological Quality of Systematic Reviews 2 (AMSTAR 2) tools. The relationship between reporting and methodological quality score was assessed with the Spearman correlation test.

RESULTS

Twenty-one studies involving 151,715 participants were included in the study. This overview showed that DPP-4I was safer and more efficacious than other anti-hyperglycemic drugs (OADs) in treating T2DM. The methodological quality of one SR was low, while the rest were very low. Thus, refinements are needed in the quality of protocol and registration information, a complete search strategy, the summary of the evidence, the listing of excluded studies, assessing the potential impact of risk of bias in RCTs, and discussing the RoB on MA results, and the funding of RCTs need improvement for generating SR. In addition, the reporting and methodological quality scores were moderately correlated (r_S = 0.66, P = 0.001).

CONCLUSIONS

DPP-4I is safer and more efficacious than OADs in treating T2DM. However, the reporting and methodological quality of the related SRs was unsatisfactory. Therefore, PRISMA and AMSTAR 2 analyses should be followed to enhance the overall quality of future SRs.

Efficacy and safety of sitagliptin and insulin for latent autoimmune diabetes in adults: A systematic review and meta-analysis

AIMS/INTRODUCTION

The optimal therapy for latent autoimmune diabetes in adults (LADA) remains undefined. Increasing evidence has shown that sitagliptin and insulin treatment can benefit patients with LADA, but the efficacy still lacks systematic evaluation. We carried out this systematic review and meta-analysis to summarize the current data on the efficacy and safety of sitagliptin combined with insulin on LADA, providing a reliable reference for the effective therapeutic treatment of LADA patients.

MATERIALS AND METHODS

We retrieved the literature in PubMed, Cochrane Library, Embase, Web of Science and CNKI from inception to August 2021. Randomized controlled trials comparing the effects of sitagliptin plus insulin with insulin alone in LADA patients were identified. The outcome measures included parameters of glycemic control, β-cell function, body mass index and adverse events. The Review Manager 5.2 and Stata 14.0 were utilized for data analysis.

RESULTS

Eight randomized controlled trials involving 295 participants were identified. Sitagliptin and insulin treatment lowered hemoglobin A1c (weighted mean difference -0.36, 95% confidence interval -0.61 to -0.10, I2  = 91.6%), increased fasting C-peptide (weighted mean difference 0.08, 95% confidence interval -0.02 to 0.17, I2  = 88.8%) and had fewer adverse events compared with insulin alone. The inter-study heterogeneity, potential publication bias and other factors might interpret asymmetrical presentation of funnel plots. There was no significant association between sitagliptin plus insulin treatment and levels of hemoglobin A1c or fasting C-peptide, regardless of the duration of intervention and sample size.

CONCLUSIONS

Sitagliptin combined with insulin can achieve better glycemic control and improve islet β-cell function with lower incidence of hypoglycemia compared with insulin alone, which provides an effective and tolerated therapeutic regimen for LADA patients. However, further well-designed and rigorous randomized controlled trials are required to validate this benefit due to the limited methodology quality of included trials.