Impact of Dipeptidyl Peptidase-4 Inhibitors on Aminotransferases Levels in Patients with Type 2 Diabetes Mellitus With Nonalcoholic Fatty Liver Disease: A Meta-Analysis of Randomized Controlled Trial

Abstract

Background

Type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD) are highly prevalent diseases that constitute enormous public health problems. The efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitors in blood glucose control in T2DM patients with NAFLD has been established, but little is known about its effect on liver enzyme levels.

Objective

This meta-analysis aimed to evaluate the influences of DPP-4 inhibitors on alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in patients with T2DM and NAFLD.

Methods

To identify the relevant studies, we searched PubMed, Embase, the Cochrane Library, Wanfang Data, and China National Knowledge Infrastructure. Means differences in liver enzymes and metabolic outcomes were meta-analyzed using a random-effects model, with subgroup analyses by gender, age, area, follow-up duration, and type of DPP-4 inhibitor. Quality assessment of the included studies was conducted using the revised Cochrane risk of bias tool.

Results

A total of 1323 patients from 16 studies were included in this meta-analysis. The results of analysis of DPP-4 inhibitors showed that the mean difference was –6.19 (95% confidence interval [CI]: –9.45 to –2.92) for ALT and –5.17 (95% CI: –8.10 to –2.23) for AST; this effect was statistically significant from the placebo group which indicates the beneficial effect on liver enzymes. Subgroup analysis revealed that while there were no significant gender differences in enzyme reductions, individuals over 55 years old experienced more pronounced decreases in ALT. Notably, Asian studies showed significant reductions in liver enzymes, contrasting with the minor variations observed in Euramerican regions, and the effectiveness of DPP-4 inhibitors was particularly pronounced during shorter follow-up periods, with effects diminishing over time. Regarding secondary outcomes, there was a notable improvement in gamma-glutamyl transpeptidase, with a mean reduction, and in HbA1c levels, indicating improved glycemic control. Homeostatic model assessment for insulin resistance levels also improved, reflecting better insulin sensitivity. Additionally, adverse event analysis confirmed that DPP-4 inhibitors were well-tolerated with a favorable safety profile.

Conclusions

DPP-4 inhibitors appear to enhance glycemic control and improve liver enzyme levels, suggesting a potentially effective therapeutic approach for managing T2DM/NAFLD and highlighting their broader metabolic benefits.