Baseline ALT levels as a marker of glycemic response to treatment with GLP-1 receptor agonists

This study aimed to assess if ALT levels, as a marker of non-alcoholic fatty liver disease, may predict HbA1c response to treatment with GLP-1 receptor agonists (GLP-1 RAs).

A retrospective, longitudinal, analytical study was conducted including patients with type 2 diabetes mellitus continuously treated with GLP-1 agonists (85% with liraglutide) for one year. Patients were divided into two groups according to baseline ALT levels, with 24 U/L (the median of the distribution) as the cut-off point. The dependent variable was HbA1c change (one-year follow-up minus baseline). The predictive value of ALT levels above 24 U/L and ALT change was analyzed using multivariate linear regression adjusted to age, gender, diabetes duration, type and dose of GLP-1 RA, baseline HbA1c, baseline body mass index (BMI), and change in BMI.

A total of 117 patients (48% females) aged 58.6 (SD 9.6) years were enrolled into the study. Treatment was associated with a change in ALT of -4.3 U/L (p=0.041) and a change in HbA1c of -1.1% (p<0.0001). Decreases in HbA1c (-1.41% vs -0.76%; p=0.045) and ALT (-9.25 vs 0.46 U/L; p=0.002) were significantly higher in patients with ALT levels above the median. In the multivariate analysis, both ALT>24 U/L (b=-0.74; 95%CI: -1.31 to -0.18; p=0.011) and ALT change (b=0.028; 95%CI: 0.010 to 0.046; p=0.003), were significant response predictors.

Elevated baseline transaminase values and decreased transaminase levels during follow-up are associated to a favorable glycemic response to GLP-1 RAs.