Serum glucagon-like peptide-1 and G-protein-coupled receptor levels are associated with albuminuria and kidney function in type 2 diabetes: A cross-sectional study

Abeer J.  Hassan; Ghid H.  Abdulhadi; Enas Jabbar  Hasan

doi:10.31450/ukrjnd.3(91).2026.04

Abeer J. Hassan Middle Technical University, Medical Technical Institute, Baghdad, Iraq https://orcid.org/0000-0002-2122-9758
Ghid H. Abdulhadi Baghdad University, College of Medicine, Baghdad, Iraq https://orcid.org/0000-0002-8645-7217
Enas Jabbar Hasan Al-Mustansiriya University, College of Basic Education, Baghdad, Iraq https://orcid.org/0000-0002-2116-8166

DOI: https://doi.org/10.31450/ukrjnd.3(91).2026.04

Keywords: diabetes mellitus type 2, diabetic nephropathies, albuminuria, glomerular filtration rate, cystatin C, glucagon-like peptide 1, receptors, G-protein-coupled, biomarkers.

Abstract

The relationship of serum glucagon-like peptide-1 (GLP-1) and G-protein-coupled receptor (GPCR) with kidney-related outcomes continues to be poorly studied. The purpose of this study was to determine whether serum GLP-1 and GPCR are related to urinary albumin-to-creatinine ratio (uACR), estimated glomerular filtration rate (eGFR), and cystatin C in patients with type 2 diabetes mellitus (T2DM).

Methods. A total of 150 participants were included in this cross-sectional study and divided into three groups: the healthy subjects (Control group), T2DM patients with albuminuria stage A1 (T2DM-A1 group), and T2DM patients with albuminuria stage A2/A3 (T2DM-A2/A3 group). There were 50 subjects in each group. The clinical information was collected: fasting glucose, HbA1c, insulin, urea, creatinine, eGFR, uACR, cystatin C, GLP-1, and GPCR values. Serum GLP-1, GPCR, and cystatin C were measured using sandwich ELISA kits. Groups were compared using non-parametric testing. Analysis of Spearman correlation was utilized in the diabetic cohort. Linear regression adjusted for age, BMI, diabetes duration, and HbA1c was conducted to identify independent associations of GLP-1 and GPCR with uACR and eGFR.

Results. GLP-1 and GPCR concentrations were gradually increasing from Сontrol group to group T2DM-A1 and group T2DM-A2/A3. Within the diabetic cohort, GLP-1 and GPCR were positively correlated with uACR and cystatin C and negatively correlated with eGFR. After adjustment for covariates, GLP-1 was associated with higher log-transformed uACR (standardized = 0.529, p < 0.001) and lower eGFR (standardized = -0.415, p < 0.001). Similarly, GPCR also showed a positive correlation with log-transformed uACR (standardized = 0.319, p = 0.002) and a negative correlation with eGFR (standardized = -0.365, p = 0.002).

Conclusions. Circulating GLP-1 and GPCR levels were associated with higher albuminuria and lower eGFR in T2DM. GLP-1 demonstrated a stronger association with albuminuria, while GPCR displayed a comparable negative association with kidney function. The study’s findings offer evidence for a cross-sectional GLP-1-GPCR kidney-related biomarker profile that characterizes the albuminuric T2DM phenotype and call for longitudinal studies to confirm the clinical utility of these markers.