Diabetes and Vascular Disease

MON-604 - Association of Serum 8-Oxoguanine DNA Glycosylase 1 and Neutrophil Gelatinase-Associated Lipocalin Levels with Endothelial Dysfunction Assessed by Flow-Mediated Dilation in Prediabetes and Type 2 Diabetes

Monday, June 15, 2026

9:00 AM - 2:00 PM CT

Late-Breaking Poster Presenter(s)

IS

Irem Sonmezoglu Kutuk, MD

Dr.
Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey

Co-Author(s)

SA

Sabri Engin Altintop, MD

Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey
RY

Refika Yorulmaz Kaya, MD

Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey
EC

Ethem Turgay Cerit, Prof. Dr.

Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey
MY

Mehmet Muhittin Yalcin, Prof. Dr.

Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey
AE

Alev Eroglu Altinova, Prof. Dr.

Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey
FT

Fusun Toruner, Prof. Dr.

Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey
MK

Mehmet Ayhan Karakoc, Prof. Dr.

Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey
MA

Mujde Akturk, Prof. Dr.

Gazi University Faculty of Medicine, Department of Internal Medicine, Division of Endocrinology and Metabolism
Ankara, Turkey

Objective:
Endothelial dysfunction is an early feature of increased cardiovascular risk in prediabetes and type 2 diabetes mellitus and is largely driven by oxidative stress and inflammation. 8-oxoguanine DNA glycosylase 1 (OGG1) is a key enzyme involved in oxidative DNA repair. Neutrophil gelatinase-associated lipocalin (NGAL) is a protein originally identified in neutrophils and also expressed by various epithelial tissues, and has been associated with vascular injury extending beyond its traditional use as a marker of renal tubular damage. However, their involvement in dysglycemia remain unclear. Therefore, this study aimed to investigate the associations of serum OGG1 and NGAL levels with endothelial function, assessed by flow-mediated dilation (FMD), in individuals with prediabetes, type 2 diabetes, and healthy controls.

Methods:
A total of 29 newly diagnosed, treatment-naive patients with T2DM, 30 patients with prediabetes, and 29 healthy controls were included. Serum OGG1 and NGAL levels were measured using ELISA. Endothelial function was assessed by brachial artery FMD.

Results:
The groups were similar in terms of age, sex, and body mass index (p>0.05). HbA1c and fasting glucose levels differed significantly among the groups (p < 0.001). FMD values were 4.40±2.56% in the T2DM group, 8.15±3.27% in the prediabetes group, and 10.75±2.81% in controls, showing a significant difference between groups (p < 0.001). OGG1 levels were 570.8 (509.6–736.3) ng/mL in T2DM, 626.9 (462.6–988.4) ng/mL in prediabetes, and 914.9 (574.0–4910.6) ng/mL in controls (p=0.008), NGAL levels were 58.4 (52.2–65.3), 59.6 (49.9–81.6), and 80.3 (56.2–289.4) ng/mL, respectively (p=0.004). Both markers were higher in the control group, with no significant difference between T2DM and prediabetes (p>0.05). Correlation analysis showed that FMD was negatively correlated with HbA1c (r=−0.672) and fasting glucose (r=−0.686), while positively correlated with OGG1 (r=0.315) and NGAL (r=0.329) (all p< 0.05). A strong positive correlation was observed between OGG1 and NGAL (r=0.785, p< 0.001).

Conclusions:
Lower OGG1 levels were observed in the prediabetes and T2DM groups, which may reflect dysregulation in oxidative stress response and DNA repair dynamics. Given the association of NGAL with FMD and OGG1 suggests that NGAL may warrant further investigation in relation to endothelial dysfunction and dysglycemia.

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