Endothelial Dysfunction in Young Adults: The Limited Prognostic Value of Electrocardiographic Parameters and the Need for Advanced Diagnostic Methods

Objective: Endothelial dysfunction (ED) is an early indicator of cardiovascular disease and plays a key role in the initiation of atherosclerosis. ED is characterized by decreased bioavailability of nitric oxide (NO), increased oxidative stress, and inflammatory responses, which trigger atherosclerotic plaque formation. Early detection of ED is important for preventing cardiovascular risk in young adults. This study aims to investigate the relationship between ED and electrocardiographic (ECG) parameters. Methods: Between January 2024 and June 2025, 60 patients aged 18–45 years without chronic disease who applied to the cardiology outpatient clinic were included in the study. Patients were divided into ED-positive (n=30) and ED-negative (n=30) groups according to NO, ICAM-1, malondialdehyde (MDA), and flow-mediated dilation (FMD) measurements. ED was defined as NO <10 µmol/L, ICAM-1 >10 ng/mL, MDA >1,500 ng/mL, and FMD <7%. Electrocardiogram (ECG) parameters were analyzed using a 12-lead ECG. Results: In the ED-positive group, NO levels were lower (4.8 vs. 5.0 µmol/L, p=0.438), ICAM-1 (10.2 vs. 6.5 ng/mL, p<0.001) and MDA (1796 vs. 305 ng/mL, p<0.001) were higher, and FMD was lower (6% vs. 10%, p<0.001). Among ECG parameters, only S-wave amplitude was higher in the ED-positive group (0.43 vs. 0.27 mV, p=0.004). Regression analysis showed that S-wave amplitude was an independent predictor of ED (odds ratio 2.662, 95% confidence interval 1.664–4.253, p<0.001). Conclusion: Biomarkers and FMD are superior to routine ECG in detecting ED. Only the S-wave amplitude was associated with ED, indicating the limited prognostic value of ECG. Biomarkers and FMD are recommended for early cardiovascular risk detection.