Oxidative stress and obesity are associated with endothelial dysfunction and subclinical atherosclerosis in adolescents

Objectives

This study explores the relationship between obesity, endothelial dysfunction, and the critical role of oxidative stress biomarkers in subclinical atherosclerosis.

Design & methods

The study included 114 adolescents aged 12–17 years from Juiz de Fora, Brazil, divided into 40 individuals with obesity and 74 controls. Physical and biochemical assessments were conducted, including measurements of Brachial Flow-Mediated Dilation (BFMD), Carotid Intima-Media Thickness (IMT), and oxidative biomarkers such as nitrite, nitrate, and 8-isoprostane. Multiple regression analyses were used to evaluate associations between obesity, oxidative biomarkers, and endothelial function.

Results

Adolescents with obesity exhibited significantly reduced BFMD at 60 s (5.44 ± 2.31 % vs. 7.82 ± 2.07 % in controls; p < 0.05) and 90 s (5.27 ± 2.64 % vs. 7.93 ± 2.12 % in controls; p < 0.05). IMT was significantly higher in the group with obesity for both the right carotid artery (0.054 ± 0.005 cm vs. 0.047 ± 0.004 cm in controls; p < 0.05) and the left carotid artery (0.053 ± 0.005 cm vs. 0.047 ± 0.004 cm in controls; p < 0.05). Additionally, 8-isoprostane levels were higher in adolescents with obesity (49.75 ± 22.62 pg/mL vs. 42.36 ± 17.35 pg/mL in controls; p < 0.05), indicating increased oxidative stress. Nitrite levels were significantly lower in adolescents with obesity (42.98 ± 10.62 nM vs. 49.94 ± 17.71 nM in controls; p < 0.05). Additionally, nitrate levels were inversely associated with IMT in both the right (p = 0.01) carotid arteries in the multiple linear regression analyses.

Conclusions

The study highlights the association between obesity and early vascular changes in adolescents, evidenced by reduced BFMD, increased IMT, and altered oxidative stress biomarkers.