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

Abstract

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.