AbstractBackgroundTo evaluate the relationship between leukocyte‐endothelial cell interactions and oxidative stress parameters in non‐diabetic patients with different grades of obesity.Material and methodsFor this cross‐sectional study, 225 subjects were recruited from January 1, 2014 to December 31, 2016 and divided into groups according to BMI (<30 kg/m², 30‐40 kg/m² and >40 kg/m²). We determined clinical parameters, systemic inflammatory markers, soluble cellular adhesion molecules, leukocyte‐endothelium cell interactions—rolling flux, velocity and adhesion—, oxidative stress parameters—total ROS, total superoxide, glutathione—and mitochondrial membrane potential in leukocytes.ResultsWe verified that HOMA‐IR and hsCRP increased progressively as obesity developed, whereas A1c, IL6 and TNFα were augmented in the BMI > 40 kg/m² group. The cellular adhesion molecule sP‐selectin was increased in patients with obesity, while sICAM, total ROS, total superoxide and mitochondrial membrane potential were selectively higher in the BMI > 40 kg/m² group. Obesity induced a progressive decrease in rolling velocity and an enhancement of rolling flux and leukocyte adhesion.ConclusionOur findings reveal that endothelial dysfunction markers are altered in human obesity and are associated with proinflammatory cytokines and increased oxidative stress parameters.