Disruption of HDL antioxidant properties in children and adolescents with obesity.

BACKGROUND

Childhood obesity is associated with alterations in lipoprotein metabolism and increased oxidative stress, assessed by lipid peroxidation products, reactive oxygen species (ROS) and nitric oxide (NO) levels, oxidized/reduced glutathione (GSH/GSSG) ratio, and the activities of superoxide dismutase (SOD) and catalase. High-density lipoproteins (HDL) play an antioxidant role, conditioned by cholesteryl ester transfer protein (CETP), paraoxonase (PON) 1, lecithin:cholesterol acyltransferase (LCAT), lipoprotein-associated phospholipase A2 (Lp-PLA2), and apolipoprotein (apo) A-I.

OBJECTIVE

This study aims to evaluate HDL antioxidant capacity in children and adolescents with obesity and the status of its conditioning factors.

METHODS

Thirty children and adolescents, 15 with obesity and 15 normal-weight controls were studied in a cross-sectional observational study. Lipid profile and high-sensitivity C-reactive protein were assessed using standardized methods. Lipid peroxidation products, ROS, NO, GSH and GSSG levels, and catalase, SOD, CETP, LCAT, PON 1 (PON and arylesterase [ARE]) and Lp-PLA2 activities were assessed by developed techniques. Total HDL antioxidant activity and its intrinsic oxidation were evaluated.

RESULTS

Children with obesity showed lower HDL cholesterol and apo A-I levels (P < .01), reduced CETP (P < .05), ARE (Lp-PLA2 < .05), LCAT (P < .05), and HDL-associated Lp-PLA2 (P < .01) activities, increased HDL intrinsic oxidation (P < 0.01) and reduced total HDL antioxidant activity (P < .05). Patients revealed increased oxidative stress: higher ROS (P < .001) and NO levels (P < .05), lower GSH/GSSG ratio (P < .01) and catalase activity (P < .001).

CONCLUSIONS

Children and adolescents with obesity exhibited reduced HDL antioxidant activity, alterations in its conditioning factors, intrinsic oxidative modification of HDL particles, and increased oxidative stress. These alterations may affect long-term cardiovascular risk in children and adolescents with obesity.