ANTIOXIDANT VITAMIN LEVELS IN PLASMA AND LOW-DENSITY-LIPOPROTEIN OF OBESE GIRLS

To investigate the antioxidant status of obese children, we analyzed b eta-carotene and alpha-tocopherol levels in plasma and low density lip oprotein (LDL). We also analyzed the fatty acid composition of LDL as a substrate for oxidative stress. The plasma beta-carotene and alpha-t ocopherol levels were relatively lower in obese girls than in normal c ontrols. However, the plasma alpha-tocopherol/lipids ratio was signifi cantly lower in obese girls than in normal controls. Both LDL beta-car otene and LDL alpha-tocopherol levels were significantly lower in obes e girls than in normal controls, although no obvious differences were observed in plasma levels. In obese girls LDL contained more polyunsat urated fatty acid (PUFA) compared with normal controls. When the perox idizability Index (PI) was calculated to estimate the susceptibility o f lipids to oxidative stress, obese girls had significantly higher PI values than normal controls. Both the LDL beta-carotene/PI ratio and t he LDL alpha-tocopherol/PI ratio were significantly lower in obese gir ls than in normal controls. These results indicate the increased susce ptibility of LDL to oxidative stress in obese girls which may promote atherosclerosis later in life.