Plasma and low density lipoproteins levels of fat- soluble vitamins in obese Egyptian girls

ABSTRACT

Obesity is an important health problem which is deeply rooted in human biologic system resulting in many complications namely atherosclerosis and coronary heart disease. This work was designed to investigate the antioxidant status of obese Egyptian girls. Lycopene, beta- carotene and alpha-tocopherol levels were analyzed in plasma and low density lipoprotein [LDL] fraction of plasma lipids as well as the fatty acids composition of LDL as a substrate for oxidative stress. Twenty two obese girls and ten age and sex matched healthy controls were included in this work. The plasma lycopene/total lipids, beta- carotene/total lipids and alpha-tocopherol/total lipids were significantly lower in the obese girls compared to controls Moreover, the three vitamins contents in LDL fraction were significantly lower than controls, although the plasma levels of the three studied vitamins showed no statistically significant differences in obese girls compared to control In obese girls group, LDL contained more polyunsaturated fatty acids [PUFA] compared to normal controls. When the peroxidizability index [PI] was calculated to estimate susceptibility of fatty acids to oxidative stress, obese girls had significantly higher PI values than normal controls. The LDL lycopene/PI, beta-carotene/PI and alpha-tocopherol/PI ratios were significantly lower in obese girls than controls. Significant negative correlations were found between the studied vitamins levels, their calculated ratios and their contents in LDL fraction when correlated to body mass index [BMI] of obese girls. The best parameters which can predict high BMI were found to be the P1 and lycopene/total lipids. These results indicate the increased susceptibility of LDL to oxidative stress in obese girls along with decreased levels of antioxidant fat-soluble vitamins. These findings may promote atherosclerosis or coronary heart disease later in their life