To investigate the correlation of plasma homocysteine(Hcy), oxidized low-density lipoprotein(OX-LDL), malondialdehyde (MDA), and body mass index(BMI) in obese children and their clinical significances.

From January 2007 to December 2007, 30 children, 17 boys and 13 girls, aged 7-12, were diagnosed as secondary obesity (group A, n=30) according to the diagnosis standard of children's obesity, that is, the height and weight exceed 20% of the ordinary children of the same age, and they have illness history of having much food and little exercise which corresponds with the adiposity. They have well-proportioned body and no heart or lung diseases, no consequent fatness caused by incretion, metabolism, or central nervous system diseases. Meanwhile, another 30 healthy children, 16 boys and 14 girls, aged 7-12, were chosen to control group (group B, n=30). Informed consent was obtained from all participants. The whole procedure of this study was conformed to the ethic standard set by the human body experiment committee of the hospital and the study has been approved by this committee. The children involved in this experiment are clear about the whole process and their guardians have signed an agreement. There had no statistic significance in age and gender between two groups (P>0.05). Levels of oxidized low-density lipoprotein, homocysteine were measured by enzyme linked immunosorbent assay(ELISA). The concentration of plasma malondialdehyde was measured by thiobarbituric acid reactive substance(TBARS) method. All children were avoided to eat high-protein food for 3 days and fasted for 12 hours before the blood samples were taken.

No significant homocysteine level differences were found in boys and girls between two groups(P>0.05). Body mass index, homocysteine, malondialdehyde, oxidized low-density lipoprotein in group A were significantly higher than those of group B. Significant correlation between homocysteine level and body mass index (r=0.44, P<0.05), homocysteine level and malondialdehyde (r=0.47, P<0.01) were found in group A. There was not any relations between homocysteine levels and oxidized low-density lipoprotein (r=0.30, P>0.05).

There was an increased oxidative stress in obese children, and the increase of homocysteine level was closely associated with lipid peroxidation. Abnormal lipid metabolism exists in obese children.

obesity; homocysteine(Hcy); malondialdehyde(MDA); oxidized low-density lipoprotein(OX-LDL); body mass index(BMI); child