[Effects of overweight and obesity on physical function among children and adolescents: a multilevel analysis]

To analyze the influence of overweight and obesity on body function among children and adolescents using a multilevel model, and to provide the basis for understanding their influence.

According to the "Reference Norms for Screening Overweight and Obesity in Chinese Children and Adolescents" set up by Working Group Obesity in China (WGOC) in 2003, we screened out individuals with overweight and obesity from the data obtained from the body and health survey of Chinese children and adolescents in 2005. The samples of the non-overweight group and the overweight group were randomly selected from the screened data by 1:1 match with samples of the obesity group by gender and city/rural area, then underwent the multilevel model to explore the influence of overweight and obesity on body function.

The single dependent variable model showed that the overweight group had significant increases in systolic blood pressure (SBP) and diastolic blood pressure (DBP) by 5.25 mmHg (1 mmHg=0.133 kPa) and 3.44 mmHg, respectively (P<0.01), when compared with the non-overweight group. There were no significant differences between the overweight and non-overweight groups in pulse and vital capacity (VC) (P>0.05), and the obesity group had significant increases in SBP, DBP, pulse and VC by 10.15 mmHg, 6.34 mmHg, 1.44 times/min and 390.04 mL, respectively (P<0.01), when compared with the non-overweight group. The multiple dependent variables model showed that the SBP, DBP and pulse of the overweight group and obesity group were significantly greater than those of non-overweight group (P<0.01). There was a significant difference between the overweight group and non-overweight group in VC (P<0.05), yet the same result was not found between the obesity group and non-overweight group (P>0.05).

Overweight and obesity may cause a decline in body function among children and adolescents, and obesity has a more obvious influence on body function.