[Relationship between obesity, overweight and physical function in students of Han nationality aged 7 - 18 years in 2010].

OBJECTIVE: To study the effects of overweight and obesity on physical function (including systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse, weight vital capacity index) in children and adolescents.

METHODS: The data of 2010 Chinese National Survey on Students Constitution and Health was analyzed. The samples of overweight and normal-weight group were randomly selected from the data by matching gender, urban or rural for getting the same number sample size as obese group (10 601 each group). The students aged 7 - 18 years were classified into 3 groups by BMI percentiles (P₅, P₁₅, P₂₅, P₅₀, P₇₅, P₈₅ and P₉₅), to analyze the change of physical function along with BMI percentile.

RESULTS: Compared to the normal-weigh group, SBP of the obese boys of all age groups increased by 8.0 - 12.0 mm Hg, DBP increased by 4.7 - 5.9 mm Hg, while SBP of the obese girls increased by 7.5 - 11.6 mm Hg, DBP increased by 4.7 - 6.1 mm Hg, with statistical significance (P < 0.05). In 13 - 15-year group, pulse of obese boys was 0.8 times/min higher than that of normal-weight. In 16 - 18-year group, pulse of obese boys was 1.1 times/min higher than that of overweight or normal-weight, while pulse of obese girls were 1.5 and 1.7 times/min higher than that of overweight and normal-weight, respectively (P < 0.05). Pulses in boys aged 7 - 9 years when BMI were P₅, P₅₀, P(95) were 87.63, 87.00, 87.83 times/min, and pulses in boys aged 10 - 12 were 85.66, 85.30, 85.43 times/min, respectively. Pulses in boys aged 13 - 15 years when BMI were P₅, P₅₀, P₉₅ were 82.60, 81.39, 82.34 times/min, and pulses in boys aged 16 - 18 years were 80.15, 79.00, 79.98 times/min. In both boys and girls of all age groups, weight vital capacity index had the trend of obese < overweight < normal-weight (P < 0.05). Compared to the normal-weight group, weight vital capacity index of overweight boys decreased by 6.4 - 8.4 ml/kg, that of obese boys decreased by 11.9 - 14.8 ml/kg, while that of overweight girls decreased by 5.3 - 7.7 ml/kg, that of obese girls decreased 11.0 - 11.5 ml/kg.

CONCLUSION: Compared to the normal-weight, overweight and obese children and adolescents had elevated blood pressure, increased pulse, decreased weight vital capacity index.