宁波市7岁以下儿童年龄别身高、体重和体重指数变化特点

Research on the growth references of height, weight and body mass index for children under 7 years old

目的探讨宁波市7岁以下儿童年龄别身高、体重、BMI变化特点及体格发育现状和规律。方法随机整群抽样调查64038名健康儿童的身高、体重，按年龄别性别计算身高、体重、BMI的均值、标准差和百分位数，与WHO（2006年）和中国9市城区（2005年）调查结果的参照标准进行比较。结果男女儿童体重、身高的年增长速度基本一致，各项指标随年龄增加而增长，年龄越小增长速度越快，且存在性别和城乡差异。儿童BMI随年龄和性别不同有明显变化，4～6个月时达高峰，以后随年龄增加而缓慢下降。结论宁波市7岁以下儿童身高、体重平均生长水平已达到甚至超过WHO标准，儿童体重、身高的年增长速度与2005年中国9市城区调查的同年龄人群平均水平总趋势一致。

Objective To understand the varying features and the trend of length/height-for-age, weight-for-age and body mass index（BMI）-for-age of children under six years old in Ningbo city, Zhejiang province. Methods By random clustered sampling, 64 038 healthy children under six years old in Ningbo were chosen and their length/height and weight measured. Means, standard deviation and percentiles of length/height-for-age, weight-for-age and BMI were calculated by SAS systems. Results of this study were compared with growth standards from WHO 2006 and nine urban areas of China, in 2005. Results Data from our study showed that the annual growth rates were basically the same in boys and girls. All these indicators increased along with age but the younger the age, the faster the growth rate appeared. There were notable differences seen between genders and urban-rural distribution. BMIs were also varied with age and sex. BMI reached peak between 4 to 6 months, then dropped slowly when age increased. Conclusion The means of length/height-for-age, weight-for-age in Ningbo city had exceeded the WHO standards, and the growth by year under six year-olds in Ningbo was close to the data from nine urban areas of China in 2005.