Objective: To observe and compare the effects of two standards on the overweight trend in urban Shanghai infants and young children. Methods: A cluster randomized controlled trial was conducted in 19 communities in two districts of Shanghai, and the subjects (n=15 019) were divided into S-group and W-group by sealed envelope randomization. The subjects were newborns born between November 2013 and December 2014. The 2005 Shanghai growth standard was applied in the S-group and the 2006 WHO growth standard was used in the W-group. At each follow-up time point age of 1, 2, 4, 6, 9, 12 and 18 months, the outpatient physician assessed the length and weight of the infants according to the standard adopted by each group and provided feeding guidance. The weight-for-age Z scores (WAZ), length-for-age Z scores (LAZ) and weight-for-length Z scores (WLZ) were calculated according to the WHO standard. Weight, length, WAZ, LAZ, WLZ and overweight ratio (WLZ≥2) were compared between the two groups using t test, Wilcoxon test and χ(2) test. Results: A total of 6 509 infants (3 391 were boys, 3 118 were girls) were in the W-group, and 8 510 infants (4 374 were boys, 4 136 were girls) were in the S-group. Among the boys, the weight values at the age of 4, 6, 9, 12, 18 months in the W-group were all lower than those in the S-group ((7.5±0.8) vs. (7.7±0.8) kg, (8.6±0.8) vs. (8.7±0.8) kg, (9.6±0.9) vs. (9.7±0.9) kg, (10.4±1.0) vs. (10.5±1.0) kg, (11.5±1.1) vs.(11.7±1.1) kg; t=4.329, 2.422, 3.739, 2.451, 2.736; P<0.01, 0.015,<0.01, 0.014, 0.009). The length had no significant difference between two groups at all months of age(all P>0.05). The overweight ratio in the W-group was lower than that in the S-group at the age of 9, 12, 18 months(3.3% (71/2 170) vs. 4.9% (143/2 927), 2.5% (51/2 037) vs. 4.5% (126/2 818), 0.8% (7/832) vs. 3.1% (39/1 266); χ(2)=6.520, 14.209, 12.350; P=0.011,<0.01,<0.01).Among the girls, except at the age of 2 months (W-group (5.6±0.6) vs. S-group (5.7±0.6), t=2.935, P=0.003), weight values had no significant difference between the two groups at other age months (all P>0.05).The length in the W-group was higher than that in the S-group at 12 and 18 months of age ((75.6±2.4) vs.(75.5±2.3)cm, (82.4±2.9) vs.(82.2±2.7) cm; t=2.351, 2.197; P=0.019, 0.028). The ratio of overweight in the W-group was lower than that of S-group at the age of 12 and 18 months (1.8% (33/1 871) vs.3.0% (80/2 658), 0.6% (5/790) vs.1.7% (20/1 178); χ(2)=6.764,4.276; P=0.009, 0.039). Conclusions: The application of WHO growth standard can help to reduce the weight gain rate of boys, promote the linear growth of girls, and thus alleviate the overweight trend of infants within 18 months. It suggested that 2006 WHO growth standard should be applied to infants within 1 year of age in Shanghai.
目的： 比较两种生长评价标准的长期应用对上海市城区婴幼儿超重肥胖的影响。 方法： 采用整群随机对照研究，选取上海市虹口区和杨浦区的19个社区为调查点。调查对象为2013年11月至2014年12月出生的正常新生儿15 019名，随访时间点为1、2、4、6、9、12、18月龄。19个社区按随机信封分配成两组，一组为上海标准组，应用2005版上海儿童体格生长评价标准，另一组为世界卫生组织（WHO）标准组，应用2006年WHO发布的儿童体格生长评价标准。在每个随访时间点，门诊医生分别采用上海标准和WHO标准对随访儿童的身高和体重进行评价及喂养指导。将随访获取的身高、体重值，根据WHO标准计算年龄的体重（WAZ），年龄的身长（LAZ）和身长的体重（WLZ），以WLZ≥2为儿童超重标准。建立社区卫生服务中心层面的重复测量资料混合效应模型，比较两组间WAZ、LAZ和WLZ，结合t检验，Wilcoxon秩和检验和χ(2)检验比较两组间各年龄段的身高、体重、WAZ、LAZ、WLZ和超重率的差异。 结果： 上海标准组8 510名（男4 374名、女4 136名），WHO标准组6 509名（男3 391名，女3 118名）。男童体重4、6、9、12、18月龄WHO标准组均低于上海标准组[（7.5±0.8）比（7.7±0.8）kg、（8.6±0.8）比（8.7±0.8）kg、（9.6±0.9）比（9.7±0.9）kg、（10.4±1.0）比（10.5±1.0）kg、（11.5±1.1）比（11.7±1.1）kg，t=4.329、2.422、3.739、2.451、2.736，P<0.01、0.015、<0.01、0.014、0.009]。男童身长各月龄两组间差异均无统计学意义（P均>0.05）。男童超重率9、12、18月龄WHO标准组低于上海标准组[3.3%（71/2 170）比4.9%（143/2 927）、2.5%（51/2 037）比4.5%（126/2 818）、0.8%（7/832）比3.1%（39/1 266），χ(2)=6.520、14.209、12.350，P=0.011、<0.01、<0.01]。女童体重除2月龄WHO标准组低于上海标准组[（5.6±0.6）比（5.7±0.6）kg，t=2.935，P=0.003]，其他月龄两组间差异均无统计学意义（P均>0.05）。女童身长12、18月龄WHO标准组均高于上海标准组[（75.6±2.4）比（75.5±2.3）cm、（82.4±2.9）比（82.2±2.7）cm，t=2.351、2.197，P=0.019、0.028]。女童超重率，12、18月龄WHO标准组均低于上海标准组[1.8%（33/1 871）比3.0%（80/2 658），0.6%（5/790）比1.7%（20/1 178），χ(2)=6.764、4.276，P=0.009、0.039]。 结论： 应用WHO标准有利于降低男童体重增长速度，促进女童身长增长，因而降低18月龄内婴幼儿的超重趋势，建议上海城区1岁内儿童应用2006年WHO标准。.
Keywords: Child; Overweight; Randomized controlled trial; Reference standards; Sex factors.