中国儿童青少年身高与日照暴露时间的关联

Analysis of association between the height and sun exposure among Chinese children and adolescents

目的探讨中国7~18岁儿童青少年身高水平与日照暴露时间之间的关联,为儿童青少年生长迟缓的防治提供科学依据。方法从2014年全国学生体质与健康调研的数据中抽取31个省会城市和直辖市的7~18岁儿童青少年73 848人,收集各省会城市日照时间、海拔高度等信息。将年平均日照暴露时间分为<1 000,1 000~1 499,1 500~1 999,2 000~2 499,≥2 500 h 5个等级,采用Pearson相关分析日照暴露与身高的关联程度;计算年龄性别身高Z评分,分析学生身高Z评分随日照暴露等级的变化情况;采用多水平模型,分析不同日照暴露等级与中国儿童青少年身高Z评分和生长迟缓之间的关系。结果身高与年平均日照暴露时间的相关性随年龄有递增的趋势,男生除10~13岁,女生除7~11岁,相关性均有统计学意义(P值均<0.05)。处于第1~4日照暴露等级内,身高Z评分的均值随日照等级的升高而逐渐增加;第5个等级身高Z评分较第4个等级有所下降,男女生呈现相同趋势。日照等级高的地区,儿童青少年生长迟缓的检出率较低。多水平分析模型控制学生和地区相关变量之后,与处于第1日照等级的学生相比,第2~5日照等级与身高Z评分均呈正相关(β=0.15~0.17),第3~5等级差异均有统计学意义(P<0.05);第2~5日照等级与生长迟缓的检出率呈负相关(β值介于-1.66~0.52),第3~5等级差异均有统计学意义(P<0.05)。男女生呈现相同趋势。结论中国儿童青少年身高与日照暴露时间整体呈正相关,年平均日照暴露时间越长的地区对身高的影响越大,该地区学生生长迟缓的发生风险也越低。

Objective To determine the association between height and the time of sun exposure in children and adoles- cents in China. Methods The data about children and adolescents aged 7-18 years of 31 provincial capital cities and municipali- ties was extracted from 2014 Chinese National Surveys on Students＂ Constitution and Health and environmental data was also collect- ed from historical data. The sun exposure time was divided into five categories, including less than 1 000 hours, 1 000-1 499 hours, 1 500-1 999 hours, 2 000-2 499 hours, and more than 2 500 hours. Height Z-score was calculated according to different a- ges and genders, and the change rules of the height of Z-score of boys and girls was analyzed according to different levels of sun ex- posure. Pearson correlation analysis and multilevel statistical models were used to evaluate the relationship between the height and the time of sun exposure. Results The correlation between height and average time of sun exposure has increasing trend along with the age in both sexes. The mean of height of Z-score gradually increase with the rising of time of sun exposure in the sun exposure grade of 1-4 level. In the fifth grade, the mean of height Z-score was lower than the fourth grade. There was the same trends in boys and girls. The stunting rate of children and adolescents was low in the region of high grade of sun exposure. According to the results of multilevel statistical models analysis, there was a positive relationship between the height Z-score and the time of sun exposure, and the risk of stunting of children and adolescents declined obviously in 2-5 levels of sun exposure compared with the lowest grade of sun exposure. Conclusion There is a positive association between time of sun exposure and height in children and adolescents aged 7-18 years. The influence of time of sun exposure on the height of students is higher in the region of high grade of sun expo- sure where the risk of stunting is lower compared to the region of lowest sun exposure.