Growth,Development And Nutritional Status Of2017Primary And Secondary School Students In Chongqing

Objective：Nutritional status is a sensitive indicator of students’ health. Malnutrition will directlyaffect the physical and mental development of teenagers and children, which may result inreduced immunity, growth retardation, and decreased learning ability. Bone age, height, bodyweight and Hb are basic indicators of reflecting the growth and development of teenagers andchildren, but also important indicators of reflecting the body characteristics and nutritionalstatus. In this paper, the author surveyed the bone age, height, weight, Hb of a number ofprimary and secondary school students in Chongqing, investigated their growth, developmentand nutritional status, aiming to provide a scientific reference for promoting school students’health care.Methods：1. Survey respondents: There are2017primary and secondary school students aging5-19years from Yuzhong District, Beibei District, Tongliang County and Qianjiang County inChongqing, including1031boys and986girls.2. Bone age determination: Perform X-ray examination of left wrist according to the“The Skeletal Development Standards of Hand and Wrist for Chinese Children-CHN method”.Calculate bone age by scoring each wrist bone, and analyze the correlation of bone age andchronological age and the difference between bone age and gender.3. Nutritional status: Measure height and weight in accordance with the “NationalStudents’ Physical Fitness and Health Standard”. Divide students into5levels of malnutrition,low weight, normal, overweight and obesity in accordance with “Weight-for-height CriterionStandards for Adolescents and Children (2000)".4Data statistical analysis: Perform statistical analysis using the SPSS19.0statisticalpackage, describe numeric variables with the mean and standard deviation, and performbetween-group comparison using t-test and chi-square test analysis. Results：1. Correlation between bone age and chronological age: A highly significant positivecorrelation was observed between bone age and chronological age; boys: r=0.942(P <0.01),girls: r=0.935(P <0.01), overall: r=0.938(P <0.01). The mean bone age was older than thechronological age at all ages.2. Comparison between bone age and chronological age in boys and girls of all ages: Themean bone age was older than the chronological age in all-age groups. There was significantdifference between bone age and chronological age in boys of all ages (P <0.05), while boneage and chronological age significantly differentiated in girls of at all ages except the7-year-old group (P <0.05).3. Height: In comparison with the national height level in the year2010, boys’ heightwas lower than the national average height at all ages except the12-year-old group (P <0.05);the average height of girls of7years old,8years old,9years old,10years old,11years old,12years old,13years old and14years old was lower than the national average height in theyear2010(P <0.05). In comparison with the average height level of Chongqing in2000, theaverage height of boys of9years old,12years old,13years old,14years old was higher thanthe Chongqing level in2000, while lower in the rest age groups. There was significantdifference among the age groups of7years old,11years old,12years old,13years old (P<0.05); girls’ height was lower than the Chongqing level in the year2000in7-year-old group,and higher in the rest age groups. Moreover, there was statistical difference among8yearsold,12years old, and13years old groups (P <0.05).4. Weight: Boys’ weight at all ages was lower than the national average level in2010,and there was significant difference among groups of9years old,10years old,11years old,and13years old (P <0.05); girls’ weight was higher than the national level in the8-year-oldand14-year-old groups, while lower than the national average level in the rest age groups (P<0.05). Moreover, girls’ weight indicated statistical difference in age groups of7and11years.The average weight of boys and girls at all ages was higher than the Chongqing level in theyear2000(P <0.05).5. Nutritional status: Among the surveyed2017students, the detection rate of normalnutrition, malnutrition, low birth weight, overweight and obesity was48.0%,2.7%,30.7%,7.0%,10.7%, respectively. The proportion of normal nutrition of boys accounted for44.2%, which was lower than that of girls (53.8%); the proportion of boys’ malnutrition accounted for3.8%, which was higher than that of girls (1.6%); the proportion of low birth weight of boyswas32.7%, higher than that of girls (28.6%); the boys’ obese ratio was12.4%, higher thanthat of girls (8.8%). There was statistical difference between boys and girls （P<0.05. Therewere298students with anemia, with the incidence being14.7%. Among the298anemiastudents, there were231students with borderline anemia, accounting for77.52%;64studentswith mild anemia, accounting for21.48%;3students with moderate anemia, accounting for1.01%.Conclusion：1. The bone age changes with the growth of the chronological age, and is highlypositively correlated with the chronological age. Bone age of the boys and girls at all ages isolder than the chronological age, suggesting higher actual growth level than the developmentlevel standardized by the chronological age, namely, earlier bone development in children andadolescents in this group.2. The height and weight of students in Chongqing present an ascending trend comparedwith the results in2000. However, the overall level of morphological development is lower,which has not yet reached the national average level, and lags behind other major cities.3. Problems including malnutrition, low birth weight, overweight and obesity exist inboys and girls, and low birth weight presents a higher incidence. The incidence ofmalnutrition, low birth weight, and obesity in boys was higher than in girls. The overallnutritional status of girls and primary school students is better than that of boys and secondaryschool students, respectively.4. There are298students with iron-deficiency anemia, accounting for14.7%, suggestingthat nutrition education and prevention of iron-deficiency anemia should be strengthened instudents.