铁缺乏对学生认知能力的影响

【作者】 王冰；

【导师】 霍军生； 孙静；

【作者基本信息】 中国疾病预防控制中心 ， 公共卫生， 2009， 硕士

【摘要】 研究背景随着我国改革开放和经济的快速发展,人口的流动不断增加。截至2007年6月底,公安部等相关部门调查显示:北京市总人口数量已经突破1700万人,其中,北京市户籍人口1204万人,流动人口数量已达到510万人,约占总人口数的三分之一。流动人口子女的教育是社会上普遍关注的问题,而他们的健康状况也受到相关部门的关注。2002年11～12月国务院妇儿工委办公室、中国儿童中心及UNICEF在全国九市进行了流动人口儿童健康状况抽样调查。结果显示:流动人口儿童的死亡率较高,常见病发病率较高,营养状况较差,卫生保健知识缺乏。调查流动人口儿童的主要食物的摄入情况与2000年全国14省城市儿童情况相比,其奶类、肉类、鱼虾类、蛋类、水果蔬菜每日食用的情况均低于城市常住儿童,导致流动人口儿童贫血、佝偻病、营养不良、生长发育迟缓等营养性疾病明显高于城市儿童。在形成人口素质的三个要素（遗传、营养和教育）中,营养状况对于人的智力和发展潜能的制约作用非常显著。生长发育时期膳食中长期营养素摄入不足,不仅影响机体的体格发育,还会影响认知能力的发育,尤其是铁缺乏。铁缺乏可引起一系列中枢神经系统功能的紊乱,包括情绪、运动和认知等多个方面。认知能力包括智力、注意力、记忆力等。缺铁可导致认知能力和学习成绩减退。且铁缺乏越严重,认知能力和学习成绩就越低下。为提高政府相关部门及社会群体对流动人口特别是他们子女健康的关注程度,我们需要进一步了解城市打工子弟学校学生的营养状况,通过系统的认知能力测试探讨铁缺乏及不同程度铁缺乏对青少年认知能力的制约作用。研究目的了解北京市大兴区蒲公英中学学生的营养和健康状况,调查学生认知能力及学习成绩,探讨铁缺乏及不同程度铁缺乏对学生认知能力及学习成绩的影响。并有针对性地提出科学合理的干预措施,为学校安排集体的膳食提供帮助。方法和对象选取北京市大兴区蒲公英中学在校学生,采用横断面调查方法于2007年6月及10月分别对学生进行营养调查,包括膳食调查（寄宿学生采用查帐法、非寄宿学生采用三日24小时膳食回顾法,计算学生膳食营养素摄入量,评价其营养状况,分析影响因素）,体格检查（身高、体重）,实验室生化检测（血红蛋白、血清铁、血清铁蛋白、血清转铁蛋白受体、血清锌、血清维生素A、尿中硫胺素及核黄素）,问卷调查（包括学生性别、年龄、民族;家庭收入;学生父母年龄、文化程度、职业等）,并对学生进行《托尼非语文智力测验》和《基本认知能力测验》,收集学生2007年6月的期末语文、数学、英语、思品、地理、历史等考试成绩。结果1、城市打工子弟学校学生营养状况1.1营养素摄入量不足:膳食营养素达到90%以上RNI/AI的有维生素C、镁、钾。达到RNI 80～90%的有能量、蛋白质。摄入不足的有维生素A、维生素B₁、维生素B₂、钙、铁、锌和硒,尤其是钙、锌和铁只有RNI/AI的32.0%、63.7%和64.9%。维生素A缺乏率为7.0%,维生素B₁缺乏率为7.4%,维生素B₂缺乏率为8.7%,34.8%的学生血清锌低于正常水平。铁缺乏较为严重,贫血率达到11.3%。1.2学生生长发育状况差:各年龄组男、女生身高和体重均值均低于北京市及大兴区总体水平。学生营养不良率高达30.3%。2、铁缺乏及不同程度铁缺乏对学生认知能力及学习成绩的影响铁缺乏学生相对于铁正常学生,认知能力差。铁缺乏学生按照贫血与否进一步分为严重铁缺乏和边缘铁缺乏。严重铁缺乏通常是指缺铁性贫血,而边缘铁缺乏通常是指缺铁不贫血。在注意力、记忆力、智力方面,平均得分最低都是缺铁性贫血学生,其次为缺铁不贫血学生,得分最高的都是铁状态正常学生。说明铁缺乏越严重,认知能力就越低下。调整社会人口学资料等混杂因素后,铁缺乏学生相对铁正常学生在记忆力、智力及认知能力总分方面有更高的不及格风险。学生的考试成绩包括语文、数学、英语和思品。其中语文和数学成绩铁缺乏学生低于铁正常学生,且差异有统计学意义。把铁缺乏学生进一步分为缺铁性贫血学生和缺铁不贫血学生,语文和数学成绩平均分缺铁性贫血学生最低,缺铁不贫血学生其次,铁正常学生最高。说明铁缺乏越严重,语文和数学成绩就越低。调整社会人口学资料等混杂因素后,铁缺乏学生相对铁正常学生在语文和数学方面有更高的不及格风险。结论1、城市打工子弟学校学生的营养状况差。营养不良、贫血、营养素缺乏率（包括铁缺乏率、锌缺乏率、维生素A缺乏率、维生素B₁缺乏率、维生素B₂缺乏率）明显高于北京市同龄学生。2、长期营养素缺乏,尤其是铁缺乏,使机体处于铁缺乏状态,导致学生认知能力,包括注意力、记忆力、智力及学习成绩差,且铁缺乏越严重,认知能力及学习成绩就越低下。更多还原

【Abstract】 BackgroundAs china’s reform opening up and rapid economic development,population mobility isincreasing. As by the end of June 2007, The Ministry of Public Security, and other relevant departments investigate: Beijing’s total population of over 17,000,000 people. Among them, Beijing household registration of the population has reached 12,040,000, the number of floating population breakthrough 5,100,000, accounting for about one-third of the total population.Migrant children’s education is widespread concern in society, they are also the health status of the same by the relevant departments. In November 2002 to December,women and children, the State Council Work Committee Office, UNICEF and the China Children’s Center in Kowloon City, the country had a floating population of children of a sample survey. The results showed that: Floating population of high child mortality rate, high incidence of diseases, poor nutrition, lack of health knowledge. Investigation of the floating population of children within 1 week of the main food intake in 2000 and 14 cities in the province of children within 1 week diet shows that their milk, meat, fish and shrimp, eggs, fruits and vegetables daily consumption of the situation Lower than those in urban resident children, migrant children leading to anemia, rickets, malnutrition, stunted growth, and other nutritional disorders were significantly higher than urban children.The quality of the population in the form of three elements （genetic, nutrition and education）, the nutritional status of the person’s intellectual development and the potential constraints of a very significant role. Dietary intake of nutrients and long-term shortage not only affects the body’s physical development, but will also affect cognitive development, especially iron deficiency. Iron deficiency can cause a range of functions of the central nervous system disorders, including emotional, physical and cognitive, and other aspects. cognitive including attention, memory, learning ability, and so on. Iron deficiency can lead to cognitive and learning ability decreased, especially in math dropped. And the more severe iron deficiency, cognitive and mathematical results will be lower.In order to enhance the relevant government departments and social groups on the movement of the population, especially the health of their children, we need a better understanding of urban school students work in the nutritional status, through the system of cognitive tests to explore varying degrees of iron deficiency and iron deficiency on the Juvenile cognitive constraints of the role.Objective Understanding of the Beijing Daxing District Pu gongying middle Schoo students nutritional and health status of the investigation and the academic ability of students to understand and explore varying degrees of iron deficiency and iron deficiency on cognitive and academic performance of students. And put forward scientific and reasonable intervention, the collective arrangements for the school meals to help.MethodCross-sectional survey methodology used in June 2007 and October respectively, the students carried out a nutrition survey, including physical examination （height, weight）, biological and chemical detection laboratory （hemoglobin, hematocrit, serum iron, serum ferritin, serum transferrin Receptor, serum zinc and serum vitamin A, thiamine in the urine, riboflavin）, Dietary surveys （selected Pu gongying middle schools in September 2007 the food consumption records of students,calculated dietary nutrient intake, nutritional status of its evaluation, impact analysis. and sampling method used for three consecutive days, the students measured in actual food intake of nutrients）, Survey （including ethnic, family income, parents of students age, educational level, occupation）, "Toni2 test of nonverbal intelligence " and "the basic cognitive tests," student survey on Chinese, mathematics, English, Moral Character,geography and history test scores in June 2007 at the end. of semester.Results1. Nutritional status of the students in Beijing Pu Gongying middle school1.1 Inadequate intake of nutrients: dietary more than 90% RNI/AI of vitamin C, magnesium and potassium. Achieve RNI 80-90 % of energy and protein. Inadequate intake of vitamin A, vitamin B₁, vitamin B₂, calcium, iron, zinc and selenium. In particular, calcium, zinc and iron only RNI/AI of 32.0 %, 63.7 % and 64.9 %.A lack of vitamin rate of 7.0 %, a lack of vitamin B₁ was 7.4 %, a lack of vitamin B₂ rate of 8.7 %, 34.8 % of students in lower than normal levels of serum zinc. iron deficiency is more serious, and anemic rate of 11.3 %.1.2 Growth and development of poor students: All age groups of boys and girls average height and weight are lower than overall level of Beijing and Daxing District. Student’s malnutrition rate as high as 30.3 %.2. Iron deficiency and iron deficiency in varying degrees of students affect on academic performance and cognitive ability.Through cognitive tests, the results showed that: Iron deficiency students opposed to normal students, poor cognitive ability. In accordance with anemia or not, the students further into marginal iron deficiency and serious iron deficiency. Severe iron deficiency usually refers to the iron deficiency anemia （IDA）, and Marginal iron deficiency usually refers to the non-iron-deficiency anemia （ID）. In attention, memory, intelligence, the lowest average score is IDA students, followed by ID students, the highest scores are the normal students. That the more severe iron deficiency, the more low cognitive ability. After social adjustment of demographic data, such as confounding factors, iron deficiency students relative normal students in memory, mental and cognitive scores have a higher failure risk.The test scores of students, including Chiese, mathematics, English and Moral Character. Among Chiese and mathematics iron deficiency students are worse than the normal students, and the difference was statistically significant. The students further divided into iron deficiency anemia（IDA） and non-iron-deficiency anemia（ID）, the lowest average score is IDA students, followed by ID students, the highest scores are the normal students. That the more severe iron deficiency, the more low average score. After social adjustment of demographic data, such as confounding factors, iron deficiency students relative normal students in Chiese and mathematics have a higher failure risk.ConclusionsCity school students to work in malnutrition, anemia, a lack of nutrients （including iron deficiency, zinc deficiency, a lack of vitamin A, a lack of vitamin B₁, vitamin B₂ lack of rate） was significantly higher than local students of the same age.Long-term lack of nutrients, especially iron deficiency,iron deficiency in the body so that the state of cognitive,including attention, memory, intelligence and academic performance is poor, and the more severe iron deficiency, cognitive and academic performance will be lower.更多还原