Characteristic analysis for change in health for Han primary and secondary school students from 1985 to 2010 in Ningxia

Abstract

Objective To analyze the dynamic trends of physical development, constitutional fitness, and pre-valence of obesity among Han children and adolescents in Ningxia aged 7-18 years from 1985 to 2010. Methods Data were collected from the National Survey on Students Constitution and Health in 1985, 1991, 1995, 2000, 2005 and 2010, respectively.Height, weight and chest circumference were used to evaluate physical development, vital capacity, 50-meter running and vital capacity versus weight ratio for the evaluation of constitutional fitness. Results 1.Weight and chest circumference increased faster than height.The average annual increase of weight among the urban girls was significantly faster than those in rural areas.2.The tempo per year of vital capacity in both boys and girls decreased during 25 years, especially after 2005.The rural students had a faster tempo than those in the urban students, and the rate in boys was higher than those in girls.Vital capacity to weight ratio in boys decreased from 2005 much more than before, and had a decreasing trend in each age group except for a few groups in girls.There was a decrease in the mean time of 50-meter running in both boys and girls from 1985 to 2005, whereas the decrease became slow during 1995-2005.The prolonged trend in 50-meter-run time existed during 2005-2010.The average prolonged speeds per decade in boys and urban students was higher than that in girls and rural areas.3.From 1985 to 2010 year, the increasing pre-valence of overweight and obesity among boys and girls was 15.0%, 25.0% and 28.1%, 12.4%, respectively.The average increasing rate was much higher in the obese than in the over-weighted children, and there were more in boys than in girls.There was a similar positive trend of increasing prevalence of overweight and obesity with the increased gross domestic product. Conclusions The physical growth and development among students in Ningxia increased rapi-dly, along with the descending trend of average annual rate of physical fitness as well as the rising trend of prevalence obesity.Some measures should be taken by the government to tackle with the situation, and the healthy intervention should be applied to the high risk population. Key words: Children and adolescents; Growth and development; Gross domestic product; Obesity; Ningxia