关键词: 骨密度, 婴幼儿, 学龄前儿童, 流行病学调查

Abstract: Objective To explore the bone mineral density(BMD) of 0 to 5-year-old children in Jiangsu province monitored by quantitative ultrasound,and to analyze the association among sex,age,births,district,season and BMD,in order to provide reference for making intervention strategies. Methods A stratified cluster random sampling method was used to select children aged 0-5 years in Jiangsu province from April 2014 to March 2015. Totally 5 289 children were investigated,including 2 786 boys and 2 503 girls. A face to face investigation was conducted by the prepared doctors with self-designed questionnaires to collect related details and the bone mineral density was measured. Analysis of covariance variance(ANOVA) was used to describe mean differences of continuous variables after adjusting potential covariates such as age,gender and chi-square test was used to examine differences in categorical variables. Results The overall detection rate of low BMD in 0 to 5-year-old children was 14.6%. And the low BMD rates in children aged 0-6 months,7-12 months,13-24 months,25-36 months,37-48 months,49-60 months and ≥60 months were 44.9%,21.9%,14.3%,10.0%,9.0%,9.1% and 11.6%,respectively,and the difference was significant(P＜0.001). No significant difference on detection rate of low BMD between boys and girls was found(14.8% vs. 14.5%,P=0.887). The detection rate of low BMD in preterm children was significantly higher than that of full-term children(20.9% vs. 14.4%,P=0.018). After adjusting the confounders of gender and age,the speed of sound(SOS) value in preterm infants was significantly lower than that in full-term infants,and SOS value in low birth weight infants was also lower than normal birth weight infants(P＜0.05). After adjusting the confounders of age,gender,gestational age,parity and birth weight,differences on SOS value was significant among different areas and seasons(P＜0.05). Conclusions The BMD level of children in Jiangsu province is generally low. And children under 1 year old are at high risk of low BMD,with the prevalence rate of 44.9% in 0 to 6-month-old infants. The BMD level of children is related to age,preterm,low birth weight,district and season,but is not influenced by gender,parity,delivery mode and dwelling district.

Key words: bone mineral density, infants, preschool children, epidemiological investigation