[Epidemiological characteristics and changes of metabolic abnormalities among students aged 6-14 in Beijing in 2015...

To study the epidemiological characteristics and changes of central obesity, abnormal blood glucose, and dyslipidemia among students aged 6-14 in Beijing.

A multi-stage stratified cluster sampling method was employed in both 2015 and 2019. Three urban districts and four suburban districts were selected from Beijing. In each district, four primary schools and four junior middle schools were sampled. In the first, third, and fifth grades of primary school and the first grade of junior middle school, two classes of students were randomly selected from each grade, among whom those participating in the dietary nutrition and health survey were required to have their blood drawn on an empty stomach. A total of 3558 students were included in 2015, and 3449 in 2019. The information of students' birthday, gender, height, waist circumference, fasting blood glucose(FBG), total cholesterol(TC), triglyceride(TG)，low density lipoprotein-cholesterol(LDL-C), high density lipoprotein-cholesterol(HDL-C)was collected. Wilcoxon rank-sum test were used to compare the differences between the two years. Prevalence of metabolic abnormalities among students with different demographic characteristics were described using composition ratios, and differences between the two years were compared using the chi-square test. Generalized linear mixed models were used to analyze the association between year and the detection rate of metabolic abnormalities, with adjustments for age, sex, and region of residence.

The study participants had a mean age of (9.6 ± 2.3) years. In 2015, there were 1822 boys (51.2%) and 1736 girls (48.8%). In 2019, there were 1756 boys (50.9%) and 1693 girls (49.1%). Compared with 2015, the quartile distributions of waist circumference to height ratio(WHtR), FBG, and LDL-C levels among students aged 6-14 in Beijing shifted downward in 2019, while those of TC, TG, and HDL-C shifted upward (P<0.05). The prevalence of central obesity decreased from 29.0% to 25.2% (χ2 = 12.47, P<0.01), that of abnormal blood glucose increased from 6.2% to 7.9% (χ2 = 7.51, P<0.01), and that of dyslipidemia decreased from 24.1% to 21.7% (χ2=5.72，P=0.02). The prevalence of both central obesity and abnormal blood glucose were higher among students aged 10-14 years than among those aged 6-9 years, higher in boys than in girls, and higher in suburban students than in urban students (P<0.05). The prevalence of dyslipidemia was lower in boys than in girls (P<0.05). After adjusting for age, sex, and region of residence, the prevalence of central obesity and dyslipidemia among students in 2019 remained significantly lower than those in 2015 (OR=0.82, 95％CI 0.74-0.92;OR=0.87, 95％CI 0.78-0.98). The prevalence of abnormal blood glucose was significantly higher in 2019 than in 2015 (OR=1.31, 95％CI 1.08-1.58).

The prevalence of central obesity and dyslipidemia among students aged 6-14 in Beijing has shown improvement, yet remains at a high level. Additionally, the prevalence of abnormal blood glucose has increased.