Zhao-Hui Cui

Prevalence of the metabolic syndrome in Chinese adolescents.

Since national figures on the occurrence of metabolic syndrome among Chinese adolescents are lacking, this study aims to estimate its prevalence and distribution among Chinese youngsters. The 2002 China National Nutrition and Health Survey is a nationally representative cross-sectional study. Applying the criteria for US adolescents, we estimated the prevalence of metabolic syndrome among 2761 adolescents aged 15 to 19 years. The prevalence of metabolic syndrome among Chinese adolescents overall was 3.7 % (10 % in US adolescents). It was 35.2 %, 23.4 % and 2.3 % among adolescents who were overweight (BMI > or = 95th percentile), at risk of overweight (BMI between 85th and 95th percentile) and normal weight (BMI below the 85th percentile), respectively. Urban boys had the highest rate (5.8 %) compared with girls and rural youngsters. Among adolescents who had a BMI > or = 85th percentile and one or two parent(s) with metabolic syndrome, the prevalence was 46.4 %. A total of 96 % of overweight adolescents had at least one and 74.1 % overweight adolescents had at least two abnormalities of metabolic syndrome. Based on these figures, it is estimated that more than three million Chinese adolescents have metabolic syndrome. Both overweight and metabolic syndrome prevalence among adolescents are still relatively low in China, but the prevalence of metabolic syndrome among Chinese overweight adolescents is similar to those living in the USA.

Physical activity level and its association with metabolic syndrome among an employed population in China

The purpose of the present study was to estimate the association of physical activity level (PAL) with metabolic syndromes among the employed population in China. Using data from the 2002 China National Nutrition and Health Survey, the PAL of 21u2003834 subjects aged 18–59u2003years was described, and its relationship with the risk of metabolic syndrome was studied after adjusting for the relative effects of smoking, drinking, diet and socioeconomic status. Information on physical activity was collected by trained investigators using a 1‐year physical activity questionnaire. PAL was classified into four categories: sedentary (PAL 1.00–1.39), low active (PAL 1.40–1.59), active (PAL 1.60–1.89) and very active (PAL 1.90–2.50). The definition of metabolic syndrome by the International Diabetes Federation 2005 was applied. The percentage of people being sedentary, low active, active and very active was 12.3%, 13.7%, 20.1% and 53.9% respectively. The crude prevalence of metabolic syndrome in the sedentary, low active, active and very active groups was 9.7%, 6.9%, 5.6% and 4.9% respectively. After adjusting for the effect of other risk factors, the higher the PAL, the lower the relative risk of metabolic syndrome as well as the individual metabolic abnormalities. The risk of overweight/obesity and metabolic syndrome was 50% and 59% less, respectively, in the adults who were very active and whose dietary fat contributed less than 20% to energy intakes when compared with their counterparts who were sedentary and consumed more fat (≥30% energy). PAL was an independent risk factor for obesity and multiple metabolic syndrome abnormalities among the employed population in China. The high‐risk population were middle‐age males living in large cities with high incomes who drink alcohol.

Evaluation of a classroom-based physical activity promoting programme

The purpose of the present study was to evaluate the effect of the Happy 10 programme on the promotion of physical activity, physical growth and development of primary school students, and on obesity control and prevention. Two similar primary schools from one district of Beijing, China were selected, one as an intervention school and the other as a control school. A Happy 10 programme was implemented at least once every school day in the intervention school for two semesters, whereas no intervention was adopted in the control school. The information on energy expenditure and duration of physical activity was collected by a validated 7‐day physical activity questionnaire. Height and weight were measured by the trained investigators following standardized procedure. Energy expenditure and intensity of each Happy 10 session were measured by a physical activity monitor. The average energy expenditure and duration of total physical activity per day among students in the intervention school increased significantly from 15.0 to 18.2u2003kcalu2003kg−1 and 2.8 to 3.3u2003h, respectively, whereas the figures significantly decreased in the control school. There was a significant difference in change of weight and body mass index between girls in the intervention and control school (2.4u2003kg vs. 4.6u2003kg; 0.47u2003kgu2003m−2 vs. 0.66u2003kgu2003m−2). The prevalence of overweight and obesity in the intervention school decreased by 0.4–5.6%, as compared with the increase by 0.6–4.5% in the control school. The average energy expenditure and intensity per 10‐min session ranged from 25.0 to 35.1u2003kcal and from 4.8 to 6.2u2003kcalu2003kg−1u2003h−1, respectively, in grades 1–5. The Happy 10 programme provides a useful strategy to promote physical activity among school children, and also plays a positive role in building up physical growth and development of girls.

Report on childhood obesity in China (8): effects and sustainability of physical activity intervention on body composition of Chinese youth.

OBJECTIVESnTo determine whether a large-scale physical activity intervention could affect body composition in primary school students in Beijing, China.nnnMETHODSnThe study design was one-year cluster randomized controlled trial of physical activity intervention (20 min of daily exercise in the classroom) with an additional year of follow-up among 4 700 students aged 8-11 years at baseline.nnnRESULTSnAfter the one-year intervention, BMI increased by 0.56 kg/m(2) (SD 1.15) in the intervention group and by 0.72 kg/m(2) (SD 1.20) in the control group, with a mean difference of -0.15 kg/m(2) (95% CI: -0.28 to -0.02). BMI z score decreased by -0.05 (SD 0.44) in the intervention group, but increased by 0.01 (SD 0.46) in the control group, with a mean difference of -0.07 (-0.13 to -0.01). After another year of follow up, compared to the control group, children in the intervention group had significantly lower BMI (-0.13, -0.25 to -0.01), BMI z score (-0.05, -0.10 to -0.01), fat mass (-0.27 kg, -0.53 to -0.02) and percent body fat (-0.53, -1.00 to -0.05). The intervention had a more pronounced effect on weight, height, BMI, BMI z score, and body composition among obese children than among normal weight or overweight children. Compared to the control group, the intervention group had a significantly higher percentage of children who maintained or reduced their BMI z score at year 1 (P=0.008) and year 2 (P=0.04).nnnCONCLUSIONSnThese findings suggest that 20 min of daily moderate to vigorous physical activity during the school year is a feasible and effective way to prevent excessive gain of body weight, BMI, and body fatness in primary school students.