The prevalence and associated factors of metabolic syndrome among Tibetan pastoralists in transition from nomadic to settled urban environment / 中华流行病学杂志

Objective: To study the prevalence and associated factors of metabolic syndrome (MS) among Tibetan pastoralists in transition from high altitude nomadic to settled urbanized environment, especially dietary factors. Methods: The community-based cross-sectional study included 920 Tibetan adults (men 419, women 501). Data were collected using questionnaires, anthropometric measurements, and biomarker tests. Questionnaires included socio-economic, lifestyle characteristics and food consumption. Principal component analysis was used to identify dietary patterns. The risk factors of MS and its components were analyzed by logistic regression model. Results: The prevalence rates of MS and its components were 32.8% (MS), 83.7% (decreased HDL-C), 62.1% (central obesity), 36.7% (elevated blood pressure), 11.8% (elevated TG), and 7.9% (elevated blood glucose), respectively. The prevalence of overweight was 31.2%, obesity 30.3%. Multivariate analysis showed smoking was associated factor for both of decreased HDL-C (OR=1.239, 95%CI: 1.025-1.496) and elevated TG (OR=1.277, 95%CI: 1.038-1.571). Alcohol drinking appeared as associated factor of elevated TG (OR=1.426, 95%CI: 1.055-1.927). However, physical activity showed as a protective factor for central obesity, decreased HDL-C, and elevated TG. With the increase of age, the adherence to the urban and western dietary patterns decreased, and that to the pastoral dietary pattern increased. By quintiles of dietary pattern scores, the urban dietary pattern was significantly associated with MS (trend test P=0.016). Conclusions: Tibetan pastoralists had high prevalence of both MS and obesity. Smoking, alcohol drinking, the transition from pastoral dietary pattern to urban dietary pattern and inadequate physical activity served as associated factors for MS and its components.

The physical development and associated factors of ninth grade students in China / 中华疾病控制杂志

Objective To analyse the status and related factors of physical development of ninth grade students in China,so as to provide reference and scientific basis for the development of adolescent’ physical health promotion programs.Methods Multiple linear regression and binomial Logistic regression models were used to analyse the data from 7 840 ninth grade students in the 2016 China Education Panel Survey.Results There were differences in the distribution of height and weight between urban and rural and between boys and girls.From the age of 14 to 16,boys were taller and heavier than girls(height cm：171.69±6.95 vs 161.54±5.58, weight kg：60.43±13.19 vs 53.21±11.69), and urban students were taller and heavier than rural students(height cm：167.93±8.16 vs 165.80±7.94；weight kg：58.18±13.16 vs 55.94±12.78). The rate of physical fitness of boys was lower than that of girls(51.8% vs 87.8%), and that of urban boys was lower than that of rural boys(45.7% vs 58.9%), and that of urban girls was higher than that of rural girls(92.0% vs 84.6%). The average age of first spermatorrhea was 13.62±1.23 years for boys and 12.87±1.07 years for girls. Sexual development of urban students appeared earlier than rural students. Multivariate linear regression analysis showed that height and weight were related to bring single-child and sleep time. Height was also related to parents’height, nationality, family economic level and exercise time, weight was also related to parents’ weight (all P<0.05). Binomial Logistic regression analysis showed that physical fitness level was related to gender, nationality, nutritional status, weight, high calorie intake, exercise time, etc (all P<0.05). Correlative factors of male first spermatorrhea were nationality, urban residence, singleton , sleep time, physical fitness level, while female menarche was related to exercise time, lunch spot and nutritional status (all P<0.05). Conclusions Comprehensive efforts and cooperation are needed to promote the normal development and physical health of the students.

Trends and risk factors of overweight and obesity among Chinese middle school students / 中华疾病控制杂志

Objective To investigate the trends and risk factors of overweight and obesity in Chinese middle school students. Methods Data from the China Education Panel Survey conducted in 2014, 2015 and 2016 were used (8 616, 8 762, 7 614; age range 11-18 years old). Overweight and obesity were defined according to Chinese sex-age-specific body mass index (BMI) cutoffs. Relationships between risk factors and BMI, overweight and obesity were tested, using linear regression and logistic regression models. Results The overall prevalence of overweight and obesity in 2016 was 15.3% (17.9% in boys, 12.6% in girls). From 2014 to 2016, the prevalence of overweight and obesity was increasing steadily. After adjusting for age and sex in 2016, being only-child, self-perceived being overweight or obese, or living in urban area were associated with higher BMI (β(SE)=0.23(0.10), β(SE)=2.83(0.14), β(SE)=0.23(0.11), respectively). Self-perceived being overweight or obese was associated with overweight and obesity (OR=4.20, 95% CI: 2.97-5.40). Conclusions Overweight and obesity rates among Chinese middle school students increased steadily from 2014 to 2016. Efforts should be made on childhood obesity prevention and control, especially target at those being only-child, living in urban areas.

Vegetable and Fruit Consumption among Chinese Adults and Associated Factors: A Nationally Representative Study of 170,847 Adults / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This study examined vegetable and fruit (VF) consumption rate and its associated factors among Chinese adults.</p><p><b>METHODS</b>Nationally representative data from the 2013 China Chronic Disease Surveillance survey were used. Dietary intake data, including VF consumption during the last 12 months, were collected. All analyses were weighted to obtain nationally representative estimates. Associations between VF consumption and other factors (e.g., meal frequency and physical activity) were examined through logistic regression analysis.</p><p><b>RESULTS</b>The average fruit consumption was 102.3 g/day (95% CI: 97.0-107.6) and the average vegetable consumption was 350.6 g/day (95% CI: 339.3-361.8). Over half (53.2%, 95% CI: 50.9-55.4) of Chinese adults met the VF consumption of 400 g/day recommended by the World Health Organization (WHO). Rural residents had a higher prevalence of low VF consumption rate than urban residents [49.20% (95% CI: 46.2%-52.2%) vs. 44.0% (95% CI: 41.7%-46.3%) P < 0.01]. Old age (OR = 1.01, 95% CI: 1.00-1.01), low educational level, low income, minority ethnicity (OR = 1.41, 95% CI: 1.15-1.74), underweight (OR = 1.17, 95% CI: 1.03-1.33), single marital status (OR = 1.20, 95% CI: 1.08-1.33), low health literacy, irregular breakfast (OR = 1.20, 95% CI: 1.04-1.38) or lunch (OR = 1.58, 95% CI: 1.26-1.99) habits, and no leisure-time physical activity were associated with low VF consumption.</p><p><b>CONCLUSION</b>Only half of Chinese adults met the VF consumption recommended by the WHO. Low socio-economic status, irregular diet, and poor health literacy were likely associated with low VF consumption. National efforts and programs are needed to promote VF consumption.</p>

Epidemics of overweight and obesity among growing childhood in China between 1997 and 2009: Impact of Family Income, Dietary Intake, and Physical Activity Dynamics / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Obesity has become a major health problem among children and adolescents worldwide. This study aimed to examine the trends of overweight and obesity among childhood in China and assess their associations with family income, dietary intake, and physical activity (PA) between 1997 and 2009.</p><p><b>METHODS</b>Two waves of cross-sectional data of Chinese children and adolescents aged 7-17 years from the China Health and Nutrition Survey were used. Weight and height were measured following standardized procedures. Dietary intake was assessed by 3 consecutive 24-h recalls. Childhood overweight and obesity were defined using the International Obesity Task Force-recommended body mass index cut-offs. Multivariate linear regression analysis was used to examine the associations of family income with diet intakes and PA. Multivariate logistic regression analysis was conducted to assess the associations of overweight and obesity with family income, dietary intake, and PA.</p><p><b>RESULTS</b>The prevalence of childhood overweight and obesity increased from 12.6% in 1997 to 22.1% in 2009, particularly in the medium- and high-family income groups, which increased by 102.7% and 90.3%, respectively. Higher fat intake (% energy), and moderate and vigorous PA were significantly associated with overweight and obesity in final model (odds ratio [OR] = 1.01, 95% confidence interval [CI]: 1.00-1.02, P = 0.004; and OR = 0.99, 95% CI: 0.98-1.00, P = 0.036, respectively).</p><p><b>CONCLUSIONS</b>The prevalence of overweight and obesity among Chinese children and adolescents has increased between 1997 and 2009. Reducing fat intake and increasing PA may help obesity prevention.</p>

Study on the impact of the choice of diastolic Korotkoff phase in childhood on prediction to adult hypertension / 中华流行病学杂志

<p><b>OBJECTIVE</b>The best approach for blood pressure (BP) measurement in children remains controversial, especially on the choice of Korotkoff phase 4 (K4) vs. Korotkoff phase 5 (K5) for diastolic BP (DBP) and to compare the differences between K4 and K5 in school-aged children and their predictions to hypertension in adult.</p><p><b>METHODS</b>The "Beijing children and adolescents BP study" cohort population consisted 2505 school-aged children aged 6 to 17 at baseline survey in 1987, when datum of systolic BP (SBP), DBP measured using K4 and K5, were collected respectively. Among them, 412 individuals with 220 males and 192 females at age of 23-37 years old, were successfully followed up and invited to take part in a clinical examination including anthropometric measurements, SBP and DBP recordings, and a questionnaires in 2005. Method for the BP measurements at both baseline and followed-up was by auscultation with a standard sphygmomanometer. Child hypertension at baseline was diagnosed according to the age-specific cutoffs recommended by the World Health Organization in 1996 (WHO 1996). Adult hypertension was diagnosed according to the China Guideline for Hypertension Prevention and Control issued in 2005. Partial correlation coefficients were calculated to describe the association of K4 and K5 in childhood with SBP and DBP level in adulthood. Multivariate logistic regression analysis was conducted to examine the impact of choice of K5 and K4 as DBP in childhood on prediction to the hypertension in adulthood. Potential confounders such as gender and adult-height were controlled for.</p><p><b>RESULTS</b>At baseline, the prevalence rates of hypertension were 5.0% with DBP measured using K4, and 2.4% with DBP measured using K5, respectively. The geometric mean difference value of K4 minus K5 (K4 - K5) was (10.1 +/- 1.7 mm Hg) (1 mm Hg = 0.133 kPa) for the 2505 school-aged children, and decreased as age increased. There was no significant difference regarding the values of K4 - K5 between males and females in all age groups except for children who at pubertal stage. The distribution of K4 - K5 value across age groups was statistically significant (P < 0.001), 59.6%, 60.5%, 56.3% and 45.1% of children who aged 6-9 years, 10-12 years, 13-15 years, and 16-17 years with their K4 - K5 value over 10 mm Hg. K4 in childhood was better correlated to both SBP and DBP in adulthood than K5. In general, K4 seemed to be superior to K5 in predicting hypertension in adulthood. The odds ratios of hypertension in adulthood were 1.69 (95% CI: 1.11-2.00), 1.45 (1.05-2.02), 2.18 (1.37-3.47), and 1.66 (1.07-2.59) with each 5 mmHg increasing of K4 measured in children aged 6-9 years, 10-12 years, 13-15 years, and 16-17 years, respectively. The agreement diagnosis between child hypertension and adult hypertension was higher for childhood DBP measured using K4 (20.2%) than that using K5 (12.8%).</p><p><b>CONCLUSION</b>There was significant difference between K4 and K5 in Chinese children and adolescents. Choice of diastolic Korotkoff blood pressure could affect DBP tracking from childhood into adulthood. K4 seemed superior to K5 when using auscultator technique to measure DBP.</p>

Impact of early menarche on adiposity during late puberty and mid-life / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the impact of menarche age (MA) on obese status in late puberty (LP) and mid-life (ML) females.</p><p><b>METHODS</b>2035 girls aged 16 to 18 years were selected from a Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study, which was performed from April to October in 2004, as the LP study population. 479 women aged 41 to 52 years were from the Fetal Origin of Adult Disease (FOAD) cohort, which established in 1995 to 2001, as the ML study population. Based on the 25 and 75 percentile of MA of each population, all subjects of LP and ML were divided into early, middle, and late matured groups, respectively. Overweight and obesity were defined by Chinese age-, gender-specific BMI criteria for LP girls, and Chinese BMI criteria for ML women while central obesity was defined by the waist-to-height ratio (WHtR) cutoff of 0.5. Multiple linear regression was used to explore the associations between MA and BMI, waist circumference (WC) and WHtR. The impact of early menarche on obese status in late life was estimated by odds ratio (OR) using logistic regression analyses.</p><p><b>RESULTS</b>The prevalence of overweight and obesity increased with the decrease of MA in both LP and ML population. When MA had a one-year advance, a 0.58 kg/m2 increase in BMI and a 1.1 cm increase in WC during LP, and a 0.35 kg/m2 increase in BMI and a 0.6 cm increase in WC during ML were observed. After adjustment for age, residence area and life style related variables, those who experienced earlier menarche were at higher risk of suffering from obesity in LP (OR :8.740, 95% CI: 3.653-20.911) and during ML (2.498, 1.145-5.453) when compared to those with later menarche. We also noticed that the risk increased for central obesity [LP: 14.280 (3.223-63. 267), ML: 15.604 (1.821-133.679)].</p><p><b>CONCLUSION</b>Menarche age appeared to be an independent predictor for obese status in LP and ML among women.</p>

Prevalence of overweight and obesity among children and adolescents in Beijing in 2004 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To determine the current prevalence of overweight and obesity among children and adolescents (2-18 years) in Beijing and its distribution by age, gender and urban-rural residence.</p><p><b>METHODS</b>As part of the Beijing Child and Adolescent Metabolic Syndrome Study, a stratified cluster representative sample of 23,422 children aged 0-18 years was selected. Anthropometric measures including weight and height were collected from 21,198 subjects aged 2-18 years from April to October in 2004. Overweight and obesity were defined according to body mass index [BMI, weight(kg)/height(m2)] cutpoints. For national and international comparisons, three sex-age-specific BMI criteria were used:1) The BMI cutoffs recommended by the Chinese Working Group on Obesity for Children (WGOC) aged 7-18 years; 2) The US 2000 CDC Growth Charts (CDC 2000) frac 34, the 85th and 95th percentiles; 3) The International Obesity Task Force (IOTF) reference.</p><p><b>RESULTS</b>The overall combined prevalence of overweight and obesity was 18.6% with obesity as 8.1% based on the CDC 2000 criteria, The figures were 17.4% and 5.1% based on the IOTF criteria. According to the WGOC criteria, the combined prevalence of obesity was 20.9% and 8.9% in children aged 7-18 years. The combined prevalence was higher in school-age children (6-18 years) than in preschool-age children (19.8% vs. 14.8%, based on the CDC 2000 criteria). Among school-age children, the prevalence was higher in boys than in girls (26.7% vs. 16.5%), in urban than in rural areas (27.0% vs. 15.9%). However, these differences were not observed in preschool-age children. It was estimated that approximately 450 000 children from 2 through 18 years of age,were overweight or obesity in Beijing.</p><p><b>CONCLUSION</b>Data from our study indicated that one fifth of the children and adolescents in Beijing were under overweight or obesity situation which was the highest in the nation. Obesity among children and adolescents in Beijing had already become a serious public health problem which deserved greater attention.</p>