Asthma and asthma related symptoms in 23,326 Chinese children in relation to indoor and outdoor environmental factors: the Seven Northeastern Cities (SNEC) Study.

BACKGROUND: Both the levels and patterns of outdoor and indoor air pollutants have changed dramatically during the last decade in China. However, few studies have evaluated the effects of the present air pollution on the health of Chinese children. This study examines the association between outdoor and indoor air pollution and respiratory diseases among children living in Liaoning, a heavy industrial province of China. METHODS: A cross-sectional study of 23,326 Chinese children aged 6 to 13 years was conducted in 25 districts of 7 cities in Northeast China during 2009. Three-year (2006-2008) average concentrations of particles with an aerodynamic diameter of ≤10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxides (NO2), and ozone (O3) were calculated from monitoring stations in each of the 25 districts. We used two-level logistic regression models to examine the effects of yearly variations in exposure to each pollutant, controlling for important covariates. RESULTS: The prevalence of respiratory symptoms was higher for those dwelling close to a busy road, those living near smokestacks or factories, those living with smokers, those living in one-story houses typically with small yards, and those with home renovation, bedroom carpet or pets. Ventilation device use was associated with decreased odds of asthma in children. The adjusted odds ratio for diagnosed-asthma was 1.34 (95% confidence interval [CI], 1.24-1.45) per 31 µg/m(3) increase in PM10, 1.23 (95%CI, 1.14-1.32) per 21 µg/m(3) increase in SO2, 1.25 (95%CI, 1.16-1.36) per 10 µg/m(3) increase in NO2, and 1.31 (95%CI, 1.21-1.41) per 23 µg/m(3) increase in O3, respectively. CONCLUSION: Outdoor and indoor air pollution was associated with an increased likelihood of respiratory morbidity among Chinese children.

Validation of the sleep disturbance scale for children and prevalence of parent-reported sleep disorder symptoms in Chinese children.

OBJECTIVE: To translate and validate the Sleep Disturbance Scale for Children (SDSC), a promising questionnaire for use among children in epidemiological studies, in Chinese children. METHODS: In total, 3525 children aged 5-16 years were randomly selected from five primary schools in Shenyang. Internal consistency, reliability and factor analyses were undertaken to assess the construct validity of the SDSC. RESULTS: Internal consistency indicated adequate reliability (Cronbach's α=0.81). Factor analytic results indicated a six-factor solution (ie, six types of sleep disorder) based on parent-reported sleep disorder symptoms. The mean total score of the SDSC was 39.28±7.83 and 156 (4.43%) children were identified as suffering from parent-reported sleep disorder. The prevalence for each sleep type disorder ranged from 3.46% to 6.30% with the highest for sleep hyperhidrosis (SHY) and the lowest for disorders of initiating and maintaining sleep. Significant differences were found between boys and girls in the prevalence of sleep breathing disorders (6.51% vs. 3.72%), SHY (8.62% vs. 4.00%) and parent-reported sleep disorders (5.19% vs. 3.67%). CONCLUSIONS: The SDSC is reliable and useful in screening for parent-reported sleep disorders in Chinese children. Compared with other countries, parent-reported sleep disorders among Chinese elementary school children were at a relatively low level of prevalence.

Gender-specific differences in associations of overweight and obesity with asthma and asthma-related symptoms in 30 056 children: result from 25 districts of Northeastern China.

OBJECTIVE: The relationship between obesity and allergic respiratory diseases in childhood is still controversial. Furthermore, significant debate on the issue of whether or not gender modifies this association also exists due to inconsistent findings. The objective of this study is to evaluate the association between obesity and respiratory health in children, and to investigate the modifications of gender on this association. METHODS: 30 056 children (aged 2-14 years) were randomly selected from 25 districts within 7 cities in Northeastern China in 2009. A standard questionnaire from the American Thoracic Society was used to characterize the children's histories of respiratory symptoms and illnesses. Child weight and height were measured, and obesity was calculated with an age and sex-specific body mass index. RESULTS: The overall prevalence rates of obesity and overweightness were 14.08% and 12.32%, respectively. Compared to the children with normal body weights, asthma and asthma-related symptoms were more prevalent in overweight and obese children. Analysis stratified by gender showed that obesity was associated with more respiratory symptoms and diseases in females than in males. A significant association between obesity and diagnosed asthma [adjusted odds ratio (aOR) = 1.28; 95% confidence interval (CI): 1.02-1.60], as well as current wheezing (aOR = 1.46; 95%CI: 1.20-1.79) was found in females but not in males. CONCLUSIONS: There is an association between asthma symptoms and obesity in these Chinese children, and obesity had a significantly larger effect on females than males.

Effects of outdoor and indoor air pollution on respiratory health of Chinese children from 50 kindergartens.

BACKGROUND: Concentrations of ambient air pollution and pollutants in China have changed considerably during the last decade. However, few studies have evaluated the effects of current ambient air pollution on the health of kindergarten children. METHODS: We studied 6730 Chinese children (age, 3-7 years) from 50 kindergartens in 7 cities of Northeast China in 2009. Parents or guardians completed questionnaires that asked about the children's histories of respiratory symptoms and risk factors. Three-year concentrations of particles with an aerodynamic diameter ≤10 µm (PM10), sulfur dioxide (SO2), and nitrogen dioxides (NO2) were calculated at monitoring stations in 25 study districts. A 2-stage regression approach was used in data analyses. RESULTS: The prevalence of respiratory symptoms was higher among children living near a busy road, those living near chimneys or a factory, those having a coal-burning device, those living with smokers, and those living in a home that had been recently renovated. Among girls, PM10 was associated with persistent cough (odds ratio [OR]PM10 = 1.44; 95% CI, 1.18-1.77), persistent phlegm (ORPM10 = 1.36; 95% CI, 1.02-1.81), and wheezing (ORPM10 = 1.31; 95% CI, 1.04-1.65). NO2 concentration was associated with increased prevalence of allergic rhinitis (OR = 1.96; 95% CI, 1.27-3.02) among girls. In contrast, associations of respiratory symptoms with concentrations of PM10, SO2, and NO2 were not statistically significant among boys. CONCLUSIONS: Air pollution is particularly important in the development of respiratory morbidity among children. Girls may be more susceptible than boys to air pollution.

Epidemiology of general obesity, abdominal obesity and related risk factors in urban adults from 33 communities of Northeast China: the CHPSNE study.

BACKGROUND: Obesity increases the risk of many diseases. However, there has been little literature about the epidemiology of obesity classified by body mass index (BMI) or waist (abdominal obesity) among urban Chinese adults. This study is to fill the gap by assessing the prevalence of obesity and associated risk factors among urban Chinese adults. METHODS: A representative sample of 25,196 urban adults aged 18 to 74 years in Northeast China was selected and measurements of height, weight and waist circumference (WC) were taken from 2009-2010. Definitions of overweight and obesity by the World Health Organization (WHO) were used. RESULTS: The overall prevalence rates of general obesity and overweight classified by BMI were 15.0% (15.7% for men and 14.3% for women, p<0.01) and 19.2% (20.8% for men and 17.7% for women, p<0.01), respectively, and the overall prevalence rate of abdominal obesity was 37.6% (31.1% for men and women 43.9% for women, p<0.01). Multivariable logistic regression showed that the elderly and those who had a history of parental obesity, alcohol drinking, or former cigarette smoking were at high risk of obesity classified by BMI or WC, whereas those with a higher level of education, higher family income, or a healthy and balanced diet were at low risk of obesity. Analysis stratified by gender showed that men with a higher level education level, a white-collar job, a cadre job, or higher family income were the high risk group, and women with a higher level of education or higher family income were the low risk group. CONCLUSIONS: Obesity and overweight have become epidemic in urban populations in China; associations of risk factors with obesity differ between men and women.