Objective: To describe the genetic structure of populations in different areas of China, and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies. Methods: By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB), we performed principal components analysis to extract the first and second principal components of the samples for the component two-dimensional diagram generation, and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China. Based on the CKB cohort data, a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated; and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated. Results: There were significant genetic structure differences in different areas of China. Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area. The first principal component corresponds to the latitude of different areas, and the second principal component corresponds to the longitude of different areas. The generated simulation data showed high false positive rate (λ=1.16), even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed, λ could not be effectively controlled (λ>1.05); while, by using a mixed linear model adjusting for the kinship matrix, λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ=0.99). Conclusions: There were large differences in genetic structure among populations in different areas of China. In molecular epidemiology studies, bias caused by population genetic structure needs to be carefully treated. For large cohort data with complex genetic structure and extensive kinship, it is necessary to use a mixed linear model for association analysis.
China ; Genetic Structures ; Genome-Wide Association Study ; Humans ; Linear Models ; Principal Component Analysis

Objective: To estimate the incidence and distribution characteristics of fall related injury in people aged ≥50 years in 8 provinces in China and related physiological, psychological and social risk factors. Methods: Cross-sectional data were collected from adults aged ≥50 years participating in the World Health Organization (WHO) study on global ageing and adult health (SAGE) round 1 in China. Two-level hierarchical logistic model was used to identify the related factors for fall-related injury. All the models were stratified by living area (urban/rural). Results: Estimated incidence of fall related injury (road traffic injury was not included) was 3.2%. Ageing and multiple chronic conditions (OR=2.55, 95%CI: 1.41-4.64) was significantly associated with the incidence of fall related injury in urban area. In rural area, depression (OR=4.33, 95% CI: 2.52-7.42) and multiple chronic conditions (OR=2.46, 95%CI: 1.37-4.41) were associated with the incidence of fall related injury. Conclusions: This study estimated the incidence of fall related injury in adults aged ≥50 years in 8 provinces in China. A significant association between multiple chronic conditions and fall related injury were found in both urban and rural residents. Targeted measures should be taken for the prevention and control of chronic diseases in elderly population.
Accidental Falls/statistics & numerical data* ; Aged ; China ; Chronic Disease/epidemiology* ; Cross-Sectional Studies ; Depression/epidemiology* ; Humans ; Incidence ; Logistic Models ; Middle Aged ; Risk Factors ; Rural Population ; Wounds and Injuries/etiology*

Objective: To investigate the associations of obesity and physical activity with cognition in the elderly. Methods: A cross-sectional survey was conducted from October 2009 to June 2010 among people aged ≥50 years selected through multistage random cluster sampling in Shanghai. The subjects' body weight, body height, waist circumference and hip circumference were measured to calculate body mass index (BMI) and waist-hip ratio (WHR), and the data on self-reported physical activity level were collected through questionnaire survey. A comprehensive battery of cognitive tests was conducted to assess subjects' cognitive functions, including verbal recall, forward digit span (FDS), backward digit span (BDS), and verbal fluency (VF). General linear model was used to examine the associations of BMI, WHR and physical activity with cognition. Results: A total of 7 913 participants were included, with a median age of 60 years. Age, sex, education level, income level, BMI, WHR and physical activity level were significantly associated with cognitive scores in univariate analysis. After adjusted for age, sex, education level and income level, BMI was no longer significantly associated with cognitive scores in all cognitive functions (all P>0.01). WHR was significantly associated with VF score (P<0.01). Abdominally obese participants had lower VF score than non-abdominally obese participants (P<0.01). Physical activity level was significantly associated with all cognitive functions (P<0.01). Compared with participants with moderate physical activity level, participants with low physical activity level had lower scores in all cognitive functions (P<0.01). Conclusion: Abdominal obesity and low physical activity level were negatively associated with cognition level in the elderly, suggesting that waist circumference control and physical activity might help maintain cognition in the elderly.
Aged ; Body Height ; Body Mass Index ; Body Weight ; China ; Cognition/physiology* ; Cross-Sectional Studies ; Exercise ; Humans ; Middle Aged ; Obesity ; Surveys and Questionnaires ; Waist Circumference ; Waist-Hip Ratio

Objective: On whole-genome scale, we tried to explore the correlation between obesity-related traits and DNA methylation sites, based on discordant monozygotic twin pairs. Methods: A total of 90 pairs of 6-17 year-old twins were recruited in Chaoyang district, Yanqing district and Fangshan district in Beijing in 2016. Information on twins was gathered through a self-designed questionnaire and results: from physical examination, including height, weight and waist circumference of the subjects under study. DNA methylation detection was chosen on the Illumina Human Methylation EPIC BeadChip. R 3.3.1 language was used to read the DNA methylation signal under quality control on samples and probes. Ebayes function of empirical Bayes paired moderated t-test was used to identify the differential methylated CpG sites (DMCs). VarFit function of empirical Bayes paired moderated Levene test was used to identify the differentially variables CpG sits (DVCs) in obese and normal groups. Results According to the obesity discordance criteria, we collected 23 pairs of twins (age range 7 to 16 years), including 12 male pairs. A total of 817 471 qualified CpG loci were included in the genome-wide correlation analysis. According to the significance level of FDR set as <0.05, no positive sites would meet this standard. When DMC CpG site cg05684382, with the smallest P value (1.26E-06) as on chromosome 12, the DVC CpG site cg26188191 with the smallest P value (6.44E-06) appeared in CMIP gene on chromosome 16. Conclusions: In this study, we analyzed the genome-wide DNA methylation and its correlation with obesity traits. After multiple testing corrections, no positive sites were found to have associated with obesity. However, results from the correlation analysis demonstrated sites cg05684382 (chr: 12) and cg26188191 (chr: 16) might have played a role in the development of obesity. This study provides a methodologic reference for the studies on discordance twins related problems.
Adolescent ; Bayes Theorem ; Beijing ; Body Weight ; Child ; DNA Methylation/genetics* ; Epigenesis, Genetic ; Female ; Genome-Wide Association Study ; Humans ; Male ; Obesity/genetics* ; Twins, Monozygotic ; Waist Circumference

Objective: To assess the association and intensity of baseline TC level with the incidence of lung cancer in men in China. Methods: Since May 2006, all the male workers, including the employees and the retirees in Kailuan Group were recruited in the Kailuan male dynamic cohort study. Information about demographics, medical history, anthropometry and TC level were collected at the baseline interview, as well as the information of newly-diagnosed lung cancer cases during the follow-up period. According to guidelines for blood lipids in Chinese adults and the distribution in the population, TC level was classified into five groups as followed: <160, 160-, 180-, 200- and ≥240 mg/dl, with the second quintile group (160- mg/dl) serving as the referent category. Cox proportional hazards regression model and restricted cubic spline (RCS) model were used to evaluate the association and the nonlinear association between baseline TC level and the risk of lung cancer in the men. Results: By December 31, 2014, for the 109 884 men, a follow up of 763 819.25 person-years was made with a median follow-up period of 7.88 years. During the follow up, 808 lung cancer cases were identified. After adjustment for age, education level, income level, smoking status, alcohol consumption level, history of dust exposure, FPG level and BMI, HR (95%CI) of lung cancer for men with lower TC level (<160 mg/dl) and higher TC level (≥240 mg/dl) were 1.34 (1.04- 1.72) and 1.45 (1.09-1.92), respectively, compared with men with normal TC level (160- mg/dl). The results didn't change significantly after exclusion of newly diagnosed cancer cases within 2 years of follow up and subjects with the history of hyperlipidemia. Conclusion: Our results showed that TC might be associated with higher risk of lung cancer. Men with lower TC level or higher TC level had higher risk for lung cancer. Keep moderate TC level might be one of the effective precaution for the prevention of lung cancer.
Adult ; Asian People ; China/epidemiology* ; Cholesterol/blood* ; Cohort Studies ; Humans ; Incidence ; Lipids ; Lung Neoplasms/ethnology* ; Male ; Proportional Hazards Models ; Prospective Studies ; Risk Factors

Objective: To investigate the effects of high iodine intake on thyroid function in pregnant and lactating women. Methods: A cross sectional epidemiological study was conducted among 130 pregnant women and 220 lactating women aged 19-40 years in areas with high environment iodine level (>300 μg/L) or proper environment iodine level (50-100 μg/L) in Shanxi in 2014. The general information, urine samples and blood samples of the women surveyed and water samples were collected. The water and urine iodine levels were detected with arsenic and cerium catalysis spectrophotometric method, the blood TSH level was detected with electrochemiluminescence immunoassay, and thyroid stimulating hormone (FT(4)), antithyroid peroxidase autoantibody (TPOAb) and anti-thyroglobulin antibodies (TGAb) were detected with chemiluminescence immunoassay. Results: The median urine iodine levels of the four groups were 221.9, 282.5, 814.1 and 818.6 μg/L, respectively. The median serum FT(4) of lactating women in high iodine area and proper iodine area were 12.96 and 13.22 pmol/L, and the median serum TSH was 2.45 and 2.17 mIU/L, respectively. The median serum FT(4) of pregnant women in high iodine area and proper iodine area were 14.66 and 16.16 pmol/L, and the median serum TSH was 2.13 and 1.82 mIU/L, respectively. The serum FT(4) levels were lower and the abnormal rates of serum TSH were higher in lactating women than in pregnant women in both high iodine area and proper iodine area, the difference was statistically significant (FT(4): Z=-6.677, -4.041, P<0.01; TSH: Z=8.797, 8.910, P<0.01). In high iodine area, the abnormal rate of serum FT(4) in lactating women was higher than that in pregnant women, the difference was statistically significant (Z=7.338, P=0.007). The serum FT(4) level of lactating women in high iodine area was lower than that in proper iodine area, the difference was statistically significant (Z=-4.687, P=0.000). In high iodine area, the median serum FT(4) in early pregnancy, mid-pregnancy and late pregnancy was 16.26, 14.22 and 14.80 pmol/L, respectively, and the median serum TSH was 1.74, 1.91 and 2.38 mIU/L, respectively. In high iodine area, the serum FT(4) level in early pregnancy was higher than that in mid-pregnancy and late pregnancy, and the serum TSH level was lower than that in mid-pregnancy and late pregnancy, the difference was statistically significant (FT(4): Z=-2.174, -2.238, P<0.05; TSH: Z=-2.985, -1.978, P<0.05). There were no significant differences in the positive rates of serum thyroid autoantibodies among the four groups of women and women in different periods of pregnancy (P>0.05). The morbidity rates of subclinical hyperthyroidism in pregnant women and lactating women in high iodine area were obviously higher than those in proper iodine areas, the difference was statistically significant (χ(2)=5.363, 5.007, P<0.05). Conclusions: Excessive iodine intake might increase the risk of subclinical hypothyroidism in pregnant women and lactating women. It is suggested to strengthen the iodine nutrition and thyroid function monitoring in women, pregnant women and lactating women in areas with high environmental iodine.
Adult ; China/epidemiology* ; Cross-Sectional Studies ; Female ; Humans ; Hypothyroidism/epidemiology* ; Iodides/administration & dosage* ; Iodine/urine* ; Lactation ; Nutritional Status ; Pregnancy ; Prevalence ; Thyroid Diseases/epidemiology* ; Thyroid Function Tests ; Thyroid Gland/physiology* ; Young Adult

Objective: To study the prevalence and characteristics of overweight and obesity among Chinese children aged 0-5 years, in 2010-2013. Methods: Data was from the'China Nutrition and Health Surveillance-0-5-Years-Old Children and Lactating Women'project in 2013. Stratified multistage cluster sampling method was used to select 55 districts/counties from 30 provinces (autonomous regions, municipalities) with the sample size of children as 32 862. Definition of overweight and obesity were according to both the WHO 2006 growth standard in children less than 5-year-old and the WHO 2007 growth reference in children of 5-years-old. Results: were calculated by complex weight based on national census from the National Bureau of Statistics in 2010. Results The overall prevalence of overweight was 8.4% among the 0-5-year-old in 2013, with 9.4% in boys and 7.2% in girls. Both of the rates from urban and rural areas were the same, as 8.4%. The prevalence rates of overweight in the 0-, 6-, 12-, 24-, 36-, 48- and 60-71 months age groups appeared as 13.0%, 11.1%, 8.3%, 6.0%, 4.8%, 3.9% and 15.9%, respectively. The rates of overweight in low, medium and high income families were 8.0%, 8.8% and 8.9%, respectively. The prevalence of obesity was 3.1% among the 0-5-year-old, with 3.6% in boys and 2.5% in girls. There was no significant difference seen in urban (3.3%) and rural areas (2.9%). The prevalence rates for obesity in the 0-, 6-, 12-, 24-, 36-, 48- and 60-71 months age groups were 5.8%, 3.8%, 2.5%, 1.6%, 1.2%, 1.3% and 7.8%, respectively. The rates of obesity in low, medium and high income families were 2.8%, 3.3% and 3.5%, respectively. Conclusion: The prevalence rates of both overweight and obesity were increasing among the 0-5-year-olds in China, suggesting that it is necessary to timely conduct the surveillance and intervention programs on overweight and obesity in this target population.
Adolescent ; Asian People/statistics & numerical data* ; Body Mass Index ; Body Weight ; Child ; Child, Preschool ; China/epidemiology* ; Female ; Humans ; Income ; Infant ; Infant, Newborn ; Lactation ; Male ; Nutritional Status ; Obesity/ethnology* ; Overweight/ethnology* ; Prevalence

Objective: To identify the spatial clustering and its temporal trends among newly detected female HIV/AIDS cases aged 15 years or older, in China from 2010 to 2016. Methods: Newly detected HIV/AIDS cases among aged 15 years or older women in China during 2010-2016 were collected, to describe their demographic characteristics, changing trends and spatial autocorrelation. This program was conducted at county level, using the ArcGIS 10.3. Results: The number of newly detected HIV/AIDS cases among aged 15 years or older women was increasing annually from 16 603 to 26 196 in 2010 and in 2016. As the main route proportion of heterosexual transmission increased from 84.25% (13 988/16 603) in 2010 to 96.29%(25 224/26 196) in 2016. Both the number and proportion of HIV/AIDS cases among elderly women ≥50 years of age increased significantly from 17.82%(2 959/16 603) to 38.10%(9 981/26 196) in 2016. Results from spatial analysis demonstrated a county-level clustered distribution of HIV/AIDS cases across the country with a rising global Moran's I value=0.55 over the years (Z=51.46, P<0.001), which was concentrating on western and southern China, covering 9 provinces/autonomous regions/municipalities (Yunnan, Guangxi, Sichuan, Xinjiang, Guizhou, Guangdong, Chongqing, Henan and Hunan). The temporal trends of hot spots differed by age groups, with the trend of epidemic shifting towards western border and southern coastal regions among women aged 15-49 years old, while the elderly women aged ≥50 years old were spreading northward from the southwestern regions. Conclusion: Our findings indicated that an increasing trend of clusters appeared on HIV epidemic among newly detected female HIV/AIDS cases aged 15 years or older in China, particularly in the western and southern regions. Prevention and intervention strategies should target on women according to their age distribution, particularly in regions with increasing trend of HIV epidemics.
Adolescent ; Adult ; Age Distribution ; Aged ; China/epidemiology* ; Epidemics ; Female ; HIV Infections/ethnology* ; Humans ; Middle Aged ; Spatial Analysis ; Young Adult

Shanghai Diet and Health Survey (SDHS) was designed to prospectively access local residents' food consumption, energy and nutrient intake, related chemical contaminant exposure, and the seasonal change trend to explore the relationship of diet with health. Data from SDHS can be used as fundamental information and scientific evidences for the development of local nutrition and food safety policies.
China ; Diet ; Energy Intake ; Health Surveys ; Nutrition Policy ; Nutrition Surveys

Objective: To analyze dietary pattern and its seasonal characteristic in residents of Shanghai. Methods: A representative sample was surveyed and followed up in four different seasons during 2012-2014. Information of food consumption was collected by 3-day 24-hour dietary recall and condiments weighing method. The intake of energy and macronutrients were calculated according to the Chinese Food Composition Table. Results: Annual average daily intake was 191.09 g for grain, 250.69 g for vegetable, 107.23 g for fruit, 223.53 g for animal food, 96.39 g for dairy products, 11.19 g for soy bean and its product, 36.54 g for cooking oil, and 7.57 g for salt. Significant differences were observed in food consumption among different seasons (P<0.05). Annual average daily intake of energy was 2 048.70 kcal, carbohydrates was 241.04 g, protein was 82.35 g, fat was 85.99 g and proportion of energy contributed by fat was 37.99%. Different seasons, age, residential areas, and income were influence factors for food consumption (P<0.05). Conclusions: Energy intake was adequate in residents of Shanghai. Unhealthy dietary pattern, including high proportion of fat and consumption of cooking oil and salt (lower than average intake of large cities, but higher than recommendation), was observed. It is necessary to take appropriate nutrition intervention, and future researches on dietary intake should consider seasonal influences.
China ; Cities ; Diet ; Energy Intake ; Feeding Behavior ; Humans ; Seasons