Objective To establish a regression algorithm model that applies to bone age estimation of Xinjiang Uygur adolescents with machine learning methods such as histogram of oriented gradient （HOG）, local binary patterns （LBP）, support vector machine （SVM）, principal component analysis （PCA）. Methods DR images of knee-joints from 275 male and 225 female subjects aged 12.0-<19.0 years old were collected, PCA method was used to reduce the dimensionality of the HOG and LBP features, and support vector regression （SVR） was used to establish a knee-joint bone age estimation algorithm model. Stratified random sampling method was used to select 215 male samples, 180 female samples for the model training set. K-fold cross validation method was used to optimize parameters of the model. The remaining samples as the independent test set was used to compare the sample's true age and model estimated age, and had an accuracy rate in the statistical error range of ±0.8 and ±1.0 years, respectively. Then the mean absolute error （MAE） and root mean square error （RMSE） were calculated. Results The accuracy rate of male in the statistical error range of ±0.8 and ±1.0 year was 80.67%, 89.33%, respectively. The MAE and RMSE were 0.486 and 0.606 years, respectively. The accuracy rate of female in the statistical error range of ±0.8 and ±1.0 years was 80.19%, 90.45%, respectively. The MAE and RMSE were 0.485 and 0.590 years, respectively. Conclusion Establishment of prediction model for bone age estimation by feature dimension reduction of HOG and LBP in DR images of knee-joint based on PCA and SVM has relatively high accuracy.
Adolescent ; Adult ; Age Determination by Skeleton/methods* ; Algorithms ; Asian People/ethnology* ; China ; Female ; Humans ; Image Processing, Computer-Assisted ; Knee Joint/diagnostic imaging* ; Machine Learning ; Male ; Principal Component Analysis ; Support Vector Machine ; Young Adult

Objective: To evaluate the association of educational level with anthropometric measurements at different adult stages and their long-term changes in adults who participated in the second re-survey of China Kadoorie Biobank (CKB). Methods: The present study excluded participants who were aged >65 years, with incomplete or extreme measurement values, or with major chronic diseases at baseline survey or re-survey. The weight at age 25 years was self-reported. Body height, body weight and waist circumference at baseline survey (2004-2008) and re-survey (2013-2014) were analyzed. Results: The present study included 3 427 men and 6 320 women. Both body weight and waist circumference (WC) increased with age. From age 25 years to baseline survey (mean age 45.2±6.5), the mean weight change per 5-year was (1.70±2.63) kg for men and (1.27±2.10) kg for women. From baseline survey to re-survey (53.2±6.5), the mean changes per 5-year for body weight were (1.12±2.61) kg for men and (0.90±2.54) kg for women; and that for WC was (3.20±3.79) cm for men and (3.83±3.85) cm for women. Among women, low educational level was consistently associated with higher body mass index (BMI) and WC at age 25 years, baseline survey and re-survey. Among men, low educational level was associated with higher BMI at age 25 years. At baseline survey and re-survey, the educational level in men was not statistically associated with BMI; but men who completed junior or senior high school showed slight higher WC and increase of WC from baseline survey to re-survey than other male participants. Conclusions: Body weight and WC increased with age for both men and women. The associations of educational level with BMI and WC were different between men and women.
Adult ; Asian People/statistics & numerical data* ; Body Height ; Body Mass Index ; Body Weight ; China/epidemiology* ; Educational Status ; Female ; Humans ; Male ; Middle Aged ; Obesity/ethnology* ; Risk Factors ; Sex Distribution ; Waist Circumference/ethnology*

OBJECTIVE: This study investigated complementary feeding practices among four ethnic groups (Han, Uygur, Tibetan, and Zhuang) based on a cross-sectional survey in rural western China. METHODS: In 2005, a stratified multistage cluster random sampling method was used to recruit 9712 children (7411 Han, 1032 Uygur, 678 Tibetan, and 591 Zhuang) between 6 and 35 months of age and their mothers from 45 counties in 10 provinces (autonomous regions, municipalities) in western China. RESULTS: The rates of early introduction (before 6 months) of complementary foods in four ethnic groups (Han, Uygur, Tibetan, and Zhuang) were 71.30%, 95.95%, 82.40%, and 72.30%, respectively. The Infant and Child Feeding Index (ICFI) for Uygur and Tibetan children was lower than that for Han children at all age groups. Uygur children were more likely to have unqualified ICFI compared with Han children in a multivariate logistic regression (odds ratio (OR)=5.138, 95% confidence interval (CI): 4.340-6.084). A higher level of maternal education, greater family wealth, and the availability of complementary feeding educational materials decreased the likelihood of an unqualified ICFI. The nutritional status of children (Han, Tibetan, and Zhuang) with qualified ICFI was better than that for children with unqualified ICFI. CONCLUSIONS Appropriate interventions are required to improve complementary feeding practices in rural western China.
Adult ; Asian People ; Child, Preschool ; China ; Cluster Analysis ; Cross-Sectional Studies ; Educational Status ; Ethnicity ; Feeding Behavior/ethnology* ; Female ; Humans ; Infant ; Infant Nutritional Physiological Phenomena/ethnology* ; Infant, Newborn ; Male ; Multivariate Analysis ; Nutritional Status ; Odds Ratio ; Rural Population ; Social Class ; Surveys and Questionnaires ; Young Adult

Objective: To examine the sex-specific associations between tobacco smoking and risk of cardiovascular diseases in Chinese adults. Methods: The present analysis included 487 373 participants from the China Kadoorie Biobank after excluding those with cancer, heart diseases, stroke at baseline survey. The baseline survey was conducted from June 2004 to July 2008. The number of follow-up years was calculated from the time that the participants completed baseline survey to the time of any event: CVD incidence, death, loss of follow-up, or December 31, 2015, whichever occurred first. We used Cox proportional hazards regression models to estimate the HRs and 95%CI of incident cardiovascular diseases with tobacco smoking. Results: During a median follow-up of 8.9 years(a total of 4.1 million person years), we documented 33 947 cases of ischemic heart diseases, 6 048 cases of major coronary diseases, 7 794 cases of intracerebral hemorrhage, and 31 722 cases of cerebral infarction. The prevalence of smoking was much higher in men (67.9%) than in women (2.7%). Smoking increased risk of all subtypes of cardiovascular diseases. Compared with nonsmokers, the multivariable-adjusted HRs (95% CI) for current smokers were 1.54 (1.43-1.66) for major coronary event, 1.28 (1.24-1.32) for ischemic heart disease, 1.18 (1.14-1.22) for cerebral infarction, and 1.07 (1.00-1.15) for intracerebral hemorrhage, respectively. Female smokers tended to have greater risk of developing major coronary event associated with amount of tobacco smoked daily (interaction P=0.006) and age when smoking started (interaction P=0.011). There was no sex difference in these two effects for ischemic heart diseases, intracerebral hemorrhage and cerebral infarction (all interaction P>0.05). Conclusions: This prospective study confirmed increased risk of all subtypes of cardiovascular diseases in current smokers. Smoking was more harmful to women than to men for major coronary event.
Adult ; Asian People/statistics & numerical data* ; Cardiovascular Diseases/epidemiology* ; China/epidemiology* ; Female ; Humans ; Incidence ; Male ; Neoplasms/epidemiology* ; Prevalence ; Prospective Studies ; Risk Factors ; Smoking/ethnology* ; Smoking Cessation ; Stroke/epidemiology* ; Tobacco Smoking/adverse effects*

Objective: To understand the distribution of cancer deaths in China in 2015 and provide reference for the prevention and control of cancer. Methods: Based on the results of Global Burden of Disease 2015, the cancer death distributions in different age groups, sex groups, provinces or by different malignant tumor in Chinese were described. Results: The age-standardized mortality rate of cancer was 159.01/100 000 in China in 2015. The mortality rate was highest in age group ≥70 years (1 102.73/100 000), and lowest in age group 5-14 years (5.40/100 000). The mortality rate in males was 2.15 times higher than that in females. The first 5 provinces with high cancer mortality rate were Anhui, Qinghai, Sichuan, Guangxi and Henan. Lung cancer, liver cancer, stomach cancer, esophageal cancer and colorectal cancer ranked 1-5 in term of mortality rate. Conclusion: The cancer mortality differed with age, gender, area and different malignant tumors, suggesting the necessity to develop targeted prevention and control strategies.
Adolescent ; Adult ; Age Distribution ; Aged ; Aged, 80 and over ; Asian People/statistics & numerical data* ; Child ; Child, Preschool ; China/epidemiology* ; Colonic Neoplasms/mortality* ; Colorectal Neoplasms/mortality* ; Female ; Humans ; Liver Neoplasms/mortality* ; Lung Neoplasms/mortality* ; Male ; Middle Aged ; Mortality/ethnology* ; Neoplasms/mortality* ; Residence Characteristics ; Sex Distribution ; Stomach Neoplasms/mortality* ; Young Adult

Objective: To evaluate the association of family history with risk of major coronary events (MCE) and ischemic heart disease (IHD). Methods: After excluding participants with heart disease, stroke or cancer at baseline survey, a total of 485 784 participants from the China Kadoorie Biobank, who had no missing data on critical variables, were included in the analysis. Cox regression analysis was used to estimate the hazard ratios (HR) and 95% CI. Subgroup analyses were performed according to the baseline characteristics. Results: During a median of 7.2 years of follow-up, we documented 3 934 incident cases of MCE and 24 537 cases of IHD. In multivariable-adjusted models, family history was significantly associated with risk of MCE and IHD. The adjusted HRs (95%CI) were 1.41 (1.19-1.65) and 1.25 (1.18-1.33), respectively. History of disease among siblings was more strongly associated with early-onset MCE than parental history (HR=2.97, 95%CI: 1.80-4.88). Moreover, the association of family history with MCE and IHD was stronger in persons who were overweight or obesive, and the association between family history and MEC was stronger in smokers. Conclusion: This large-scale, prospective study indicated that family history was an independent risk factor for MCE and IHD in China. The intervention targeting major known lifestyle risk factors and the management of chronic diseases should be strengthened for Chinese population, especially for the individuals with family history were at high risk.
Asian People/statistics & numerical data* ; China/epidemiology* ; Coronary Disease/genetics* ; Humans ; Incidence ; Myocardial Ischemia/genetics* ; Overweight/ethnology* ; Proportional Hazards Models ; Prospective Studies ; Risk Assessment ; Risk Factors ; Smoking/ethnology*

Objective: To investigate the prevalence of hyperuricemia (HUA) in the elderly in China. Methods: A randomized stratified cluster sampling survey was conducted. And 5 376 residents aged ≥60 year in 7 Beijing, Xi'an and Harbin in northern China and Chengdu, Chongqing, Changsha and Shanghai in southern China were surveyed. A unified questionnaire was used to collect their basic information, and blood samples were taken from them to detect the level of plasma uric acid (UA). The differences in hyperuricemia prevalence among different groups were compared with χ(2) test. Results: The mean concentration of plasma UA was 302.8 μmol/L in the elderly surveyed, 329.5 μmol/L in males and 282.7 μmol/L in females, 272.4 μmol/L in rural residents and 315.5 μmol/L in urban residents. Our study showed the prevalence of hyperuricemia was 13.1% in the elderly surveyed. The prevalence of hyperuricemia in women (14.1%) was higher than that in men (12.0%) (P<0.05); and the prevalence of hyperuricemia was higher in urban residents (15.8%) than in rural residents (6.9%) (P<0.01); in southern area (16.0%) than in northern area (11.6%) (P<0.01). Both the plasma UA level and the prevalence of hyperuricemia increased with age in those aged ≥60 years. The average prevalence of hyperuricemia were 9.5%, 11.9%, 14.5%, 16.4% and 21.9% and the plasma UA levels were 287.7, 295.9, 308.1, 311.6 and 323.3 μmol/L respectively in age group ≥60, 65, 70, 75 and 80 years (P<0.01). Conclusion: The result showed that mean concentration of plasma UA was 302.8 μmol/L and the overall prevalence of hyperuricemia was 13.1% in the elderly surveyed in China. The prevalence of hyperuricemia in females was higher than in males, in urban residents than in rural residents and in southern area than in northern area. Both the UA level and prevalence of hyperuricemia increased with age.
Age Distribution ; Aged ; Aged, 80 and over ; Asian People/statistics & numerical data* ; China/epidemiology* ; Female ; Humans ; Hyperuricemia/ethnology* ; Male ; Middle Aged ; Prevalence ; Rural Population ; Sex Distribution ; Surveys and Questionnaires ; Urban Population ; Uric Acid/blood*

Objective: To explore the relations between the prevalence of multiple chronic diseases and cigarette smoking behavior in the Chinese adults. Methods: Based on the results: from the 2013 Chronic Disease Risk Factor Surveillance (NCD Surveillance), 176 534 Chinese residents aged 18 years and above, covering 298 counties (districts) in 31 provinces, was randomly recruited, using the multi-stage stratified clustering sampling method. Information on demographics, cigarette smoking (status, quantity and period) was obtained through face-to-face interviews and questionnaires. Anthropometric data and blood samples were collected and properly stored for analysis. Results In total, 175 386 adults were included for statistical analyses, with 42.7% as males and 57.3% as females. The prevalence rates of hypertension, high total cholesterol and high triglycerides were 30.4%, 7.2% and 18.0% in male smokers, 35.6%, 14.0%, 10.3% and 15.9% in female smokers respectively, which were all higher than those in the respective non-smokers. Male smokers were found under lower risk on hypertension, but 19% higher on total glycerides when compared with non-smokers of the same sex(OR=1.19, 95%CI:1.10-1.30), when multiple risk factors were under control. Male current smokers with more than 20 cigarettes per day have 41% (OR=1.41, 95%CI: 1.28-1.55) higher risk of high TG than non-smokers. Female smokers presented 40% (OR=1.40, 95%CI: 1.15-1.70) higher risk in high glycerides than the non-smokers. Specifically, women smoking longer than 20 years have 60% (OR=1.60, 95%CI: 1.31-1.95) higher risk of high TG than women smoking less than 20 years. Conclusions: Prevalence rates of certain chronic diseases were seen higher in smokers of both genders. People with longer history of smoking or being heavier smokers, appeared at advanced risk on developing chronic diseases.
Adult ; Aged ; Asian People ; Chronic Disease/ethnology* ; Cigarette Smoking/ethnology* ; Female ; Humans ; Hypertension/epidemiology* ; Male ; Prevalence ; Risk Factors ; Sex Distribution ; Sex Factors ; Smoking Cessation ; Surveys and Questionnaires

Objective: To investigate the demographic characteristics of falls and fall-related injuries in Chinese elderly population. Methods: In 2013, the 4(th) round Chronic Non-communicable Disease and Risk Factor Surveillance in China was conducted in 31 provinces. A stratified multi-stage cluster sampling was used to select the samples. A total number of 98 629 community-based adults aged 60 years and older received a set of standardized questionnaires with a face to face interview. The prevalence rates of falls and consequent injuries were compared between different genders, age groups, levels of education and areas of residency. Results: The overall prevalence of falls among elderly in the previous 6 months was 8.0%(95%CI: 7.5%-8.5%). The prevalence was increasing with age and decreasing with the levels of education, and higher in females (9.1%) than in males (6.8%), with differences statistically significant (χ(2)=74.1, P<0.01). Prevalence rates were also seen higher in rural (8.6%), in widowed (11.0%) residents and in farmers or house workers than those in urban areas (7.2%), in non-widowed (7.0%), or having other jobs, with differences all statistically significant (χ(2)=7.7, P<0.01, χ(2)=128.0, P<0.01). 52.6% of the elderly got injured when fell. The proportion of injury was greater in females (54.8%) than that in males (49.6%), with differences statistically significant (χ(2)=10.2, P<0.01). Proportion of most frequent types of injuries were hip fractures (7.3%), hand/arm fractures (12.5%), head injury (8.0%) and bruise (53.6%) respectively. The proportion of hip fractures was 12.4% in elderly over 80 year of age, also was the highest. Conclusions: Results from the present study showed that elderly suffered high prevalence of falls.Statistically significant differences were seen in residents with different groups as genders, age, education levels, marital status, urban/rural areas or jobs. Group-based comprehensive prevention and intervention on falls should be strengthened.
Accidental Falls/statistics & numerical data* ; Adult ; Aged ; Aging ; Asian People ; China/epidemiology* ; Female ; Fractures, Bone/ethnology* ; Hip Fractures/ethnology* ; Humans ; Male ; Prevalence ; Residence Characteristics ; Risk Factors ; Rural Population ; Sex Factors ; Surveys and Questionnaires ; Urban Population

Objective: To understand the distribution and characteristics of people aged ≥40 years who are at high risk of COPD in China and provide evidence for COPD prevention and control. Methods: The survey was conducted among the subjects selected through multi-stage stratified cluster sampling from 31 provinces (autonomous regions and municipalities) in China for 2014-2015 national chronic obstructive pulmonary disease surveillance. A total of 75 107 people aged ≥40 years in 125 surveillance points were surveyed in face to face interviews. Subjects who met at least one of the following conditions, including chronic respiratory symptoms, exposure to risk factors, medical history of respiratory diseases, and family history, were defined as population at high risk. The weighted proportion of the population at high risk of COPD and 95%CI were estimated by using complex sampling design. Results: Among eligible 74 296 subjects, the proportion of population at high risk of COPD was 89.5% (95%CI: 87.8%-91.2%). The proportion significantly increased with age (P<0.001). The proportion of the population at high risk was significantly higher in men than in women (P<0.001), and in rural area than in urban area (P<0.001). The highest proportion of population at high risk was observed in men in rural area in western China. The proportion of population at high risk of COPD who met at least two conditions was 32.0% (95%CI:29.7%-34.2%), the proportion of those who met at least three conditions was 7.4% (95%CI: 6.6%- 8.3%), and the proportion of those who met all the conditions was 1.5% (95%CI: 1.2%-1.8%). Among population at high risk of COPD, those who only had exposure to one risk factor accounted for 61.7% (95%CI: 59.8%-63.7%). Conclusion: About 90% of people aged ≥40 years in China are at high risk for COPD. It is necessary to conduct population-based screening for COPD and take comprehensive measures to reduce prevalence of risk factors.
Adult ; Asian People/statistics & numerical data* ; China/epidemiology* ; Female ; Humans ; Male ; Prevalence ; Pulmonary Disease, Chronic Obstructive/ethnology* ; Risk Factors ; Rural Population ; Surveys and Questionnaires ; Urban Population