Association between fresh fruit consumption and the risk of chronic obstructive pulmonary disease-related hospitalization and death in Chinese adults: A prospective cohort study / 中华医学杂志(英文版)

BACKGROUND@#Existing evidence suggests that fruit consumption is a significant influencing factor for chronic obstructive pulmonary disease (COPD), but this is unclear in the Chinese population. We examined the association of fresh fruit consumption with the risk of COPD-related hospitalization and death in a nationwide, population-based prospective cohort from China.@*METHODS@#Between 2004 and 2008, the China Kadoorie Biobank recruited >0.5 million adults aged 30 to 79 years from ten diverse regions across China. After excluding individuals diagnosed with major chronic diseases and prevalent COPD, the prospective analysis included 421,428 participants. Cox regression was used to calculate the hazard ratios (HRs) for the association between fresh fruit consumption and risk of COPD-related hospitalization and death, with adjustment for established and potential confounders.@*RESULTS@#During a mean follow-up of 10.9 years, 11,292 COPD hospitalization events and deaths were documented, with an overall incidence rate of 2.47/1000 person-years. Participants who consumed fresh fruit daily had a 22% lower risk of COPD-related hospitalization and death compared with non-consumers (HR = 0.78, 95% confidence interval [CI]: 0.71-0.87). The inverse association between fresh fruit consumption and COPD-related hospitalization and death was stronger among non-current smokers and participants with normal body mass index (BMI) (18.5 kg/m 2 ≤ BMI < 24.0 kg/m 2 ); the corresponding HRs for daily fresh fruit consumption were 0.78 (95% CI: 0.68-0.89) and 0.69 (95% CI: 0.59-0.79) compared with their counterparts, respectively.@*CONCLUSIONS@#High-frequency fruit consumption was associated with a lower risk of COPD in Chinese adults. Increasing fruit consumption, together with cigarette cessation and weight control, should be considered in the prevention and management of COPD.

Minimal improvement in coronary artery disease risk prediction in Chinese population using polygenic risk scores: evidence from the China Kadoorie Biobank / 中华医学杂志(英文版)

BACKGROUND@#Several studies have reported that polygenic risk scores (PRSs) can enhance risk prediction of coronary artery disease (CAD) in European populations. However, research on this topic is far from sufficient in non-European countries, including China. We aimed to evaluate the potential of PRS for predicting CAD for primary prevention in the Chinese population.@*METHODS@#Participants with genome-wide genotypic data from the China Kadoorie Biobank were divided into training ( n = 28,490) and testing sets ( n = 72,150). Ten previously developed PRSs were evaluated, and new ones were developed using clumping and thresholding or LDpred method. The PRS showing the strongest association with CAD in the training set was selected to further evaluate its effects on improving the traditional CAD risk-prediction model in the testing set. Genetic risk was computed by summing the product of the weights and allele dosages across genome-wide single-nucleotide polymorphisms. Prediction of the 10-year first CAD events was assessed using hazard ratios (HRs) and measures of model discrimination, calibration, and net reclassification improvement (NRI). Hard CAD (nonfatal I21-I23 and fatal I20-I25) and soft CAD (all fatal or nonfatal I20-I25) were analyzed separately.@*RESULTS@#In the testing set, 1214 hard and 7201 soft CAD cases were documented during a mean follow-up of 11.2 years. The HR per standard deviation of the optimal PRS was 1.26 (95% CI:1.19-1.33) for hard CAD. Based on a traditional CAD risk prediction model containing only non-laboratory-based information, the addition of PRS for hard CAD increased Harrell's C index by 0.001 (-0.001 to 0.003) in women and 0.003 (0.001 to 0.005) in men. Among the different high-risk thresholds ranging from 1% to 10%, the highest categorical NRI was 3.2% (95% CI: 0.4-6.0%) at a high-risk threshold of 10.0% in women. The association of the PRS with soft CAD was much weaker than with hard CAD, leading to minimal or no improvement in the soft CAD model.@*CONCLUSIONS@#In this Chinese population sample, the current PRSs minimally changed risk discrimination and offered little improvement in risk stratification for soft CAD. Therefore, this may not be suitable for promoting genetic screening in the general Chinese population to improve CAD risk prediction.

Genetic and healthy lifestyle factors in relation to the incidence and prognosis of severe liver disease in the Chinese population / 中华医学杂志(英文版)

BACKGROUND@#Severe liver disease (SLD), including cirrhosis and liver cancer, constitutes a major disease burden in China. We aimed to examine the association of genetic and healthy lifestyle factors with the incidence and prognosis of SLD.@*METHODS@#The study population included 504,009 participants from the prospective China Kadoorie Biobank aged 30-79 years. The individuals were from 10 diverse areas in China without a history of cancer or liver disease at baseline. Cox regression was used to estimate adjusted hazard ratios (HRs) for incident SLD and death after SLD diagnosis associated with healthy lifestyle factors (smoking, alcohol, physical activity, and central adiposity). Additionally, the contribution of genetic risk for hepatitis B virus (HBV, assessed by genetic variants in major histocompatibility complex, class II, DP/DQ [ HLA - DP / DQ ] genes) was also estimated.@*RESULTS@#Compared with those with 0-1 healthy lifestyle factor, participants with 2, 3, and 4 factors had 12% (HR 0.88 [95% confidence interval [CI] 0.85, 0.92]), 26% (HR 0.74 [95%CI: 0.69, 0.79]), and 44% (HR 0.56 [95%CI: 0.48, 0.65]) lower risks of SLD, respectively. Inverse associations were observed among participants with both low and high genetic risks (HR per 1-point increase 0.83 [95%CI: 0.74, 0.94] and 0.91 [95%CI: 0.82, 1.02], respectively; Pinteraction = 0.51), although with a non-significant trend among those with a high genetic risk. Inverse associations were also observed between healthy lifestyle factors and liver biomarkers regardless of the genetic risk. Despite the limited power, healthy lifestyle factors were associated with a lower risk of death after incident SLD among participants with a low genetic risk (HR 0.59 [95%CI: 0.37, 0.96]).@*CONCLUSIONS@#Lifestyle modification may be beneficial in terms of lowering the risk of SLD regardless of the genetic risk. Moreover, it is also important for improving the prognosis of SLD in individuals with a low genetic risk. Future studies are warranted to examine the impact of healthy lifestyles on SLD prognosis, particularly among individuals with a high genetic risk.

Ideal cardiovascular health and mortality: pooled results of three prospective cohorts in Chinese adults / 中华医学杂志(英文版)

BACKGROUND@#Evidence on the relations of the American Heart Association's ideal cardiovascular health (ICH) with mortality in Asians is sparse, and the interaction between behavioral and medical metrics remained unclear. We aimed to fill the gaps.@*METHODS@#A total of 198,164 participants without cancer and cardiovascular disease (CVD) were included from the China Kadoorie Biobank study (2004-2018), Dongfeng-Tongji cohort (2008-2018), and Kailuan study (2006-2019). Four behaviors (i.e., smoking, physical activity, diet, body mass index) and three medical factors (i.e., blood pressure, blood glucose, and blood lipid) were classified into poor, intermediate, and ideal levels (0, 1, and 2 points), which constituted 8-point behavioral, 6-point medical, and 14-point ICH scores. Results of Cox regression from three cohorts were pooled using random-effects models of meta-analysis.@*RESULTS@#During about 2 million person-years, 20,176 deaths were recorded. After controlling for demographic characteristics and alcohol drinking, hazard ratios (95% confidence intervals) comparing ICH scores of 10-14 vs. 0-6 were 0.52 (0.41-0.67), 0.44 (0.37-0.53), 0.54 (0.45-0.66), and 0.86 (0.64-1.14) for all-cause, CVD, respiratory, and cancer mortality. A higher behavioral or medical score was independently associated with lower all-cause and CVD mortality among the total population and populations with different levels of behavioral or medical health equally, and no interaction was observed.@*CONCLUSIONS@#ICH was associated with lower all-cause, CVD, and respiratory mortality among Chinese adults. Both behavioral and medical health should be improved to prevent premature deaths.

Heritability of tea drinking and its relationship with cigarette smoking in the Chinese male adult twins.

The aims of this study are to estimate the contributions of genetic factors to the variation of tea drinking and cigarette smoking, to examine the roles of genetic factors in their correlation and further to investigate underlying causation between them. We included 11 625 male twin pairs from the Chinese National Twin Registry (CNTR). Bivariate genetic modelling was fitted to explore the genetic influences on tea drinking, cigarette smoking and their correlation. Inference about Causation through Examination of FAmiliaL CONfounding (ICE FALCON) was further used to explore the causal relationship between them. We found that genetic factors explained 17% and 23% of the variation in tea drinking and cigarette smoking, respectively. A low phenotypic association between them was reported (rph = 0.21, 95% confidence interval [CI]: [0.19, 0.24]), which was partly attributed to common genetic factors (rA = 0.45, 95% CI [0.19, 1.00]). In the ICE FALCON analysis with current smoking as the exposure, tea drinking was associated with his own (ßself = 0.39, 95% CI [0.23, 0.55]) and his co-twin's smoking status (ßco-twin = 0.25, 95% CI [0.10, 0.41]). Their association attenuated with borderline significance conditioning on his own smoking status (p = 0.045), indicating a suggestive causal effect of smoking status on tea drinking. On the contrary, when we used tea drinking as the predictor, we found familial confounding between them only. In conclusion, both tea drinking and cigarette smoking were influenced by genetic factors, and their correlation was partly explained by common genetic factors. In addition, our finding suggests that familial confounders account for the relationship between tea drinking and cigarette smoking. And current smoking might have a causal effect on weekly tea drinking, but not vice versa.

Multimorbidity patterns and association with mortality in 0.5 million Chinese adults / 中华医学杂志(英文版)

BACKGROUND@#Few studies have assessed the relationship between multimorbidity patterns and mortality risk in the Chinese population. We aimed to identify multimorbidity patterns and examined the associations of multimorbidity patterns and the number of chronic diseases with the risk of mortality among Chinese middle-aged and older adults.@*METHODS@#We used data from the China Kadoorie Biobank and included 512,723 participants aged 30 to 79 years. Multimorbidity was defined as the presence of two or more of the 15 chronic diseases collected by self-report or physical examination at baseline. Multimorbidity patterns were identified using hierarchical cluster analysis. Cox regression was used to estimate the associations of multimorbidity patterns and the number of chronic diseases with all-cause and cause-specific mortality.@*RESULTS@#Overall, 15.8% of participants had multimorbidity. The prevalence of multimorbidity increased with age and was higher in urban than rural participants. Four multimorbidity patterns were identified, including cardiometabolic multimorbidity (diabetes, coronary heart disease, stroke, and hypertension), respiratory multimorbidity (tuberculosis, asthma, and chronic obstructive pulmonary disease), gastrointestinal and hepatorenal multimorbidity (gallstone disease, chronic kidney disease, cirrhosis, peptic ulcer, and cancer), and mental and arthritis multimorbidity (neurasthenia, psychiatric disorder, and rheumatoid arthritis). During a median of 10.8 years of follow-up, 49,371 deaths occurred. Compared with participants without multimorbidity, cardiometabolic multimorbidity (hazard ratios [HR] = 2.20, 95% confidence intervals [CI]: 2.14 - 2.26) and respiratory multimorbidity (HR = 2.13, 95% CI:1.97 - 2.31) demonstrated relatively higher risks of mortality, followed by gastrointestinal and hepatorenal multimorbidity (HR = 1.33, 95% CI:1.22 - 1.46). The mortality risk increased by 36% (HR = 1.36, 95% CI: 1.35 - 1.37) with every additional disease.@*CONCLUSION@#Cardiometabolic multimorbidity and respiratory multimorbidity posed the highest threat on mortality risk and deserved particular attention in Chinese adults.

Genome-wide associations between alcohol consumption and blood DNA methylation: evidence from twin study.

Aim: Alcohol intake alters DNA methylation profiles and methylation might mediate the association between alcohol and disease, but limited number of positive CpG sites repeatedly replicated. Materials & methods: In total, 57 monozygotic (MZ) twin pairs discordant for alcohol drinking from the Chinese National Twin Registry and 158 MZ and dizygotic twin pairs in the Swedish Adoption/Twin Study of Aging were evaluated. DNA methylation was detected using the Infinium HumanMethylation450 BeadChip. Results: Among candidate CpG sites, cg07326074 was significantly correlated with drinking after adjusting for covariates in MZ twins in both datasets but not in the entire sample or dizygotic twins. Conclusion: The hypermethylation of cg07326074, located in the tumor-promoting gene C16orf59, was associated with alcohol consumption.

Usage of printing equipment in college teachers' offices and influencing factors of released particulate matter / 环境与职业医学

Background Printing and copying equipment is likely to release a large amount of particulate matter, thereby endangering human health. However, there is insufficient research on the level of particulate matter released by printers in offices and its influencing factors. Objective This study is designed to investigate the usage of printing equipment in college teachers' offices and the level of indoor particulate matter during printing, and to explore the influence of printer location and indoor ventilation on the particulate matter pollution level released during printer operation. Methods From 9:00 to 16:00 on January 4 to 6, 2021, 20 faculty offices in a university in Beijing were selected by convenient sampling to measure the indoor particulate matter level during printing, and to investigate the printing equipment usage of 31 users in the offices. Besides, experiments were designed to explore the influence of position and distance from a printer, ventilation, and the distance between a printer and a nearby window during ventilation on the number concentration of particulate matter released by the printers. Results Except one printer being placed on the ground, the other 30 printers were placed on office desks (0.71±0.16) m above the ground. Among them, 65% of the printers (n=20) were less than 1 m away from the users horizontally, and 74% of the users (n=23) accessed the printers 1-5 times a week, printing (7.03±4.07) pages per time. The peak mass concentrations in users' offices during printing of PM10, PM2.5, and PM1 were (21.96±12.96), (7.92±5.54), and (5.77±5.00) μg·m−3, respectively, and the peak number concentration of PM0.25−0.28 was (40941±36926) P·L−1. The experiments showed that when the particle sizer was located in the front, side, and back of the printers, the peak values of PM0.25−0.28 number concentration during printing were (24257±551), (12588±1354), and (11192±249) P·L−1, respectively, and the difference among them was statistically significant (F=214.9, P<0.01); when the particle sizer was placed 0.1, 0.2, and 0.3 m away from the printers, the peak values of PM0.25−0.28 number concentration during printing were (24257±551), (19847±1426), and (16480±878) P·L−1, respectively, and the difference among them was statistically significant (F=44.66, P<0.01); when the experiment room was ventilated or not, the peak values of PM0.25−0.28 number concentration during printing were (18595±488) and (24257±551) P·L−1, respectively, and the difference between them was statistically significant (F=192.6, P<0.01); when the distance between the printer and the window was 1, 2, 3 m, the peak values of PM0.25-0.28 number concentration during printing were (16780±823), (18347±348), and (18595±488) P·L−1, respectively, and the difference among them was statistically significant (F=8.407, P<0.05). Conclusion The overall printer workload is small and the concentration of particulate matter in the faculty offices is low when the printers are working. Printer position, distance, ventilation, and the distance from a nearby window under ventilation conditions are factors affecting the concentration of particulate matter released by the printers.

A population-based seroprevalence survey of severe acute respiratory syndrome coronavirus 2 infection in Beijing, China

BACKGOUNDThe spread of Coronavirus Disease 2019 (COVID-19) had been controlled in China. The seroprevalence of COVID-19 in Beijing has not been evaluated. METHODSIn April, residents in Beijing were randomly enrolled. Blood samples were collected and antibodies to SARS- CoV-2 were tested by two colloidal gold kits. All colloidal gold positive serums were then tested by Micro- neutralization assay. RESULTSNone of 2,184 residents participated was tested positive by micro-neutralization assay. The seroprevalence of COVID-19 in Beijing was estimated < 0.17%. CONCLUSIONSThe seroprevalence of COVID-19 was low in April suggesting that community-wide spread was prevented in Beijing.

Frequency of bowel movements and risk of Parkinson’s disease: a prospective cohort study in adults in China / 中华流行病学杂志

Objective@#To evaluate the association between the frequency of bowel movement (BMF) and the risk of Parkinson’s disease (PD).@*Methods@#In this study, 510 134 participants from the China Kadoorie Biobank (CKB) were included after excluding those who reported to had been diagnosed with cancer at baseline survey. The baseline survey was conducted from 2004 to 2008. The study used the data from the baseline survey and follow-up until December 31, 2016. Cox proportional hazards regression models were used to estimate the HRs and the 95%CIs of risk of PD diagnosis with BMF.@*Results@#During an average follow-up period of (9.9±1.9) years, 808 participants were diagnosed with PD. Compared with participants who had bowel movements every day, the multivariable-adjusted HR (95%CI) for those who had bowel movements<3 times/week, once every 2-3 days, and>1 time/day were 3.62 (2.88-4.54), 2.13 (1.74-2.60), and 0.81 (0.63-1.05), respectively. The linear trend test results of the association between BMF and risk of PD diagnosis was significant (P<0.001). Compared with the participants who had bowel movements ≥1 time/day, the multivariable-adjusted HR (95%CI) for those who had bowel movements<1 time/day was 3.13 (2.32-4.23) within the 5 years of follow- up and was 2.48 (2.05-3.01) beyond the 5 years of follow-up. The gender specific results were similar. The association of BMF<1 time/day with risk of PD diagnosis was stronger in older participants.@*Conclusions@#The participants with low BMF at baseline survey would have higher risk for PD diagnosis in the subsequent 10 years on average. Since abnormal decrease of BMF is easy to be found, programs could be set up for the early screening of PD in older people, along with other early symptoms of PD.

Prevalence of'healthy lifestyle'in Chinese adults / 中华流行病学杂志

Objective To examine the prevalence of'healthy lifestyle'from data extracted from the China Kadoorie Biobank (CKB) of 0.5 million adults from ten areas across China.Methods After excluding participants with self-reported histories of coronary heart disease,stroke or cancer,a total of 487 198 participants at baseline (2004-2008) and 22 604 participants at second survey (2013-2014),were included for analysis.'Healthy lifestyle'was defined as haing the following characteristics:a) never smoking or having stopped smoking for reasons other than illness;b) alcohol drinking ＜25 g/day (men)/＜ 15 g/day (women);c) diet rich in vegetables,fruits,legumes and fish,but low in red meat;d) upper quarter of the physical activity level;e) body mass index of 18.5-23.9 kg/m2 and waist circumstance ＜85 cm (men)/80 cm (women).We calculated the healthy lifestyle scores (HLS) by counting the number of all the healthy lifestyle factors,with a range from 0 to 6.Results At baseline,prevalence rates of the above five healthy lifestyles (except physical activity) were 70.6％,92.6％,8.7％,52.6％ and 59.0％,respectively,with the mean HLS being 3.1± 1.2.Most participants (81.4％) had 2-4 healthy components,while only 0.7％ (0.2％ in men and 1.0％ in women) of all the participants had all six healthy lifestyles.Participants who were women,at younger age,with more schooling and rural residents,were more likely to adhere to the healthy lifestyle.After ten years,the mean HLS showed a slight decrease.Conclusion The prevalence of optimal lifestyles in Chinese adults appeared extremely low.Levels of'healthy lifestyle'varied greatly among those populations with different socio-demographic characteristics across the ten areas in China.

Relationship between educational level and long-term changes of body weight and waist circumference in adults in China / 中华流行病学杂志

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.

Study on genetic structure differences and adjustment strategies in different areas of China / 中华流行病学杂志

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 fast 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.

Interpretation for the group standards in data management for large population-based cohorts / 中华流行病学杂志

Precision medicine became the key strategy in development priority of science and technology in China.The large population-based cohorts become valuable resources in preventing and treating major diseases in the population,which can contribute scientific evidence for personalized treatment and precise prevention.The fundamental question of the achievements above,therefore,is how to construct a large population-based cohort in a standardized way.The Chinese Preventive Medicine Association co-ordinated experienced researchers from Peking University and other well-known institutes to write up two group standards Technical specification of data processing for large population-based cohort study (T/CPMA 001-2018) and Technical specification of data security for large population-based cohort study (T/CPMA 002-2018),on data management.The standards are drafted with principles of emphasizing their scientific,normative,feasible,and generalizable nature.In these two standards,the key principles are proposed,and technical specifications are recommended in data standardization,cleansing,quality control,data integration,data privacy protection,and database security and stability management in large cohort studies.The standards aim to guide the large population-based cohorts that have been or intended to be established in China,including national cohorts,regional population cohorts,and special population cohorts,hence,to improve domestic scientific research level and the international influence,and to support decision-making and practice of disease prevention and control.

Data science in large cohort studies / 中华流行病学杂志

Large cohort study gained its popularity in biomedical research and demonstrated its application in exploring disease etiology and pathogenesis,improving the prognosis of disease,as well as reducing the burden of diseases.Data science is an interdisciplinary field that uses scientific methods from computer science and statistics to extract insights or knowledge from data in a specific domain.The results from the combination of the two would provide new evidence for developing the strategies and measures on disease prevention and control.This review included a brief introduction of data science,descriptions on characteristics of large cohort data according to the development of the study design,and application of data science at each stage of a large cohort study,as well as prospected the application of data science in the future large cohort studies.

Prevalence of'healthy lifestyle'in Chinese adults / 中华流行病学杂志

Objective To examine the prevalence of'healthy lifestyle'from data extracted from the China Kadoorie Biobank (CKB) of 0.5 million adults from ten areas across China.Methods After excluding participants with self-reported histories of coronary heart disease,stroke or cancer,a total of 487 198 participants at baseline (2004-2008) and 22 604 participants at second survey (2013-2014),were included for analysis.'Healthy lifestyle'was defined as haing the following characteristics:a) never smoking or having stopped smoking for reasons other than illness;b) alcohol drinking ＜25 g/day (men)/＜ 15 g/day (women);c) diet rich in vegetables,fruits,legumes and fish,but low in red meat;d) upper quarter of the physical activity level;e) body mass index of 18.5-23.9 kg/m2 and waist circumstance ＜85 cm (men)/80 cm (women).We calculated the healthy lifestyle scores (HLS) by counting the number of all the healthy lifestyle factors,with a range from 0 to 6.Results At baseline,prevalence rates of the above five healthy lifestyles (except physical activity) were 70.6％,92.6％,8.7％,52.6％ and 59.0％,respectively,with the mean HLS being 3.1± 1.2.Most participants (81.4％) had 2-4 healthy components,while only 0.7％ (0.2％ in men and 1.0％ in women) of all the participants had all six healthy lifestyles.Participants who were women,at younger age,with more schooling and rural residents,were more likely to adhere to the healthy lifestyle.After ten years,the mean HLS showed a slight decrease.Conclusion The prevalence of optimal lifestyles in Chinese adults appeared extremely low.Levels of'healthy lifestyle'varied greatly among those populations with different socio-demographic characteristics across the ten areas in China.

Relationship between educational level and long-term changes of body weight and waist circumference in adults in China / 中华流行病学杂志

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.

Study on genetic structure differences and adjustment strategies in different areas of China / 中华流行病学杂志

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 fast 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.

Interpretation for the group standards in data management for large population-based cohorts / 中华流行病学杂志

Precision medicine became the key strategy in development priority of science and technology in China.The large population-based cohorts become valuable resources in preventing and treating major diseases in the population,which can contribute scientific evidence for personalized treatment and precise prevention.The fundamental question of the achievements above,therefore,is how to construct a large population-based cohort in a standardized way.The Chinese Preventive Medicine Association co-ordinated experienced researchers from Peking University and other well-known institutes to write up two group standards Technical specification of data processing for large population-based cohort study (T/CPMA 001-2018) and Technical specification of data security for large population-based cohort study (T/CPMA 002-2018),on data management.The standards are drafted with principles of emphasizing their scientific,normative,feasible,and generalizable nature.In these two standards,the key principles are proposed,and technical specifications are recommended in data standardization,cleansing,quality control,data integration,data privacy protection,and database security and stability management in large cohort studies.The standards aim to guide the large population-based cohorts that have been or intended to be established in China,including national cohorts,regional population cohorts,and special population cohorts,hence,to improve domestic scientific research level and the international influence,and to support decision-making and practice of disease prevention and control.

Data science in large cohort studies / 中华流行病学杂志

Large cohort study gained its popularity in biomedical research and demonstrated its application in exploring disease etiology and pathogenesis,improving the prognosis of disease,as well as reducing the burden of diseases.Data science is an interdisciplinary field that uses scientific methods from computer science and statistics to extract insights or knowledge from data in a specific domain.The results from the combination of the two would provide new evidence for developing the strategies and measures on disease prevention and control.This review included a brief introduction of data science,descriptions on characteristics of large cohort data according to the development of the study design,and application of data science at each stage of a large cohort study,as well as prospected the application of data science in the future large cohort studies.