[Heritability and genetic correlation of body mass index and coronary heart disease in Chinese adult twins].

Objective: To examine the heritability of body mass index (BMI) and coronary heart disease (CHD), and to explore whether genetic factors can explain their correlation. Methods: Participants were from 11 provinces/municipalities reqistered in the Chinese National Twin Registry (CNTR) from 2010 to 2018. Participants data were collected from face-to-face questionnaire survey. Bivariate structure equation model was used to estimate the heritability and the genetic correlation of BMI and CHD. Results: A total of 20 340 pairs of same-sex twins aged ≥25 years were included in this study. After adjusting for age and gender, the heritability of BMI and CHD was 0.52 (95%CI: 0.49-0.55) and 0.76 (95%CI: 0.69-0.81), respectively. Further, a genetic correlation was identified between BMI and CHD (rA=0.10, 95%CI:0.02-0.17). Conclusion: In Chinese adult twin population, BMI and CHD are affected by genetic factors, and their correlation can be attributed to the common genetic basis.

Fast and deterministic switching of a vortex core induced by an out-of-plane current in notch disks.

The magnetic vortex, as one of the most interesting magnetic solitons, has attracted great interest over the past two decades. A fast and reliable method to switch vortex polarity and chirality is one of the key issues for various applications. Based on micromagnetic simulation, here we report a fast, low energy cost and deterministic switching of a vortex core, by the designing of a notch structure in disks and the use of out-of-plane current geometry. We demonstrate that with such a design, the multiple switching problems found in notch disk systems can be avoided. Furthermore, the switching time can be reduced by more than 50% compared with disks without notches.

[Correlation between fasting plasma glucose, HbA1c and DNA methylation in adult twins].

OBJECTIVE: To explore the cytidine-phosphate-guanosine (CPG) sites associated with fas-ting plasma glucose (FPG) and glycated haemoglobin (HbA1c) in twins. METHODS: In the study, 169 pairs of monozygotic twins were recruited in Qingdao, Zhejiang, Jiangsu, Sichuan and Heilongjiang in June to December of 2013 and June 2017 to October 2018. The methylation was detected by Illumina Infinium HumanMethylation450 BeadChip and Illumina Infinium MethylationEPIC BeadChip. According to the Linear Mixed Effect model (LME model), fasting plasma glucose and HbA1c were taken as the main effects, the methylation level (ß value) was taken as the dependent variable, continuous variables, such as age, body mass index (BMI), blood pressure, components of blood cells, surrogate variables generated by SVA, and categorical variables, such as gender, smoking and drinking status, hypoglycemic drugs taking, were included in the fixed effect model as covariates, and the identity numbers (ID) of the twins was included in the random effect model. The intercept was set as a random. Regression analysis was carried out to find out the CpG sites related to fasting blood glucose or HbA1c, respectively. RESULTS: In this study, 338 monozygotic twins (169 pairs) were included, with 412 459 CpG loci. Among them, 114 pairs were male, and 55 pairs were female, with an average age of (48.2±11.9) years. After adjustment of age, gender, BMI, blood pressure, smoking, drinking, blood cell composition, and other covariates, and multiple comparison test, 7 CpG sites (cg19693031, cg01538969, cg08501915, cg04816311, ch.8.1820050F, cg06721411, cg26608667) were found related to fasting blood glucose, 3 of which (cg08501915, ch.8.1820050f, cg26608667) were the newly found sites in this study; whereas 10 CpG sites (cg19693031, cg04816311, cg01538969, cg01339781, cg01676795, cg24667115, cg09029192, cg20697417, ch.4.1528651F, cg16097041) were found related to HbA1c, and 4 of which(cg01339781, cg24667115, cg20697417, and ch.4.1528651f) were new. We found that cg19693031 in TXNIP gene was the lowest P-value site in the association analysis between DNA methylation and fas-ting plasma glucose and HbA1c (PFPG=2.42×10-19, FDRFPG<0.001; PHbA1c=1.72×10-19, FDRHbA1c<0.001). CONCLUSION: In this twin study, we found new CpG sites related to fasting blood glucose and HbA1c, and provided some clues that partly revealed the potential mechanism of blood glucose metabolism in terms of DNA methylation, but it needed further verification in external larger samples.

[Bivariate heritability estimation of resting heart rate and common chronic disease based on extended pedigrees].

OBJECTIVE: To estimate the univariate heritability of resting heart rate and common chronic disease such as hypertension, diabetes, and dyslipidemia based on extended pedigrees in Fujian Tulou area and to explore bivariate heritability to test for the genetic correlation between resting heart rate and other relative phenotypes. METHODS: The study was conducted in Tulou area of Nanjing County, Fujian Province from August 2015 to December 2017. The participants were residents with Zhang surname and their relatives from Taxia Village, Qujiang Village, and Nanou Village or residents with Chen surname and their relatives from Caoban Village, Tumei Village, and Beiling Village. The baseline survey recruited 1 563 family members from 452 extended pedigrees. The pedigree reconstruction was based on the family information registration and the genealogy booklet. Univariate and bivariate heritability was estimated using variance component models for continuous variables, and susceptibility-threshold model for binary variables. RESULTS: The pedigree reconstruction identified 1 seven-generation pedigree, 2 five-generation pedigrees, 23 four-generation pedigrees, 186 three-generation pedigrees, and 240 two-generation pedigrees. The mean age of the participants was 57.2 years and the males accounted for 39.4%. The prevalence of hypertension, diabetes, dyslipidemia in this population was 49.2%, 10.0%, and 45.2%, respectively. The univariate heritability estimation of resting heart rate, hypertension, and dyslipidemia was 0.263 (95%CI: 0.120－0.407), 0.404 (95%CI: 0.135－0.673), and 0.799 (95%CI: 0.590－1), respectively. The heritability of systolic blood pressure, diastolic blood pressure, fasting glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol was 0.379, 0.306, 0.393, 0.452, 0.568, 0.852, and 0.387, respectively. In bivariate analysis, there were phenotypic correlations between resting heart rate with hypertension, diabetes, diastolic blood pressure, fasting glucose, and triglyceride. After taking resting heart rate into account, there were strong genetic correlations between resting heart rate with fasting glucose (genetic correlation 0.485, 95%CI: 0.120－1, P<0.05) and diabetes (genetic correlation 0.795, 95%CI: 0.181－0.788, P<0.05). CONCLUSION: Resting heart rate was a heritable trait and correlated with several common chronic diseases and related traits. There was strong genetic correlation between resting heart rate with fasting glucose and diabetes, suggesting that they may share common genetic risk factors.

[Rethinking public health education and public health workforce development in China].

During the fighting against COVID-19, both the public health education and public health workforce of China have exposed important challenges. The present review discusses dilemmas and weakness that relate to the position of public health education in the higher education system, public health education system, curriculum system, teaching methods, practice-based teaching, training of highly qualified personnel in public health, public health teachers, remuneration and non-monetary honorable rewards for the public health workforce. Suggestions are also proposed for each of the challenges.

[Analysis of characteristics and influencing factors of fine particulate matters and submicron particulate matters in printing shop].

Objective: To analyze the physical characteristics of fine particulate matters (PM(2.5)) and submicron particulate matters (PM(1)), and investigate the factors influencing the emission peak of printer particles. Methods: A 12-hour particle concentration monitoring for PM(2.5) and PM(1) was conducted in a printing shop on January 5(th), 2018. PM(2.5) in the air was analyzed after the monitoring process to figure out morphological characteristics and element composition of printer particles. Besides, experiments were carried out in an enclosed space to detect the number concentration peaks of PM(1) during every printing process. Influencing factors investigated in this study were printer types, toner coverages and interval time between different printing processes. Results: The 12-hour particles concentration monitoring showed that the number concentration of PM(1) and the mass concentration of PM(2.5) were 7.510×10(4) pt/cm(3) and 96.85 µg/m(3). The diameter of most PM(2.5) was less than 100 nm, with a fractal dimension of 2.591. Most PM(2.5) appeared as regular spheres with typical agglomeration phenomenon, while some were in rhabditiform or irregular shapes. Element analysis showed that PM(2.5) was mainly composed of C, O, Si, Ca, with less metallic element. The PM(1) emission peak values of three printers were 3.60×10(4), 3.43×10(4), 0.31×10(4) pt/cm(3), respectively and the difference was not statistically significant (χ(2)=5.42, P>0.05). When the page coverage rate was 0%, 2.5%, 5%, 10%, 20% and 50%, the PM(1) emission peak value of printer A was 6.74×10(4), 4.62×10(4), 3.82×10(4), 2.82×10(4), 1.00×10(4) and 1.08×10(4) pt/cm(3), and the difference was also not statistically significant (χ(2)=7.01, P>0.05). The natural logarithm of PM(1) emission peak value in printing work was associated with the resting time before printing and the change value of heating roller temperature (r value was 0.83 and 0.89, respectively, all P values<0.05). Conclusion: PM(2.5) and PM(1) in the printing shop stayed at a high level. Particles appeared as various shapes and element compositions were complex. The temperature change of heating roller was one of most important factors that lead to the increased number concentration peak of PM(1).

[Correlation between blood pressure and DNA methylation in adult twins].

OBJECTIVE: To explore the DNA methylation sites correlated with blood pressure (systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure) in adult twin population. METHODS: A total of 476 twins from the Chinese National Twin Registry were selected as the research population. Questionnaires were used to collect demographic characteristics, lifestyle, disease status and other information, and blood pressure, height, weight and other anthropometric indicators were measured. The genome-wide DNA methylation of whole blood samples was detected by using Infinium HumanMethylation450 BeadChip. The DNA methylation sites correlated with blood pressure were analyzed by constructing mixed effect model with adjusting potential confounding factors, and the significant level was false discovery rate <0.05. RESULTS: After data quality control, 465 twins (122 pairs of monozygotic twins, 104 pairs of dizygotic twins, 13 individuals from 13 pairs of twins) aged (44.8±13.2) years were finally enrolled. There were more males and more monozygotic twins, and the current smokers and current regular drinkers both accounted for more than 30%. No significant CpG site was found after multiple testing in the correlation study between genome-wide DNA methylation and blood pressure by using the collected twins. However, the cg07761116 located on chromosome 10 had low P value in the correlation analysis of 3 blood pressure indices (systolic blood pressure, diastolic blood pressure, mean arterial pressure), suggesting that this site might be correlated with blood pressure. The other 7 sites had low P value in the correlation analysis of the two blood pressure indices, respectively, which pointed to genes involved in neurological development, protein homeostasis, inflammatory reaction and other pathways. CONCLUSION: There is no sufficient evidence to support any DNA methylation site correlated with blood pressure, which may be caused by insufficient sample size and other reasons. This study could provide a reference for subsequent similar twin studies, and subsequent studies can focus on the cg07761116 located on chromosome 10 and other sites with low P values.

[Mendelian randomization analysis of the relationship between obesity and DNA methylation].

Objective: To explore the association between DNA methylation and body mass index (BMI) using Mendelian randomization analysis. Methods: A total of 469 participants were selected from the Chinese National Twin Registry in 2013, who were living in Shandong, Jiangsu, Zhejiang, and Sichuan provinces, and at least 18 years of age. A questionnaire survey and physical examination were conducted to collect demographic, clinical, and behavioral information. Peripheral blood cells were collected to detect genotype and methylation status. Association analyses between DNA methylation and BMI and between CpGs and cis-SNP were conducted. With rs748212 as the instrumental variable, the association between cg15053022 and BMI was explored using the Mendelian randomization method. Results: A total of 469 participants were selected. The mean age of participants was (44.8±13.2) years and the BMI was (25.0±3.8) kg/m(2). Nine BMI-related DNA methylation sites were found and DNA methylation site cg15053022 in the ATP4A gene was negatively associated with cis-SNP rs748212 (ß=-0.020); the mean methylation level of AA, AC, and CC were 0.212±0.025, 0.242±0.024, and 0.264±0.028, respectively. rs748212 was associated with BMI (ß=0.04, P=0.007) and closely related to cg15053022 (F=237.66, P=0.143). Mendelian randomization analysis showed lower methylation levels at cg15053022 were associated with higher BMI (ß=-1.97, P<0.001). Conclusion: This study supported the impact of cg15053022 methylation in the ATP4A gene on BMI using Mendelian randomization analysis and provided the basis for using Mendelian randomization analysis in methylation studies.

[Major depressive disorder in relation with coronary heart disease and stroke in Chinese adults aged 30-79 years].

OBJECTIVE: To investigate the associations of major depressive disorder with coronary heart disease (CHD) and stroke in Chinese adults aged 30-79 years. METHODS: In 2004-2008, China Kadoorie Biobank was conducted in 10 geographically defined regions (5 urban and 5 rural) of China. A total number of 512 891 participants aged 30-79 years were recruited in the baseline survey. A laptop-based electronic questionnaire was administrated face-to-face by trained health workers, collecting the general demographic and socio-economic status, dietary and other lifestyle behaviours (e.g. smoking, alcohol drinking, physical activity), medical history and family history of common chronic diseases. Major depressive episodes (MDE) in the past 12 months were assessed with the World Health Organization composite international diagnostic interview-short form (CIDI-SF). The physical measurements included the heights and weights, which were used to calculate the body mass indexes (BMI).Chi squared and t test were used to compare the differences in participants characteristics according to their major depressive disorder. Logistic models were employed to estimate the odds ratios (OR) and 95% CI of their major depressive disorder with prevalent coronary heart disease and stroke. RESULTS: Among the 512 891 participants, 3 281 (0.6%) showed an MDE in the preceding 12 months, 15 472 (3.0%) reported prevalent CHD, and 8 884 (1.7%) reported prevalent stroke. Major depressive disorder was significantly associated with an increased risk of CHD and risk of stroke. Age- and gender-adjusted ORs (95% CI) were 1.80 (1.53-2.12) for CHD and 2.53 (2.09-3.05) for stroke. The associations were significant after further adjustment for potential confounders, such as other socio-demographic status, smoking, alcohol drinking, physical activity, and BMI, prevalent hypertension, diabetes as well as family history of cardiovascular diseases (OR=1.83, 95% CI=1.54-2.18 for CHD; OR=2.19, 95% CI=1.79-2.69 for stroke). Moreover, gender significantly interacted with MDE on prevalent stroke (P for multiplicative interaction=0.013). The men with an MDE in the past 12 months had the highest risk of stroke in the joint analyses of gender and depression disorder (OR=5.02, 95% CI=3.70-6.82). CONCLUSION: The findings from this large cross-sectional study suggest that the presence of MDE is a risk factor for both CHD and stroke in Chinese adults aged 30-79 years, but further prospective studies are warranted to validate the results.

[Progress in research of relationship between marital status and cancer].

In recent 30 years, the global burden of cancer has become more serious, and one of social problem is population aging, plus declining birth rate, declining marriage rate and increasing divorce rate. Marriage is one of the most intimate and long-term social relations, and previous research had piecemeal reports of its impact on cancer morbidity and mortality without systematic review of evidence in high-quality population based epidemiological research. This paper summarizes the progress in research of the relationship between marital status and cancer to provide reference for future research and cancer prevention and control.

[Physical activity and its influencing factors in patients with diabetes mellitus: a comparative study between China and the United Kingdom].

Objective: To compare the differences in low-level physical activity (PA) and related influencing factors in patients with diabetes mellitus in China and the United Kingdom (UK). Methods: Using baseline survey data from the China Kadoorie Biobank and the UK Biobank, we analyzed the association between diabetes mellitus and low-level PA using logistic regression, with the participants' self-reported whether they had diabetes mellitus as the independent variable, and low-level PA as the dependent variable. Results: We included 509 254 Chinese adults and 359 763 British adults in the analysis. After adjusting for multiple factors, we found that both Chinese and British patients with diabetes mellitus were at elevated risk for low-level PA, with corresponding ORs (95%CIs) of 1.15 (1.12-1.19) and 1.37 (1.32-1.41), respectively. Patients with diabetes mellitus with longer disease duration and poorer glycemic control were at greater risk of having low-level of PA. Female, rural-distributed, employed, never-smoking Chinese diabetics, and male, urban-distributed, retired/unemployed, quit-smoking British diabetics were more likely to have low-level PA. Conclusions: Chinese and British patients with diabetes mellitus were more likely to have low-level PA compared with the general population, but the risk of low-level PA for patients in both countries varied by population characteristics. Therefore, PA guidelines and intervention measures should be based on the characteristics of individuals in the target countries and regions, which could improve PA levels among patients with diabetes mellitus.

[Current status of tuberculosis burden in China].

Tuberculosis, caused by Mycobacterium tuberculosis, is an infectious disease that most often affects the lungs. China is still among the high-burden tuberculosis countries in the world. Although the estimated incidence of tuberculosis in China has declined in recent years, the declining rate is slow. It still faces major issues such as a slower rate of decline, a widening gap between estimated and notified incidence, higher risk among middle-aged and older adults, a high number of cases among agriculture and related workers, and a heavier disease burden in the country's western regions. In addition, latent tuberculosis infection, drug-resistant tuberculosis, tuberculosis coinfection with HIV, and extrapulmonary tuberculosis have also exacerbated the disease burden of tuberculosis to some extent. This paper reviewed the epidemic characteristics of tuberculosis, the epidemiological triad, three links and two factors in the transmission process, the disease burden, and other aspects to provide a reference for formulating prevention and control strategies on tuberculosis.

[A prospective study on the relationship between exposure to solid fuels for heating and its duration and the risk of morbidity of respiratory diseases among residents aged 30-79 years].

Objective: To research the association between exposure to solid fuels for heating and its duration and the risk of respiratory diseases morbidity. Methods: Data from the China Kadoorie Biobank project sited in Pengzhou City, Sichuan Province. Cox proportional hazard regression model was used to analyze the association between exposure to solid fuels for heating and its duration and the risk of total respiratory diseases and the association between exposure to solid fuels for heating and the risk of chronic obstructive pulmonary disease (COPD) and pneumonia among respiratory diseases. Results: A total of 46 082 participants aged 30-79 years were enrolled, with 11 634 (25.25%) heating during the winter, of whom 8 885 (19.28%) used clean fuels and 2 749 (5.97%) used solid fuels, of whom 34 448 (74.75%) did not heat. After controlling for multiple confounding factors, Cox proportional hazard regression model was used, which revealed that compared with clean fuels, unheating could reduce the risk of total respiratory disease (HR=0.81,95%CI:0.77-0.86), COPD (HR=0.86,95%CI:0.78-0.95) and pneumonia (HR=0.80,95%CI:0.74-0.86), respectively. Exposure to solid fuels increased the risk of total respiratory disease (HR=1.10, 95%CI:1.01-1.20) and were not associated with COPD and pneumonia. Compared with no solid fuel exposure, the risk of total respiratory disease (1-19 years:HR=1.23, 95%CI:1.10-1.37; 20-39 years:HR=1.25, 95%CI:1.16-1.35; ≥40 years:HR=1.26, 95%CI:1.15-1.39) and COPD (1-19 years: HR=1.21, 95%CI:1.03-1.42; 20-39 years: HR=1.30, 95%CI:1.16-1.46; ≥40 years:HR=1.35, 95%CI:1.18-1.54) increased with the length of exposure of solid fuels (trend test P<0.001). Solid fuels exposure for 1-19 years and 20-39 years increased the risk of COPD by 23% (HR=1.23,95%CI:1.02-1.49) and 16% (HR=1.16, 95%CI:1.00-1.35). Conclusion: Heating solid fuels exposure increases the risk of total respiratory disease, COPD, and pneumonia.

[An observational and Mendelian randomization study of the associations of body mass index with plasma amino acids and acylcarnitines in Chinese adults].

Objective: To explore the relationship between BMI and levels of plasma amino acids and acylcarnitines in Chinese adults. Methods: Based on 2 182 individuals with targeted mass spectrometry metabolomic measurements from the first resurvey of the China Kadoorie Biobank, we assessed the linear and nonlinear associations between BMI and plasma levels of 20 amino acids and 40 acylcarnitines using linear regression models and restricted cubic spline models, and identified BMI-related metabolic pathways. We conducted one-sample Mendelian randomization (MR) with BMI genetic risk scores as the instrumental variable further to explore the potential causal relationships between BMI and 20 amino acids and 40 acylcarnitines, and tested for horizontal pleiotropy using the MR-Egger method. Results: Observational analyses found that BMI was associated with increased plasma levels of 3 branched-chain amino acids (isoleucine, leucine, and valine), 2 aromatic amino acids (phenylalanine and tyrosine), 3 other amino acids (cysteine, glutamate, lysine), and 7 acylcarnitines (C3, C4, C5, C10, C10:1, C14, and C16), and with decreased circulating levels of asparagine, serine, and glycine. Pathway analysis identified 7 BMI-related amino acids metabolic pathways (false discovery rate corrected all P<0.05), including branched-chain amino acids and aromatic amino acids biosynthesis, glutathione metabolism, etc. BMI showed a nonlinear relationship with leucine, valine, and threonine, and a linear relationship with other amino acids and acylcarnitines. One-sample MR analyses revealed that BMI was associated with elevated levels of tyrosine and 4 acylcarnitines [C5-DC(C6-OH), C5-M-DC, C12-DC, and C14], with tyrosine and acylcarnitine C14 positively correlated with BMI in both observational [the ß values (95%CIs) were 0.057 (0.044-0.070) and 0.018 (0.005-0.032), respectively] and One-sample MR analyses [the ß values (95%CIs) were 0.102 (0.035-0.169) and 0.104 (0.036-0.173), respectively]. The MR analyses of the current study satisfied the 3 core assumptions of instrumental variable. Conclusions: BMI was associated with circulating 11 amino acids and 7 acylcarnitines in Chinese adults, involving several pathways such as branched-chain amino acid and aromatic amino acid metabolism, fatty acid metabolism, and oxidative stress. There may be a causal relationship between BMI and tyrosine and acylcarnitine C14.

[Relationship between physical activity and the risk of morbidity of cerebrovascular disease in Sichuan Province: a prospective study].

Objective: To investigate the morbidity of cerebrovascular disease among residents ≥30 years in Pengzhou, Sichuan Province, and analyze the effect of physical activity level on the risk of morbidity of cerebrovascular disease. Methods: From 2004 to 2008, people from Pengzhou, Sichuan Province were randomly selected. All the local people aged 30-79 were asked to receive a questionnaire survey, physical examination, and long-term follow-up to determine the morbidity of cerebrovascular disease. The physical activity level and the morbidity of cerebrovascular disease were described, and Cox proportional hazard regression models were used to evaluate the association of domain-specific physical activity with the risk of morbidity of cerebrovascular disease. Results: In 55 126 participants, there were 5 290 new cases of cerebrovascular disease, with a cumulative incidence of 9.60%. After the adjustment for multiple confounding factors, multivariate Cox proportional hazard regression analysis showed that increased levels of occupational, transportation, and total physical activity reduced the risk of cerebrovascular disease and its subtypes (cerebral hemorrhage, cerebral infarction). The highest group of occupational physical activity level had the lowest risk of cerebrovascular disease, with a hazard ratio (HR) value of 0.81 (95%CI: 0.75-0.88), the highest group of transportation physical activity level had the lowest risk of cerebrovascular disease, with an HR value of 0.84 (95%CI: 0.78-0.91), the highest group of total physical activity level had the lowest risk of cerebrovascular disease, with an HR value of 0.87 (95%CI: 0.80-0.94), compared with the lowest group of corresponding physical activity. No association was found between the household/leisure-time physical activity level and the risk of cerebrovascular disease and its subtypes (cerebral hemorrhage, cerebral infarction). Conclusions: In project areas of Pengzhou, Sichuan Province, increased physical activity has been associated with reduced morbidity of cerebrovascular disease and its subtypes (cerebral hemorrhage, cerebral infarction). Increased levels of physical activity in adults are encouraged for health benefits.

[Association between waist circumference and ischemic stroke: a prospective study in adults from Qingdao].

Objective: To analyze the association between waist circumference (WC) and ischemic stroke (IS). Methods: The data for the present study were from the prospective cohort study of China Kadoorie Biobank in Qingdao. Using baseline information and IS events of the participants, the Cox proportional hazard regression model and restricted cubic spline (RCS) were used to analyze the association between WC and IS. Results: A total of 33 355 participants were included in the study, with 302 008.88 person-years of follow-up. A total of 1 093 new cases of IS were observed. Multivariate Cox proportional hazard regression model analysis showed that compared to the respondents with normal WC (male <85.0 cm, female <80.0 cm), respondents with excessive WC (male ≥85.0 cm, female ≥80.0 cm) had a 78% higher risk of IS incidence [hazard ratio(HR)=1.78, 95%CI: 1.51-2.10], and the risk increased by 72% (HR=1.72, 95%CI: 1.40-2.12) and 83% (HR=1.83, 95%CI: 1.40-2.39) in men and women. According to the RCS, the increase in WC and the risk of IS showed an "S" trend of nonlinear dose-response relationship. Conclusions: The risk of IS would increase with the WC. Keeping a normal WC is important for preventing IS.

[A prospective study on association between sleep duration and the risk of chronic obstructive pulmonary disease in adults in Suzhou].

Objective: To investigate the prospective association of sleep duration with the development of chronic obstructive pulmonary disease (COPD) in adults in Suzhou. Methods: The study used the data of 53 269 participants aged 30-79 years recruited in the baseline survey from 2004 to 2008 and the follow-up until December 31, 2017 of China Kadoorie Biobank (CKB) conducted in Wuzhong District, Suzhou. After excluding participants with airflow limitation, self-reported chronic bronchitis/emphysema/coronary heart disease history at the baseline survey and abnormal or incomplete data, a total of 45 336 participants were included in the final analysis. The association between daily sleep duration and the risk for developing COPD was analyzed by using a Cox proportional hazard regression model, and the hazard ratio (HR) values and their 95%CI were calculated. The analysis was stratified by age, gender and lifestyle factors, and cross-analysis was conducted according to smoking status and daily sleep duration. Results: The median follow-up time was 11.12 years, with a total of 515 COPD diagnoses in the follow-up. After adjusting for potential confounders, multifactorial Cox proportional hazard regression analysis showed that daily sleep duration ≥10 hours was associated with higher risk for developing COPD (HR=1.42, 95%CI: 1.03-1.97). The cross analysis showed that excessive daily sleep duration increased the risk for COPD in smokers (HR=2.49, 95%CI: 1.35-4.59, interaction P<0.001). Conclusion: Longer daily sleep duration (≥10 hours) might increase the risk for COPD in adults in Suzhou, especially in smokers.

[A prospective study of association between physical activity and ischemic stroke in adults].

Objective: To explore the prospective associations between physical activity and incident ischemic stroke in adults. Methods: Data of China Kadoorie Biobank study in Tongxiang of Zhejiang were used. After excluding participants with cancers, strokes, heart diseases and diabetes at baseline study, a total of 53 916 participants aged 30-79 years were included in the final analysis. The participants were divided into 5 groups according to the quintiles of their physical activity level. Cox proportional hazard regression models was used to calculate the hazard ratios (HR) for the analysis on the association between baseline physical activity level and risk for ischemic stroke. Results: The total physical activity level in the participants was (30.63±15.25) metabolic equivalent (MET)-h/d, and it was higher in men [(31.04±15.48) MET-h/d] than that in women [(30.33±15.07) MET-h/d] (P<0.001). In 595 526 person-years of the follow-up (average 11.4 years), a total of 1 138 men and 1 082 women were newly diagnosed with ischemic stroke. Compared to participants with the lowest physical activity level (<16.17 MET-h/d), after adjusting for socio-demographic factors, lifestyle, BMI, waist circumference, and SBP, the HRs for the risk for ischemic stroke in those with moderate low physical activity level (16.17-24.94 MET-h/d), moderate physical activity level (24.95-35.63 MET-h/d), moderate high physical activity level (35.64-43.86 MET-h/d) and the highest physical activity level (≥43.87 MET-h/d) were 0.93 (95%CI: 0.83-1.04), 0.87 (95%CI: 0.76-0.98), 0.82 (95%CI: 0.71-0.95) and 0.76 (95%CI: 0.64-0.89), respectively. Conclusion: Improving physical activity level has an effect on reducing the risk for ischemic stroke.

[Associations of body mass index and waist circumference with risk of chronic kidney disease in adults in China].

Objective: To examine the associations of BMI and waist circumference (WC) with the risk of chronic kidney disease (CKD) and its subtypes in adults in China. Methods: The data from the China Kadoorie Biobank were used. After excluding those with cancer, coronary heart disease, stroke, or CKD at baseline survey, 480 430 participants were included in this study. Their body height and weight, and WC were measured at baseline survey. Total CKD was defined as diabetic kidney disease (DKD), hypertensive nephropathy (HTN), glomerulonephritis (GN), chronic tubulointerstitial nephritis (CTIN), obstructive nephropathy (ON), CKD due to other causes, and chronic kidney failure. Cox proportional hazards regression model was used to estimate the associations between exposure factors and risks of outcomes. Results: During a follow-up period of (11.8±2.2) years, 5 486 cases of total CKD were identified, including 1 147 cases of DKD, 340 cases of HTN, 1 458 cases of GN, 460 cases of CTIN, 598 cases of ON, 418 cases of CKD due to other causes, and 1 065 cases of chronic kidney failure. After adjusting for socio-demographic factors, lifestyle factors, baseline prevalence of hypertension and diabetes, and WC and compared to participants with normal BMI (18.5-23.9 kg/m2), the hazard ratios (HRs) of total CKD for underweight (<18.5 kg/m2), overweight (24.0-27.9 kg/m2), and obese (≥28.0 kg/m2) were 1.42 (95%CI: 1.23-1.63), 1.00 (95%CI: 0.93-1.08) and 0.98 (95%CI: 0.87-1.10), respectively. Stratification analysis by WC showed that BMI was negatively associated with risk for total CKD in non-central obese participants (WC: <85.0 cm in men and <80.0 cm in women) (HR=0.97, 95%CI: 0.96-0.99), while the association was positive in central obese participants (≥90.0 cm in men and ≥85.0 cm in women) (HR=1.03, 95%CI: 1.01-1.05). The association between BMI and GN was similar to that of total CKD. BMI was associated with an increased risk for HTN, with a HR of 1.12 (95%CI: 1.06-1.18) per 1.0 kg/m2 higher BMI. After adjusting for potential confounders and BMI, compared to participants with non-central obesity, the HRs for pre-central obesity (WC: 85.0-89.9 cm in men and 80.0-84.9 in women) and central obesity were 1.26 (95%CI: 1.16-1.36) and 1.32 (95%CI: 1.20-1.45), respectively. With the exception of HTN and CTIN, WC was positively associated with risks for all CKD subtypes. Conclusions: BMI-defined underweight and central obesity were independent risk factors for total CKD, and BMI and WC had different associations with risks for disease subtypes.

[Prospective association study of sleep status and risk of coronary heart disease in adults in Suzhou].

Objective: To investigate the association between sleep status and the risk for coronary heart disease in adults in Suzhou. Methods: Using the baseline and follow up information of 53 269 local residents aged 30-79 years in China Kadoorie Biobank conducted in Wuzhong District, Suzhou, 51 929 subjects were included in this study after excluding those reporting coronary heart disease, stroke and cancer at the baseline survey. A Cox proportional hazards regression model was used to analyze the association of healthy sleep score (0-3 points) and sleep factors (snoring, insomnia, long sleep duration and nap) with the risk for coronary heart disease. Results: The median follow-up time was 11.12 years, and 1 304 individuals were diagnosed with coronary heart disease during the follow-up. After adjusting for potential confounders, occasional snoring (HR=1.20, 95%CI: 1.04-1.38), usual snoring (HR=1.17, 95%CI: 1.02-1.33), insomnia disorder (HR=1.41, 95%CI: 1.12-1.78), daytime dysfunction (HR=1.56, 95%CI: 1.20-2.03) and perennial nap (HR=1.37, 95%CI: 1.19-1.59) were associated with increased risk of coronary heart disease. Compared with those with sleep score of 0 - 1 (low sleep quality), the people with sleep score of 3 had reduced risk of coronary heart disease by 26% (HR=0.74, 95%CI: 0.63-0.87). Stratified analysis showed that the association of healthy sleep score 3 with risk of coronary heart disease was stronger in low physically active individuals (interaction P<0.05). Conclusions: Snoring, insomnia disorders, daytime dysfunction, and perennial napping were all associated with increased risk for coronary heart disease, and keep healthy sleep mode might reduce the risk for coronary heart disease in adults.