[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.

[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.

[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.

[Prevalence of urinary incontinence in middle-aged and elderly adults in 10 areas in China].

Objective: To describe the population and area distribution differences in the prevalence of urinary incontinence in middle-aged and elderly adults in 10 areas in China. Methods: A total of 24 913 participants aged 45-95 years who completed the third resurvey of China Kadoorie Biobank during 2020-2021 were included. The prevalence of urinary incontinence was assessed by an interviewer-administered questionnaire, and urinary incontinence was classified as only stress urinary incontinence, only urgency urinary incontinence and mixed urinary incontinence. The prevalence of urinary incontinence and its subtypes were reported by sex, age and area, and the severity of urinary incontinence and treatment were described. Results: The average age of the participants was (65.4±9.1) years. According to the seventh national census data in 2020, the age-standardized prevalence rates of urinary incontinence was 25.4% in women and 7.0% in men. The age-standardized prevalence rates of only stress, only urgency and mixed incontinence were 1.7%, 4.2% and 1.2% in men and 13.5%, 5.8% and 6.1% in women, respectively. The prevalence rates of urinary incontinence and all subtypes in men and the prevalence of urinary incontinence and all subtypes except only stress urinary incontinence in women all increased with age (P<0.001). After adjusting for age, the prevalence of urinary incontinence in both men and women were higher in rural area than in urban area (P<0.001). The treatment rates in men and women with urinary incontinence were 15.4% and 8.5%, respectively. Conclusions: The prevalence of urinary incontinence was high in middle-aged and elderly adults in China, and the prevalence rate was higher in women than in men, but the treatment rate of urinary incontinence was low.

[Progress and practice of objective measurement of physical behaviors in large-scale cohort research].

Due to the limited reliability of traditional self-completed questionnaire, the accuracy of measurement of physical behaviors (physical activity, sedentary behavior and sleep) is not high. With the development of technology, wearable devices (e.g. accelerometer) can be used for more accurate measurement of physical behaviors and have great application potential in large-scale research. However, the data of objective measurement of physical behaviors from large-scale cohort research in Asian populations is still limited. Between August 2020 and December 2021, the 3rd resurvey of China Kadoorie Biobank (CKB) project used Axivity AX3 wrist triaxial accelerometer to collect the data of participants' daily activity and sleep status. A total of 20 370 participants from 10 study areas were included in the study, in whom 65.2% were women, and the age was (65.4±9.1) years. The participants' physical activity level varied greatly in different study areas. The objective measurement of participants' physical behaviors in CKB project has provided valuable resources for the description of 24-hour patterns of physical behaviors and evaluation of the health effect of physical activity, sedentary behavior and sleep as well as their association with diseases in the elderly in China.

[Epidemiological characteristics of preserved vegetable intake in adults in 10 areas of China].

Objective: To describe the epidemiological characteristics of intakes of different types of preserved vegetables in participants from the China Kadoorie Biobank (CKB). Methods: The CKB project conducted baseline survey, the first resurvey, and the second resurvey during 2004-2008, 2008, and 2013-2014, respectively. According to the average intake levels of salted and sour pickled vegetables in the second resurvey, the 10 survey areas were classified as the area where people mainly consumed salted vegetables, the area where people mainly consumed sour pickled vegetables, and the area where people rarely consumed preserved vegetables. For the first two areas, logistic regression model was used to describe the temporal trends and population distribution of preserved vegetable intake and analyze the distribution of other dietary factors. Results: The area where people mainly consumed salted vegetables included Qingdao, Harbin, Suzhou, and Zhejiang (baseline participant number: 204 036), while the area where people mainly consumed sour pickled vegetables included Gansu and Sichuan (baseline participant number: 105 573). In the area where people mainly consumed salted vegetables, the average intake frequencies of preserved vegetables was 3.1, 3.3, and 1.8 days/week in the baseline survey, the first resurvey, and the second resurvey, respectively, showing a declining trend (P<0.001). Similarly, the average intake frequencies of preserved vegetables were 2.8, 2.7, and 1.6 days/week in the baseline survey, the first resurvey and the second resurvey in the area where people mainly consumed sour pickled vegetables (P<0.001). At baseline survey, the married and those had lower education level tended to have more preserved vegetable intakes in both areas (P<0.001). In the area where people mainly consumed salted vegetables, the elderly had higher frequency of preserved vegetable intake (P<0.001), which was converse in the area where people mainly consumed sour pickled vegetables. In the participants with higher frequency of preserved vegetable intake, more people consumed spicy food daily and preferred salty food (P<0.05). Conclusions: The area and population specific differences in the type and frequency of preserved vegetable intake were observed in adults in the CKB project in China. Besides, the average level of preserved vegetable intake showed a declining trend. Preserved vegetable intake might be associated with other dietary habits.

[A prospective cohort study of factors associated with longevity in older adults in 10 areas of China].

Objective: To evaluate the associations of sociodemographic characteristics and lifestyle factors with longevity status in older adults in China. Methods: After excluding those born after 31st December 1938, a total of 51 870 older adults from the China Kadoorie Biobank (CKB) were included. The attained age was defined according to the survival age or age on 31st December 2018. According to the attained age, the old persons were categorized into non-longevity (died before age 80 years) and longevity (attained age ≥80 years). The longevity group was further divided into two groups: longevity with death occurring before 2019, and longevity and survival to 2019. The information about socio-demographic characteristics and lifestyles was collected at the 2004-2008 baseline survey. Multinomial logistic regression models were used to analyze the associations between exposure factors and outcomes by taking the non-longevity group as the reference group. Results: A total of 51 870 older adults aged 65-79 years in the baseline survey were included for analysis. During a follow-up for (10.2±3.5) years, 38 841 participants were longevity, and 30 354 participants still survived at the end of 2018. Compared to men, rural populations, non-married individuals, those with an annual household income of less than 10 000 yuan, and those with education levels of primary school or below, the adjusted ORs(95%CI) for longevity and survival to 2019 in women, urban residents, married individuals, those with annual household incomes ≥20 000 yuan, and those with education levels of college or university were 1.68 (1.58-1.78), 1.69 (1.61-1.78), 1.15 (1.10-1.21), 1.44 (1.36-1.53), and 1.32 (1.19-1.48), respectively. The OR (95%CI) for longevity and survival to 2019 was 1.09 (1.08-1.10) for those with an increase of 4 MET-hour/day in total physical activity level. With those who never or almost never smoked, had no alcohol drinking every week, had normal weight (BMI: 18.5-23.9 kg/m2), and WC <85 cm (man)/<80 cm (woman) as the reference groups, the ORs(95%CI) of longevity and survival to 2019 were 0.64 (0.60-0.69) for those smoking ≥20 cigarettes per day, 1.29 (1.14-1.46) for those with alcohol drinking every week, 1.13 (1.01-1.26) for those with pure alcohol drinking <30 g per day, 0.56 (0.52-0.61) for those being underweight, 1.27 (1.19-1.36) for those being overweight, 1.23 (1.11-1.36) for those with obesity, and 0.86 (0.79-0.93) for those with central obesity. Further stratified analysis by WC was performed. In the older adults with WC <85 cm (man)/<80 cm (woman), the ORs (95%CI) of longevity and survival was 1.80 (1.69-1.92) for those with each 5 kg/m2 increase in BMI and 1.02 (0.96-1.08) for those with WC ≥85 cm (man)/≥80 cm (woman). There was a statistically significant difference in the association between BMI and longevity between the two WC groups (interaction test P<0.001). Conclusion: This study showed that women, the married, those with higher socioeconomic status and education level, and those with healthy lifestyles were more likely to achieve longevity.

[Epidemiological distribution of mosaic loss of chromosome Y in adult men in 10 areas in China and its prospective association with lung cancer].

Objective: To detect the prevalence of mosaic loss of chromosome Y in adult men in ten study areas in China, describe the epidemiological distribution of mosaic loss of chromosome Y (mLOY) carriers and assess its prospective association with lung cancer. Methods: Based on the data from baseline survey, genetic analysis and follow-up (as of December 31, 2018) from China Kadoorie Biobank, we used Mosaic Chromosomal Alterations pipeline to detect mLOY carriers in 10 areas in China and described the epidemiological characteristics of mLOY carriers in adult men, including age, area distribution, lifestyle and disease history. We used multivariate logistic regression model to identify the potential relevant factor of mLOY. Cox proportional hazard regression model was fitted to assess the prospective association of mLOY with lung cancer. Stratification analysis were conducted to evaluate the potential modification effects of smoking and age. We also conducted mediation analysis to assess the mediating effect of mLOY in the association between smoking and lung cancer. Results: A total of 42 859 adult men were included in our analysis, in whom 2 458 mLOY carriers were detected (5.7%). The detection rate increased with age (P<0.05). The detection rate was higher in urban area (7.3%±0.2%) than that in rural area (4.7%±0.1%). The results of logistic regression analysis indicated that smoking might be a risk factor for the detection of mLOY (OR=1.49, 95%CI:1.36-1.64). After follow-up for average 11.1 years, 1 041 lung cancer cases were observed. The prospective analysis showed that mLOY carriers had an increased risk for lung cancer by 24% compared with non-mLOY carriers (HR=1.24, 95%CI:1.01-1.52) and expanded mLOY carriers (mLOY cell proportion ≥10%) had an increased risk for lung cancer by 50% (HR=1.50, 95%CI:1.13-2.00). Stratification analysis showed no modification effects of smoking and age in the association between mLOY and lung cancer (interaction P>0.05). Mediation analysis showed that mLOY could be a mediating factor in the association between smoking and lung cancer, the estimated effect was 0.09 (0.01-0.17). Conclusions: There were significant differences in the detection rate of mLOY in adult men with different social-economic characteristics and lifestyles in ten areas in China. Besides, mLOY carriers, especially expanded mLOY carriers, had increased risk for lung cancer and mLOY might be a mediating factor in the association between smoking and lung cancer.

[Study on the associations of meeting intensive systolic blood pressure control goals with risk for incident cardiovascular and cerebrovascular diseases among the adult hypertensive patients in China].

Objective: To evaluate the associations of meeting intensive systolic blood pressure (SBP) control goals with risk for incident cardiovascular and cerebrovascular diseases among the adult hypertensive patients in China. Methods: We used data from adult hypertensive patients from the China Kadoorie Biobank. logistic regression models evaluated the influencing factors of meeting intensive and standard SBP control goals. Cox proportional hazard models evaluated the associations between meeting intensive vs. standard SBP control goals and risk for incident cardiovascular and cerebrovascular diseases. Results: A total of 3 628 hypertensive patients who reported continuous medication use were included in this study, of which 5.0% of the participants met the goals of intensive SBP control (≤130 mmHg). Participants with higher educational attainment (OR=2.36,95%CI: 1.32-4.04), healthier diet (OR=2.09,95%CI: 1.45-2.96), daily intake of fresh fruit (OR=1.67,95%CI: 1.17-2.36) and combination treatment (OR=1.82,95%CI: 1.03-3.09) were more likely to meet intensive SBP control goal after adjustment of age, sex and urban/rural areas. During an average follow-up of (10.0±3.7) years, 1 278 cases of composite cardiovascular outcome were recorded. This study did not find a statistical correlation between achieving the goal of enhanced SBP control and the occurrence of composite cardiovascular and cerebrovascular outcomes (HR=0.89, 95%CI: 0.63-1.25). For major adverse cardiovascular events (MACE), cerebrovascular diseases, stroke, and ischemic stroke, we observed a trend of decrease in risk of outcomes with more intensive SBP control (trend test P<0.05). Conclusions: We observed decreased risk for MACE and cerebrovascular diseases with more intensive SBP control. However, there was no significant risk reduction for cardiovascular and cerebrovascular diseases when meeting the intensive SBP control goal, compared to the standard SBP control goal.

[Epidemiological distribution characteristics of peripheral blood mosaic chromosomal alteration in adults from 10 regions of China].

Objective: To describe the epidemiological distribution characteristics of peripheral blood mosaic chromosomal alteration (mCA) in community adults aged 30-79 years in 10 regions of China. Methods: A total of 100 297 participants with complete baseline information (demographic characteristics, lifestyle, physical examination, etc.) and genotyping data of blood-derived DNA in ten regions of the China Kadoorie Biobank study were included. The mCAs were detected with the Mosaic Chromosomal Alterations pipeline, and logistic regression models were used to compare the differences in the detection rate of mCAs in different regions and populations. Results: A total of 5 810 mCA carriers were detected, with the detection rate of 5.8%. The standardized detection rate was 5.1%. The baseline detection rate of mCA increased with age, which were 3.4%, 5.0%, and 9.4% in those aged 30-, 51-, and >60 years, respectively (trend test P<0.001). A more significant proportion of mCAs were found in men (8.0%) than women (4.0%), as well as in urban areas (6.4%) than in rural areas (5.3%), the difference was significant (P<0.001). After adjusting for age and gender, the detection rate of mCA was higher in current smokers or people quitting smoking due to illness and people with low physical activity level, and the mCA detection rate was lower in obesy people (5.3%) than that in people with normal body weight (5.9%) (P=0.006). Conclusions: The detection rate of mCAs varied with region and population in community adults aged 30-79 years in 10 regions of China. The study results might contribute to the molecular identification of aging populations and guide precision prevention of age-related diseases such as cancers.

[Tea consumption and cancer: a Mendelian randomization study].

Objective: A Mendelian randomization (MR) analysis was performed to assess the relationship between tea consumption and cancer. Methods: There were 100 639 participants with the information of gene sequencing of whole genome in the China Kadoorie Biobank. After excluding those with cancer at baseline survey, a total of 100 218 participants were included in this study. The baseline information about tea consumption were analyzed, including daily tea consumption or not, cups of daily tea consumption, and grams of daily tea consumption. We used the two-stage least square method to evaluate the associations between three tea consumption variables and incidence of cancer and some subtypes, including stomach cancer, liver and intrahepatic bile ducts cancer, colorectal cancer, tracheobronchial and lung cancer, and female breast cancer. Multivariable MR and analysis only among nondrinkers were used to control the impact of alcohol consumption. Sensitivity analyses were also performed, including inverse variance weighting, weighted median, and MR-Egger. Results: We used 54, 42, and 28 SNPs to construct non-weighted genetic risk scores as instrumental variables for daily tea consumption or not, cups of daily tea consumption, and grams of daily tea consumption, respectively. During an average of (11.4±3.0) years of follow-up, 6 886 cases of cancer were recorded. After adjusting for age, age2, sex, region, array type, and the first 12 genetic principal components, there were no significant associations of three tea consumption variables with the incidence of cancer and cancer subtypes. Compared with non-daily tea drinkers, the HR (95%CI) of daily tea drinkers for cancer and some subtypes, including stomach cancer, liver and intrahepatic bile ducts cancer, colorectal cancer, tracheobronchial and lung cancer, and female breast cancer, are respectively 0.99 (0.78-1.26), 1.17 (0.58-2.36), 0.86 (0.40-1.84), 0.85 (0.42-1.73), 1.39 (0.85-2.26) and 0.63 (0.28-1.38). After controlling the impact of alcohol consumption and performing multiple sensitivity analyses, the results were similar. Conclusion: There is no causal relationship between tea consumption and risk of cancer in population in China.

[Incidence of chronic obstructive pulmonary disease and risk factors in the Suzhou cohort].

Objective: To understand the incidence of chronic obstructive pulmonary disease (COPD) in the Suzhou cohort, and explore the risk factors for the development of COPD in Suzhou, and provide a scientific basis for COPD prevention. Methods: This study was based on the China Kadoorie Biobank project in Wuzhong District, Suzhou. After excluding individuals with airflow obstruction and self-reported chronic bronchitis, emphysema, or pulmonary heart disease at baseline, 45 484 individuals were finally included in the analysis. Cox proportional risk models were used to analyze risk factors of COPD and calculate hazard ratios and 95% confidence interval (CI) in the Suzhou cohort. The effect modifications of smoking on the association between other risk factors and COPD were evaluated. Results: Complete follow-up was available through December 31, 2017. Participants were followed up for a median of 11.12 years, and 524 individuals were diagnosed with COPD during the follow-up period; the incidence was 105.54 per 100 000 person-years. Multivariate Cox proportional risk regression models showed that age (HR=3.78, 95%CI:3.32-4.30), former smoking (HR=2.00, 95%CI:1.24-3.22), current smoking (<10 cigarettes/day, HR=2.14, 95%CI:1.36-3.35;≥10 cigarettes/day, HR=2.69, 95%CI:1.60-4.54), history of respiratory disease (HR=2.08, 95%CI:1.33-3.26), daily sleep duration ≥10 hours (HR=1.41, 95%CI:1.02-1.95) were associated with increased risk of COPD. However, education level of primary school and above (primary or junior high school, HR=0.65, 95%CI:0.52-0.81; high school and above, HR=0.54, 95%CI:0.33-0.87), consuming fresh fruit daily (HR=0.59, 95%CI:0.42-0.83) and consuming spicy food weekly (HR=0.71, 95%CI:0.53-0.94) were associated with reduced risk of COPD. Conclusions: The incidence of COPD is low in Suzhou. Older age, smoking, history of respiratory disease, and long sleep duration were risk factors for the development of COPD in the Suzhou cohort.

[Prospective association between physical activity and mortality in patients with chronic kidney disease].

Objective: To investigate the prospective association of physical activity with all-cause, cardiovascular disease (CVD), and chronic kidney disease (CKD) mortality in CKD patients in China. Methods: Cox proportional hazard models were used to evaluate the association of total, domain-specific, and intensity-specific physical activity with the risk of all-cause, CVD, and CKD mortality based on data from the baseline survey of China Kadoorie Biobank. Results: During a median follow-up of 11.99 (11.13, 13.03) years, there were 698 deaths in 6 676 CKD patients. Compared with the bottom tertile of total physical activity, participants in the top tertile had a lower risk of all-cause, CVD, and CKD mortality, with hazard ratios (HRs) (95%CIs) of 0.61 (0.47-0.80), 0.40 (0.25-0.65), and 0.25 (0.07-0.85), respectively. Occupational, commuting, and household physical activity were negatively associated with the risk of all-cause and CVD mortality to varying degrees. Participants in the top tertile of occupational physical activity had a lower risk of all-cause (HR=0.56, 95%CI: 0.38-0.82) and CVD (HR=0.39, 95%CI: 0.20-0.74) mortality, those in the top tertile of commuting physical activity had a lower risk of CVD mortality (HR=0.43, 95%CI: 0.22-0.84), and those in the top tertile of household physical activity had a lower risk of all-cause (HR=0.61, 95%CI: 0.45-0.82), CVD (HR=0.44, 95%CI: 0.26-0.76) and CKD (HR=0.03, 95%CI: 0.01-0.17) mortality, compared with the bottom tertile of corresponding physical activity. No association of leisure-time physical activity with mortality was observed. Both low and moderate-vigorous intensity physical activity were negatively associated with the risk of all-cause, CVD and CKD mortality. The corresponding HRs (95%CIs) were 0.64 (0.50-0.82), 0.42 (0.26-0.66) and 0.29 (0.10-0.83) in the top tertile of low intensity physical activity, and the corresponding HRs (95%CIs) were 0.63 (0.48-0.82), 0.39 (0.24-0.64) and 0.23 (0.07-0.73) in the top tertile of moderate-vigorous intensity physical activity. Conclusion: Physical activity can reduce the risk of all-cause, CVD, and CKD mortality in CKD patients.

[Relationship between smoking and the risk of morbidity of chronic obstructive pulmonary diseases among residents aged 30 years and above in Sichuan Province: a prospective study].

Objective: To investigate the morbidity of chronic obstructive pulmonary diseases (COPD) in residents aged 30 years and above in Sichuan Province, and analyze the effect of smoking on the risk of morbidity on COPD. Methods: From 2004 to 2008, people were randomly selected from Pengzhou, Sichuan Province. All the local people aged 30-79 years were asked to receive questionnaire survey, physical examination and pulmonary function testing, and long-term follow-up to determine the morbidity of COPD. Cox proportional hazard regression model was used to analyze the relationship between smoking and COPD. Results: In 46 540 participants, the current smoking rates were 67.31% in males and 8.67% in females, there were 3 101 new cases of COPD, with a cumulative incidence of 6.66%. Adjusted for age, gender, occupation, marriage, income level, educational level, BMI, daily total physical activity, current cooking frequency, whether there was smoke exhaust device at present and frequency of passive smoking exposure, multivariate Cox proportional hazard regression analysis showed that compared with the non-smoking population, current smoking and quitting smoking increased the risk of COPD, with HR of 1.42 (95%CI:1.29-1.57) and 1.34 (95%CI:1.16-1.53). Compared with people who never or occasionally smoke, the risk of morbidity on COPD increased with the increase of average daily smoking volume, mixed smoking at present, mixed smoking at the beginning increased the risk of COPD, with HR of 1.79 (95%CI: 1.42-2.25) and 2.12 (95%CI: 1.53-2.92), started smoking at the age of <18 years old and ≥18 years old increased the risk of COPD, with HR of 1.61 (95%CI:1.43-1.82) and 1.34 (95%CI: 1.22-1.48), inhaling into the mouth, throat and lung during smoking increased the risk of COPD, with HR of 1.30 (95%CI: 1.16-1.45), 1.63 (95%CI: 1.45-1.83) and 1.37 (95%CI: 1.21-1.55). Adjusted for multiple confounding factors and adjusted for regression dilution bias, the average daily smoking volume, the age of starting smoking and the depth of smoking inhalation had an impact on the incidence of COPD, and the gender difference was particularly prominent. Conclusions: Smoking increased the risk of morbidity on COPD, which was related to the average daily smoking volume, the type of smoking, the age of starting smoking and the depth of smoking inhalation. Tobacco control should comprehensively consider the specific characteristics of smoking, so as to prevent COPD.

[Prevalence of chronic kidney disease and its association with lifestyle factors in adults from 10 regions of China].

Objective: To investigate the distribution of chronic kidney disease (CKD) in participants from the China Kadoorie Biobank (CKB) study and evaluate the association between lifestyle risk factors and CKD. Methods: Based on the baseline survey data and follow-up data (as of December 31, 2018) of the CKB study, the differences in CKD cases' area and population distributions were described. Cox proportional hazards regression model was used to estimate the association between lifestyle risk factors and the risk of CKD. Results: A total of 505 147 participants, 4 920 cases of CKD were recorded in 11.26 year follow up with a incidence rate of 83.43/100 000 person-years. Glomerulonephropathy was the most common type. The incidence of CKD was higher in the urban area, men, and the elderly aged 60 years and above (87.83/100 000 person-years, 86.37/100 000 person-years, and 132.06/100 000 person-years). Current male smokers had an increased risk for CKD compared with non-smokers or occasional smokers (HR=1.18, 95%CI: 1.05-1.31). The non-obese population was used as a control group, both general obesity determined by BMI (HR=1.19, 95%CI: 1.10-1.29) and central obesity determined by waist circumference (HR=1.27, 95%CI: 1.19-1.35) were associated with higher risk for CKD. Conclusion: The risks for CKD varied with area and population in the CKB cohort study, and the risk was influenced by multiple lifestyle factors.

[Characteristics of daytime napping and its correlation with chronic diseases in Chinese adults].

Objective: To describe the prevalence of daytime nap habit in participants of the China Kadoorie Biobank (CKB) study, across 10 study regions and explore its correlation with prevalence of major chronic diseases. Methods: Participants with a self-reported pre-diagnosis of any cancer at baseline survey were excluded. Logistic regression models were used to analyze the differences in study regions and age distribution of the prevalence daytime nap habit, and its correlation with the prevalence of diabetes, hypertension, coronary heart disease (CHD), stroke, chronic obstructive pulmonary disease (COPD), and chronic liver diseases. Results: Among 510 145 participants, 39.9% had daytime nap habit in summer and 20.8% had daytime nap habit all the year round. Urban-rural differences were observed in the prevalence of summer nap habit and perennial nap habit. Daytime nap in summer was common in rural areas and Suzhou, with prevalence ranged from 32.9% to 73.3%. Haikou and Liuzhou had higher prevalence of perennial nap (60.4% and 63.3%). The proportion of people with daytime nap habit all the year round increased with age (P for trend <0.001), the proportion was highest in those aged 70- years (31.9%). Daytime nap habit in summer was positively correlated with the prevalence of diabetes, hypertension, CHD and chronic liver disease with OR of 1.10 (95%CI: 1.07-1.14), 1.03 (95%CI:1.02-1.05), 1.07 (95%CI: 1.02-1.12) and 1.07 (95%CI:1.00-1.14), respectively. Daytime nap habit all the year round was positively correlated with the prevalence of diabetes, hypertension, CHD, stroke, COPD and chronic liver disease with OR of 1.33 (95%CI: 1.29-1.37), 1.11 (95%CI: 1.09-1.13), 1.39 (95%CI: 1.33-1.45), 1.33 (95%CI: 1.26-1.41), 1.12 (95%CI: 1.08-1.16) and 1.27 (95%CI:1.18-1.37) respectively. Conclusion: There were regional and age differences in prevalence of daytime nap habit among CKB participants. Daytime nap habit, especially daytime nap habit all the year round, was positively correlated with the prevalence of major chronic diseases.

[Correlation between sleep status and frailty in adults aged 30-79 years in China].

Objective: To explore the correlation between sleep status and frailty in adults aged 30-79 years in China, and explore the potential effect modification of general and central obesity. Methods: Based on the baseline data of the China Kadoorie Biobank, we used multinomial logistic regression to analyze the correlation between long and short sleep duration, insomnia disorder, snoring, and unhealthy sleep score with risks of pre-frailty and frailty. Both overall and obesity-stratified analyses were performed. Result: Among the 512 724 participants, 2.3% had frailty and 40.1% had pre-frailty. There was a U-shaped relationship between sleep duration and frailty score. Short (OR=1.21, 95%CI: 1.19-1.23) or long sleep duration (OR=1.19, 95%CI: 1.17-1.21), insomnia disorder (OR=2.09, 95%CI: 2.02-2.17), and snoring (OR=1.61, 95%CI: 1.59-1.63) were all positively correlated with pre-frailty, and dose-response relationships were observed between unhealthy sleep score and pre-frailty (P for trend<0.001), with OR values of 1.46 (1.44-1.48), 1.97 (1.93-2.00) and 3.43 (3.21-3.67) respectively for those having unhealthy sleep score of 1 to 3. These sleep problems were also positively correlated with frailty. Compared with the overweight or obesity group, stronger relationships were observed between short sleep duration and frailty or pre-frailty and between insomnia disorder and pre-frailty, while the relationships between snoring and frailty and pre-frailty were weaker in the participants with normal weight (P for interaction <0.007 for all). We also observed similar effect modification by central obesity. Conclusion: Long or short sleep duration, insomnia disorder, snoring and higher unhealthy sleep scores were positively correlated with pre-frailty or frailty, general and central obesity status could modify the relationships.

[Association between body mass index and coronary heart disease in Qingdao: a prospective study].

Objective: To analyze the association between body mass index (BMI) and coronary heart disease. Methods: The data for the present study were from the prospective cohort study of China Kadoorie Biobank (CKB) in Qingdao, a total of 33 355 participants aged 30-79 years were included in the study. Cox regression analyses were performed to evaluate the association between BMI and coronary heart disease. Results: During the follow-up for an average 9.2 years, a total of 2 712 cases of ischemic heart disease (IHD) and 420 cases of major coronary events (MCE) were found. Multivariate Cox regression analysis showed that, compared with participants with normal BMI, the participants who were overweight had a 41% and 87% higher risk of IHD and MCE, the adjusted HR were 1.41 (95%CI: 1.27-1.56) and 1.87 (95%CI: 1.43-2.44), respectively. The participants who were obesity had 91% and 143% higher risk of IHD and MCE, the adjusted HR were 1.91 (95%CI: 1.72-2.13) and 2.43 (95%CI: 1.82-3.24), respectively. Conclusion: Overweight and obesity might increase the risk for IHD and MCE.

[Association between self-reported gingival bleeding and prevalent hypertension among adults in a cross-sectional study in Zhejiang province].

Objective: To explore the association between self-reported gingival bleeding and prevalent hypertension among adults in Zhejiang with a cross-sectional study. Methods: After excluding participants with self-reported, physician-diagnosed heart diseases, stroke, diabetes, cancer, and those who never or rarely brush their teeth at baseline study, 48 625 participants aged 30-79 in the China Kadoorie Biobank (CKB) study from Tongxiang, Zhejiang were included for the final analysis. Three multivariable logistic regression models were used to estimate the odds ratios (ORs) for the associations of self-reported gingival bleeding with prevalent hypertension. Results: The mean age of women was (51.2±9.2) years, and 42.9% of participants had prevalent hypertension. The percentage of self-reported frequent gingival bleeding was 6.56% (95%CI: 6.38%-6.75%), significantly higher among women (8.08%, 95%CI: 7.82%-8.35%) than among men (4.36%, 95%CI: 4.12%-4.60%) (P<0.001). After adjusting for socio-demographic factors, behavioral lifestyle, sleep duration, BMI, waist circumference, snoring, in comparison with men whose gingivae never or rarely bleed while brushing teeth, the odds ratio (95%CI) of hypertension for those with occasional, and frequent gingival bleeding were 1.04 (0.96-1.12) and 1.18 (1.02-1.37), respectively (trend P =0.038). The corresponding figures for women were 0.96 (0.91-1.02) and 0.95 (0.86-1.05), respectively (trend P=0.344). Conclusion: Frequent gingival bleeding was positively associated with prevalent hypertension among men.