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.

Objective:To investigate the association between solid fuel use for heating, smoking, and respiratory diseases.Methods:This study is based on the Qingdao project of the China Kadoorie Biobank. After screening, 26 165 individuals were included in the study. We employed Cox proportional hazards regression models, stratified by risk age (in 5-year intervals) and sex while adjusting for confounding variables such as occupation and physical activity level to analyze the association between solid fuel use for heating, smoking, and increased risk of respiratory diseases.Results:Among the 26 165 participants, the average age of those using solid fuel for heating was (52.57±10.31) years, with females constituting 58.04% and former/current smokers accounting for 65.38%. The results indicated that both the solid fuel group and the former/current smoking group had a higher risk of respiratory diseases, with hazard ratios ( HR) (95% CI) of 1.21 (1.04-1.41) and 1.41 (1.16-1.71), respectively. For the duration of solid fuel use, the HR (95% CI) for 20 years or more, it was 1.27 (1.07-1.51). The multiplicative interaction term between solid fuel use and smoking was statistically significant. Conclusions:The use of solid fuel for heating and smoking significantly increases the risk of respiratory diseases, and there may be a multiplicative interaction between solid fuel use and smoking.

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.
Male ; Humans ; Female ; Coronary Artery Disease/genetics* ; Biological Specimen Banks ; East Asian People ; Risk Assessment/methods* ; Genetic Predisposition to Disease/genetics* ; Risk Factors ; Genome-Wide Association Study

BACKGROUND/OBJECTIVES: This study examined the relationship between famine exposure in early life and the risk of type 2 diabetes in adulthood during the 1959–1961 Chinese Famine. SUBJECTS/METHODS: A total of 3,418 individuals aged 35–74 years free of diabetes from two studies in 2006 and 2009 were followed up prospectively in 2009 and 2012, respectively. Famine exposure was classified as unexposed (individuals born in 1962–1978), fetal exposed (individuals born in 1959–1961), child exposed (individuals born in 1949–1958), and adolescent/adult exposed (born in 1931–1948). A logistic regression model was used to assess the relationship between famine exposure and diabetes after adjustment for potential covariates. RESULTS: During a three-year follow-up, the age-adjusted incidence rates of type 2 diabetes were 5.7%, 14.5%, 12.7%, and 17.8% in unexposed, fetal-exposed, child-exposed, and adolescent/adult-exposed groups, respectively (P < 0.01). Relative to the unexposed group, the relative risks (95% confidence interval) for diabetes were 2.15 (1.29–3.60), 1.53 (0.93– 2.51), and 1.65 (0.75–3.63) in the fetal-exposed, child-exposed, and adolescent/adult-exposed groups, after controlling for potential covariates. The interactions between famine exposure and obesity, education level, and family history of diabetes were not observed, except for the urbanization type. Individuals living in rural areas with fetal and childhood famine exposure were at a higher risk of type 2 diabetes, with relative risks of 8.79 (1.82–42.54) and 2.33 (1.17–4.65), respectively. CONCLUSIONS These findings indicate that famine exposure in early life is an independent predictor of type 2 diabetes, particularly in women. Early identification and intervention may help prevent diabetes in later life.

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.

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.

Objective:To explore the gene-body mass index (BMI) interaction on coronary heart disease (CHD) in the Chinese adult twins.Methods:A total of 20 340 same-sex twin pairs registered in the Chinese National Twin Registry (CNTR) were enrolled in this study. Classical twin structure equation model was used to estimate the gene-BMI interaction on CHD.Results:After adjusting for age, we found that genetic variance of CHD differed as the function of BMI in male twins, which indicated the presence of a gene-BMI interaction on CHD ( P=0.008).The genetic moderating effect ( βa) was -0.14 (95% CI: -0.22--0.04), indicating that for each logarithmic transformation value of BMI increase, genetic path parameters would decrease by 0.14, which would result in the decrease of genetic variance of CHD. And the heritability of CHD was 0.77 (95% CI: 0.65-0.86) among the male twins with lower BMI (<24.0 kg/m 2), but 0.56 (95% CI: 0.33-0.74) among the male twins with high BMI (≥24.0 kg/m 2). However, there was no evidence suggesting that BMI could moderate genetic variants of CHD in female. Conclusion:We found a significant gene-BMI interaction on CHD in the Chinese male adult twins in China, and the heritability of CHD was higher among the twins whose BMI was <24.0 kg/m 2.

Objective:To describe the differences in body mass index (BMI) distribution in adult twins registered in Chinese National Twin Registry (CNTR), and provide evidence for the risk factor analysis and prevention and control of overweight or obesity.Methods:A total of 32 725 twin pairs aged 18 years and above who completed the questionnaire survey during 2010-2018 and had complete registered information in CNTR and normal body weight and length were included in the analysis on the population and region specific distributions of BMI of twin pairs and the difference in BMI in twin pairs.Results:The twin pairs included in the analysis were aged (34.6±12.4) years, the twin pairs of same gender accounted for 79.7%. The average BMI was 22.5 kg/m 2. The overall prevalence of obesity and overweight was 4.9% and 23.7%, respectively. Participants who were men, 50-59 years old, married, had lower education level, and lived in northern China had higher overweight rate and obesity rate ( P<0.001). The difference in overweight or obesity prevalence between monozygotic (MZ) twin pars and dizygotic (DZ) twin pairs was not significant, but firstborn twin pairs had slightly higher rates of overweight and obesity than later-born twin pairs ( P<0.05). The analysis in same gender-twin pairs indicated that the difference in BMI was associated with age (trend test: P<0.001), and the difference was more obvious in DZ twin pair in MZ pair and this difference increased with age. The concordant rate of BMI was higher in MZ twin pairs than DZ twin pairs ( P<0.05). Conclusion:The distribution of BMI of twin pairs varied with population and region and BMI varied with age due to its genetic nature.

Objective:To explore the modification effect of physical activity on the genetic effects of type 2 diabetes mellitus (T2DM).Methods:The univariate moderation model was fitted to calculate the modifying effect of physical activity on the genetic effects of T2DM based on the data of 12 107 pairs of same gender twins aged 30 years and older enrolled by the Chinese National Twin Registry in 11 provinces/cities in China.Results:After adjusting for age and gender, the heritability of T2DM was 0.56 (0.31-0.84). Qualified physical activity could attenuate the genetic effects of T2DM. The heritability of T2DM in twin pairs with qualified physical activity was 0.46 (0.06-0.88), which was lower than that in twin pairs without qualified physical activity during the same model [0.68(0.36-0.94)].Conclusion:T2DM is a moderate genetic disease, physical activity can modify the genetic effects of T2DM.

Objective:To quantitate the association between birth weight and phenotypes of physical indicators in adulthood, i.e. BMI and waist circumference (WC) and to what degree genetic or environmental factors affect birth weight-obesity association.Methods:A total of 6 623 gender matched twin pairs aged 25 to 79 years were recruited through the Chinese National Twin Registry. The twins reported their own birth weight, current height and weight, and WC using a self-administered questionnaire. BMI was calculated according to the self-reports of body height and weight. Within twin-pair design was used to quantitate the association between birth weight and phenotypes related to obesity while bivariate structural equation models were used to decompose the phenotype correlation.Results:After adjusted for multiple factors, twin-pair analyses within monozygotic (MZ) showed that, on average, a 1.0 kg increase in birth weight corresponded to an increase of 0.33 kg/m 2 in BMI and 0.95 cm in WC in adulthood ( P<0.001). Bivariate structural equation models showed significant positive unique environmental correlation between birth weight and the two obesity-related phenotypes. Conclusion:The study supported the role of twin-specific supply line factors on relationship between birth weight and physical indicators in adulthood.