Objective: To describe the distribution characteristics of hypertension among adult twins in the Chinese National Twin Registry (CNTR) and to provide clues for exploring the role of genetic and environmental factors on hypertension. Methods: A total of 69 220 (34 610 pairs) of twins aged 18 and above with hypertension information were selected from CNTR registered from 2010 to 2018. Random effect models were used to describe the population and regional distribution of hypertension in twins. To estimate the heritability, the concordance rates of hypertension were calculated and compared between monozygotic twins (MZ) and dizygotic twins (DZ). Results: The age of all participants was (34.1±12.4) years. The overall self-reported prevalence of hypertension was 3.8%(2 610/69 220). Twin pairs who were older, living in urban areas, married, overweight or obese, current smokers or ex-smokers, and current drinkers or abstainers had a higher self-reported prevalence of hypertension (P<0.05). Analysis within the same-sex twin pairs found that the concordance rate of hypertension was 43.2% in MZ and 27.0% in DZ, and the difference was statistically significant (P<0.001). The heritability of hypertension was 22.1% (95%CI: 16.3%- 28.0%). Stratified by gender, age, and region, the concordance rate of hypertension in MZ was still higher than that in DZ. The heritability of hypertension was higher in female participants. Conclusions: There were differences in the distribution of hypertension among twins with different demographic and regional characteristics. It is indicated that genetic factors play a crucial role in hypertension in different genders, ages, and regions, while the magnitude of genetic effects may vary.
Adult ; Female ; Humans ; Male ; Alcohol Drinking ; Diseases in Twins/genetics* ; Hypertension/genetics* ; Twins, Dizygotic/genetics* ; Twins, Monozygotic/genetics*

Objective: To describe the distribution characteristics of hyperlipidemia in adult twins in the Chinese National Twin Registry (CNTR) and explore the effect of genetic and environmental factors on hyperlipidemia. Methods: Twins recruited from the CNTR in 11 project areas across China were included in the study. A total of 69 130 (34 565 pairs) of adult twins with complete information on hyperlipidemia were selected for analysis. The random effect model was used to characterize the population and regional distribution of hyperlipidemia among twins. The concordance rates of hyperlipidemia were calculated in monozygotic twins (MZ) and dizygotic twins (DZ), respectively, to estimate the heritability. Results: The age of all participants was (34.2±12.4) years. This study's prevalence of hyperlipidemia was 1.3% (895/69 130). Twin pairs who were men, older, living in urban areas, married,had junior college degree or above, overweight, obese, insufficient physical activity, current smokers, ex-smokers, current drinkers, and ex-drinkers had a higher prevalence of hyperlipidemia (P<0.05). In within-pair analysis, the concordance rate of hyperlipidemia was 29.1% (118/405) in MZ and 18.1% (57/315) in DZ, and the difference was statistically significant (P<0.05). Stratified by gender, age, and region, the concordance rate of hyperlipidemia in MZ was still higher than that in DZ. Further, in within-same-sex twin pair analyses, the heritability of hyperlipidemia was 13.04% (95%CI: 2.61%-23.47%) in the northern group and 18.59% (95%CI: 4.43%-32.74%) in the female group, respectively. Conclusions: Adult twins were included in this study and were found to have a lower prevalence of hyperlipidemia than in the general population study, with population and regional differences. Genetic factors influence hyperlipidemia, but the genetic effect may vary with gender and area.
Adult ; Female ; Humans ; Male ; Middle Aged ; Young Adult ; China/epidemiology* ; Diseases in Twins/genetics* ; Hyperlipidemias/genetics* ; Metabolic Diseases ; Twins, Dizygotic ; Twins, Monozygotic/genetics*

Objective: To describe the distribution characteristics of type 2 diabetes in twins in Chinese National Twin Registry (CNTR), provide clues and evidence for revealing the influence of genetic and environmental factors for type 2 diabetes. Methods: Of all twins registered in the CNTR during 2010-2018, a total 18 855 twin pairs aged ≥30 years with complete registration information were included in the analysis. The random effect model was used to describe the population and area distribution characteristics and concordance of type 2 diabetes in twin pairs. Results: The mean age of the subjects was (42.8±10.2) years, the study subjects included 10 339 monozygotic (MZ) twin pairs and 8 516 dizygotic (DZ) twin pairs. The self-reported prevalence rate of type 2 diabetes was 2.2% in total population and there was no sighificant difference between MZ and DZ. Intra-twin pairs analysis showed that the concordance rate of type 2 diabetes was 38.2% in MZ twin pairs, and 16.0% in DZ twin pairs, the difference was statistically significant (P<0.001). The concordance rate of type 2 diabetes in MZ twin parts was higher than that in DZ twin pairs in both men and women, in different age groups and in different areas (P<0.05). Further stratified analysis showed that in northern China, only MZ twin pairs less than 60 years old were found to have a higher concordance rate of type 2 diabetes compared with DZ twin pairs (P<0.05). In southern China, the co-prevalence rate in male MZ twin pairs aged ≥60 years was still higher than that in DZ twin pairs (P<0.05). Conclusion: The twin pairs in this study had a lower self-reported prevalence of type 2 diabetes than the general population. The study results suggested that genetic factors play a role in type 2 diabetes prevalence in both men and women, in different age groups and in different areas, however, the effect might vary.
Adult ; China/epidemiology* ; Diabetes Mellitus, Type 2/genetics* ; Diseases in Twins/genetics* ; Female ; Humans ; Male ; Middle Aged ; Registries ; Twins, Dizygotic ; Twins, Monozygotic/genetics*

Objective: To describe the distribution characteristics of coronary heart disease in adult twins recruited from Chinese Twin Registry (CNTR), and provide clues and evidence for the effect of genetic and environmental influences on coronary heart disease. Methods: By using the data of CNTR during 2010-2018, a total of 34 583 twin pairs aged ≥18 years who completed questionnaire survey and had related information were included in the current study to analyze the population and area distribution characteristics of coronary heart disease. Random effect models were used to compare the differences between groups. The concordane rate of coronary heart disease were calculated respectively in monozygotic (MZ) twin pairs and dizygotic (DZ) twin pairs to estimate the heritability. Results: The twin pairs included in this analysis were aged (34.2±12.4) years. The overall prevalence rate of coronary heart disease in twin pairs was 0.7%. Twin pairs who were women, older, obese and lived in northern China had higher prevalence of coronary heart disease (P<0.05). Intra-pair analysis in the same-sex twin pairs found that the concordane rate of coronary heart disease was higher in MZ twin pairs (25.3%) than in DZ twins (7.4%), and the difference was statistically significant (P<0.001). The overall heritability of coronary heart disease was 19.3% (95%CI: 11.8%-26.8%). Stratified by gender, age and area, the concordane rate was still higher in MZ twin pairs than in DZ pairs. Participants who were women, aged 18-30 years or ≥60 years and lived in northern China had a higher heritability of coronary heart disease. Conclusion: The distribution of coronary heart disease in twin pairs differed in populations and areas. The prevalence of coronary heart disease was affected by genetic factors, but the effect varied with age, gender and area.
Adolescent ; Adult ; China/epidemiology* ; Coronary Disease/genetics* ; Diseases in Twins/genetics* ; Female ; Humans ; Male ; Twins, Dizygotic ; Twins, Monozygotic/genetics*

Objective: To explore the gene-lifestyle interaction on coronary heart disease (CHD) in adult twins of China. Methods: Participants were selected from twin pairs registered in the Chinese National Twin Registry (CNTR). Univariate interaction model was used to estimate the interaction, via exploring the moderation effect of lifestyle on the genetic variance of CHD. Results: A total of 20 477 same-sex twin pairs aged ≥25 years were recruited, including 395 CHD cases, and 66 twin pairs both had CHD. After adjustment for age and sex, no moderation effects of lifestyles, including current smoking, current drinking, physical activity, intake of vegetable and fruit, on the genetic variance of CHD were found (P>0.05), suggesting no significant interactions. Conclusion: There was no evidence suggesting statistically significant gene-lifestyle interaction on CHD in adult twins of China.
Adult ; China/epidemiology* ; Coronary Disease/genetics* ; Diseases in Twins/genetics* ; Humans ; Life Style ; Twins/genetics* ; Twins, Dizygotic ; Twins, Monozygotic

Objective: To describe the distribution characteristics of tea consumption in adult twins recruited in the Chinese National Twin Registry (CNTR) and provide clues to genetic and environmental influences on tea consumption. Methods: Enrolled in CNTR during 2010-2018, 25 264 twin pairs aged 18 years and above were included in subsequent analysis. Random effect models were used to estimate tea consumption in the population and regional distribution characteristics. The concordance rate of the behavior and difference in consumption volume of tea within pairs were also described. Results: The mean age of all subjects was (35.38±12.45) years old. The weekly tea consumers accounted for 17.0%, with an average tea consumption of (3.36±2.44) cups per day. The proportion of weekly tea consumers was higher among males, 50-59 years old, southern, urban, educated, and the first-born in the twin pair (P<0.05), and lower among unmarried individuals (P<0.001). Within-pair analysis showed that the concordance rate of tea consumption of monozygotic (MZ) twins was higher than that of dizygotic (DZ) twins and the overall heritability of tea consumption was 13.45% (11.38%-15.51%). Stratified by the characteristics mentioned above, only in males, the concordance rate of MZ showed a tendency to be greater than that of DZ (all P<0.05). The differences in consumption volume of tea within twin pairs were minor in MZ among males (P<0.05), while the differences were not significant in female twins. Conclusion: There were discrepancies in the distribution of tea consumption among twins of different demographic and regional characteristics. Tea consumption was mainly influenced by environmental factors and slightly influenced by genetic factors. The size of genetic factors varied with gender, age, and region, and gender was a potential modified factor.
Adult ; China ; Diet ; Female ; Humans ; Male ; Middle Aged ; Tea ; Twins, Dizygotic ; Twins, Monozygotic ; Young Adult

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.
Body Mass Index ; Coronary Disease/epidemiology* ; Humans ; Myocardial Ischemia/epidemiology* ; Obesity/epidemiology* ; Overweight/epidemiology* ; Prospective Studies

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 (β 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 (P_FPG=2.42×10^-19, FDR_FPG<0.001; P_HbA1c=1.72×10^-19, FDR_HbA1c<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.
Adult ; Blood Glucose ; CpG Islands ; DNA Methylation ; Epigenesis, Genetic ; Fasting ; Female ; Glycated Hemoglobin A ; Humans ; Male ; Middle Aged ; Twins, Monozygotic

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.
Adult ; Blood Pressure ; Body Weight ; CpG Islands ; DNA Methylation ; Female ; Humans ; Male ; Middle Aged ; Twins, Monozygotic

OBJECTIVETo determine whether elevated serum uric acid (UA) levels are associated with type 2 diabetes diagnosed using HbA1c levels among Chinese adults.

METHODSWe conducted two population-based cross-sectional studies in Qingdao in China in 2006 and 2009. A total of 6894 (39.4% men) subjects aged 35-74 years were included in the data analysis. Newly diagnosed diabetes was defined as HbA1c level of ⋝6.5%, and prediabetes was classified as HbA1c level between 5.7% and 6.4% according to the International Diabetes Federation criteria. Multivariate logistic regression was employed to assess the association between UA and prevalence of type 2 diabetes defined using Glycated hemoglobin A1c (HbA1c) levels.

RESULTSSubjects with prediabetes had higher UA levels than those with normal glucose tolerance, newly diagnosed diabetes, and known diabetes, with corresponding values of 325.1 (82.5) µmol/L, 310.9 (84.2) µmol/L, 291.3 (81.7) µmol/L, 305.2 (83.6) µmol/L, respectively (P<0.001 for all comparisons). Binary logistic regression analysis showed that UA was a possible predictor for the prevalence of type 2 diabetes diagnosed using HbA1c levels, and the second quartile of UA levels had a higher odds ratio (OR: 4.088; 95% CI: 2.900-5.765) for HbA1c than the other quartiles after adjusting for age, body mass index, sex, marital status, education, income, alcohol consumption, smoking, and cardiometabolic parameters.

CONCLUSIONSerum UA is significantly associated with type 2 diabetes diagnosed using HbA1c levels, independent of other cardiometabolic parameters.

Adult ; Aged ; Asian Continental Ancestry Group ; statistics & numerical data ; China ; epidemiology ; Cross-Sectional Studies ; Diabetes Mellitus, Type 2 ; blood ; epidemiology ; Female ; Glycated Hemoglobin A ; metabolism ; Humans ; Male ; Middle Aged ; Prevalence ; Uric Acid ; blood