[Analysis of distribution characteristics and influencing factors of chord µ in young myopia].

Objective: To explore and analyze the distribution characteristics of chord µ related parameters, as well as the pupil center's relative position to the coaxial corneal light reflex on the corneal surface, and the influencing factors in young myopia. Methods: This was a cross-sectional study. A total of 761 myopic patients (761 eyes) were collected from March 2021 to December 2021 in the Refractive Surgery Center of Tianjin Eye Hospital, including 388 males and 373 females, with an average age of (24±6) years. The relationship between age, sex, diopter, anterior and posterior corneal surface parameters, and chord µ related parameters was analyzed, including the x and y absolute values of the pupil center, chord µ length, and angle. The normality of the data was tested using the Kolmogorov-Smirnov test, and the influencing factors of chord µ were analyzed through Pearson and Spearman correlation analysis. Results: The equivalent spherical degree and chord µ length were (-5.47±1.66) D and (0.178±0.095) mm, respectively. The chord µ length followed an approximately normal distribution. The chord µ length of 266 eyes (35%) was distributed in the range of 0.120 to 0.200 mm, while the chord µ length of 479 eyes (63%) was<0.200 mm, and the chord µ length of 620 eyes (81%) was<0.260 mm. The chord µ angle distribution accounted for the largest proportion in the superior nasal quadrant (45.6%), followed by the superior temporal quadrant (34.3%), the inferior temporal quadrant (10.1%), and the inferior nasal quadrant (10.0%). High myopia (r=0.11, P=0.002) and high astigmatism (r=0.08, P=0.023) were associated with an increase in chord µ length. The higher the degree of myopia, the smaller the chord µ angle (r=-0.09, P=0.019). The larger the ISV (r=0.09, P=0.017), IVA (r=0.08, P=0.025), and IHD (r=0.08, P=0.039) on the anterior surface of the cornea, the longer the chord µ length. The higher the astigmatism of the posterior corneal surface, the greater the absolute value of the Y coordinate of the pupil center (r=0.07, P=0.044), and the longer the chord µ length (r=0.08, P=0.035), and the smaller the chord µ angle (r=-0.08, P=0.032). Conclusions: The chord µ length of young myopic individuals in China followed an approximately normal distribution, with the majority located in the superior nasal and superior temporal quadrants. High myopia, high astigmatism, and irregular corneal shape are the main factors related to an increase in chord µ length.

[Research on indicators of ideological and political resource database construction for curriculum of "Epidemiology"].

Objective: To construct indicators of the ideological and political resource database construction for the curriculum of "Epidemiology". Methods: Two rounds of expert consultation were conducted in 15 experts from 4 universities and 1 textbook publishing house using the Delphi method, and the importance and feasibility scores of the indicators were calculated with the degree of concentration and coordination of experts' opinions. Results: In the two rounds of consultation, the experts' positive coefficient of the two questionnaires were both 100.00% (15/15), the authoritative coefficients of experts were both 0.83, and the Kendall's W was 0.27 (P<0.05) and 0.33 (P<0.05), respectively. Consensus was reached on 4 primary indicators and 31 secondary indicators. Conclusion: The process of this study is scientific, and the indicators for the construction of ideological and political resource database for the curriculum of "Epidemiology" are authoritative, which can promote the establishment of ideological and political resource database for the curriculum of "Epidemiology".

[A descriptive analysis on hypertension in adult twins in China].

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.

[A descriptive analysis of hyperlipidemia in adult twins in China].

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.

[Introduction for One Health Joint Plan of Action (2022-2026)].

Four organizations, including the Food and Agriculture Organization of the United Nations, the United Nations Environment Programme, WHO, and the World Organization for Animal Health, recently launched a new One Health Joint Plan of Action (2022-2026) which was the first time that the Quadripartite had issued a joint action plan on One Health. The action plan aimed to address the health challenges in the human, animal, plant, and environment, focusing on improving capabilities in six action tracks including One Health capacities, emerging and re-emerging zoonotic diseases, neglected tropical and vector-borne diseases, food safety, antimicrobial resistance and environment. This introduction will give an overview and brief translation of the background, content, and the plan's value, to help readers understand the joint action plan quickly.

[A descriptive analysis of tea consumption in adult twins in China].

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.

[Review of genome-wide association research of aging phenotypes].

"Active health" has been emphasized in "Healthy China 2030" in dealing with the challenges of population aging, so the anti-aging strategies are requires to be more precise and effective at both individual and population levels. Aging is influenced by both genetic and environmental factors. In the recent 20 years, the research of genetics of human ageing has been greatly facilitated owning to the development of high-throughput sequencing techniques, statistical methodology for multi-omics data, as well as the growing qualified evidence of large-scale population-based genomic research. This paper provides a review of genome-wide association research of aging.

[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.

[A descriptive analysis on type 2 diabetes in twins in China].

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.

[A descriptive analysis on coronary heart disease in adult twins in China].

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.

[Gene-lifestyle interaction on coronary heart disease in adult twins of China].

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.

[A descriptive analysis on body mass index distribution in adult twin pairs in China].

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/m2. 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.

[Modification of physical activity on genetic effects of type 2 diabetes mellitus: a twin pairs cohort study in China].

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.

[Gene-body mass index interaction on coronary heart disease in Chinese adult twins].

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 (ßa) 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/m2), but 0.56 (95%CI: 0.33-0.74) among the male twins with high BMI (≥24.0 kg/m2). 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/m2.

[Epidemiological characteristics of COVID-19 cases in outbreak in Xinfadi market in Beijing].

Objective: To understand the epidemiological characteristics of COVID-19 cases, including asymptomatic cases and symptomatic cases, in the outbreak in Xinfadi market in Beijing. Methods: Data and epidemiological survey reports of COVID-19 cases in Xinfadi market in Beijing were extracted from China's Infectious Disease Information System. Epidemiological characteristics of symptomatic cases and asymptomatic cases were analyzed and compared by using software SPSS 19.0. Results: From June 11 to July 10, 2020, a total of 368 laboratory-confirmed COVID-19 cases reported in Xinfadi market, in which, 335 (91.03%) were symptomatic and 33 (8.97%) were asymptomatic. The cases were distributed in 11 districts, and most cases (252/368, 68.48%) were reported in Fengtai district. The incidence curve of the cases showed a typical outbreak pattern, the case number peaked on 13 June. The median age of the cases were 43 years (QR: 31-51). The asymptomatic cases (M=32, QR: 29-46) were younger than the symptomatic cases (M=43, QR: 31-52), the difference was significant (Z=2.416, P=0.016). The ratio of male to female was 1.26∶1. Most cases (236/368, 64.13%) were engaged in catering service and public place service. 73.91% (272/368) of the cases had historg of direct exposures in the Xinfadi market. 54.08%(199/368) of cases were detected through nucleic acid testing and screening. Mild and moderate cases accounted for 99.10% (332/335) and no death occurred. Conclusion: The COVID-19 cases in the outbreak in Xinfadi market were mainly engaged in catering service and public place service. The asymptomatic cases were younger than the symptomatic cases.

[Current status of COVID-19 pandemic and progress in response strategy].

As the approaching of autumn and winter in northern hemisphere, COVID-19, mainly transmitted through respiratory droplets and close contact, has posed new challenge to the countries across the world. This paper summarizes the current status of COVID-19 pandemic and related responses performed in terms of the variation of SARS-CoV-2, global situation reports, herd immunity and the influence of asymptomatic infection on COVID-19 prevention and control in China, as well as vaccine development progress and case treatment for the purpose of providing reference to further improve the COVID-19 prevention and control strategy in China.

[Nutritional risk screening and related factors of cancer patients in community of Shanghai, 2018-2019].

Objective: To study the risk of malnutrition and related factors of cancer patients in community of Shanghai. Methods: From October 2018 to January 2019, four communities, Pengpu New Village Street, Pengpu Town, Jiangning Road Street, and Caojiadu Street, from 14 communities in Jing 'an District, Shanghai City, were selected by using a random cluster sampling method based on the Shanghai Cancer Registration and reporting system. All cases of malignant tumors and benign tumors of the central nervous system were included. A total of 4 396 questionnaires were distributed. After the exclusion of 9 invalid questionnaires, 3 310 valid questionnaires were included with a rate of 99.73%. A self-designed questionnaire was used to collect data including basic demographic characteristics, history of malignant, physical and psychological pain, nutritional demands and cognitive status. Malnutrition Universal Screening Tools (MUST) was used to analyze the nutritional risk of cancer patients in the community. Multivariate logistic regression model was applied to analyze potential factors. Results: Among the 3 310 cancer patients who completed the survey, the average age of study participants was (64.05±13.02), and 1 467 cases (44.32%) were males. The incidence rate of nutritional risk was 12.84% (425/3 310). The result of logistic regression analysis showed that compared with male, other cancer patients and no physical pain, the risk factors of the occurrence of nutritional included: female (OR=1.53,95%CI:1.23-1.92), head and neck malignant tumors (OR=1.42,95%CI:1.07-1.90), bronchus/lung malignant tumors (OR=1.93,95%CI:1.43-2.61), liver, biliary/pancreatic malignant tumors (OR=2.11,95%CI:1.21-3.65) and upper gastrointestinal malignant tumors (OR=6.04,95%CI:4.31-8.46), patients with physical pain (OR=1.39,95%CI:1.02-1.89). Conclusion: Nutritional risk of cancer patients is higher in community of Shanghai. Gender, location of tumors and physical pain are associated with the occurrence of nutritional risk.

[Association between perceived built environment attributes and adults' leisure-time physical activity in four cities of China].

Objective: To explore the associations between perceived built environment attributes and adults' leisure-time physical activity in four cities of China. Methods: Multistage cluster random sampling method was used to select adults aged 25 to 64 in Hangzhou, Suzhou, Chengdu, and Qingdao. Data were collected from June 2017 to July 2018. The perception of the urban built environment was assessed by the neighborhood environment walkability scale-abbreviated (NEWS-A), and the physical activity was assessed by the International Physical Activity Questionnaire. Generalized linear mixed models were used to explore the relationship between the perceived built environment and leisure-time physical activities. Results: A total of 3 789 participants were included in the analysis. After adjusting for potential confounders, better access to public services (OR=1.34, 95%CI: 1.02-1.75) and higher aesthetic quality (OR=1.37, 95%CI: 1.09-1.73) were positively associated with the possibility of engaging in leisure-time physical activity in the past week. Similarly, these two attributes were positively associated with leisure-time walking. Higher scores on the perception of street connectivity were positively associated with leisure-time walking [exp(ß)=1.09, 95%CI: 1.00-1.19]. Higher residential density [exp(ß)=1.000 4, 95%CI:1.000 0-1.000 8], better access to physical activity destinations[exp(ß)=1.09, 95%CI: 1.00-1.19], and better aesthetics [exp(ß)=1.11, 95%CI:1.00-1.22] were associated with higher leisure-time physical activity. Similarly, these three attributes were positively associated with the possibility of meeting the WHO recommendations. Conclusion: Changing some urban built environment attributes may increase leisure-time physical activity.

[Advances on the asymptomatic infection of COVID-19].

The COVID-19 outbreak in China has been gradually controlled. At present, the management and risk assessment of asymptomatic infected cases has become an urgent problem to be addressed. Asymptomatic case is mainly detected by close contact screening, cluster epidemic investigation, infection source tracking investigation, and active detection of target population. Currently, research on the spread risk from asymptomatic cases was limited, and lacking the data relates to the distribution of asymptomatic cases in large community population. Pathogen detection using PCR is suitable for screening in close contacts of confirmed cases and should be started as early as possible. The antibody test is more suitable for screening in general population where the source of infection is unclear. The management of asymptomatic cases now in China focuses on isolation and medical observation according to the guideline of "early detection, early report, early isolation and early treatment" .

[Heritability of alcohol intake among adult twins, calculate by the structural equation model].

Objective: To explore the genetic and environmental effects on alcohol intake. Methods: Data on 9 231 pairs of adult twins of the same sex was collected from the Chinese National Twin Registry (CNTR), between 2015 and 2018 and used in this study. Structural equation model was used to estimate the effects of genetic and environmental factors on alcohol intake. Results: A total of 9 231 pairs of twins were included in the analysis, of which 6 085 pairs were monozygotic (MZ). The average age of MZ was (36.91±13.07) years old, and males accounted for 56.80%. The average age of dizygotic twins (DZ) was (35.22±12.48) years old, and males accounted for 55.91%. There were 350 pairs of alcohol-drinking twins were with high-risk, accounting for 1.90% and another 367 pairs (1.99%) were with medium-risk. Alcohol-drinkers with medium-risk were affected by additive genetics, common and unique environmental factors, seen among the twins. The overall heritability appeared as 24.3% (95%CI: 0 to 56.8%). Furthermore, 50.7% of the variation (95%CI: 20.4%-79.0%) could be explained by the common environmental factors and 24.9% (95%CI: 18.3%-36.5%) by unique environmental factors. High-risk related drinking behavior was affected by both common and unique environmental factors. The common environmental component appeared as 75.6% (95%CI: 69.6%-80.8%) and unique environmental component as 24.4% (95%CI: 19.2%-30.4%), respectively. Gender difference was seen in the heritability of those with medium or high-risk drinking behaviors. The heritability of men was 30.8% (95%CI: 9.8%-53.5%), while in women it was mainly affected by the environment. Conclusion: Both alcohol drinkers with medium and high-risk drinking behaviors were mainly affected by the environment factors and gender. With the increase of drinking volume, the effect of environment on drinking behaviors became more obvious.