中国成年双生子饮茶行为分布特征

目的 描述中国双生子登记系统（CNTR）成年双生子饮茶行为的分布特征,探索饮茶行为在双生子人群中的分布规律,为探究遗传和环境因素对饮茶行为的影响提供线索。方法 样本选自2010-2018年在CNTR进行登记的双生子,纳入≥18岁且具有饮茶信息的双生子共25 264对进行分析,描述双生子中饮茶行为的人群、地区分布特征,以及不同卵型双生子饮茶行为一致率和对内饮茶量差异分布情况。结果 研究对象年龄（35.38±12.45）岁,每周饮茶者占比17.0%,饮茶量（3.36±2.44）杯/d。男性、50~59岁、南方、城镇、文化程度高、双生子中先出生的个体中每周饮茶者比例较高（P<0.05）,未婚者中比例较低（P<0.001）。双生子对内分析发现同卵饮茶行为一致率均大于异卵,饮茶遗传度为13.45%（11.38%~15.51%）,除女性亚组外,不同性别、年龄、地区间饮茶一致率差异有统计学意义（均P<0.05）;根据性别、年龄、地区分层后仅男性同卵一致率始终呈大于异卵趋势。同性别双生子对内饮茶量差异在男性中呈现同卵小于异卵的特征（P<0.05）,而女性中差异不明显。结论 本研究双生子人群饮茶行为的分布存在人群和地区差异,饮茶行为主要受环境因素影响,遗传因素影响较弱,且遗传效应大小在不同性别、年龄、地区间不尽相同,性别可修饰这一遗传作用。     

中国成年双生子高血压的分布特征

目的描述中国双生子登记系统(CNTR)成年双生子高血压的分布特征, 探索高血压在我国双生子人群中的分布规律, 为探索遗传和环境因素对高血压的作用提供线索。方法研究对象选自2010-2018年于CNTR进行登记的双生子, 纳入≥18岁具有高血压患病信息的69 220名(34 610对)双生子进行分析。采用随机效应模型描述双生子中高血压患病的人群、地区分布特征。比较不同卵型间双生子的高血压同病率, 估算遗传度。结果研究对象年龄为(34.1±12.4)岁。双生子人群高血压报告患病率为3.8%(2 610/69 220)。年长、居住于城镇、已婚、超重或肥胖者、当前吸烟或曾经吸烟、当前饮酒或曾经饮酒人群中高血压报告患病率更高(P<0.05)。同性别双生子对内分析发现, 同卵双生子高血压同病率(43.2%)高于异卵双生子(27.0%), 差异有统计学意义(P<0.001), 高血压遗传度为22.1%(95%CI:16.3%～28.0%)。在不同性别、年龄、地区分层中, 同卵双生子高血压同病率大于异卵双生子, 在女性人群中, 高血压的遗传度更高。结论本研究中双生子人群的高血压分布存在人群...     

中国成年双生子人群冠心病分布特征

目的:描述中国双生子登记系统（CNTR）成年双生子冠心病的分布特征,探索我国双生子人群中冠心病的分布规律,为遗传和环境对于冠心病的作用提供线索和依据。方法:基于2010-2018年在CNTR进行登记的双生子,纳入≥18岁34 583对双生子进行分析,描述冠心病的人群、地区分布特征,分别计算同卵双生子（MZ）和异卵双生子...     

出生体重与成年期体格指标的双生子研究

目的 研究出生体重与成年期体格指标（BMI、腰围）表型的相关性,分解相关性可能的来源。方法 本研究使用中国双生子登记系统基线调查的年龄在25~79岁间的同性别双生子对（共6 623对）,通过问卷调查收集其出生体重、目前身高、体重及腰围。采用双生子对内对照设计的方法探索出生体重与成年期体格指标的相关性,采用结构方程模型分解相关性的来源。结果 在调整多种混杂因素后,同卵双生子对内分析结果显示出生体重每增加1.0 kg,成年后BMI增加0.33 kg/m²,腰围增加0.95 cm。结构方程模型结果显示出生体重与BMI、腰围均存在双生子个体特有环境因素的相关。结论 该研究支持成年期体格指标与出生体重的相关受双生子间特有因素的影响。     

中国成年双生子高脂血症的分布特征

目的描述中国双生子登记系统(CNTR)成年双生子高脂血症的分布特征, 初步探索遗传和环境因素对高脂血症的影响。方法研究对象来自CNTR在全国11个项目地区募集的双生子, 纳入成年且具有高脂血症信息的69 130名(34 565对)双生子进行分析。采用随机效应模型描述高脂血症的人群、地区分布特征。分别计算不同卵型双生子的高脂血症同病率, 估算遗传度。结果研究对象年龄为(34.2±12.4)岁。双生子人群高脂血症患病率为1.3%(895/69 130)。男性、年长、城镇、已婚、大专及以上文化程度、超重、肥胖、体力活动不足、当前吸烟和曾经吸烟、当前饮酒和曾经饮酒人群中高脂血症患病率较高。双生子对内分析发现, 同卵双生子高脂血症同病率为29.1%(118/405), 高于异卵双生子的18.1%(57/315), 差异有统计学意义(P<0.05)。在不同年龄、地区及性别分层中, 同卵双生子同病率仍呈现高于异卵双生子的趋势。进一步同性别双生子对内分析发现, 在北方组和女性组中, 高脂血症遗传度分别为13.04%(95%CI:2.61%～23.47%)、18.59%(95%CI:4.43%～3...     

中国双生子人群2型糖尿病分布特征

目的描述中国双生子登记系统(CNTR)双生子的2型糖尿病分布特征, 为揭示遗传和环境因素对2型糖尿病的影响提供线索和依据。方法 CNTR 2010-2018年项目登记的所有双生子中, 纳入≥30岁且有完整登记信息的18 855对双生子作为研究对象。采用随机效应模型描述2型糖尿病的人群、地区分布特征以及对内一致性的分布。结果研究对象年龄(42.8±10.2)岁, 同卵双生子(MZ)10 339对, 异卵双生子(DZ)8 516对。全人群中2型糖尿病报告患病率为2.2%, MZ和DZ报告患病率差异无统计学意义。双生子对内分析发现2型糖尿病MZ同病率为38.2%, DZ为16.0%, 差异有统计学意义(P<0.001), 在不同性别、年龄和地区中MZ同病率均大于DZ(P<0.05)。进一步分层分析, 在北方, 仅在<60岁人群中发现MZ同病率大于DZ(P<0.05);而南方, ≥60岁男性MZ同病率也大于DZ(P<0.05)。结论本研究的双生子人群2型糖尿病报告患病率低于一般人群, 在不同性别、年龄和地区中均提示遗传因素在2型糖尿病中起作用, 但其作用大小可能不...     

中国9省(市)成年双生子体重指数遗传度估计

目的 探讨中国9省(市)成年双生子BMI遗传度情况。方法 收集中国双生子登记系统9省(市)成年双生子信息, 采用结构方程模型计算11 122对双生子BMI遗传度。结果研究对象中同卵双生子6 226对, 异卵双生子4 896对, 年龄范围25～85(39.0±10.8)岁。按地区分层, 男性BMI遗传度最高的是天津, 为67.8%(95%CI:50.1%～85.8%), 最低的是浙江, 为42.1%(95%CI:27.2%～60.9%);女性最高的是四川, 为56.2%(95%CI:47.5%～70.0%), 最低的是黑龙江, 为11.2%(95%CI:0～31.7%)。按性别分层, 相同地区的男性BMI遗传度均高于女性, 其中黑龙江男性和女性的遗传度差异最大, 分别为55.3%(95%CI:35.5%～80.0%)和11.2%(95%CI:0～31.7%), 而四川男性和女性的遗传度差异最小, 分别为61.5%(95%CI:40.7%～86.4%)和56.2%(95%CI:47.5%～70.0%)。结论 中国不同地区和不同性别人群BMI遗传度存在差别。     

基于中国双生子人群的冠心病遗传-BMI交互作用研究

目的 分析冠心病患病的遗传-BMI交互作用。方法 利用中国双生子登记系统募集的20 340对≥ 25岁的同性别双生子,构建单变量遗传-环境交互作用模型,通过评估BMI对冠心病遗传效应的修饰作用反映冠心病的遗传-BMI交互作用。结果 调整年龄后,在男性中发现BMI对冠心病患病受到的遗传效应有负向修饰作用,遗传效应修饰系数（β_a）及95% CI为-0.14（-0.22~-0.04）,说明log-BMI每增加1个标准差,冠心病的遗传通径系数减小0.14,从而导致冠心病的遗传效应减小。而且低BMI（<24.0 kg/m²）男性冠心病患病的遗传度为0.77（0.65~0.86）,而高BMI（≥ 24.0 kg/m²）组对应模型中的遗传度为0.56（0.33~0.74）。在女性中未观察到冠心病的遗传-BMI交互作用。结论 中国成年男性双生子人群中发现冠心病患病的遗传-BMI交互作用,且遗传因素在低BMI组冠心病患病中发挥更重要的作用。     

农村男性人群体质指数与心血管疾病死亡关系的前瞻性随访研究

目的 探究农村男性人群体质指数和心血管疾病死亡风险的关系。方法 以唐河、凤凰县农村地区纳入“影响成年人死亡相关危险因素的前瞻性研究”项目的22 282名≥40岁的男性人群为研究对象,应用Cox比例风险回归模型计算基线不同BMI分组的人群在随访期间的心血管疾病（CVD）死亡的风险（HR）值。结果 研究对象人群随访年限为（19.1±8.7）年,随访期间共死亡10 828人,死亡比例为48.6%,有4 504例死亡归因于心血管疾病。其中1 279例死于缺血性心脏病（IHD）,1 201例死于缺血性卒中（IS）,1 317例死于出血性卒中（HS）,707例死于其他心血管疾病。用Cox比例风险回归模型（调整地区、年龄、民族、文化程度、职业、吸烟、饮酒、血压等因素）进行多因素分析显示,以BMI<18 kg/m²为参照,当20 kg/m²≤BMI<22 kg/m²时患CVD的死亡风险最低,HR=0.95（95% CI：0.83~1.09）,但从统计学分析,各组BMI的死亡风险差异均无统计学意义（P>0.05）;当20 kg/m²≤BMI<22 kg/m²时人群患IHD的死亡风险最低,HR=0.64（95% CI：0.52~0.80）（P<0.05）,当BMI≥24 kg/m²时人群IHD死亡风险与BMI<18 kg/m²人群的风险之间差异无统计学意义（P>0.05）;IS死亡风险与人群BMI变化无显著性差异（P>0.05）;当18 kg/m²≤BMI<24 kg/m²时人群患HS的死亡风险高于BMI<18 kg/m²组人群（P<0.05）,其中26 kg/m²≤BMI<28 kg/m²时人群患HS死亡风险最高,HR=1.88（95% CI：1.18~2.99）。结论 偏瘦或正常体重人群的CVD、IHD的死亡风险最低,超重人群的HS死亡风险较高,保持合理体重可降低心血管疾病患者的死亡风险。     

利用结构方程模型计算成年双生子饮酒遗传度的研究

目的 分析遗传和环境因素对饮酒的影响。方法 对2015-2018年中国双生子登记系统募集的9 231对成年同性别双生子,利用结构方程模型对饮酒相关变量进行拟合,估计遗传因素和环境因素对其的影响。结果 共纳入9 231对双生子进行分析,其中同卵双生子6 085对。同卵双生子年龄（36.91±13.07）岁,男性占56.80%;异卵双生子年龄（35.22±12.48）岁,男性占55.91%。双生子高风险饮酒者共350人,占1.90%,中风险饮酒者共367人,占1.99%。中风险饮酒受加性遗传、双生子共享环境及各自环境的影响,遗传度为24.3%（95% CI：0～56.8%）,共享环境可解释50.7%（95% CI：20.4%～79.0%）,特殊环境可解释24.9%（95% CI：18.3%～36.5%）。而高风险饮酒则主要受双生子共享环境及各自特殊环境的影响,共享环境可解释75.6%（95% CI：69.6%～80.8%）,特殊环境可解释24.4%（95% CI：19.2%～30.4%）。中高风险饮酒的遗传度具有一定的性别差异,男性中遗传度为30.8%（95% CI：9.8%～53.5%）,在女性中则主要受到环境的影响。结论 中高风险饮酒行为主要受环境影响,有一定的性别差异,且随着饮酒量的增加,环境对于饮酒行为的影响作用更趋显著。     

Accuracy of self-reported anthropometric measures — Findings from the Finnish Twin Study

ObjectiveTo determine the accuracy of self-reported height, weight, body mass index (BMI) and waist circumference (WC) compared to the measured values, and to assess the similarity between self-reported and measured values within dizygotic (DZ) and monozygotic (MZ) twin pairs.MethodsThe data on self-reported and measured height, weight and WC values as well as measured hip circumference (HC) were collected from 444 twin individuals (53–67 years old, 60% women). Accuracies between self-reported and measured values were assessed by Pearson’s correlation coefficients, Cohen’s kappa coefficients and Bland-Altman 95% limits of agreement. Intra-class correlation was used in within-pair analyses.ResultsThe correlations between self-reported and measured values were high for all variables (r = 0.86–0.98), although the agreement assessed by Bland-Altman 95% limits had relatively wide variation. The degree of overestimating height was similar in both sexes, whereas women tended to underestimate and men overestimate their weight. Cohen’s kappa coefficients between self-reported and measured BMI categories were high: 0.71 in men and 0.70 in women. Further, the mean self-reported WC was less than the mean measured WC (difference in men 2.5 cm and women 2.6 cm). The within-pair correlations indicated a tendency of MZ co-twins to report anthropometric measures more similarly than DZ co-twins.ConclusionsSelf-reported anthropometric measures are reasonably accurate indicators for obesity in large cohort studies. However, the possibility of more similar reporting among MZ pairs should be taken into account in twin studies exploring the heritability of different phenotypes.     

Lifestyle and blood pressure levels in male twins in Utah

Healthy male monozygotic (MZ) and dizygotic (DZ) twin pairs (MZ pairs = 77; DZ pairs = 88) were studied to assess the effect of dietary intake, physical activity, physical fitness, body mass index (BMI), sum of the triceps and subscapular skinfold measurements, alcohol and caffeine consumption, and smoking patterns on blood pressure. Data on physical activity, detailed dietary intake, medical history, and demographics were obtained from a questionnaire. A bicycle ergometer was used to estimate level of fitness; other medical information was ascertained from physical examination. After normalizing the study variables, intraclass correlations for BMI and the sum of the triceps and subscapular skinfold measurements were higher in MZ than in DZ twin pairs (BMI: MZ r = 0.76, DZ r = 0.48; skinfolds: MZ r = 0.73, DZ r = 0.28), as were VO2max(MZ r = 0.63, DZ r = 0.25) and post-bike heart rate (MZ r = 0.69, DZ r = 0.19). Both systolic (SBP) and diastolic blood pressure (DBP) had high heritability estimates (SBP = 0.60, and DBP = 0.66). Using factor analysis, four major lifestyle factors were identified and categorized as: 1) dietary intake; 2) a factor heavily weighted by cigarette smoking, alcohol and caffeine consumption; 3) fatness; 4) physical activity and physical fitness. Adjustment for these factors did not alter heritability estimates for either SBP or DBP.     

Comparison of analysis of variance and maximum likelihood based path analysis of twin data: Partitioning genetic and environmental sources of covariance

In order to investigate currently used model fitting strategies for twin data, analysis of variance (ANOVA) and path-maximum-likelihood (PATH-ML) methods of analyzing twin data were compared using simulation studies of 50 monozygotic (MZ) and 50 dizygotic (DZ) twin pairs. Phenotypic covariance was partitioned into additive genetic effects (A), environmental effects common to cotwins (C), and environmental variance unique to individuals (E). ANOVA and PATH-ML had identical power to detect total covariance. The PATH-ML AE model was much more powerful than ANOVA comparisons of rMZ and rDZ to detect A. However, to be unbiased, the AE model requires the assumption that C = 0.0. To allow use of the AE model to estimate A, the null hypothesis C = 0.0 is tested by comparing the goodness of fit of the ACE and AE models. Simulation of 50 MZ and 50 DZ pairs revealed that C must be greater than 55% of total variance before the null hypothesis would be rejected (P < 0.05) 80% of the time. Several recent publications were reviewed in which the null hypothesis C = 0.0 was accepted and apparently upwardly biased estimates of A, containing C, were presented with unrealistic P values. It was concluded that use of the AE model to estimate A gives an inflated view of the power of relatively small twin studies. It was recommended that ANOVA or comparison of the ACE and CE PATH-ML models be used to estimate and test the significance of A as neither requires that C = 0.0. © Wiley-Liss, Inc.     

中国18岁以下双生子出生体重与超重/肥胖的关联分析

目的 分析出生体重与儿童时期超重/肥胖间的关联。方法 使用中国双生子登记系统基线调查的<18岁双生子人群(共8267对),采用双生子对内对照设计方法,探索出生体重与儿童青少年时期BMI及超重/肥胖之间的关联。结果 调整性别和卵型的影响后,出生体重每增加0.5 kg,超重/肥胖的风险:幼儿及学龄前期(≥ 2且<6岁)儿童增加0.87倍,学龄期(≥ 6且<12岁)儿童增加0.69倍,青春期(≥ 12且<18岁)青少年增加0.28倍。结论 双生子出生体重与幼儿及学龄期超重/肥胖存在正向关联,但在指导实施公共卫生干预措施时仍需谨慎。     

母亲孕前体质指数及孕期增重与学龄前儿童超重肥胖的关系研究

目的 探讨母亲孕前BMI及孕期增重与学龄前儿童超重肥胖的关系。方法 2016年6-11月,以广州市4 303名3~5岁学龄前儿童为研究对象,根据WHO标准和中国成人肥胖标准分别判断儿童和母亲孕前体重状态,参照美国医学研究所孕期增重推荐值判断母亲孕期增重情况。应用多因素二分类非条件logistic回归模型和协方差分析母亲孕前BMI和孕期增重与学龄前儿童超重肥胖的关系。结果 矫正混杂因素后,logistic回归分析显示,母亲孕前超重肥胖的儿童发生超重肥胖的风险是母亲孕前体重正常儿童的1.820倍（OR=1.820,95% CI：1.368~2.422）;与母亲孕期增重适宜的儿童相比,母亲孕期增重过度的儿童超重肥胖发生风险增加（OR=1.296,95% CI：1.007~1.667）。协方差分析结果也显示,母亲孕前体重超重肥胖和母亲孕期增重过度均增加儿童BMI Z值。根据母亲孕前BMI分为3组进行分层分析,结果显示,不同孕期增重组间儿童超重肥胖发生风险差异无统计学意义（P>0.05）。但与母亲孕前BMI适宜且孕期增重适宜组相比,母亲孕前超重肥胖且孕期增重过度组的儿童发生超重肥胖的风险增加（OR=1.574,95% CI：1.029~2.409）。结论 母亲孕前超重和孕期增重过度均增加学龄前儿童超重肥胖的风险,且母亲孕前超重较孕期增重过度对学龄前儿童超重肥胖发生的影响更大。     

Concordance for mortality with special reference to ischaemic heart disease and cerebrovascular disease: A Study on the Swedish Twin Registry

The Swedish Twin Registry contains about 11 000 same-sexed twin pairs born between 1886 and 1925 with both members alive when the registry was formed in 1961. During the years 1962 to 1973, 2780 deaths occurred. 727 deaths were due to ischaemic heart disease (IHD), 345 due to cerebrovascular disease (CVD), and 727 due to cancer. The rate of concordance for the whole twin population revealed a significantly (p < 0.05) higher concordance rate for IHD among the male monozygotic (MZ) pairs as compared to the dizygotic (DZ) pairs (15.8% versus 8.0%). The corresponding figures for the female pairs were 11.0% (MZ) and 7.5% (DZ), respectively. With regard to death in CVD and cancer, the rates of concordance were about the same for MZ and DZ pairs in both males and females. When subgrouping was made for age groups, the difference in concordance rate for IHD in males was still more pronounced for the younger age group, born 1901–1925, (16.1% versus 5.4%). These data may indicate the existence of a genetic determination on death in IHD, especially in males, whereas a genetic determination on death in CVD and cancer seems more uncertain.     

Characteristics of monozygotic male and female twins discordant for overweight: a descriptive study

OBJECTIVES: BMI is highly heritable. Yet, trends in obesity highlight environmental influences on body weight. Monozygotic (MZ) twins discordant for overweight offer a unique opportunity to examine these factors. METHODS: MZ male (n=8 pairs) and female twins (n=10 pairs) discordant for overweight (defined as the BMI of one twin being at least 24.5, and the BMI of his/her co-twin being below 24.5 and at least three points lower) were identified from the Mid-Atlantic Twin Registry. Variables were assessed via self-report questionnaires. RESULTS: One overweight and two non-overweight females met criteria for bulimia nervosa. Rates of dieting and binge eating were high among all males and females. Hunger scores were higher among non-overweight females; disinhibition scores were higher among overweight males. Only one non-overweight and three overweight males smoked; 90% of non-overweight and 40% of overweight females smoked. CONCLUSIONS: Assessing tobacco use and eating disorders may be important when sampling on the basis of family members who are discordant for BMI. Finally, results suggest possibilities for interventions in individuals at-risk for overweight.