男性儿童青少年血清Apelin遗传度及影响因素双生子研究

利用双生子研究分析影响男性儿童青少年血清Apelin的遗传和环境因素,为探讨年龄、体质量指数(BMI)和肥胖在其中的作用提供依据.方法 选择7~18岁男性双生子162名,平均年龄(12.2±3.7)岁,其中同卵双生子100名,异卵双生子62名.利用DNA微卫星多态性鉴定卵性.应用Mx结构方程模型分别计算年龄、BMI及肥胖调整前后Apelin的遗传度,并分析年龄、BMI和肥胖对Apelin的影响.结果 Apelin水平与年龄呈正相关,肥胖组男童Apelin水平低于正常组(P<0.05).Apelin的遗传度为41%,共同环境方差和独特环境方差分别占37%和22%.调整年龄、BMI及肥胖后,遗传方差比例降低.结论 男性儿童青少年Apelin水平与年龄、肥胖度相关.Apelin受遗传和环境因素的共同影响.     

成年双生子血尿酸遗传度研究

目的 用双生子研究方法 对成年人血尿酸的遗传度进行估计.方法 从青岛双生子库募集成年双生子.测量身高、体重和血尿酸.相同性别的双生子采用16个多态标记进行卵型鉴定.通过校正年龄、性别和BMI,来构建结构方程模型估计遗传度.结果 共收集687对双生子数据,其中同卵双生子420对,异卵双生子267对.经平方根转换后,男性血尿酸水平(17.47±1.91)略高于女性(15.22±1.70)(P＜0.0001),通过校正年龄、性别和BMI后双生子血尿酸的组内相关系数分别为,同卵双生子0.70、异卵双生子0.40.运用性别限制模型进行拟合,最佳模型AE模型,加性别遗传因素和特殊环境因素共同作用血尿酸的水平.血尿酸的遗传度为70.5%(95%CI:65.9～74.6),特殊环境因素占29.5%(95%CI:25.4～34.2).结论 遗传因素是影响样本双生子血尿酸水平的主要因素.     

不同发育期双生子皮褶厚度及体成分分析

目的 分析遗传与环境因素不同发育期双生子皮褶厚度及体成分的作用特点.方法 测量376对6～18岁同性别双生子(同卵245对,异卵131对)肱三头肌、肩胛下皮褶厚度,用长岭和Brozek公式估算体成分;用Mx软件拟合最佳模型,计算各指标遗传与环境方差组分,分析年龄、性别和不同发育期的作用.结果 全部双生子分性别校正年龄后,各指标遗传度在0.59～0.87之间;不同发育期各指标遗传度存在差异,肱三头肌皮褶、肩胛下皮褶、2处皮褶厚度之和、体脂百分比的遗传度男生在青春期前期最低,分别为0.55,0.62,0.53,0.51,女生在青春期晚期最低,分别为0.53,0.43,0.24,0.40;男、女瘦体重遗传度随青春期发育进程呈增加趋势.结论 遗传因素对儿童青少年皮褶厚度和体成分起主要作用,但年龄、性别和不同发育阶段对其也有一定影响.     

双生子的血清脂质和脂蛋白遗传度及影响因素分析

目的　分析儿童、青少年的血脂指标遗传度及影响因素。方法　选择 5～ 19岁双生子2 36对 ,平均年龄 (11 2± 3 4 )岁 ,其中同卵双生子 14 3对 ,异卵双生子 93对。在DNA卵性鉴定基础上 ,以组内相关系数法及Falconer公式计算调整年龄性别前后的遗传度 ,偏态数据进行对数转换 ;校正年龄性别 ,分析相关体格、生化指标对血脂的影响。结果　同卵与异卵双生子间甘油三酯对内方差及相关系数的差异均无显著性 ;总胆固醇、高密度脂蛋白胆固醇 (HDL C)、低密度脂蛋白胆固醇 (LDL C)和脂蛋白 (a)对内方差及相关系数的差异有显著性 ,遗传度估计值分别为 0 5 6、0 5 5、0 4 9和 0 5 8,调整年龄性别后各指标估计遗传度分别为 0 6 3、0 6 3、0 5 5和 0 6 4。总胆固醇、HDL C、LDL C和脂蛋白(a)与年龄呈负相关 ;女孩的总胆固醇、HDL C、LDL C稍高于男孩。校正年龄性别后除脂蛋白 (a)外各血脂指标多数与体重指数、体脂率及培利迪西指数相关 ,与血压、血糖和血钙等也有相关性。结论　总胆固醇、HDL C、LDL C和脂蛋白 (a)受遗传因素影响较大 ,而甘油三酯主要受环境因素影响。儿童的血脂水平受年龄和性别的影响 ,与反映体脂和机体营养发育的指标相关。     

6～18岁双生子BMI遗传度及与青春期关系

目的 分析山东省6～18岁双生子BMI的遗传度及青春期影响。方法 于2021年11月通过山东省3县区453对6～18岁同性别双生子构建结构方程模型计算BMI遗传度，探究青春期对BMI遗传度的影响及性别差异。结果 调整性别、年龄后6～18岁儿童青少年BMI的遗传度为0.84(95%CI=0.80～0.88)，青春期前期BMI的遗传度为0.81(95%CI=0.74～0.86)，青春期后期BMI的遗传度为0.88(95%CI=0.81～0.93)；男生和女生青春期前期BMI遗传度分别为0.77(95%CI=0.67～0.85)和0.85(95%CI=0.77～0.91)，青春期后期分别为0.92(95%CI=0.82～0.97)和0.86(95%CI=0.76～0.92)。结论 遗传因素对青春期前后BMI变异具有重要影响，BMI的遗传度在青春期后期增加，且在男生中更为明显。     

汉族儿童青少年体型遗传的双生子研究

目的分析遗传与环境因素对儿童青少年体型的影响,并探讨其中年龄和性别的作用。方法采用Heath-Carter法对376对6～18岁同性别汉族双生子（同卵双生子245对,异卵双生子131对）的体型三因子进行计算。调整另外两项体型因子后,用Mx软件拟合最佳模型,计算各体型因子的遗传与环境方差组分,分析年龄和性别的作用,并按体格突增分期估算不同发育期各因子的遗传度。结果校正年龄后,男生内、中、外三因子的遗传度分别为0．45,0．80,0．44;女生内、中、外三因子的遗传度分别为0．82,0．79,0．81;男生内因子的遗传度在青春期晚期明显高于前期（t=4．99,P〈0．01）和早期（t=6．16,P〈0．01）,外因子的遗传度在青春期晚期明显低于前期（t=3．35,P〈0．01）和早期（t=4．12,P〈0．01）;女生内因子（t=2．77,P〈0．01）、中因子（t=2．08,P〈0．05）的遗传度均为青春期前期明显高于早期。结论遗传因素对女生体型的影响明显高于男生,尤以内因子和外因子最为明显,男生中因子主要受遗传因素影响,内、外因子受环境因素影响较大。不同发育阶段对体型各因子遗传度的影响应引起重视。     

双生子儿童贫血状况分析

目的通过分析双生子儿童贫血状况和贫血同病率,探讨其遗传和环境效应.方法选取5～19岁双生子228对,其中MZ(单卵双生子)142对,DZ(二卵双生子)86对,在DNA卵性鉴定基础上,以成对法计算同病一致率、调整BMI前后组内相关系数及遗传度.结果双生子儿童贫血检出率与一般人群无明显差异,贫血同病一致率分别为MZ 0.28,DZ 0.15,Hb(血红蛋白)遗传度为0.23.调整BMI前后MZ与DZ组内相关系数和遗传度无显著变化.结论儿童贫血状态受遗传及环境因素共同影响,环境效应更明显.     

儿童青少年注意问题与焦虑/抑郁的双生子研究

了解儿童青少年双生子注意问题和焦虑/抑郁的遗传度,为探讨遗传和环境因素对儿童青少年注意问题和焦虑/抑郁的影响程度提供依据.方法 采用Achenbach儿童行为量表(CBCL)家长用问卷,对从北京地区和山东地区招募的527对同性别6~18岁双生子进行调查,采用相关系数法计算注意问题和焦虑/抑郁的遗传度.结果 不同卵性双生子中男、女比例差异无统计学意义(x2=0.083,P>0.05).注意问题和焦虑/抑郁得分在同卵双生子和异卵双生子间差异均无统计学意义(t值分别为0.024,-0.593,P值均>0.05).儿童青少年注意问题遗传度为0.78,焦虑/抑郁遗传度为0.52.结论 遗传对儿童青少年注意问题有高等强度影响,遗传和环境因素共同作用于儿童青少年焦虑与抑郁.     

双生子学龄儿童体格发育遗传学分析

目的 分析遗传与环境因素对学龄双生子儿童体格发育的影响,分析其中年龄和性别的作用.方法测量297对6～12岁(同卵167对,同性别异卵90对,异性别异卵40对)学龄儿童身高、坐高、体重、胸围、肱三头肌皮褶、肩胛下皮褶、髂前皮褶厚度;用Mx软件拟合最佳结构方程模型.结果各体格指标均与年龄相关,仅肱三头肌皮褶厚度与性别相关;各指标的遗传模型均为ACES,遗传方差组分高于环境方差组分,男性皮褶厚度的共同环境效应高于女性,皮褶厚度的年龄方差(0.02 ～0.17)明显低于其他指标(0.35 ～0.74);校正年龄后,遗传度分别为身高(男0.80,女0.83)、坐高(男0.76,女0.79)、体重(男0.53,女0.73)、胸围(男0.72,女0.66)、肱三头肌皮褶(男0.51,女0.87)、肩胛下皮褶(男0.56,女0.86)、髂前皮褶(男0.51,女0.83),女生体重及皮褶厚度的遗传度均明显高于男生.结论遗传因素对学龄儿童体格发育起主要作用,但年龄、性别对其也有一定影响.     

遗传因素对体型指征影响程度的双生子研究

目的利用广汉市募集的成年双生子数据,探讨遗传因素对身高、体重、体重指数(BMI)等体型指征的影响程度。方法选择广汉市自愿参加双生子队列观察的253对18岁及以上双生子为研究对象,并以150对非双生子为对照,通过问卷调查、体格检查、卵型鉴定等方法收集体型指征(身高、体重、体重指数)信息,形成数据库,运用组内相关系数法计算遗传度。结果异卵双生子的身高、体重、体重指数对内表型方差均大于同卵双生子,而对间表型方差差异无统计学意义;同卵双生子组内相关系数高于异卵双生子;身高、体重、体重指数遗传度分别为0.87、0.89、0.71;男性身高、体重、体重指数平均遗传度分别为0.68、0.71、0.67;女性分别为0.67、0.64、0.76。结论不同性别间各体型指征遗传度不同,遗传因素对身高、体重、体重指数的影响均较大,但环境因素的作用也不可忽视,可通过后天对环境因素的调整,在遗传潜力内发育并维持体型特征。     

Genetic and shared environmental influences on children's 24-h food and beverage intake: sex differences at age 7 y

BACKGROUND: The genetics of habitual food and beverage intake in early childhood is poorly understood. OBJECTIVE: The objective was to test the magnitude of genetic and environmental influences on 24-h food and beverage intake in 7-y-old children. The association between intake of specific food-beverage categories and child body mass index (BMI; in kg/m(2)) was also tested. DESIGN: A classic twin design was conducted, using the MacArthur Longitudinal Study of Twins. There were 792 children, including 396 boys from 102 monozygotic and 96 dizygotic twin pairs and 396 girls from 112 monozygotic and 86 dizygotic twin pairs; Children's 24-h dietary intake was estimated by parental recall, from which 9 composite food-beverage categories were derived. Height and weight were converted to BMI. Biometrical analyses of children's daily intake of food-beverage categories and BMI were conducted. RESULTS: There was consistent evidence of genetic influences on children's 24-h intake of food and beverages (servings/d), especially among boys. Seven categories showed significant heritability estimates among boys, ranging from 12% (fish and lemon) to 79% (peanut butter and jelly). Only 3 categories showed significant heritability estimates among girls, ranging from 20% (bread and butter) to 56% (fish and lemon). BMI showed a genetic correlation only with bread and butter intake in girls. CONCLUSION: The magnitude of genetic and environmental influences on children's 24-h food and beverage intake differed for boys and girls, which suggests sex differences in the development of eating patterns. Heritability estimates were generally large, although other eating phenotypes may be necessary for identifying genetic correlations with adiposity.     

Twin study of genetic and environmental effects on lipid levels

A study of 106 pairs of monozygotic (MZ) and 94 pairs of dizygotic (DZ) twins tested the hypothesis that part of the previously described genetic influence on blood lipid levels can be ascribed to closer similarities among MZ than among DZ twin pairs in environmental factors that affect lipid levels. Participants were adult twin volunteers (age 17-66; 64 male and 136 female pairs) who were selected from the NH & MRC Twin Registry or were respondents to advertisements. They completed a 4-day weighed food diary from which mean nutrient intake was derived. Information on lifestyle and demographic variables was obtained by questionnaire and a nonfasting blood sample was taken for measures of total, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol and the HDL2 and HDL3 subfractions. Height and weight were measured, and body mass index (BMI) was calculated (kg/m2). Estimates of the heritability of sex-adjusted lipid levels were 0.72 for total cholesterol, 0.79 for HDL cholesterol, 0.69 for HDL2, 0.20 for HDL3, 1.06 for LDL cholesterol, and 0.44 for sex-adjusted BMI. In all cases except for HDL3, genetic variance was statistically significant. After adjusting for the effects of environmental variables in three different ways, the estimates of heritability were somewhat lower for total cholesterol, HDL2, and BMI, and those for HDL cholesterol (borderline) and LDL cholesterol (definitely) remained statistically significant but were decreased. A genetic influence on HDL3 was not found. Adjusted heritability estimates obtained from one method of analysis were 0.35 for total cholesterol, 0.49 for HDL, 0.04 for HDL2, -0.34 for HDL3, 0.66 for LDL, and 0.32 for BMI. These results suggest that the assumptions made in the classical twin study approach are not appropriate when examining genetic effects on lipid levels or BMI, or indeed on any biological variable that may be affected by environmental factors that tend to be more similar in MZ twins than in DZ twins. In these circumstances, more complex models may be needed to differentiate between genetic and environmental influences.     

Genetic and environmental determination of tracking in subcutaneous fat distribution during adolescence

BACKGROUND: The distribution of fat and adipose tissue is an important predictor of disease risk. Variation in fat distribution during adolescence is correlated with fat distribution in adulthood. OBJECTIVE: The objective was to gain insight into the relative contribution of genes and environment to the stability of subcutaneous fat distribution from early adolescence into young adulthood. DESIGN: Ratio of trunk to extremity skinfold thickness (TER) data from the Leuven Longitudinal Twin Study (n = 105 Belgian twin pairs followed from 10 to 18 y of age) was entered into a longitudinal path analysis. RESULTS: The best-fitting model included additive genetic sources of variance and nonshared environment. Heritabilities ranged between 84.3% (95% CI: 63.9-92.3%) and 88.6% (95% CI: 76.5-94.1%) in boys and between 78.4% (95% CI: 59.3-88.3%) and 88.3% (95% CI: 77.0-93.8%) in girls. The majority of the phenotypic tracking (boys: 0.40-0.78; girls: 0.38-0.72) could be attributed to the moderate-to-high genetic correlations (rG) (between 0.27-0.84 and 0.38-0.80 for the various age intervals in boys and girls, respectively). This rG could be attributed to both genetic sources of variance, which are the same throughout adolescence, as well as genetic sources of variance that are "switched-on" at a certain age, the effect of which is then transmitted to subsequent observations. Environmental correlations (rE) in boys ranged between 0.51 and 0.70 but contributed relatively little to phenotypic tracking because the amount of variance explained by the environment was low (11.4-15.7%). In girls rE was low to moderate at best (0.09-0.48). CONCLUSION: Phenotypic tracking in subcutaneous fat distribution during adolescence is predominantly explained by additive genetic sources of variance.     

学龄儿童行为遗传双生子研究

目的 利用双生子人群估计学龄儿童行为指标的遗传度,为降低儿童行为问题的发生提供依据.方法 采用Achenbach's儿童行为量表对在呼和浩特市募集的166对6～12岁双生子心理行为问题进行调查.对调查结果进行结构方程模型拟合,估算学龄儿童行为指标的遗传度.结果 行为总粗分遗传度为男30.26％,女32.80％;各行为分因子遗传度分别为焦虑/抑郁(男46.79％,女74.99％)、退缩(男56.45％,女78.33％)、思维(男58.95％,女63.25％)、注意力(男79.14％,女40.11％)、社会化问题(男26.13％,女52.09％)、违规行为(男37.09％,女0.00％)、攻击性行为(男84.57％,女50.15％)、其他问题(男75.21％,女70.29％).注意力和攻击性行为的遗传度存在性别效应,男生的遗传度均明显高于女生.年龄对学龄儿童行为问题的遗传效应无明显影响.结论 学龄儿童行为问题受遗传与环境因素的共同影响,注意力和攻击性行为的遗传效应可能存在性别作用.     

Heritability of body mass index in pre-adolescence, young adulthood and late adulthood

Increased body mass index (BMI) is a worldwide health issue. Individual differences in the susceptibility to increased BMI could be related to genes or environment. We performed a systematic review of genetic studies on BMI in pre-adolescence, young adulthood and late adulthood. We searched PubMed and EMBASE with heritability, body mass index, BMI, weight, height, anthropometry and twins as search terms. Studies reporting intra-pair correlations of healthy twin pairs that were raised together were included. This resulted in the inclusion of 8,179 monozygotic (MZ) and 9,977 dizygotic (DZ) twin pairs from twelve published studies in addition to individual participant data for 629 MZ and 594 DZ pairs from four twin registries. Structural equation modelling with intra-pair twin correlations showed that the heritability of BMI remained high over all age categories ranging from 61% (95% CI 54-64%) to 80% (95% CI 76-81%) for male and female subjects combined, while unique environmental influences increased from 14% (95% CI 13-15%) to 40% (95% CI 37-43%) with increasing age. Heritability of BMI remains consistently high over different age categories. Environmental changes over time do not seem to have as big a relative impact on an individual's weight as previously reported, suggesting a mainly genetic influence on variation in BMI over the years.     

Genetic variance of blood pressure levels in infant twins

A cohort of 166 twin pairs (67 monozygotic and 99 dizygotic) born at the Jackson Memorial Hospital/University of Miami Medical Center between July 1, 1976 and December 31, 1980, was followed from birth to one year of age in order to estimate the genetic variance of blood pressure during the first year of life. The sex-adjusted summary estimate of heritability for systolic blood pressure during all of infancy was 0.22 (p less than 0.001), but statistically significant genetic variance was not found for diastolic blood pressure. When using blood pressures from six to 12 months of age, adjusted for infant sex, heritability was estimated as 0.33 (p less than 0.001) for systolic blood pressure and 0.24 (p = 0.04) for diastolic blood pressure; adjustment for body weight reduced these estimates to 0.27 (p less than 0.001) and 0.17 (p = 0.13), respectively.     

学龄前双生子儿童围度指标的遗传学研究

【目的】 分析遗传和环境因素对学龄前双生子儿童围度发育的影响及其性别和年龄因素的作用。 【方法】 对3~6岁101对双生子(同卵双生子42对、同性别异卵双生子30对,异性别异卵双生子29对)的头围、胸围、腰围、臀围、上臂围及小腿围进行测量;对测量结果进行结构方程模型拟合,并估算各指标遗传度。 【结果】 最佳模型除头围为AES外,其他各指标均为ACES模型,遗传、环境、年龄因素对各指标均有不同程度影响。校正年龄后,各指标遗传度为:头围(男0.83,女0.75)、胸围(男0.56,女0.43)、腰围(男0.77,女0.72)、臀围(男0.49,女0.63)、上臂围(男0.58,女0.36)、小腿围(男0.82,女0.76)。 【结论】 学龄前儿童头围、腰围、小腿围主要受遗传因素影响,胸围、臀围、上臂围受环境因素影响相对较大。