Search results for "Dizygotic"
showing 10 items of 77 documents
Differential models of twin correlations in skew for body-mass index (BMI)
2018
Background Body Mass Index (BMI), like most human phenotypes, is substantially heritable. However, BMI is not normally distributed; the skew appears to be structural, and increases as a function of age. Moreover, twin correlations for BMI commonly violate the assumptions of the most common variety of the classical twin model, with the MZ twin correlation greater than twice the DZ correlation. This study aimed to decompose twin correlations for BMI using more general skew-t distributions. Methods Same sex MZ and DZ twin pairs (N = 7,086) from the community-based Washington State Twin Registry were included. We used latent profile analysis (LPA) to decompose twin correlations for BMI into mul…
The effects of social anxiety on alcohol and cigarette use across adolescence: Results from a longitudinal twin study in Finland.
2016
Conflicting reports exist on the direction of the relationship between social anxiety (SA) and alcohol/cigarette use (AU/CU) and alcohol/nicotine dependence (AD/ND), with both positive and negative associations reported. A prospective, longitudinal sample of Finnish twins (n = 1,906) was used to test potential explanations for these discrepancies. Specifically, this study used peer, parent, and teacher ratings of SA, and a clinical interview screening item for social anxiety disorder (SAD-Sc) to examine associations between SA and AU/CU and AD/ND from early adolescence into young adulthood. Peer-rated SA was negatively associated with AU, CU, and AD from age 14 through age 22, implying a pr…
Genetic contribution to the relationship between personality and depressive symptoms among older women.
2009
BackgroundPrior studies suggest that certain types of personality are at higher risk for developing depressive disorders. This study examined the relationship between old age depressive symptoms and two middle-age personality dimensions, neuroticism and extraversion.MethodThe present study is part of the Finnish Twin Study on Aging, where altogether 409 female twins who had completed the Eysenck Personality Inventory at the age of 38–51 years were studied for depressive symptoms 28 years later using Center for the Epidemiologic Studies Depression Scale. Logistic regression analysis suitable for dependent data and univariate and Cholesky models for decomposing the genetic and environmental f…
Genetic and environmental effects on body mass index during adolescence: a prospective study among Finnish twins
2009
To study genetic and environmental factors affecting body mass index (BMI) and BMI phenotypic correlations across adolescence. Prospective, population-based, twin cohort study. We used twin modeling in 2413 monozygotic and same-sex and opposite-sex dizygotic Finnish twin pairs born in 1983–1987 and assessed using self-report questionnaires at 11–12, 14 and 17 years of age. Heritability of BMI was estimated to be 0.58–0.69 among 11–12- and 14-year-old boys and girls, 0.83 among 17-year-old boys and 0.74 among 17-year-old girls. Common environmental effects shared by siblings were 0.15–0.24 among 11–12- and 14-year-old boys and girls but no longer discernible at 17 years of age. Unique enviro…
Childhood Verbal Development and Drinking Behaviors from Adolescence to Young Adulthood: A Discordant Twin-Pair Analysis
2012
BACKGROUND: Studies suggest that better cognitive and verbal abilities in childhood predict earlier experimentation with alcohol and higher levels of drinking in adolescence, whereas poorer ability is related to a higher likelihood of remaining abstinent. Whether individual differences in language development in childhood predict differences in adolescent drinking behaviors has not been studied. METHODS: To address that question, we compared co-twins from twin pairs discordant for their childhood language development and studied associations of parental reports of within-pair differences in age at speaking words, age at learning to read, and expressive language skills during school age with…
Leisure-Time and Occupational Physical Activity Associates Differently with Epigenetic Aging
2021
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It does take a village: nonfamilial environments and children's behavior.
2003
Family characteristics influence children's behavioral development, but so do variations in schools, neighborhoods, and communities. We documented extrafamilial environmental effects by fitting maximum likelihood models to questionnaire data collected from double dyads consisting of twins and their classmate controls. The classmate controls in each double dyad were genetic strangers living in separate households, but they shared school, neighborhood, and community environments with their yoked twin pair and with one another. At ages 11 to 12, the control classmates showed significant similarities in religious practices and smoking and drinking patterns, demonstrating that environmental inf…
Leisure-time physical activity and nutrition: a twin study
2010
AbstractObjectiveTo determine the association between long-term leisure-time physical activity/inactivity and eating behaviours in twin pairs discordant for physical activity for 30 years.DesignCo-twin control design with cross-sectional data collection using questionnaire on eating habits and 5 d food diary. Differences in eating behaviours between physically active and inactive co-twins were analysed with pairwise tests.SettingFinland.SubjectsSixteen same-sex twin pairs (seven monozygotic and nine dizygotic, mean age 60 years) discordant for physical activity, selected from the Finnish Twin Cohort on the basis of physical activity discordance for 30 years, blinded to their possible differ…
Physical Activity in Adolescence as a Predictor of Alcohol and Illicit Drug Use in Early Adulthood: A Longitudinal Population-Based Twin Study
2009
AbstractWe investigated prospectively whether physical activity level in adolescence predicts use of alcohol and illicit drugs in early adulthood. We studied 4,240 individual twins (1,870 twin pairs). We classified those who consistently reported frequent leisure physical activity at ages 16, 17 and 181/2 as persistent exercisers, those exercising less than three times monthly as persistently inactive, and all others as occasional exercisers. To control for familial confounds, within-family analyses compared activity-substance use associations in co-twins discordant for baseline physical activity. Individual-based analyses showed no clear association between baseline physical activity and s…
Widespread pain among 11-year-old Finnish twin pairs
2001
Objective To examine the prevalence of widespread musculoskeletal pain (WSP) symptoms in 11-year-old Finnish twins and to determine the relative role of genetic and environmental factors in the etiology of WSP. Methods Data on current pain items were collected from 1995 to 1998 from a national sample of Finnish families with 11-year-old twins born between 1984 and 1987. The presence of WSP was determined using a validated questionnaire method. Pairwise similarity was computed for 583 monozygotic (MZ) pairs, 588 same-sex dizygotic (DZ) pairs, and 618 opposite-sex DZ twin pairs. Variance components for genetic and environmental factors were estimated using biometric structural equation modeli…