Search results for "Twin study"
showing 10 items of 115 documents
Genetic and Environmental Influences on BMI From Late Childhood to Adolescence are Modified by Parental Education
2011
To investigate how parental education modifies genetic and environmental influences on variation in BMI during adolescence, self-reported BMI at 11-12, 14, and 17 years of age was collected from a population sample of 2,432 complete Finnish twin pairs born in 1983-1987. Based on parental report, twins were divided to those with high (both parents high school graduates), mixed level (one parent a graduate, the other not), and limited (neither parent a graduate) parental education. Genetic and environmental influences on variation in BMI in different education classes were modeled using twin analysis. Heritability of BMI among 11-12-year-olds with high parental education was 85-87% whereas it…
Intrauterine growth pattern and birthweight discordance in twin pregnancies: a retrospective study
2013
Background: Twins, compared to singletons, have an increased risk of perinatal mortality and morbidity, due mainly to a higher prevalence of preterm birth and low birthweight. Intrauterine growth restriction (IUGR) is also common and can affect one or both fetuses. In some cases, however, one twin is much smaller than the other (growth discordance). Usually, high birthweight discordance is associated with increased perinatal morbidity. The aim of this study is to describe the epidemiological features of a population of twins at birth, with particular reference to the interpretation and clinical effects of birthweight discordance. Methods: We evaluated retrospectively the clinical features o…
Motives for physical activity in older men and women : A twin study using accelerometer-measured physical activity
2019
Motives for physical activity may vary considerably by age, sex, and the level of physical activity. We aimed to examine motives for physical activity in older men and women with different physical activity levels as well as whether genetic and/or environmental factors explain those motives. Finnish twins (mean age 72.9 years, 262 full twin pairs) self-reported their motives for physical activity. Time spent on moderate-to-vigorous physical activity was monitored using a hip-worn accelerometer. Comparisons between the different physical activity groups of older twins (n = 764-791/motive dimension) were analyzed using the Wald test, and effect sizes were calculated as Cohen's d. Quantitative…
Multiple sclerosis in twins from continental Italy and Sardinia: a nationwide study.
2005
Knowledge about the balance between heritable and nonheritable risk in multiple sclerosis (MS) is based on twin studies in high-prevalence areas. In a study that avoided ascertainment limitations and directly compared continental Italy (medium-prevalence) and Sardinia (high-prevalence), we ascertained 216 pairs from 34,549 patients. This gives a twinning rate of 0.62% among MS patients, significantly less than that of the general population. In continental Italy, probandwise concordance was 14.5% (95% confidence interval, 5.1-23.8) for monozygotic and 4.0% (95% confidence interval, 0.8-7.1) for dizygotic twins. Results in Sardinia resemble those in northern populations but in limited number…
Peer reports of adaptive behavior in twins and singletons: is twinship a risk or an advantage?
2003
We compared twins to their gender-matched singleton classmates in peer-assessed behavioral adjustment. Our samples include 1874 11- to 12-year-old Finnish twins (687 monozygotic, MZ; 610 same-sex dizygotic, SSDZ; 577 opposite-sex dizygotic, OSDZ) and their 23,200 non-twin classmates. Data were collected using a 30-item Multidimensional Peer Nomination Inventory containing three factors and their subscales. We found twin-singleton differences: classmates rated twin girls and boys higher than gender-matched singletons in Adaptive Behaviors (constructive, compliant, and socially active behavior), and those effects were particularly evident among OSDZ twins for assessments of social interaction…
Sport disciplines, types of sports, and waist circumference in young adulthood – a population-based twin study
2017
Purpose: The benefits of physical activity (PA) in preventing abdominal obesity are well recognized, but the role of different sport disciplines remains open. We aimed, therefore, to investigate how participation in different sport disciplines, and the number and types of sports engaged in are associated with waist circumference (WC) in young adulthood. Methods: This population-based cohort study comprised 4027 Finnish twin individuals (1874 men), with a mean age of 34 y (32-37), who answered a survey, including self-measured WC. We extracted the number and identified the types (aerobic, power, and mixed) of the different sport disciplines respondents reported participating in. Results: The…
Decreased prevalence of left-handedness among females with male co-twins: evidence suggesting prenatal testosterone transfer in humans?
2009
Studies of singletons suggest that right-handed individuals may have higher levels of testosterone than do left-handed individuals. Prenatal testosterone levels are hypothesised to be especially related to handedness formation. In humans, female members from opposite-sex twin pairs may experience elevated level of prenatal exposure to testosterone in their intra-uterine environment shared with a male. We tested for differences in rates of left-handedness/right-handedness in female twins from same-sex and opposite-sex twin pairs. Our sample consisted of 4736 subjects, about 70% of all Finnish twins born in 1983–1987, with information on measured pregnancy and birth related factors. Circulati…
Genetic and environmental influences on the fibrinolytic system: a twin study.
2004
SummaryThe determination of heritability is a key issue to assess the predictive power of polymorphisms for disease in clinical studies. The aim of this study was to determine the heritability of proteins and activation markers of the fibrinolytic system in a large cohort of healthy twins. Heritability was calculated as 0.76 for thrombin activatable fibrinolysis inhibitor (TAFI), 0.44 for plasminogen activator inhibitor-1 (PAI-1), and 0.43 for tissue plasminogen activator. No significant genetic influence was observed for α2-antiplasmin-plasmin-complex and D-dimer. Heritability explained by single gene polymorphisms was 25.2% for TAFI 505G>A, 31.5% for 1542C>G, and 50.0% for combinati…
Leisure-time physical activity and high-risk fat: a longitudinal population-based twin study.
2009
Exercise is thought to reduce high-risk body fat, but intervention studies are frequently limited by short follow-ups and observational studies by genetic selection. Therefore, we studied the effects of a physically inactive vs active lifestyle on high-risk (visceral, liver and intramuscular) fat in twin pairs discordant for leisure-time physical activity habits for over 30 years.A longitudinal population-based twin study.Sixteen middle-aged (50-74 years) same-sex twin pairs (seven monozygotic (MZ), nine dizygotic (DZ)) with long-term discordance for physical activity habits were comprehensively identified from the Finnish Twin Cohort (TWINACTIVE study). Discordance was initially defined in…
Chernobyl exposure as stressor during pregnancy and hormone levels in adolescent offspring
2008
Background: Animal research suggests a programming effect of prenatal stress in the fetal period, resulting in disruptions in behavioural and neuromotor development. Physiological changes that mediate these effects include alterations in the hypothalamic-pituitary-adrenal axis and in testosterone levels. This human study focuses on changes related to these physiological systems after prenatal stress exposure. Methods: We examined the potential effect of prenatal stress associated with the Chernobyl disaster in an ongoing genetic epidemiological study in Finland. One birth cohort of twins (n = 121 twin pairs) was exposed in utero to maternal stress, and their saliva cortisol and testosterone…