Search results for "Twin study"

Catechol-O-Methyltransferase Gene Polymorphism Is Associated with Skeletal Muscle Properties in Older Women Alone and Together with Physical Activity

2008

BackgroundMuscle strength declines on average by one percent annually from midlife on. In postmenopausal women this decrement coincides with a rapid decline in estrogen production. The genetics underlying the effects of estrogen on skeletal muscle remains unclear. In the present study, we examined whether polymorphisms within COMT and ESR1 are associated with muscle properties and assessed their interaction and their combined effects with physical activity.Methodology/principal findingsA cross-sectional data analysis was conducted with 434 63-76-year-old women from the population-based Finnish Twin Study on Aging. Body anthropometry, muscle cross-sectional area (mCSA), isometric hand grip a…

Heritability of anterior chamber depth and axial length: a population-based twin study among 66 to 79-year old female twins.

2014

The Associations Between Leisure-Time Physical Activity and Academic Performance: A Twin Study

2021

Background: Both genetic and environmental influences have been shown to contribute to the association between physical activity and overall academic performance. The authors examined whether leisure-time physical activity (LTPA) shares genetic and environmental variances between spelling, essay writing, reading aloud, reading comprehension, and mathematics in early adolescence. Moreover, they investigated whether genetic polymorphisms associated with physical activity behavior affect these academic skills. Methods: Participants were 12-year-old Finnish twins (n = 4356–4370 twins/academic skill, 49% girls). Academic skills were assessed by teachers, and LTPA was self-reported. Polygenic sco…

Is personality related to permanent earnings? Evidence using a twin design

2018

Using twin survey combined with register-based panel data on labor market outcomes, the authors examine the association between personality characteristics and long-term earnings among prime working-age individuals. The long-term earnings were measured over the 1990–2008 period. The sample contains 4,642 twin pairs, of which 53% are females. In contrast to previous studies, this paper uses the within-twin dimension of the data to control for shared family background and confounding genetic factors. The results suggest that unobserved genetic differences may introduce omitted variable bias in standard ordinary least square results. After controlling for shared environment and genetic backgro…

Factors behind Leisure-Time Physical Activity Behavior Based on Finnish Twin Studies: The Role of Genetic and Environmental Influences and the Role o…

2014

Different approaches are being taken to clarify the role of various factors in the development of physical activity behaviors. Genetic studies are a new area of physical activity research and also the motives for physical activity have been widely studied. The purpose of this paper is to review the findings emerging from the longitudinal genetic studies on leisure-time physical activity and to evaluate the associations between motivational factors and leisure-time physical activity. The focus is to review recent findings of longitudinal Finnish twin studies. The results of the latest longitudinal Finnish twin studies point to the existence of age-specific genetic and environmental influence…