The role of genetics and environment in lifting force and isometric trunk extensor endurance.

2004

Background and Purpose. Our understanding of what different back performance tests are measuring is limited. The purpose of this study was to investigate the relative contributions of genetics and unique and common environmental factors for 3 tests of back muscle performance in a classic twin analysis. Subjects. The subjects were a population-based sample of 122 monozygotic and 131 dizygotic male twin pairs aged 35 to 69 years (X̄=49.9, SD=7.7). Methods. Variance component analysis was applied to estimate genetic and environmental influences on isokinetic and psychophysical lifting and isometric trunk extensor endurance test performance. The Cholesky decomposition genetic factor model was u…

Tobacco, Cannabis, and Other Illicit Drug Use Among Finnish Adolescent Twins: Causal Relationship or Correlated Liabilities?*

2010

Contains fulltext : 90566.pdf (Publisher’s version ) (Open Access) Objective: Among Finnish adolescent twins, we compared (a) a model that describes a direct impact of liability to tobacco use on cannabis and other illicit drug use with (b) a model that included a shared underlying liability for these substances. Furthermore, the extent to which genetic and environmental influences contribute to the covariation between liabilities to use these substances was examined. Method: Tobacco and illicit drug use were assessed at age 17.5 years. Twin data on 3,744 individuals were analyzed using standard biometrical methods. Two alternative multivariate models were fit and compared with Mx, a statis…

Perceived sleep quality and its precursors in adolescents

1999

This study investigated perceived sleep quality among 11-, 13and 15-year-old Finnish adolescents (n = 4187). Additionally, associations of selected behavioural, social and psychological factors with subjective sleep quality were examined among 15-year-olds. This study is part of an international, WHO-co-ordinated survey of school children’s health and lifestyle (the HBSC Study). In Finland, research data represented the whole country. The data were collected during March–May 1994. Pupils responded anonymously to a standardized questionnaire during a class period. About every 10th adolescent felt that their sleep quality was at most satisfactory, about 30% of pupils had had difficulties in f…

Externalizing Behaviors and Cigarette Smoking as Predictors for Use of Illicit Drugs: A Longitudinal Study Among Finnish Adolescent Twins

2010

We examined whether externalizing problem behaviors (hyperactivity–impulsivity, aggressiveness, and inattention) predict illicit drug use independently, or whether their associations with drug use are mediated through cigarette smoking. We used a prospective longitudinal design within theFinnTwin12-17study among Finnish adolescents with baseline at age 12 and follow-up surveys at ages 14 and 17. Path models were conducted withMplusand included 1992 boys and 2123 girls. The outcome was self-reported ever use of cannabis or other illicit drugs at age 17. The predictors were: externalizing behaviors (hyperactivity–impulsivity, aggressiveness, and inattention) assessed by teachers and parents (…

Perceived tiredness among adolescents and its association with sleep habits and use of psychoactive substances

1997

This study investigated the variation in perceived tiredness among 11, 13 and 15-year-old Finnish adolescents (n = 4187). Additionally interrelationships between sleep habits, use of psychoactive substances (alcohol, tobacco and coffee) and perceived tiredness among 15-year-olds were examined. This study is part of an international, WHO-coordinated survey of school children's health and lifestyle (the HBSC Study). In Finland, research data represented the whole country. The data were collected in March-May 1994. Pupils responded anonymously to a standardized questionnaire during a class period. Subjective tiredness was very common and increased with age among adolescents. Perceived tirednes…

Konfirmatoristen faktorimallien ja faktoreiden rakenneyhtälömallien ryhmä- ja tasovertailuista : 15-vuotiaiden suomalaisnuorten aamuvireisyyden, unil…

1998