Etiology and correlates of alcohol misuse in early midlife.

Background: Early midlife individuals (ages 30-40) experience demographic shifts that may influence the remainder of adult life. Although new or persistent alcohol misuse is common during this period, early midlife is understudied in alcohol use literature. We examined the heritability of alcohol misuse; the associations between alcohol misuse and sociodemographic factors, physical health, and well-being; and whether these associations were robust in cotwin comparisons.

Traumatic life events as predictors for depression in middle-aged men and women: A Finnish twin study.

Background: We examined exposure to adulthood traumatic life events (TLEs) and their associations with depression in women and men. Then we examined whether those associations are independent of exposure loading and vulnerability including familial confounding.

Methods: The fourth survey in 2011 of the population-based Finnish Twin Cohort had 8410 participants (45 % men, mean age 60 years).

Association between adolescent alcohol use and cognitive function in young adulthood: A co-twin comparison study.

Background And Aims: Studies on adolescent alcohol use and cognition are often unable to separate the potential causal effects of alcohol use on cognition from shared etiological influences, including genetic influences or other substance use comorbidities also known to be associated with cognition, such as nicotine use. The present study aimed to fill this gap and clarify the relationship between adolescent alcohol use and young adult cognition by accounting for both measured and unmeasured confounders.

Design: A random effects model accounting for nesting in families was used to control for measured confounders.

Effect of 10-Week Whole-Body Vibration Training on Falls and Physical Performance in Older Adults: A Blinded, Randomized, Controlled Clinical Trial with 1-Year Follow-Up.

Whole-body vibration training (WBV) training has shown positive effects on bone strength, muscle strength, and balance, but the evidence on fall prevention is not yet persuasive. This study aimed to evaluate the effectiveness of WBV training in preventing falls and improving physical performance among older adults at fall risk. The study was an assessor- and participant-blinded, randomized, and controlled 10-week training trial with a 10-month follow-up.

Life-Course Associations Between Smoking and Depressive Symptoms. A 30-Year Finnish Follow-up Study.

Introduction: Relatively little is known about whether the association between smoking and depressive symptoms changes with age and how the trajectories of smoking and depressive symptoms are intertwined during the life course. In this population-based study, these associations were examined from young adulthood to middle age.

Methods: Participants of a Finnish cohort study (N = 1955) were assessed at the ages of 22, 32, 42, and 52 using questionnaires covering daily smoking (yes/no) and the short 13-item Beck Depression Inventory.

A Nationally Representative Study of the Hardening Hypothesis Among Educational Groups Over Four Decades.

Introduction: As smoking prevalence has decreased, there has been debate about "hardening" (smokers are more resistant to established tobacco control measures) or "softening" (smokers are more responsive to interventions) of the remaining smoking population. Despite growing evidence to reject the "hardening" hypothesis, there is lack of long-term population-based studies to test this hypothesis by educational level.

Aims And Methods: Repeated cross-sectional population-based surveys during 1978-2014 and in 2018 were utilized.

Self-reported sleep bruxism and mortality in 1990-2020 in a nationwide twin cohort.

Background: The association of sleep bruxism with mortality has not been studied.

Objectives: Altogether 12 040 subjects from the nationwide Finnish twin cohort were included in the analyses. We examined whether self-reported sleep bruxism is associated with increased risk of mortality, and if so, whether the effect is independent of known common risk factors.

Exploring the relationships between adolescent alcohol misuse and later life health outcomes.

Background: We sought to clarify the impact of adolescent alcohol misuse on adult physical health and subjective well-being. To do so, we investigated both the direct associations between adolescent alcohol misuse and early midlife physical health and life satisfaction and the indirect effects on these outcomes attributable to subsequent alcohol problems.

Method: The sample included 2733 twin pairs (32% monozygotic; 52% female) from the FinnTwin16 study.

Self-reported sleep bruxism in 1990 and 2011 in a nationwide twin cohort: Evidence of trait persistence and genetic liability.

Background: Due to different assessment modes employed, a clear picture of the prevalence of sleep bruxism across time cannot be formed. Moreover, studies on the persistent or fluctuating nature of sleep bruxism have yielded divergent and even contradictory results. The aim of the present study was to evaluate in a nationwide twin cohort whether self-reported sleep bruxism was correlated longitudinally, pairwise and cross-twin over a 20-year period.

Changing genetic architecture of body mass index from infancy to early adulthood: an individual based pooled analysis of 25 twin cohorts.

Background: Body mass index (BMI) shows strong continuity over childhood and adolescence and high childhood BMI is the strongest predictor of adult obesity. Genetic factors strongly contribute to this continuity, but it is still poorly known how their contribution changes over childhood and adolescence. Thus, we used the genetic twin design to estimate the genetic correlations of BMI from infancy to adulthood and compared them to the genetic correlations of height.

Smoking remains associated with education after controlling for social background and genetic factors in a study of 18 twin cohorts.

We tested the causality between education and smoking using the natural experiment of discordant twin pairs allowing to optimally control for background genetic and childhood social factors. Data from 18 cohorts including 10,527 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs discordant for education and smoking were analyzed by linear fixed effects regression models. Within twin pairs, education levels were lower among the currently smoking than among the never smoking co-twins and this education difference was larger within DZ than MZ pairs.

Factors contributing to psychological distress in the working population, with a special reference to gender difference.

Background: Psychological distress refers to non-specific symptoms of stress, anxiety and depression, and it is more common in women. Our aim was to investigate factors contributing to psychological distress in the working population, with a special reference to gender differences.

Methods: We used questionnaire data from the nationally representative Finnish Regional Health and Well-being Study (ATH) collected in the years 2012-2016 (target population participants aged 20 +, n = 96,668, response rate 53%), restricting the current analysis to those persons who were working full-time and under 65 of age (n = 34,468).

The associations of smoking dependence motives with depression among daily smokers.

Aims: To investigate how strongly smoking dependence and smoking dependence motives are associated with depressive symptoms among daily smokers and if these associations are independent of measured confounders and shared familial factors.

Design: Cross-sectional individual-based and within-pair analyses.

Setting: Fourth wave of the population-based Finnish Twin Cohort conducted in 2011.

Correlates and genetics of self-reported sleep and awake bruxism in a nationwide twin cohort.

Background: Sleep bruxism (SB) and awake bruxism (AB) have been considered different entities, although co-occurrence between them has been shown. While genetic factors have a marked influence on phenotypic variance in liability to SB, this remains unclear for AB.

Aim: To examine the degree of co-occurrence of SB and AB, and whether they have common correlates and also twin similarity of SB and AB bruxism traits by zygosity and sex.

Accuracy of self-reported anthropometric measures - Findings from the Finnish Twin Study.

Objective: To determine the accuracy of self-reported height, weight, body mass index (BMI) and waist circumference (WC) compared to the measured values, and to assess the similarity between self-reported and measured values within dizygotic (DZ) and monozygotic (MZ) twin pairs.

Methods: The data on self-reported and measured height, weight and WC values as well as measured hip circumference (HC) were collected from 444 twin individuals (53-67 years old, 60% women). Accuracies between self-reported and measured values were assessed by Pearson's correlation coefficients, Cohen's kappa coefficients and Bland-Altman 95% limits of agreement.

Associations of sitting time with leisure-time physical inactivity, education, and body mass index change.

We aimed to investigate the associations of long-term leisure-time physical inactivity, body mass index (BMI) change, and education with sitting time in a 35-year follow-up based on self-reports in surveys. Influences of working status in 2011 and familial confounding on the associations were tested. Data were based on the population-based Finnish Twin Cohort of 5232 twins (53-67-year-old, 41% men) with four surveys in 1975-2011.

The Older Finnish Twin Cohort - 45 Years of Follow-up.

The older Finnish Twin Cohort (FTC) was established in 1974. The baseline survey was in 1975, with two follow-up health surveys in 1981 and 1990. The fourth wave of assessments was done in three parts, with a questionnaire study of twins born during 1945-1957 in 2011-2012, while older twins were interviewed and screened for dementia in two time periods, between 1999 and 2007 for twins born before 1938 and between 2013 and 2017 for twins born in 1938-1944.

The CODATwins Project: The Current Status and Recent Findings of COllaborative Project of Development of Anthropometrical Measures in Twins.

The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity.

Parental Education and Genetics of BMI from Infancy to Old Age: A Pooled Analysis of 29 Twin Cohorts.

Objective: The objective of this study was to analyze how parental education modifies the genetic and environmental variances of BMI from infancy to old age in three geographic-cultural regions.

Methods: A pooled sample of 29 cohorts including 143,499 twin individuals with information on parental education and BMI from age 1 to 79 years (299,201 BMI measures) was analyzed by genetic twin modeling.

Results: Until 4 years of age, parental education was not consistently associated with BMI.

Association of current and former smoking with body mass index: A study of smoking discordant twin pairs from 21 twin cohorts.

Background: Smokers tend to weigh less than never smokers, while successful quitting leads to an increase in body weight. Because smokers and non-smokers may differ in genetic and environmental family background, we analysed data from twin pairs in which the co-twins differed by their smoking behaviour to evaluate if the association between smoking and body mass index (BMI) remains after controlling for family background.

Methods And Findings: The international CODATwins database includes information on smoking and BMI measured between 1960 and 2012 from 156,593 twin individuals 18-69 years of age.

Association between long-term smoking and leisure-time physical inactivity: a cohort study among Finnish twins with a 35-year follow-up.

Objectives: To investigate longitudinal associations of smoking and a change in smoking status with leisure-time physical inactivity. In addition, to control whether familial confounding (genetics and shared environment) influences the associations.

Methods: Data were based on the population-based Finnish Adult Twin Cohort of 5254 twin individuals born in 1945-1957 (41% men) and who participated in all four surveys over a 35-year follow-up (1975-2011).