Turkheimer E

The pillars of health: influence of multiple lifestyle behaviors on body mass index and depressive symptoms in adult twins

Duncan GE, Avery AR, Tsang S, Watson NF, Williams BD, Turkheimer E. Background Guidelines promoting healthy lifestyles are cornerstones of chronic disease prevention and treatment. The purpose of this study is to investigate independent and joint associations of five key health behaviors with health outcomes (body mass index (BMI kg/m2) and depressive symptoms) in adult […]

Association Between Low Back Pain and Body Mass Index in Adult Twins: An analysis of monozygotic and dizygotic twins of the Washington State Twin Registry

Liechty A, Tsang S, Turkheimer E, Duncan GE. Background Context LBP is a common and significant cause of disability worldwide, however; questions about cause still remain. Purpose To investigate the association between low back pain (LBP), body mass index (BMI), and moderate to vigorous physical activity (MVPA) in a twin sample. Study Design Cross sectional […]

Psychometric and Classification Properties of the Peas in a Pod Questionnaire

Avery AR, Turkheimer E, Tsang S, Duncan GE We examined the item properties of the Two Peas Questionnaire (TPQ) among a sample of same-sex twin pairs from the Washington State Twin Registry. With the exception of the ‘two peas’ item, three of the mistakenness items showed differential item functioning. Results showed that the monozygotic (MZ) […]

Cohort Profile: TWINS study of environment, lifestyle behaviours and health

Duncan GE, Avery A, Hurvitz PM, Moudon AV, Tsang S, Turkheimer E. The role of built and social environments in supporting healthy lifestyles has received increased attention over the past decade, as research and prevention paradigms have shifted from a focus on individual-level behaviour change to macro-level influences embedded within social-ecological models of health that […]

Sleep Duration and Post-Traumatic Stress Disorder Symptoms: A Twin Study

McCall CA, Turkheimer E, Tsang S, Avery A, Duncan GE, Watson NF. Study Objectives Long and short sleep duration are associated with greater risk of developing post-traumatic stress disorder (PTSD); however, it is unknown how genetic and environmental influences impact this relationship. Thus, we investigated the association between sleep duration and PTSD symptoms using twin […]

The Washington State Twin Registry: 2019 Update

Duncan GE, Avery AR, Strachan E, Turkheimer E, Tsang S. It has been over 5 years since the last special issue of Twin Research and Human Genetics on ‘Twin Registries Worldwide: An Important Resource for Scientific Research’ was published. Much progress has been made in the broad field of twin research since that time, and the current […]

Differential models of twin correlations in skew for body-mass index (BMI)

Tsang S, Duncan GE, Dinescu D, Turkheimer E. 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 […]

Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts

Silventoinen K, Jelenkovic A, Hopper JL, Busjahn A, Cozen W, Mack TM, Sumathipala A, Harris JR, Goldberg JH, Harden KP, Duncan GE, Buchwald D, Turkheimer E, Kaprio J, et al. Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences […]

Cross-sectional association between soda consumption and body mass index in a community-based sample of twins

Eney AE, Tsang S, Delaney JA, Turkheimer E, Duncan GE. Background Consumption of sugar-sweetened beverages, such as soda, have been shown to play an important role in weight gain. Although soda consumption has been associated with body mass index (BMI) in many studies, it has been difficult to ascertain a true causal relationship between soda […]

Differences in genetic and environmental variation in adult body mass index by sex, age, time period, and region: an individual-based pooled analysis of 40 twin cohorts

Silventoinen K, Jelenkovic A, Cozen W, Mack T, Sumathipala A, Christensen K, Busjahn A, Duncan GE, Buchwald D, Goldberg JH, Hopper JL, Sung J, Turkheimer E, Kaprio J, et al. Background  Genes and the environment contribute to variation in adult body mass index [BMI (in kg/m2)], but factors modifying these variance components are poorly understood. […]

Neighborhood deprivation and depression in adult twins: genetics and gene×environment interaction

Strachan E, Duncan G, Horn E, Turkheimer E. Background Depression is a significant problem and it is vital to understand its underlying causes and related policy implications. Neighborhood characteristics are implicated in depression but the nature of this association is unclear. Unobserved or unmeasured factors may confound the relationship. This study addresses confounding in a […]

A Twin Study on Perceived Stress, Depressive Symptoms, and Marriage

Beam CR, Dinescu D, Emery R, Turkheimer E. Marriage is associated with reductions in both perceived stress and depressive symptoms, two constructs found to be influenced by common genetic effects. A study of sibling twins was used to test whether marriage decreases the proportion of variance in depressive symptoms accounted for by genetic and environmental […]

Is Marriage a Buzzkill? A Twin Study of Marital Status and Alcohol Consumption

Dinescu D, Turkheimer E, Beam CR, Horn EE, Duncan G, Emery RE. Married adults have consistently been found to drink less than their single or divorced counterparts. This correlation may not be causal, however, as people nonrandomly “select” into marriage and into alcohol use. The current study uses a sample of 2,425 same-sex twin pairs […]

Socioeconomic modifiers of genetic and environmental influences on body mass index in adult twins

Dinescu D, Horn EE, Duncan G, Turkheimer E Objective Individual measures of socioeconomic status (SES) suppress genetic variance in body mass index (BMI). Our objective was to examine the influence of both individual-level (i.e., educational attainment, household income) and macrolevel (i.e., neighborhood socioeconomic advantage) SES indicators on genetic contributions to BMI. Method The study used […]

Sleep Duration and Area-Level Deprivation in Twins

Watson NF, Horn E, Duncan GE, Buchwald D, Vitiello MV, Turkheimer E Study Objectives We used quantitative genetic models to assess whether area-level deprivation as indicated by the Singh Index predicts shorter sleep duration and modifies its underlying genetic and environmental contributions. Methods Participants were 4,218 adult twin pairs (2,377 monozygotic and 1,841 dizygotic) from […]

Associations Between Fast-Food Consumption and Body Mass Index: A Cross-Sectional Study in Adult Twins

Cohen-Cline H, Lau R, Moudon AV, Turkheimer E, Duncan GE Obesity is a substantial health problem in the United States, and is associated with many chronic diseases. Previous studies have linked poor dietary habits to obesity. This cross-sectional study aimed to identify the association between body mass index (BMI) and fast-food consumption among 669 same-sex […]

Behavioral and Environmental Modification of the Genetic Influence on Body Mass Index: A Twin Study

Horn EE, Turkheimer E, Strachan E, Duncan GE Body mass index (BMI) has a strong genetic basis, with a heritability around 0.75, but is also influenced by numerous behavioral and environmental factors. Aspects of the built environment (e.g., environmental walkability) are hypothesized to influence obesity by directly affecting BMI, by facilitating or inhibiting behaviors such […]

Access to green space, physical activity and mental health: a twin study

Cohen-Cline H, Turkheimer E, Duncan GE Increasing global urbanisation has resulted in a greater proportion of the world’s population becoming exposed to risk factors unique to urban areas, and understanding these effects on public health is essential. The aim of this study was to examine the association between access to green space and mental health […]

Quasi-causal associations of physical activity and neighborhood walkability with body mass index: A twin study

Duncan GE, Cash SW, Horn EE, Turkheimer E Physical activity, neighborhood walkability, and body mass index (BMI, kg/m(2)) associations were tested using quasi-experimental twin methods. We hypothesized that physical activity and walkability were independently associated with BMI within twin pairs, controlling for genetic and environmental background shared between them. Data were from 6376 (64% female; 58% […]

Stepping towards causation in studies of neighborhood and environmental effects: How twin research can overcome problems of selection and reverse causation

Duncan GE, Mills B, Strachan E, Hurvitz P, Huang R, Moudon AV, Turkheimer E No causal evidence is available to translate associations between neighborhood characteristics and health outcomes into beneficial changes to built environments. Observed associations may be causal or result from uncontrolled confounds related to family upbringing. Twin designs can help neighborhood effects studies […]