Duncan GE

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 walkability moderates the association between low back pain and physical activity: A co-twin control study

Zadro JR, Shirley D, Pinheiro MB, Bauman A, Duncan GE, Ferreira PH. The aim of this study was to investigate whether neighborhood walkability moderates the association between low back pain (LBP) and physical activity (PA), using a co-twin design to control for genetics and shared environmental factors. A cross-sectional analysis was performed on 10,228 twins […]

Does the sex of one’s co-twin affect height and BMI in adulthood? A study of dizygotic adult twins from 31 cohorts

Bogl LH, Jelenkovic A, Christensen K, Cozen W, Mack TM, Duncan GE, Buchwald D, Hopper JL, Silventoinen K, Kaprio J, et al. Background The comparison of traits in twins from opposite-sex (OS) and same-sex (SS) dizygotic twin pairs is considered a proxy measure of prenatal hormone exposure. To examine possible prenatal hormonal influences on anthropometric […]

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 […]

Genetic and environmental influences on adult human height across birth cohorts from 1886 to 1994

Jelenkovic A, Sumathipala A, Christensen K, Hopper JL, Cozen W, Mack TM, Sung J, Duncan GE, Buchwald D, Harris JR, Goldberg JH, Kaprio J, Silventoinen K, et al. Human height variation is determined by genetic and environmental factors, but it remains unclear whether their influences differ across birth-year cohorts. We conducted an individual-based pooled analysis […]

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 […]

Genetic and environmental effects on body mass index from infancy to the onset of adulthood: an individual-based pooled analysis of 45 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) study

Silventoinen K, Jelenkovic A, Busjahn A, Cozen W, Mack TM, Craig JM, Harden KP, Duncan GE, Buchwald D, Goldberg JH, Kaprio J, et al. Background Both genetic and environmental factors are known to affect body mass index (BMI), but detailed understanding of how their effects differ during childhood and adolescence is lacking. Objectives We analyzed […]

Genetic and environmental influences on height from infancy to early adulthood: An individual-based pooled analysis of 45 twin cohorts

Jelenkovic A, Craig JM, Sumathipala A, Harden KP, Cozen W, Mack TM, Hopper JL, Duncan GE, Buchwald D, Sung J, Harris JR, Busjahn A, Goldberg JH, Kaprio J, Silventoinen K, et al. Height variation is known to be determined by both genetic and environmental factors, but a systematic description of how their influences differ by sex, age and […]

Cross Sectional Association between Spatially Measured Walking Bouts and Neighborhood Walkability

Hwang LD, Hurvitz PM, Duncan GE Walking is the most popular choice of aerobic physical activity to improve health among U.S. adults. Physical characteristics of the home neighborhood can facilitate or hinder walking. The purpose of this study was to quantify neighborhood walking, using objective methods and to examine the association between counts of walking […]

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 […]

Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age: A Study of the CODATwins Project

Jelenkovic A, Craig JM, Sumathipala A, Harden KP, Cozen W, Mack TM, Hopper JL, Duncan GE, Buchwald D, Sung J, Harris JR, Busjahn A, Goldberg JH, Kaprio J, Silventoinen K, et al. A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference […]

The CODATwins Project

The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits Silventoinen K, Craig JM, Sumathipala A, Harden KP, Cozen W, Mack TM, Hopper JL, Duncan GE, Buchwald D, Sung J, Harris JR, Busjahn A, Goldberg JH, Kaprio J, et al. […]

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 […]

Validation and Application of Portable Particulate Device in the UW Twin Registry

PI: Edmund Seto and Glen DuncanProject number: 5R21ES024715Project dates: 3/1/2015–2/28/2017 This research addresses the mission of the National Institutes of Environmental Health Sciences by increasing our understanding of how the environment influences human health through validation of a new wearable device that measures multiple environmental toxicants in real-time and space, called the Portable University of Washington […]

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 […]

Emerging technologies for assessing physical activity behaviors in space and time

Hurvitz PM, Moudon AV, Kang B, Saelens BE, Duncan GE Precise measurement of physical activity is important for health research, providing a better understanding of activity location, type, duration, and intensity. This article describes a novel suite of tools to measure and analyze physical activity behaviors in spatial epidemiology research. We use individual-level, high-resolution, objective […]