Publications

Epigenome-Wide Association Study of Systemic Effects of Obesity Susceptibility in Human Twins

Duncan GE, Avery A, Maamar MB, Nilsson EE, Beck D, Skinner MK. The current study was designed to use an epigenome-wide association approach (EWAS) to identify potential systemic DNA methylation alterations that are associated with obesity using 22 discordant twin pairs. Buccal cells (from a cheek swab) were used as a non-obesity relevant purified marker […]

Quasi-causal associations between chronotype and post-traumatic stress disorder symptoms: A twin study

McCall CA, Turkheimer E, Tsang S, Avery A, Duncan GE, Watson NF. Objective The evening (“night owl”) chronotype is associated with greater severity and lifetime prevalence of post-traumatic stress disorder (PTSD) symptoms compared to morning or intermediate chronotypes. This twin study investigated the gene-environment relationships between chronotype, recent PTSD symptoms, and lifetime intrusive symptoms. Methods […]

Cross-Sectional Study of Location-Based Built Environments, Physical Activity, Dietary Intake, and Body Mass Index in Adult Twins

Duncan GE, Sun F, Avery AR, Hurvitz PM, Moudon AV, Tsang S, Williams BD. We examined relationships between walkability and health behaviors between and within identical twin pairs, considering both home (neighborhood) walkability and each twin’s measured activity space. Continuous activity and location data (via accelerometry and GPS) were obtained in 79 pairs over 2 […]

Sex differences in lifetime prevalence of low back pain: A multinational study of opposite-sex twin pairs

Calais-Ferreira L, Pozzobon D, Pinheiro MB, Blyth FM, Ordoñana JR, Duncan GE, Hopper JL, Ferreira PH, Ferreira ML. Background Low back pain (LBP) is more likely to occur in people with a family history of this condition, highlighting the importance of accounting for familial factors when studying the individual risk of LBP. We conducted a […]

Epigenome-wide association study of physical activity and physiological parameters in discordant monozygotic twins

Duncan GE, Avery A, Thorson JLM, Nilsson EE, Beck D, Skinner MK. An epigenome-wide association study (EWAS) was performed on buccal cells from monozygotic-twins (MZ) reared together as children, but who live apart as adults. Cohorts of twin pairs were used to investigate associations between neighborhood walkability and objectively measured physical activity (PA) levels. Due […]

Cross-sectional associations between neighbourhood walkability and objective physical activity levels in identical twins

Duncan GE, Avery AR, Hurvitz P, Vernez-Moudon A, Tsang S Objectives  Physical activity is a cornerstone of chronic disease prevention and treatment, yet most US adults do not perform levels recommended for health. The neighborhood–built environment (BE) may support or hinder physical activity levels. This study investigated whether identical twins who reside in more walkable […]

Measuring and modelling perceptions of the built environment for epidemiological research using crowd-sourcing and image-based deep learning models

Larkin A, Krishna A, Chen L, Amram O, Avery AR, Duncan GE, Hystad P. Background Perceptions of the built environment, such as nature quality, beauty, relaxation, and safety, may be key factors linking the built environment to human health. However, few studies have examined these types of perceptions due to the difficulty in quantifying them […]

Bring Your Own Location Data: Use of Google Smartphone Location History Data for Environmental Health Research

Hystad P, Amram O, Oje F, Larkin A, Boakye K, Avery A, Gebremedhin A, Duncan G. Background Environmental exposures are commonly estimated using spatial methods, with most epidemiological studies relying on home addresses. Passively collected smartphone location data, like Google Location History (GLH) data, may present an opportunity to integrate existing long-term time-activity data. Objectives […]

Positive lifestyle behaviours and emotional health factors are associated with low back pain resilience

Roberts KE, Beckenkamp PR, Ferreira ML, Duncan GE, Calais-Ferreira L, Gatt JM, Ferreira P. Purpose To evaluate the relationship between lifestyle behaviours, emotional health factors, and low back pain (LBP) resilience. Methods This retrospective longitudinal study utilised 1,065 twins with a recent history of LBP from the Washington State Twin Registry. A lifestyle behaviour score […]

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

Silventoinen K, Li W, Jelenkovic A, Sund R, Yokoyama Y, Aaltonen S, Piirtola M, Sugawara M, Tanaka M, Matsumoto S, Baker LA, Tuvblad C, Tynelius P, Rasmussen F, Craig JM, Saffery R, Willemsen G, Bartels M, van Beijsterveldt CEM, Martin NG, Medland SE, Montgomery GW, Lichtenstein P, Krueger RF, McGue M, Pahlen S, Christensen K, […]

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 […]

Do married and/or cohabiting individuals fare better during the COVID-19 pandemic? Satisfaction with life and depression among adult twins in the United States

Tsang S, Avery AR, Duncan GE Due to social distancing measures implemented to mitigate the COVID-19 pandemic, individuals are spending more time isolated at home with limited physical social interactions. The current study investigated whether marriage and/or cohabitation is associated with satisfaction with life and depression among 732 adult same-sex twin pairs (monozygotic and dizygotic) […]

Changes in physical activity levels and mental health during COVID-19: Prospective findings among adult twin pairs

Duncan GE, Avery AR, Tsang S, Williams BD, Seto E. Background Physical distancing and other COVID-19 pandemic mitigation strategies have negatively impacted physical activity (PA) levels and mental health in cross-sectional studies. The purpose of this study was to investigate associations between changes in PA and mental health outcomes during the COVID-19 pandemic, following implementation […]

Reassessing relationships between appetite and adiposity in people at risk of obesity: a twin study using fMRI

Sewaybricker LE, Melhorn SJ, Rosenbaum JL, Askren MK, Tyagi V, Webb MF, De Leon MRB, Grabowski TJ, Schur EA Background Neuroimaging studies suggest that appetitive drive is enhanced in obesity. Objective To test if appetitive drive varies in direct proportion to the level of body adiposity after accounting for genetic factors that contribute to both […]

Differences in Stress and Anxiety Among Women With and Without Children in the Household During the Early Months of the COVID-19 Pandemic

Avery AR, Tsang S, Seto EYW, Duncan GE The COVID-19 pandemic and resulting lockdowns have had a disproportionate impact on parents of children under 18, particularly women. Mandatory school closures and loss of childcare resulted in parents balancing work, teaching, and childcare needs. A number of studies have examined changes in mental health of parents, […]

Educational attainment of same-sex and opposite-sex dizygotic twins: An individual-level pooled study of 19 twin cohorts

Silventoinen K, Bogl LH, Jelenkovic A, et al. Comparing twins from same- and opposite-sex pairs can provide information on potential sex differences in a variety of outcomes, including socioeconomic-related outcomes such as educational attainment. It has been suggested that this design can be applied to examine the putative role of intrauterine exposure to testosterone for […]

GPS-based built environment measures associated with adult physical activity

Boakye KA, Amram O, Schuna JM, Duncan GE, Hystad P. Studies often rely on home locations to access built environment (BE) influences on physical activity (PA). We use GPS and accelerometer data collected for 288 individuals over a two-week period to examine eight GPS-derived BE characteristics and moderate-to-vigorous PA (MVPA) and light-to-moderate-vigorous PA (LMVPA). NDVI, […]

Measurement of neighborhood-based physical activity bouts

Duncan GE, Hurvitz PM, Moudon AV, Avery AR, Tsang S. This study examined how buffer type (shape), size, and the allocation of activity bouts inside buffers that delineate the neighborhood spatially produce different estimates of neighborhood-based physical activity. A sample of 375 adults wore a global positioning system (GPS) data logger and accelerometer over 2 […]

Genetic and environmental influences on posttraumatic stress disorder symptoms and disinhibited eating behaviors

Afari N, Gasperi M, Dochat C, Wooldridge JS, Herbert MS, Schur EA, Buchwald DS. Posttraumatic stress disorder (PTSD) and eating disorders (ED) frequently co-occur, but the mechanisms underlying this association remain unclear. EDs are characterized by features of maladaptive eating behaviors including disinhibited eating and cognitive dietary restraint. Identifying the genetic overlap between PTSD symptoms […]

Is COVID-19 keeping us up at night? Stress, anxiety, and sleep among adult twins

Tsang S, Avery AR, Seto EYW, Duncan GE In response to the COVID-19 pandemic, a variety of social distancing measures to mitigate the virus outbreak have been implemented. These measures may have unintended consequences on individuals’ well-being, such as increased stress, anxiety, and sleep disruptions. We investigated the extent to which individuals’ mental health status […]