For Twins

Physical Activity in Twins (PAT) follow-up study

This study continues on work conducted from 2012-15 exploring the role of the built environment in supporting healthy lifestyles. The built environment is defined as human-made surroundings, such as buildings, streets, and transportation systems, which support or hinder human activity. Although this topic has gained increasing attention from many researchers over the last several years, […]

Usability of a Personal Air Pollution Monitor: Design-Feedback Iterative Cycle Study

Background: There is considerable evidence that exposure to fine particulate matter (PM2.5) air pollution is associated with a variety of adverse health outcomes. However, true exposure-outcome associations are hampered by measurement issues, including compliance and exposure misclassification. Objective: This paper describes the use of the design-feedback iterative cycle to improve the design and usability of a new […]

Hypothalamic Gliosis by MRI and Visceral Fat Mass Negatively Correlate with Plasma Testosterone Concentrations in Healthy Men

Objective: This study aimed to determine whether a relationship was evident between gliosis in the mediobasal hypothalamus (MBH) and plasma testosterone concentrations in men. Methods: A total of 41 adult men (aged 18-50 years) from 23 twin pairs underwent fasting morning blood draw and brain magnetic resonance imaging. T2 relaxation time was used to quantify gliosis in […]

Study Design and Rationale for the Mood and Methylation Study: A Platform for Multi-Omics Investigation of Depression in Twins

Major depression is a complex disorder with no single, direct causal mechanism. Morbidity has been linked to genetic processes, developmental history, and unique environmental exposures. Epigenetic mechanisms, especially DNA methylation, are also likely important factors in the pathogenesis of major depressive disorder (MDD). A community-based twin sample has many advantages for epigenetic studies, given the […]

DNA methylation associated with healthy aging of elderly twins

Variation in healthy aging and lifespan is ascribed more to various non-genetic factors than to inherited genetic determinants, and a major goal in aging research is to reveal the epigenetic basis of aging. One approach to this goal is to find genomic sites or regions where DNA methylation correlates with biological age. Using health data […]

Gene Expression and the Microbiome in Twins (GEMsTone)

Cells in the human body contain DNA. Each cell expresses, or turns on, a fraction of its genes in a process known as gene regulation. Genes can be expressed depending on your genetic history, your lifestyle, and your environment. Microbes are very small life forms such as bacteria that exist on or in the human body. […]

Childhood Trauma, DNA Methylation of Stress-related Genes, and Depression: Findings from Two Monozygotic Twin Studies

Objective: DNA methylation has been associated with both early life stress and depression. This study examined the combined association of DNA methylation at multiple CpG probes in five stress-related genes with depressive symptoms and tested whether these genes methylation mediated the association between childhood trauma and depression in two monozygotic (MZ) twin studies. Methods: The current analysis […]

Twin Breast Cancer Study

Dr. Thomas Mack of the USC California Twin Program is reaching out to twins diagnosed with breast cancer in order to understand why some women remain free from breast cancer when other women with the same genetics and upbringing are affected. What we know: As a group, twin women of any age, including identical twin […]

Using Smart City Technology to Make Healthcare Smarter

Smart cities use information and communication technologies (ICT) to scale services include utilities and transportation to a growing population. In this article we discuss how smart city ICT can also improve healthcare effectiveness and lower healthcare cost for smart city residents. We survey current literature and introduce original research to offer an overview of how […]

Associations between social capital and depression: A study of adult twins

Social capital is associated with depression independently of individual-level risk factors. We used a sample of 1586 same-sex twin pairs to test the association between seven measures of social capital and two related measures of neighborhood characteristics with depressive symptoms accounting for uncontrolled selection factors (i.e., genetics and shared environment). All measures of cognitive social […]

FTO genotype impacts food intake and corticolimbic activation

Background: Variants in the first intron of the fat mass and obesity-associated (FTO) gene increase obesity risk. People with “high-risk” FTO genotypes exhibit preference for high-fat foods, reduced satiety responsiveness, and greater food intake consistent with impaired satiety. Objective: We sought central nervous system mechanisms that might underlie impaired satiety perception in people with a higher risk […]

What Twin Studies Tell Us About Brain Responses to Food Cues

Purpose of review: Functional magnetic resonance imaging (fMRI) using visual food cues provides insight into brain regulation of appetite in humans. This review sought evidence for genetic determinants of these responses. Recent findings: Echoing behavioral studies of food cue responsiveness, twin study approaches detect significant inherited influences on brain response to food cues. Both polygenic (whole genome) […]

Trust is heritable, whereas distrust is not

Why do people distrust others in social exchange? To what degree, if at all, is distrust subject to genetic influences, and thus possibly heritable, and to what degree is it nurtured by families and immediate peers who encourage young people to be vigilant and suspicious of others? Answering these questions could provide fundamental clues about the sources of individual differences […]

Genetic and Environment Influences on Sleep, Pain, and Depression Symptoms in a Community Sample of Twins

Objective: We used quantitative genetic methods to evaluate whether sleep quality, pain, and depression symptoms share a common genetic diathesis, to estimate the genetic and environmental sources of covariance among these symptoms, and to test for possible causal relationships. Methods: A community sample of 400 twins from the University of Washington Twin Registry completed standardized self-report questionnaires. […]

Dexamethasone-suppressed Salivary Cortisol and Pain Sensitivity in Female Twins

Objectives: Hypothalamic-pituitary-adrenal (HPA) axis dysregulation is associated with chronic pain. Studying pain sensitivity and the HPA axis could elucidate the role of stress in chronic pain development, which might be influenced by familial factors, including genes. Methods: Associations between pain sensitivity and salivary cortisol and familial confounding in these associations were examined in 88 female, community-based twin […]

Transcriptional Signatures of Sleep Duration Discordance in Monozygotic Twins

Introduction: Habitual short sleep duration is associated with adverse metabolic, cardiovascular, and inflammatory effects. Co-twin study methodologies account for familial (eg, genetics and shared environmental) confounding, allowing assessment of subtle environmental effects, such as the effect of habitual short sleep duration on gene expression. Therefore, we investigated gene expression in monozygotic twins discordant for actigraphically phenotyped […]

New Study Opportunity

A research group at the University of Washington is seeking identical twins ages 9 to 14 for an exciting new brain imaging study! Twins will have their brains scanned while they engage in computer coding tasks. Twin participants will receive a print out of their brain scan, and parents will receive a written assessment report […]

Effects of Anxiety on Caloric Intake and Satiety-Related Brain Activation in Women and Men

Objective: To test the relationship of anxiety to caloric intake and food cue perception in women and men. Methods: Fifty-five twins (26 complete, 3 incomplete pairs; 51% women) underwent 2 functional magnetic resonance imaging (fMRI) scans (before and after a standardized meal) and then ate at an ad libitum buffet to objectively assess food intake. State and […]

Why are you asking for my SSN and mother’s maiden name?

Why are you asking for my social security number? We will ask for your social security number on the enrollment survey. However, it is not necessary for you to provide your social security number when you enroll as a member of the Washington State Twin Registry. This number can help us find you if you move or lose […]

Cross Sectional Association between Spatially Measured Walking Bouts and Neighborhood Walkability

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 bouts in the home neighborhood and […]