Registry Survey Data

Does neighbourhood deprivation influence low back pain and arthritis: An empirical study using multilevel twin design

Objective: Neighbourhood deprivation has been found to be associated with many health conditions, but its association with low back pain (LBP) and arthritis is unclear. This study aimed to examine the association between neighbourhood deprivation with LBP and arthritis, and its potential interaction with individual socioeconomic status (SES) on these outcomes. Methods: Monozygotic (MZ) twins from the […]

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

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 study of opposite-sex twin pairs investigating sex differences in LBP while accounting for (genetic and shared environmental) familial […]

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

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: We used the reduced Horne-Östberg Morningness-Eveningness Questionnaire (rMEQ) to assess chronotype in […]

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

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 was built using variables of body mass index, physical activity engagement, sleep quality, smoking […]

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 […]

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

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 twins. Methods: We included 6,048 twin pairs from a community-based registry. Five […]

Does it matter where you live? The effect of neighbourhood walkability on recovery from low back pain.

It is unknown whether the built environment influences recovery from low back pain (LBP). Objective: To investigate whether neighbourhood walkability influences the recovery from LBP after adjusting for genetics and shared environmental factors. Study group: We conducted a longitudinal analysis of adult twins with LBP from the Washington State Twin Registry (average follow-up: 1.7 years). […]

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

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 study of monozygotic (MZ) and dizygotic (DZ) twins […]

Central and Peripheral Symptoms in Network Analysis are Differentially Heritable A Twin Study of Anxious Misery

Background: Evidence suggests that depression and anxiety disorders are genetically based. Although symptoms of these internalizing disorders tend to correlate, the degree to which the related symptoms are heritable is unclear. This overlap has been conceptualized as Anxious Misery and existing research examining similar constructs of negative affect has revealed moderate heritability. However, it is […]

Psychometric and Classification Properties of the Peas in a Pod Questionnaire

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) and dizygotic (DZ) pairs may differ in their […]

Associations between changes in resilient coping and posttraumatic stress disorder symptoms

The pervasive, damaging nature of posttraumatic stress disorder (PTSD) presents enormous clinical challenges. Understanding the relationship between patients’ perceptions of PTSD symptoms and resilient coping strategies may prompt investigation of clinical interventions that improve adaptive, resilient coping skills. In this study, we examined whether changes in resilient coping were related to changes over time in […]

Neighborhood Deprivation Moderates Shared and Unique Environmental Influences on Hazardous Drinking: Findings from a Cross-Sectional Co-Twin Study

Background: There has been increased interest in the interplay of genetic and environmental factors in the development of problematic alcohol use, including socioeconomic conditions of the neighborhood. Using a co-twin design, we examined the extent to which contributions of genetic, shared environmental, and unique environmental influences on hazardous drinking differed according to levels of neighborhood […]

Insomnia and posttraumatic stress symptoms: Evidence of shared etiology

Posttraumatic stress disorder (PTSD) and insomnia are comorbid clinical conditions that are thought to result from genetic and environmental effects. Though studies have established the heritability of these disorders independently, no study to date has examined the genetic contributions to the relation between insomnia and PTSD symptoms (PTSS). The present study assessed this gap in […]

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

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 models. Methods: Data were obtained from 1,865 monozygotic and 758 dizygotic twin […]

The Washington State Twin Registry: 2019 Update

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 special issue is a follow-up to update the scientific community […]

Probabilistic walking models using built environment and sociodemographic predictors

Background: Individual sociodemographic and home neighborhood built environment (BE) factors influence the probability of engaging in health-enhancing levels of walking or moderate-to-vigorous physical activity (MVPA). Methods are needed to parsimoniously model the associations. Methods: Participants included 2392 adults drawn from a community-based twin registry living in the Seattle region. Objective BE measures from four domains […]

Heritability of Type 2 Diabetes in the Washington State Twin Registry

Approximately 12% of U.S. adults have type 2 diabetes (T2D). Diagnosed T2D is caused by a combination of genetic and environmental factors including age and lifestyle. In adults 45 years and older, the Discordant Twin (DISCOTWIN) consortium of twin registries from Europe and Australia showed a moderate-to-high contribution of genetic factors of T2D with a […]

A twin study of genetic influences on nephrolithiasis in women and men

Background: Nephrolithiasis is a complex phenotype influenced by both genetic and environmental factors. Previously we found a genetic component to stone disease using a sample of male twin pairs. We now report on the genetic contribution to stones in a sample of female and male twin pairs. Methods: We conducted a classic twin study of kidney stones […]

Familial factors predicting recovery and maintenance of physical activity in people with low back pain: insights from a population-based twin study

Background: It is unknown how familial factors influence the recovery from low back pain (LBP) and the maintenance activity behaviours. We aimed to investigate whether individual and within-family physical activity (PA) and sedentary behaviour influenced recovery from LBP, and maintenance of PA and sedentary behaviour in people with and without LBP. Methods: Longitudinal logistic regression analyses were […]