Publications

Psychological distress in twins with urological symptoms

Objective: Interstitial cystitis/painful bladder syndrome (IC/PBS) is a chronic pain condition with unclear underlying etiology. Our objectives were to determine whether psychological distress was higher in twins with urological symptoms commonly found in IC/PBS than in twins without, and if so, did familial influences contribute to this association. Method: Data from 1165 female twins in a community-based […]

A twin study of sleep duration and body mass index

Study objective: To determine the relative importance of genetic and environmental contributions to the association between sleep duration and body mass index (BMI). Methods: Twins from the University of Washington Twin Registry, a community-based sample of U.S. twins, provided self-reported height and weight for BMI calculation and habitual sleep duration. A generalized estimating equation model evaluated the […]

Genetic and environmental influences on restrained eating behavior

Objective: We examined the relative contributions of genetic and environmental influences to restrained eating. Method: Restrained eating was assessed by the Restraint Scale in a survey mailed to all twins enrolled in the University of Washington Twin Registry. We used structural equation modeling to estimate genetic and nongenetic contributions to restrained eating. Results: 1,196 monozygotic (MZ), 456 same-sex […]

A twin study of depression and migraine: Evidence for a shared genetic vulnerability

Objective: To determine if shared genetic or environmental vulnerabilities could underlie depression and migraine. Background: Depression and migraine headaches frequently coexist and their comorbidity may be due to shared etiologies. Methods: Female twins in the University of Washington Twin Registry responded to a mailed survey regarding their health history. Depression and migraine were determined by self-report of a […]

Are post-traumatic stress disorder symptoms and temporomandibular pain associated? Findings from a community-based twin registry

Aims: To determine whether symptoms of post-traumatic stress disorder (PTSD) are related to the pain of temporomandibular disorders (TMD) in a community-based sample of female twin pairs, and if so, to ascertain whether the association is due to the presence of chronic widespread pain (CWP) and familial/genetic factors. Methods: Data were obtained from 630 monozygotic and 239 […]

Unique environmental effects on physical activity participation: a twin study

Background: The health benefits of regular physical activity are well established. However, the relative contribution of heritable and environmental factors to physical activity participation remains controversial. Using a cut-point of 60 minutes of total activity per week, data from the GenomEUtwin project revealed consistent genetic influence on physical activity participation in 37,051 twin pairs from seven […]

Twin analyses of fatigue

Prolonged fatigue of ≥1 month duration and chronic fatigue of ≥6 months duration are both commonly seen in clinical practice, yet little is known about the etiology or epidemiology of either symptom. Chronic fatigue syndrome (CFS), while rarer, presents similar challenges in determining cause and epidemiology. Twin studies can be useful in elucidating genetic and […]

Feeling bad in more ways than one: comorbidity patterns of medically unexplained and psychiatric conditions

Background: Considerable overlap in symptoms and disease comorbidity has been noted among medically unexplained and psychiatric conditions seen in the primary care setting, such as chronic fatigue syndrome, low back pain, irritable bowel syndrome, chronic tension headache, fibromyalgia, temporomandibular joint disorder, major depression, panic attacks, and posttraumatic stress disorder. Objective: To examine interrelationships among these 9 conditions. […]

University of Washington Twin Registry: construction and characteristics of a community-based twin registry

The University of Washington Twin Registry is a community-based registry of twins identified from the Washington State Department of Licensing. A fortuitous quirk in the Washington State drivers’ license and identification number assignment, and collaborative Washington State laws, permitted us to build a statewide registry. Since obtaining approval from the Washington State Attorney General, the […]

A twin study of posttraumatic stress disorder symptoms and chronic widespread pain

Previous studies of the association between posttraumatic stress disorder (PTSD) and chronic widespread pain (CWP) or fibromyalgia have not examined the role of familial or genetic factors. The goals of this study were to determine if symptoms of PTSD are related to CWP in a genetically informative community-based sample of twin pairs, and if so, […]

Is the association between posttraumatic stress disorder symptoms and poor health due to a common familial or genetic factor?

Objective: The objective of this study was to identify genetic, familial and environmental contributions to the association between posttraumatic stress disorder (PTSD) symptoms and poor health. Methods: A community sample of 1852 twin pairs was assessed for symptoms of PTSD [with the Impact of Events Scale (IES)] and self-reported global health status using a single five-level question. […]

Genetic and environmental influences on insomnia, daytime sleepiness, and obesity in twins

Study objectives: To better understand the relationships of insomnia, sleepiness, and obesity. Design: Classic twin study. Setting: A community-based twin registry in Washington State. Patients or participants: One thousand forty-two monozygotic and 828 dizygotic twin pairs participating in the University of Washington Twin Registry. Interventions: N/A. Measurements and results: Twins were, on average, 32 years old; 61% were women, and 19.5% […]

Genetic pleiotropy between asthma and obesity in a community-based sample of twins

Background: Asthma and obesity are common conditions that are strongly associated. This association might be due to shared genetic or environmental causes. Objective: We sought to determine whether a shared genetic cause is responsible for the association between asthma and obesity and to estimate the magnitude of shared genetic cause. Methods: The analyses were performed with 1001 monozygotic […]