For Twins

In adult twins, visceral fat accumulation depends more on exceeding sex-specific adiposity thresholds than on genetics

Objective: We recently reported sex-specific percent body fat (%BF) thresholds (males=23%, females=38%) above which, visceral adipose tissue (VAT) significantly increases. Using monozygotic (MZ) and dizygotic (DZ) twins, we examined the influence of genetics on regional fat distribution measured by dual-energy X-ray absorptiometry, above and below these sex-specific thresholds for VAT accumulation. Methods: Fifty-eight twin pairs (44 MZ, […]

Heritability of Pain Catastrophizing and Associations with Experimental Pain Outcomes: A Twin Study

This study used a twin paradigm to examine genetic and environmental contributions to pain catastrophizing and the observed association between pain catastrophizing and cold-pressor task (CPT) outcomes. Male and female monozygotic (n = 206) and dizygotic twins (n = 194) from the University of Washington Twin Registry completed a measure of pain catastrophizing and performed […]

Clinical and evoked pain, personality traits, and emotional states: Can familial confounding explain the associations?

Objectives: Pain is a complex phenomenon influenced by context and person-specific factors. Affective dimensions of pain involve both enduring personality traits and fleeting emotional states. We examined how personality traits and emotional states are linked with clinical and evoked pain in a twin sample. Methods: 99 female twin pairs were evaluated for clinical and evoked pain using […]

Stepping towards causation in studies of neighborhood and environmental effects: How twin research can overcome problems of selection and reverse causation

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 overcome selection and reverse causation problems in specifying causal mechanisms. Beyond quantifying genetic effects […]

A twin study of differences in the response of plasma ghrelin to a milkshake preload in restrained eaters

Background: Genetic, physiological, and psychological factors can affect food intake, but twin studies can distinguish inherited from environmental contributors. We examined the influence of attempted cognitive control of eating (“restrained eating”) on levels of appetite-regulating hormones. Methods: Sixteen female, monozygotic twin pairs, discordant for Restraint Scale score (i.e., one twin a restrained eater with score>15 whereas the […]

Salivary cortisol and cold pain sensitivity in female twins

Background: There is a dearth of knowledge about the link between cortisol and pain sensitivity. Purpose: We examined the association of salivary cortisol with indices of cold pain sensitivity in 198 female twins and explored the role of familial confounding. Methods: Three-day saliva samples were collected for cortisol levels and a cold pressor test was used to collect […]

Emerging technologies for assessing physical activity behaviors in space and time

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 data collected in a space-time framework to investigate built and […]

Adverse childhood experiences, health perception, and the role of shared familial factors in adult twins

To examine the relationship between adverse childhood experiences (ACE) and health perception in adulthood, and to explore the contribution of shared familial factors to these associations. Data were collected from 180 female twins (90 pairs) from the community-based University of Washington Twin Registry. Participants completed questionnaires including the modified ACE Questionnaire, Traumatic Life Events Questionnaire, […]

Acquired differences in brain responses among monozygotic twins discordant for restrained eating

We studied whether self-reported intent to exert cognitive control over eating was associated with differences in brain response to food cues, independent of genetic background. Subjects were ten pairs of identical twins in which one twin was a restrained eater and the co-twin was unrestrained, as classified by the Herman and Polivy Restraint Scale. Before […]

C-Reactive Protein and Pain Sensitivity: Findings from Female Twins

Background: Systemic inflammation and pain sensitivity may contribute to the development and maintenance of chronic pain conditions. Purpose: We examined the relationship between systemic inflammation as measured by C-reactive protein (CRP) and cold pain sensitivity in 198 female twins from the University of Washington Twin Registry. We also explored the potential role of familial factors in this […]

Sleep Duration and Metabolism in Twins

PI: Nathaniel WatsonProject Number: 5K23HL083350Project Dates: 5/01/2007–3/31/2012 This K23 award will allow Dr. Watson to become an investigator proficient in genetic epidemiology and the design and conduct of interdisciplinary research on gene-environment interactions in sleep medicine. The training and research activities will focus on complex environmental and genetic influences on habitual sleep duration and the impact […]

Twin Study of Chronic Widespread Pain

PI: Niloofar AfariProject Number: 5R01AR051524Project Dates: 9/25/2005–7/31/2011 Chronic widespread pain (CWP) occurs in 4-13% of people and is one of the defining characteristics of Fibromyalgia (FM). Although tender points were originally considered as essential to the diagnosis of FM, it is now felt that they reflect pain severity and distress, and that FM lies at one […]

An Interdisciplinary Study of Eating Behavior in Twins

PI: Ellen SchurProject Number: 1K23DK070826Project Dates: 6/15/2005–5/31/2010 This K23 award will allow Dr. Schur to become an independent investigator proficient in the design and conduct of interdisciplinary research on eating behavior and weight regulation. The training and research activities focus on complex environmental and genetic influences on eating habits and appetite regulation. The application proposes an […]