2012

Study objectives: To examine whether sleep duration modifies genetic and environmental influences on body mass index (BMI). Design: Genotype-environment interaction twin study. Setting: University of Washington Twin Registry. Patients or participants: A population-based sample of US twins (1,088 pairs, 604 monozygotic, 484 dizygotic; 66% female; mean age = 36.6 yr, standard deviation (SD) = 15.9 yr). Interventions: N/A. Measurements and […]

We used a classical twin design and measures of neighborhood walkability and social deprivation, using each twin’s street address, to examine genetic and environmental influences on the residential location of 1389 same-sex pairs from a US community-based twin registry. Within-pair correlations and structural equation models estimated these influences on walkability among younger (ages 18-24.9) and […]

Background: Data from primary care and community samples suggest higher rates of post-traumatic stress disorder (PTSD) among individuals with chronic fatigue syndrome (CFS). Objective: This study investigated the co-occurrence of CFS, PTSD, and trauma symptoms and assessed the contribution of familial factors to the association of CFS with lifetime PTSD and current traumatic symptoms. Method: Data on lifetime […]

Aims: To determine whether shared genetic influences are responsible for the association between pain from temporomandibular disorders (TMD) and migraine headache. Methods: Data were obtained from 1,236 monozygotic and 570 dizygotic female twin pairs from the University of Washington Twin Registry. TMD pain was assessed with a question about persistent or recurrent pain in the jaw, temple, […]

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 […]

We used the community-based University of Washington Twin Registry to investigate the genetic association between circadian type and sleep duration. Habitual sleep duration was obtained by self-report and circadian type was measured using a reduced 5-item Horne–Östberg Morningness–Eveningness questionnaire. Univariate and bivariate genetic analyses were fit using structural equation models. We used multinomial logistic regression […]