For Twins

Probabilistic walking models using built environment and sociodemographic predictors

Moudon AV, Huang R, Stewart OT, Cohen-Cline H, Noonan C, Hurvitz PM, Duncan GE. 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 […]

Salience network connectivity is reduced by a meal and influenced by genetic background and hypothalamic gliosis

Sewaybricker LE, Melhorn SJ, Askren MK, Webb MF, Tyagi V, De Leon MRB, Grabowski TJ, Seeley WW, Schur EA. BACKGROUND/OBJECTIVES The salience network (SN) comprises brain regions that evaluate cues in the external environment in light of internal signals. We examined the SN response to meal intake and potential genetic and acquired influences on SN […]

Heritability of Type 2 Diabetes in the Washington State Twin Registry

Avery AR, Duncan GE 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 […]

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

Goldfarb DS, Avery AR, Beara-Lasic L, Duncan GE, Goldberg J. 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 […]

The Genetics and Epigenetics of Healthy Aging in Twins

Aging is complex process, involving both genetic and non-genetic factors.  Genetics contribute to the rate of change for bodily functions and risk of disease, but these changes can also be influenced by the environment. The goal of this study was to learn more about the genes that are related to healthy aging, and how the […]

Study of Air Pollution in Twins (R33 phase)

This study seeks to understand how the environment influences our health by using a new device (the Portable Particle Monitor, PUWPM) that measures toxins in the environment, which was built and tested during the first phase of this study. These toxins include air pollution, noise, and allergens. Exposure to particle pollution can result in increased hospital […]

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, […]

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

Zadro JR, Shirley D, Duncan GE, Ferreira PH. 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 […]

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

Berkseth KE, Rubinow KB, Melhorn SJ, Webb MF, De Leon MRB, Marck BT, Matsumoto AM, Amory JK, Page ST, Schur EA. 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) […]

DNA methylation associated with healthy aging of elderly twins

Kim S, Wyckoff J, Morris AT, Succop A, Avery A, Duncan GE, Michal Jazwinski S. 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 […]

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. […]

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

Cook DJ, Duncan G, Sprint G, Fritz R. 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 […]

Differential models of twin correlations in skew for body-mass index (BMI)

Tsang S, Duncan GE, Dinescu D, Turkheimer E. Background Body Mass Index (BMI), like most human phenotypes, is substantially heritable. However, BMI is not normally distributed; the skew appears to be structural, and increases as a function of age. Moreover, twin correlations for BMI commonly violate the assumptions of the most common variety of the […]

FTO genotype impacts food intake and corticolimbic activation

Melhorn SJ, Askren MK, Chung WK, Kratz M, Bosch TA, Tyagi V, Webb MF, De Leon MRB, Grabowski TJ, Leibel RL, Schur EA. 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 […]

Examination of Cross-Sectional Associations of Neighborhood Deprivation and Alcohol Outlet Density With Hazardous Drinking Using a Twin Design

Rhew IC, Kosterman R, Duncan GE, Mair C. Objective The purpose of this study was to examine whether neighborhood socioeconomic deprivation and alcohol outlet density are associated with hazardous drinking using a co-twin design to control for confounding because of genetic and shared environmental factors. Method The study sample included cross-sectional data from 1,996 same-sex […]

What Twin Studies Tell Us About Brain Responses to Food Cues

Schur E, Carnell S. 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 […]

Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts

Silventoinen K, Jelenkovic A, Hopper JL, Busjahn A, Cozen W, Mack TM, Sumathipala A, Harris JR, Goldberg JH, Harden KP, Duncan GE, Buchwald D, Turkheimer E, Kaprio J, et al. Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences […]

Cross-sectional association between soda consumption and body mass index in a community-based sample of twins

Eney AE, Tsang S, Delaney JA, Turkheimer E, Duncan GE. Background Consumption of sugar-sweetened beverages, such as soda, have been shown to play an important role in weight gain. Although soda consumption has been associated with body mass index (BMI) in many studies, it has been difficult to ascertain a true causal relationship between soda […]