Usability of a Personal Air Pollution Monitor: Design-Feedback Iterative Cycle Study

Background: There is considerable evidence that exposure to fine particulate matter (PM2.5) air pollution is associated with a variety of adverse health outcomes. However, true exposure-outcome associations are hampered by measurement issues, including compliance and exposure misclassification. Objective: This paper describes the use of the design-feedback iterative cycle to improve the design and usability of a new […]

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

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) from 23 twin pairs underwent fasting morning blood draw and brain magnetic resonance imaging. T2 relaxation time was used to quantify gliosis in […]

Study Design and Rationale for the Mood and Methylation Study: A Platform for Multi-Omics Investigation of Depression in Twins

Major depression is a complex disorder with no single, direct causal mechanism. Morbidity has been linked to genetic processes, developmental history, and unique environmental exposures. Epigenetic mechanisms, especially DNA methylation, are also likely important factors in the pathogenesis of major depressive disorder (MDD). A community-based twin sample has many advantages for epigenetic studies, given the […]

DNA methylation associated with healthy aging of elderly twins

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 find genomic sites or regions where DNA methylation correlates with biological age. Using health data […]

Childhood Trauma, DNA Methylation of Stress-related Genes, and Depression: Findings from Two Monozygotic Twin Studies

Objective: DNA methylation has been associated with both early life stress and depression. This study examined the combined association of DNA methylation at multiple CpG probes in five stress-related genes with depressive symptoms and tested whether these genes methylation mediated the association between childhood trauma and depression in two monozygotic (MZ) twin studies. Methods: The current analysis […]

Using Smart City Technology to Make Healthcare Smarter

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 original research to offer an overview of how […]

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

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 classical twin model, with the MZ twin correlation greater […]

Associations between social capital and depression: A study of adult twins

Social capital is associated with depression independently of individual-level risk factors. We used a sample of 1586 same-sex twin pairs to test the association between seven measures of social capital and two related measures of neighborhood characteristics with depressive symptoms accounting for uncontrolled selection factors (i.e., genetics and shared environment). All measures of cognitive social […]

Associations between neighbourhood characteristics and depression: a twin study

Background: Depression is an important contributor to the global burden of disease. Besides several known individual-level factors that contribute to depression, there is a growing recognition that neighbourhood environment can also profoundly affect mental health. This study assessed associations between three neighbourhood constructs-socioeconomic deprivation, residential instability and income inequality-and depression among adult twin pairs. The twin […]

FTO genotype impacts food intake and corticolimbic activation

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 food intake consistent with impaired satiety. Objective: We sought central nervous system mechanisms that might underlie impaired satiety perception in people with a higher risk […]

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

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 adult twin pairs (mean age = 36.6; 65.9% female) from […]