[Show abstract][Hide abstract] ABSTRACT: The International Network of Twin Registries (INTR) aims to foster scientific collaboration and promote twin research on a global scale by working to expand the resources of twin registries around the world and make them available to researchers who adhere to established guidelines for international collaboration. Our vision is to create an unprecedented scientific network of twin registries that will advance knowledge in ways that are impossible for individual registries, and includes the harmonization of data. INTR will also promote a broad range of activities, including the development of a website, formulation of data harmonization protocols, creation of a library of software tools for twin studies, design of a search engine to identify research partners, establishment of searchable inventories of data and biospecimens, development of templates for informed consent and data sharing, organization of symposia at International Society of Twin Studies conferences, support for scholar exchanges, and writing grant proposals.
Twin research and human genetics : the official journal of the International Society for Twin Studies. 12/2014; 17(6):574-7.
[Show abstract][Hide abstract] ABSTRACT: Posttraumatic stress disorder (PTSD) is associated with an increased risk of ischemic heart disease, though the pathophysiologic mechanisms remain unclear. Carotid artery intima-media thickness (CIMT) is a measure of subclinical atherosclerosis. We examined whether PTSD and combat exposure were associated with CIMT in Vietnam War-era twins after controlling for shared genetic and childhood factors. Between 2002 and 2010, we studied 465 middle-aged twins from the Vietnam Era Twin Registry who were free from cardiovascular disease. PTSD was diagnosed using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and CIMT was measured by ultrasound. Mixed-effects regression models were used to examine individual, between-pair, and within-pair associations. Approximately 13% of participants met the criteria for PTSD, and 45% served in the Vietnam Theater. PTSD was associated with 32.7 μm higher CIMT (95% confidence interval (CI): 0.9, 64.5) after adjustment for confounders. The average CIMT for the pair increased by 59.7 μm for each additional twin with PTSD (95% CI: 15.9, 104.2). We found no significant within-pair differences in CIMT when comparing PTSD-discordant co-twins. Results for combat exposure were similar, but its association with CIMT weakened after adjustment for PTSD (95% CI: 7.0, 45.3). Among Vietnam War-era veterans, combat exposure and PTSD are associated with CIMT, though the associations are largely mediated by shared childhood factors.
[Show abstract][Hide abstract] ABSTRACT: Objective: Silent myocardial ischemia is common in asymptomatic subjects without a prior history of coronary artery disease (CAD) and is associated with increased morbidity and mortality. Our objective was to determine whether endothelial dysfunction is associated with silent myocardial ischemia and whether the association is independent of genetic and familial factors.
Material and methods: We examined 416 male monozygotic and dizygotic twins aged 47 to 63 years, free of symptomatic CAD. Subclinical ischemia was diagnosed by [13 N] ammonia positron emission tomography at rest and after adenosine stress. Endothelial function was measured by flow-mediated dilation (FMD) of the brachial artery. Generalized estimating equations were used for analysis.
Results: Fixed perfusion defects were found in 24 (6%) twins and reversible perfusion defects in 90 (22%) twins, indicating subclinical ischemia. There was an inverse correlation between FMD and the reversible perfusion defect score (r = − 0.14, p = 0.01) but not the fixed defect score (r = − 0.017, p = 0.73). From the lowest to the highest quartile of FMD, the prevalence of reversible defects decreased 28% to 14%, p = 0.008. In multivariable analysis, reversible defects were significantly associated with each quartile of decreasing FMD (OR = 1.3; 95% 1.1, 2.5). In 54 twin pairs discordant for endothelial dysfunction (FMD ≤ 7% dilation from baseline), twins with endothelial dysfunction had 9% higher likelihood of having perfusion defects than their co-twins without endothelial dysfunction (p = 0.041).
Conclusions: Endothelial dysfunction is independently associated with silent ischemia and this association is not confounded by genetic or other shared familial factors.
[Show abstract][Hide abstract] ABSTRACT: Growing evidence has linked posttraumatic stress disorder (PTSD) to insulin resistance and type-2 diabetes, but most previous studies were cross-sectional. We examined the association between PTSD and incidence of diabetes in a prospective study of middle-aged male twins from the Vietnam Era Twin Registry. Lifetime PTSD was diagnosed at baseline with the Diagnostic Interview Schedule (DIS) according to DSM-III-R criteria. Subthreshold PTSD was defined by meeting some, but not all, criteria for PTSD. A total of 4340 respondents without self-reported diabetes at baseline were included. Of these, 658 reported a new diagnosis of treated diabetes over a median of 19.4 years of follow-up. At baseline, twins with PTSD showed more behavioral and metabolic risk factors such as overweight and hypertension. The age-adjusted cumulative incidence of diabetes was significantly higher in twins with PTSD (18.9%) than those without PTSD (14.4%), [odds ratio (OR) = 1.4, 95% confidence interval (CI) 1.03-1.8], and intermediate in those with subthreshold PTSD (16.4%) (OR = 1.2, 95% CI 0.9-1.5, p for trend = 0.03). Adjustment for military, lifestyle and metabolic factors diminished the association. No significant association was found comparing twin pairs discordant for PTSD. In conclusion, PTSD was prospectively associated with a 40% increased risk of new-onset type-2 diabetes which was partially explained by a cluster of metabolic and behavioral risk factors known to influence insulin resistance. Shared biological or behavioral precursors which occur within families may lead to both PTSD and insulin resistance/diabetes. Thus, PTSD could be a marker of neuroendocrine and metabolic dysregulation which may lead to type-2 diabetes.
[Show abstract][Hide abstract] ABSTRACT: Aims. Self-report questionnaires are frequently used in clinical and epidemiologic studies to assess post-traumatic stress disorder (PTSD). A number of studies have evaluated these scales relative to clinician administered structured interviews; however, there has been no formal evaluation of their performance relative to non-clinician administered epidemiologic assessments such as the Composite International Diagnostic Interview (CIDI). We examined the diagnostic performance of two self-report PTSD scales, the PTSD checklist (PCL) and the Vietnam Era Twin Registry (VET-R) PTSD scale, compared to the CIDI. Methods. Data were derived from a large epidemiologic follow-up study of PTSD in 5141 Vietnam Era Veterans. Measures included the PCL, VET-R PTSD scale and CIDI. For both the PCL and VET-R PTSD scale, ROC curves, areas under the curve (AUC), sensitivity, specificity, % correctly classified, likelihood ratios, predictive values and quality estimates were generated based on the CIDI PTSD diagnosis. Results. For the PCL and VET-R PTSD scale the AUCs were 89.0 and 87.7%, respectively. Optimal PCL cutpoints varied from the 31-33 range (when considering sensitivity and specificity) to the 36-56 range (when considering quality estimates). Similar variations were found for the VET-R PTSD, ranging from 31 (when considering sensitivity and specificity) to the 37-42 range (when considering quality estimates). Conclusions. The PCL and VET-R PTSD scale performed similarly using a CIDI PTSD diagnosis as the criterion. There was a range of acceptable cutpoints, depending on the metric used, but most metrics suggested a lower PCL cutpoint than in previous studies in Veteran populations.
Epidemiology and Psychiatric Sciences 06/2014; · 3.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There are few longitudinal cohort studies examining associations between incident MRI findings and incident spine-related symptom outcomes. Prior studies do not discriminate between the two distinct outcomes of low back pain (LBP) and radicular symptoms. To address this gap in the literature, we conducted a secondary analysis of existing data from the Longitudinal Assessment of Imaging and Disability of the Back (LAIDBACK). The purpose of this study was to examine the association of incident lumbar MRI findings with two specific spine-related symptom outcomes:1) incident chronic bothersome LBP, and 2) incident radicular symptoms such as pain, weakness, or sensation alterations in the lower extremity.
[Show abstract][Hide abstract] ABSTRACT: 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.
Sixteen female, monozygotic twin pairs, discordant for Restraint Scale score (i.e., one twin a restrained eater with score > 15 whereas the co-twin was unrestrained), were selected from the University of Washington Twin Registry. Serial plasma ghrelin concentrations were monitored during meals and a preload study paradigm involving intake of a milkshake followed by an ad libitum ice cream “taste test.”
Body weight, body mass index, resting energy expenditure, and fasting leptin levels were very similar between restrained and unrestrained twins. In a preload study, twins ate similar amounts of ice cream shortly after drinking identical milkshakes (mean ± SD; restrained 239 ± 158 vs. unrestrained 228 ± 132 kilocalories; P = 0.83). However, ghrelin concentrations during the preload study were significantly higher (P = 0.03) in restrained twins than in their unrestrained co-twins. Regardless of restraint status, ghrelin levels prior to the preload study were prospectively and positively associated with ice cream intake (P = 0.001).
Compared to their unrestrained co-twins, restrained twins had higher endogenous ghrelin levels during a preload study, but ate similar amounts. This finding is consistent with exertion of cognitive control relative to the state of physiologic appetite stimulation. Moreover, these findings in twins suggest that higher ghrelin levels result from restrained eating behavior and not from genetic predisposition.
[Show abstract][Hide abstract] ABSTRACT: We used quantitative genetic models to assess whether sleep duration modifies genetic and environmental influences on depressive symptoms.
Participants were 1,788 adult twins from 894 same-sex twin pairs (192 male and 412 female monozygotic [MZ] pairs, and 81 male and 209 female dizygotic [DZ] pairs] from the University of Washington Twin Registry. Participants self-reported habitual sleep duration and depressive symptoms. Data were analyzed using quantitative genetic interaction models, which allowed the magnitude of additive genetic, shared environmental, and non-shared environmental influences on depressive symptoms to vary with sleep duration.
Within MZ twin pairs, the twin who reported longer sleep duration reported fewer depressive symptoms (ec = -0.17, SE = 0.06, P < 0.05). There was a significant gene × sleep duration interaction effect on depressive symptoms (a'c = 0.23, SE = 0.08, P < 0.05), with the interaction occurring on genetic influences that are common to both sleep duration and depressive symptoms. Among individuals with sleep duration within the normal range (7-8.9 h/night), the total heritability (h(2)) of depressive symptoms was approximately 27%. However, among individuals with sleep duration within the low (< 7 h/night) or high (≥ 9 h/night) range, increased genetic influence on depressive symptoms was observed, particularly at sleep duration extremes (5 h/night: h(2) = 53%; 10 h/night: h(2) = 49%).
Genetic contributions to depressive symptoms increase at both short and long sleep durations.
Watson NF; Harden KP; Buchwald D; Vitiello MV; Pack AI; Stachan E; Goldberg J. Sleep duration and depressive symptoms: a gene-environment interaction. SLEEP 2014;37(2):351-358.
[Show abstract][Hide abstract] ABSTRACT: The American Heart Association (AHA) recently developed the Cardiovascular Health Index (CVHI), a health metric consisting of 7 modifiable risk factors. The relationship of the CVHI with preclinical markers, such as carotid intima-media thickness (CIMT) has not been assessed.
We examined 490 male monozygotic and dizygotic twins without overt cardiovascular disease. CIMT was measured using B-mode ultrasonography. Each of the 7 CVHI components (blood pressure, fasting glucose, total cholesterol, body mass index, physical activity, healthy diet, and smoking) was given a point score of 0, 1, or 2 to represent poor, intermediate, or ideal health, respectively. A CVHI summation score was computed (range 0 to 14) and categorized as inadequate (0 to 4), average (5 to 9), or optimum (10 to 14) cardiovascular health. Mixed-model regression was used to examine the association of the CVHI with CIMT.
The mean age of the twins was 55.4 years, and 61% were monozygotic. The mean CIMT was 0.75 (±0.11) mm and the mean CVHI score was 7.7 (±2.1). There was an inverse correlation between CVHI and CIMT (Spearman r=-0.22, P<0.01). For every 5-unit increase in overall CVHI score (indicating better cardiovascular health category), CIMT decreased by 0.045 mm (P<0.001) after adjusting for demographic variables and other confounders. Within monozygotic twin pairs, a 5-unit increment in CVHI score was associated with a 0.05 mm lower CIMT (P<0.001).
The CVHI is independently associated with CIMT and the association is not confounded by shared genetic and other familial factors.
Journal of the American Heart Association. 01/2014; 3(1):e000282.
[Show abstract][Hide abstract] ABSTRACT: To assess the relationship of posttraumatic stress disorder (PTSD) with health functioning and disability in Vietnam-era Veterans.
A cross-sectional study of functioning and disability in male Vietnam-era Veteran twins. PTSD was measured by the Composite International Diagnostic Interview; health functioning and disability were assessed using the Veterans RAND 36-Item Health Survey (VR-36) and the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0). All data collection took place between 2010 and 2012.
Average age of the 5,574 participating Veterans (2,102 Vietnam theater and 3,472 non-theater) was 61.0 years. Veterans with PTSD had poorer health functioning across all domains of VR-36 and increased disability for all subscales of WHODAS 2.0 (all p < .001) compared with Veterans without PTSD. Veterans with PTSD were in poorer overall health on the VR-36 physical composite summary (PCS) (effect size = 0.31 in theater and 0.47 in non-theater Veterans; p < .001 for both) and mental composite summary (MCS) (effect size = 0.99 in theater and 0.78 in non-theater Veterans; p < .001 for both) and had increased disability on the WHODAS 2.0 summary score (effect size = 1.02 in theater and 0.96 in non-theater Veterans; p < .001 for both). Combat exposure, independent of PTSD status, was associated with lower PCS and MCS scores and increased disability (all p < .05, for trend). Within-pair analyses in twins discordant for PTSD produced consistent findings.
Vietnam-era Veterans with PTSD have diminished functioning and increased disability. The poor functional status of aging combat-exposed Veterans is of particular concern.
Quality of Life Research 12/2013; · 2.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Informal caregiving can be deleterious to mental health, but research results are inconsistent and may reflect an interaction between caregiving and vulnerability to stress.
We examined psychological distress among 1,228 female caregiving and non-caregiving twins. By examining monozygotic and dizygotic twin pairs discordant for caregiving, we assessed the extent to which distress is directly related to caregiving or confounded by common genes and environmental exposures.
Caregiving was associated with distress as measured by mental health functioning, anxiety, perceived stress, and depression. The overall association between caregiving and distress was confounded by common genes and environment for mental health functioning, anxiety, and depression. Common environment also confounded the association of caregiving and perceived stress.
Vulnerability to distress is a factor in predicting caregivers' psychosocial functioning. Additional research is needed to explicate the mechanisms by which common genes and environment increase the risk of distress among informal caregivers.
Annals of Behavioral Medicine 11/2013; · 4.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Diurnal preference changes across the lifespan. However, the mechanisms underlying this age-related shift are poorly understood. The aim of this twin study was to determine the extent to which genetic and environmental influences on diurnal preference are moderated by age. Seven hundred and sixty-eight monozygotic and 674 dizygotic adult twin pairs participating in the University of Washington Twin Registry completed the reduced Morningness-Eveningness Questionnaire as a measure of diurnal preference. Participants ranged in age from 19 to 93 years (mean = 36.23, SD = 15.54) and were categorized on the basis of age into three groups: younger adulthood (19-35 years, n = 1715 individuals), middle adulthood (36-64 years, n = 1003 individuals) and older adulthood (65+ years, n = 168 individuals). Increasing age was associated with an increasing tendency towards morningness (r = 0.42, p < 0.001). Structural equation modeling techniques parsed the variance in diurnal preference into genetic and environmental influences for the total sample as well as for each age group separately. Additive genetic influences accounted for 52%[46-57%], and non-shared environmental influences 48%[43-54%], of the total variance in diurnal preference. In comparing univariate genetic models between age groups, the best-fitting model was one in which the parameter estimates for younger adults and older adults were equated, in comparison with middle adulthood. For younger and older adulthood, additive genetic influences accounted for 44%[31-49%] and non-shared environmental influences 56%[49-64%] of variance in diurnal preference, whereas for middle adulthood these estimates were 34%[21-45%] and 66%[55-79%], respectively. Therefore, genetic influences on diurnal preference are attenuated in middle adulthood. Attenuation is likely driven by the increased importance of work and family responsibilities during this life stage, in comparison with younger and older adulthood when these factors may be less influential in determining sleep-wake timing. These findings have implications for studies aimed at identifying specific non-shared environmental influences, as well as molecular genetic studies aimed at identifying specific polymorphisms associated with diurnal preference.
Chronobiology International 10/2013; · 4.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Social engagement has many demonstrated benefits for aging non-Hispanic Whites in the U.S. This study examined data from the U.S. Health and Retirement Study to determine whether these benefits were similar among American Indians and Alaska Natives older than 50 years. Linear regression techniques were used to examine the associations between level of social engagement, scores for memory and mental status, and self-reported health among 203 American Indian and Alaska Native elders who participated in the Health and Retirement Study and had data available between 1998 and 2010. Level of social engagement was significantly associated with memory, mental status, and self-reported health. However, only the association of social engagement with mental status and self-reported health remained significant (p = 0.04 and p = 0.05, respectively) after adjusting for sociodemographic variables, number of known health conditions, and scores on the Center for Epidemiologic Studies Depression scale. Level of social engagement was not associated with patterns of decline across time in cognitive or physical health. Higher levels of social engagement are associated with better physical and cognitive functioning in American Indian and Alaska Native elders. Future studies should examine whether this association acts through cognitive stimulation, increase in physical activity resulting from social engagement, or access to resources that support physical and cognitive health.
[Show abstract][Hide abstract] ABSTRACT: The aims of this paper are to examine the relationship between psychological trauma symptoms and Type 2 diabetes prevalence, glucose control, and treatment modality among 3776 American Indians in Phase V of the Strong Heart Family Study.
This cross-sectional analysis measured psychological trauma symptoms using the National Anxiety Disorder Screening Day instrument, diabetes by American Diabetes Association criteria, and treatment modality by four categories: no medication, oral medication only, insulin only, or both oral medication and insulin. We used binary logistic regression to evaluate the association between psychological trauma symptoms and diabetes prevalence. We used ordinary least squares regression to evaluate the association between psychological trauma symptoms and glucose control. We used binary logistic regression to model the association of psychological trauma symptoms with treatment modality.
Neither diabetes prevalence (22%-31%; p=0.19) nor control (8.0-8.6; p=0.25) varied significantly by psychological trauma symptoms categories. However, diabetes treatment modality was associated with psychological trauma symptoms categories, as people with greater burden used either no medication, or both oral and insulin medications (odds ratio=3.1, p<0.001).
The positive relationship between treatment modality and psychological trauma symptoms suggests future research investigate patient and provider treatment decision making.
Journal of diabetes and its complications 09/2013; · 2.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Caregiving can have a profound effect on the health of the caregiver, yet research on caregiving among American Indians is limited. The purpose of this study was to examine the influence of caregiving on the health-related quality of life (HRQoL) of American Indians enrolled in the Education And Research Towards Health (EARTH) study. Participants in the EARTH study represented three different tribes in the Northern Plains and Southwestern regions of the United States who completed self-administered, computer-assisted questionnaires between 2003 and 2006. Participants were classified as caregivers if at least one adult relied on them for personal care or as non-caregivers (n = 3,736). Caregivers were further classified according to type; those caring for an adult with unspecified needs (CAU, n = 482) and those caring for an adult with mental or physical difficulties (CAD, n = 295). HRQoL was measured using the mental and physical health component scores of the Medical Outcomes Study 12-item Short-Form Health Survey. Regional differences emerged with regard to caregiver type. Across both regions, non-caregivers reported significantly better mental and physical health than CAD, and the health of participants classified as CAU did not differ from that of non-caregivers. The health of American Indian caregivers depends on the kind of care provided, but detailed measures of caregiving are necessary to understand how caregiving influences health. This has implications for the design of effective interventions in tribal communities.
Journal of the American Geriatrics Society 09/2013; · 4.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There is a dearth of knowledge about the link between cortisol and pain sensitivity.
We examined the association of salivary cortisol with indices of cold pain sensitivity in 198 female twins and explored the role of familial confounding.
Three-day saliva samples were collected for cortisol levels and a cold pressor test was used to collect pain ratings and time to threshold and tolerance. Linear regression modeling with generalized estimating equations examined the overall and within-pair associations.
Lower diurnal variation of cortisol was associated with higher pain ratings at threshold (p = 0.02) and tolerance (p < 0.01). The relationship of diurnal variation with pain ratings at threshold and tolerance was minimally influenced by familial factors (i.e., genetics and common environment).
Understanding the genetic and non-genetic mechanisms underlying the link between HPA axis dysregulation and pain sensitivity may help to prevent chronic pain development and maintenance.
Annals of Behavioral Medicine 08/2013; · 4.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To determine whether posttraumatic stress disorder (PTSD) is associated with coronary heart disease (CHD) using a prospective twin study design and objective measures of CHD.
It has long been hypothesized that PTSD increases the risk of CHD but empirical evidence using objective measures is limited.
We conducted a prospective study of middle-aged male twins from the Vietnam Era Twin Registry. Among twin pairs without self-reported CHD at baseline, we selected pairs discordant for a lifetime history of PTSD, pairs discordant for a lifetime history of major depression, and pairs without either condition. All underwent a clinic visit after a median follow-up of 13 years. Outcomes included clinical events (myocardial infarction, other hospitalizations for CHD and coronary revascularization) and quantitative measures of myocardial perfusion by [N13] positron emission tomography, including a stress total severity score (STSS) and coronary flow reserve (CFR).
A total of 562 twins (281 pairs) were included with mean age of 42.6 yrs at baseline. The incidence of CHD was more than double in twins with PTSD (22.6%) than those without PTSD (8.9%; p<0.001). The association remained robust after adjusting for lifestyle factors, other CHD risk factors and major depression (OR=2.2, 95% confidence interval, 1.2-4.1). STSS was significantly higher (+ 95%, p=0.001) and CFR lower (-0.21, p=0.02) in twins with PTSD than those without, denoting worse myocardial perfusion. Associations were only mildly attenuated within 117 twin pairs discordant for PTSD.
Among Vietnam era veterans, PTSD is a risk factor for CHD.
Journal of the American College of Cardiology 06/2013; · 14.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective
Epigenetic mechanisms have been implicated in the pathogenesis of psychiatric disorders. The serotonin transporter gene (SLC6A4) is a key candidate gene for depression. We examined the association between SLC6A4 promoter methylation variation and depressive symptoms using 84 monozygotic twin pairs.MethodsDNA methylation level in the SLC6A4 promoter region was quantified by bisulfite pyrosequencing using genomic DNA isolated from peripheral blood leukocytes. The number of current depressive symptoms was assessed using the Beck Depressive Inventory II (BDI-II). The association between methylation variation and depressive symptoms was examined using matched twin-pair analyses, adjusting for body mass index, smoking, physical activity, and alcohol consumption. Multiple testing was controlled by adjusted false discovery rate (q value).ResultsIntrapair difference in DNA methylation variation at 10 of the 20 studied CpG sites is significantly correlated with intrapair difference in BDI scores. Linear regression using intrapair differences demonstrates that intrapair difference in BDI score was significantly associated with intrapair differences in DNA methylation variation after adjusting for potential confounders and correction for multiple testing. On average, a 10% increase in the difference in mean DNA methylation level was associated with 4.4 increase in the difference in BDI score (95% confidence interval = 0.9-7.9, p = .01).Conclusions
This study provides evidence that variation in methylation level within the promoter region of the serotonin transporter gene is associated with variation in depressive symptoms in a large sample of monozygotic twin pairs. This relationship is not confounded by genetic and shared environment. The 5-HTTLPR genotype also does not modulate this association.
Psychosomatic Medicine 06/2013; · 4.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ObjectiveA functional promoter polymorphism in the monoamine oxidase A (MAOA) gene has been implicated in neuropsychiatric disorders and also moderates the association between early-life stress and mental disorders, which often co-occur with cardiovascular disease. No study has examined the relationship between MAOA genotype, childhood trauma, and subclinical atherosclerosis. The objective of this investigation was to examine whether childhood trauma moderates the association between MAOA genotype and subclinical atherosclerosis.MethodsA sample including 289 middle-aged male twin pairs was studied. Subclinical atherosclerosis was assessed by brachial flow-mediated dilation (FMD) using ultrasound. Childhood trauma, before age 18 years, was measured with the Early Trauma Inventory and included physical, emotional, and sexual abuse as well as general trauma. Generalized estimating equation models were used to test the main and interactive effects of the MAOA genotype and each domain of childhood trauma on FMD, adjusting for known risk factors.ResultsGeneral trauma was the most prevalent childhood trauma (28.4%), followed by physical abuse (25.0%), emotional abuse (19.4%), and sexual abuse (11.6%). MAOA genotype was not associated with any domain of childhood trauma. There was no significant evidence for a main effect for the MAOA genotype (β = .02, p = .82) or childhood trauma (.005 < β < .10, p > .54) FMD. However, a significant interaction was observed between MAOA genotype and physical (βinteraction = .37, p = .026) or emotional abuse (βinteraction = .43, p = .025) on subclinical atherosclerosis.Conclusions
Childhood trauma modulates the impact of MAOA variant on subclinical atherosclerosis, independent of traditional cardiovascular risk factors.
Psychosomatic Medicine 05/2013; · 4.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Previous studies suggest that acculturation may influence the experience of pain. STUDY DESIGN: We conducted a cross-sectional study to estimate the association between acculturation and the prevalence, intensity, and functional limitations of pain in older Hispanic adults in the United States. METHODS SUBJECTS: Participants were English- (HE) and Spanish-speaking (HS) Hispanic and non-Hispanic White (NHW) individuals aged 50 years and older who were interviewed for the Health and Retirement Study during 1998-2008. MEASURES: We measured: 1) acculturation as defined by language used in interviews, and 2) the presence, intensity, and functional limitations of pain. ANALYSIS: We applied logistic regression using generalized estimating equations, with NHW as the reference category. RESULTS: Among 18,593 participants (16,733 NHW, 824 HE, and 1,036 HS), HS had the highest prevalence (odds ratio [OR] = 1.3; 95% confidence interval [CI = 1.1-1.4) and intensity (OR = 1.6; 95% CI = 1.4-1.9) of pain, but these differences were not significant after adjusting for age, sex, years of education, immigration status (U.S.- vs non-U.S-born), and health status (number of health conditions). Even after adjustment, HS reported the lowest levels of functional limitation (OR = 0.7; 95% CI 0.6-0.9). CONCLUSION: Pain prevalence and intensity were not related to acculturation after adjusting for sociodemographic factors, while functional limitation was significantly lower among HS even after adjusting for known risk factors. Future studies should explore the reasons for this difference.