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Atrial fibrillation (AF) is the most common arrhythmia in the United States, affecting approximately 1 in 10 adults, and its prevalence is expected to rise as the population ages. Treatment options for AF are limited; moreover, the development of new treatments is hindered by limited (1) knowledge regarding human atrial electrophysiological endpoints (e.g., conduction velocity [CV]) and (2) accurate experimental models. Here, we measured the CV and refractory period, and subsequently calculated the conduction wavelength, in vivo (four subjects with AF and four controls), and ex vivo (atrial slices from human hearts). Then, we created an in vitro model of human atrial conduction using induced pluripotent stem (iPS) cells. This model consisted of iPS-derived human atrial cardiomyocytes plated onto a micropatterned linear 1D spiral design of Matrigel. The CV (34-41 cm/s) of the in vitro model was nearly five times faster than 2D controls (7-9 cm/s) and similar to in vivo (40-64 cm/s) and ex vivo (28-51 cm/s) measurements. Our iPS-derived in vitro model recapitulates key features of in vivo atrial conduction and may be a useful methodology to enhance our understanding of AF and model patient-specific disease.

Although dispositional optimism and pessimism are associated with cardiovascular disease (CVD), their relative independence and unique contributions to CVD risk are unclear. This study addressed these issues by using multiple indicators of optimism and pessimism and linking them to objective risk factors for CVD. A diverse sample of adults (N = 300) completed baseline assessments (including global reports of optimism and pessimism), a 2-day/1-night EMA protocol with ambulatory blood pressure (BP) at 45-min intervals, and had inflammatory markers and carotid intima media imaging collected. EMA reports of momentary positive and negative expectations were averaged to form intraindividual (person) means of optimism and pessimism, respectively. Optimism and pessimism were only modestly correlated between- and within-assessment methods. Higher pessimism, regardless of assessment method, predicted both lower odds of whether BP dipping occurred and a smaller degree of dipping, but was unrelated to other biomarkers. Optimism was not uniquely predictive of CVD risk factors. Pessimism thus appears to exhibit stronger relative contribution to risk indicators of CVD than optimism.

ObjectiveEpidemiologic data increasingly support sleep as a determinant of cardiovascular disease risk. Fewer studies have investigated the mechanisms underlying this relationship using objective sleep assessment approaches. Therefore, the aim of this study was to examine associations between daily blood pressure (BP) and both objectively assessed sleep duration and efficiency.MethodsA diverse community sample of 300 men and women aged 21 to 70 years, enrolled in the North Texas Heart Study, participated in the study. Actigraphy-assessed sleep was monitored for two consecutive nights with ambulatory BP sampled randomly within 45-minute blocks on the first and second day as well as the second night.ResultsOverall, sleep duration results paralleled those of sleep efficiency. Individuals with lower sleep efficiency had higher daytime systolic (B = -0.35, SE = 0.11, p = .0018, R = 0.26) but not diastolic BP (B = -0.043, SE = 0.068, p = .52, R = 0.17) and higher nighttime BP (systolic: B = -0.37, SE = 0.10, p < .001, R = .15; diastolic: B = -0.20, SE = 0.059, p < .001, R = .14). Moreover, lower sleep efficiency on one night was associated with higher systolic (B = -0.51, SE = 0.11, p < .001, R = 0.23) and diastolic BP (B = -0.17, SE = 0.065, p = .012, R = .16) the following day. When 'asleep' BP was taken into account instead of nighttime BP, the associations between sleep and BP disappeared. When both sleep duration and efficiency were assessed together, sleep efficiency was associated with daytime systolic BP, whereas sleep duration was associated with nighttime BP.ConclusionsLower sleep duration and efficiency are associated with higher daytime systolic BP and higher nighttime BP when assessed separately. When assessed together, sleep duration and efficiency diverge in their associations with BP at different times of day. These results warrant further investigation of these possible pathways to disease.

Summary: Natural short sleepers (NSS)—individuals who report minimal sleepiness or daytime dysfunction despite habitually sleeping less than the recommended amount (i.e., <7 h)—are a focus of growing interest in sleep research. Yet, the predominance of research on NSS has relied on subjective reports of functionality. The present study examined subjective and objective sleepiness among actigraphy‐verified NSS in comparison with recommended (7–9 h/day) length sleepers (RLS) who reported similarly minimal daytime dysfunction. The study tested the hypothesis that under conditions of low environmental stimulation, NSS have increased risk of drowsiness and sleep onset, regardless of perceived alertness. The NSS and RLS groups were identified via screening and verified with a 14 day assessment with actigraphy, sleep diaries, and morning ratings of sleep restoration. In‐laboratory resting electroencephalography (EEG) data were analysed using a computerised EEG‐based algorithm (Vigilance Algorithm Leipzig; VIGALL) to classify second‐by‐second changes in objective sleepiness ranging from cognitively active alertness to sleep onset. Results demonstrated that NSS exhibited significantly higher drowsiness and sleep onset ('microsleeps') across 15 min of resting EEG despite perceptions of lower subjective sleepiness compared to RLS. Findings suggest that irrespective of perceived sleep restoration and alertness, NSS appear to be at high risk of objective sleepiness that is rapidly unmasked under conditions of low environmental stimulation. Such apparent discrepancy between subjective and objective sleepiness has potentially important public health implications. Future research directions, including tests of mechanisms and tailored sleep extension intervention, are discussed. [ABSTRACT FROM AUTHOR]

ObjectiveShort sleep duration has been linked with a wide array of poor mental and physical health outcomes. Such risks, however, may be moderated by demographic factors such as gender and race/ethnicity. In a diverse community sample, the current study examined the relationship between gender, race/ethnicity and objectively measured sleep duration, controlling for select potential confounds.MethodsParticipants were 300 community adults (50% female), aged 21 to 70 years, and included 60% non-Hispanic Whites, 15% non-Hispanic Blacks, 19% Hispanic/Latino, and 6% other. As part of a larger study, participants wore an actigraphy device over two nights to assess sleep duration (averaged across both nights). Gender and race/ethnicity were used as grouping variables in a two-way analysis of covariance (ANCOVA) predicting objectively assessed total sleep time, with age, income, and employment status as covariates.ResultsOn average, males slept 34 min less than females (P=.002). After controlling for socioeconomic factors, there was a gender by race/ethnicity interaction (P=.030). Within males, Hispanics slept 45 min less than non-Hispanic Whites (P=.002) and 57 min less than non-Hispanic others (P=.008). Males also slept significantly less than females within the non-Hispanic White (difference=-22.9; P=.016) and the Hispanic (difference=-77.1; P

IntroductionPsychosocial factors are increasingly recognised as important determinants of cardiovascular disease risk. The North Texas Heart Study aims to understand the mechanisms responsible for this association with a focus on social vigilance (ie, scanning the environment for social threats). There is also growing interest in supplementing traditional methods (eg, survey assessment of psychosocial risk paired with cross-sectional and longitudinal health outcomes) with daily or repeated momentary assessment of psychosocial factors. However, there are relatively few longitudinal studies directly comparing these approaches with hard endpoints.Methods and analysisThe North Texas Heart Study proposes a longitudinal measurement burst design to examine psychosocial determinants of subclinical atherosclerosis. A sample of 300 healthy community participants, stratified by age and gender, will complete survey measures, as well as 2 days of ecological momentary assessment at baseline and at a 2-year follow-up. A range of psychosocial and behavioural factors, objective biomarkers, as well as carotid intima-media thickness (cIMT) will be assessed at both time points. Unadjusted and adjusted models will evaluate cross-sectional associations and determinants of change in the cIMT.Ethics and disseminationThe Institutional Review Board at the study coordinating institute (University of North Texas) has approved this study. Positive, negative or inconclusive primary and ancillary findings will be disseminated in scientific journals and conferences.

Perceived social support has been reliably related to lower rates of morbidity and mortality. However, studies modeling C-reactive protein (CRP) as an important biological pathway linking social support to health have produced inconsistent results. Given purported ethnic/racial differences in sensitivity to social resources, the present study tested if ethnicity/race moderated the link between perceived support and CRP in a diverse community sample of 300 participants from the North Texas Heart Study. Consistent with prior research, there was no overall link between social support and CRP levels. However, the association between social support and high sensitivity (hs)-CRP levels was moderated by ethnicity/race as perceived support predicted lower hs-CRP levels primarily in African Americans. These results suggest the importance of considering how ethnicity/race may inform models on the complex biological mechanisms linking social support to health.

BackgroundAlthough the quality of one's social relationships has been linked to important physical health outcomes, less work has been conducted examining family and friends that differ in their underlying positivity and negativity.PurposeThe main aim of this study was to examine the association between supportive, aversive, and ambivalent family/friends with levels of C-reactive proteins.MethodsThree hundred participants from the North Texas Heart Study completed the social relationships index and a blood draw to assess high-sensitivity C-reactive proteins (hs-CRPs).ResultsAfter standard controls, the number of supportive family members predicted lower hs-CRP levels, whereas the number of ambivalent family members predicted higher hs-CRP levels. These links were independent of depressive symptoms and perceived stress.ConclusionsThese data highlight the importance of considering specific types of relationships and their underlying positive and negative aspects in research on social ties and physical health.

Objective: Technology is changing theway individuals socially connect. However, not much is known about how online forms of social exchanges might link to outcomes that predict longevity. This preregistered study examined the association between online social support and social negativity with self-rated health (SRH) and potential pathways responsible for such links. Method: In this preregistered analysis, a sample of 1,356 U.S. residents was recruited based on the U.S. Census track. Participants were at least 18-year-old social media users and completed the study online. Well-validated measures of online social support, online social negativity, general offline perceived support, internet addiction, social anxiety, and SRH were obtained. Results: Main results indicate that both online social support and social negativity were related to better SRH. However, the association between social negativity and better SRH was due to its statistical overlap with online social support. The association between online social support and SRH was primarily mediated by offline social support. Conclusions: These results highlight the importance of considering how positive and negative online social interactions are related to health outcomes. It also highlights potential pathways that might be targeted for interventions. [ABSTRACT FROM AUTHOR]

Life satisfaction has been linked to lower cardiovascular disease mortality. However, much less is known about the biological mechanisms linking life satisfaction to physical health. In addition, the dyadic context of life satisfaction has not been considered despite increasing evidence that partners influence each other in health-relevant ways. These questions were addressed with 94 married couples who completed measures of life satisfaction and had their blood drawn for determination of interleukin-6 (IL-6) and C-reactive protein (CRP). Actor-partner models showed that higher actor levels of life satisfaction predicted lower levels of IL-6 and CRP (p's < .05), whereas partner levels of life satisfaction did not predict any measure of inflammation. The actor results were not mediated by marital satisfaction or health behaviors. Finally, no actor x partner interactions were significant and these links were not moderated by marital satisfaction. These data highlight inflammation as a potentially important biological mechanism linking actor reports of life satisfaction to lower cardiovascular mortality., Author(s): Bert N. Uchino [sup.1] , Robert G. Kent de Grey [sup.1] , Sierra Cronan [sup.1] , Timothy W. Smith [sup.1] , Ed Diener [sup.1] , Samantha Joel [sup.1] , [...]

Background and Objectives: Although dispositional optimism and pessimism have been prospectively associated with health outcomes, little is known about how these associations manifest in everyday life. This study examined how short-term optimistic and pessimistic expectations were associated with psychological and physiological stress processes. Methods: A diverse sample of adults (N = 300) completed a 2-day/1-night ecological momentary assessment and ambulatory blood pressure (ABP) protocol at ∼45-minute intervals. Results: Moments that were more optimistic than typical for a person were followed by moments with lower likelihood of reporting a stressor, higher positive affect (PA), lower negative affect (NA), and less subjective stress (SS). Moments that were more pessimistic than typical were not associated with any affective stress outcome at the following moment. Neither optimism nor pessimism were associated with ABP, and did not moderate associations between reporting a stressor and outcomes. Discussion: These findings suggest that intraindividual fluctuations in optimistic and pessimistic expectations are associated with stressor appraisals. [ABSTRACT FROM AUTHOR]