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Diastolic dysfunction (DD), an abnormality in cardiac left ventricular (LV) chamber compliance, is associated with increased morbidity and mortality. Although DD has been extensively studied in older populations, co-morbidity patterns are less well characterized in middle-aged subjects. We screened 156,434 subjects with transthoracic echocardiogram reports available through Vanderbilt's electronic heath record and identified 6,612 subjects 40 to 55 years old with an LV ejection fraction ≥50% and diastolic function staging. We tested 452 incident and prevalent clinical diagnoses for associations with early-stage DD (n = 1,676) versus normal function. There were 44 co-morbid diagnoses associated with grade 1 DD including hypertension (odds ratio [OR] = 2.02, 95% confidence interval [CI] 1.78 to 2.28, p <5.3 × 10-29), type 2 diabetes (OR 1.96, 95% CI 1.68 to 2.29, p = 2.1 × 10-17), tachycardia (OR 1.38, 95% CI 0.53 to 2.19, p = 2.9 × 10-6), obesity (OR 1.76, 95% CI 1.51 to 2.06, p = 1.7 × 10-12), and clinical end points, including end-stage renal disease (OR 3.29, 95% CI 2.19 to 4.96, p = 1.2 × 10-8) and stroke (OR 1.5, 95% CI 1.12 to 2.02, p = 6.9 × 10-3). Among the 60 incident diagnoses associated with DD, heart failure with preserved ejection fraction (OR 4.63, 95% CI 3.39 to 6.32, p = 6.3 × 10-22) had the most significant association. Among subjects with normal diastolic function and blood pressure at baseline, a blood pressure measurement in the hypertensive range at the time of the second echocardiogram was associated with progression to stage 1 DD (p = 0.04). In conclusion, DD was common among subjects 40 to 55 years old and was associated with a heavy burden of co-morbid disease.
Copyright © 2018 Elsevier Inc. All rights reserved.
BACKGROUND - Delirium during critical illness results from numerous insults, which might be interconnected and yet individually contribute to long-term cognitive impairment. We sought to describe the prevalence and duration of clinical phenotypes of delirium (ie, phenotypes defined by clinical risk factors) and to understand associations between these clinical phenotypes and severity of subsequent long-term cognitive impairment.
METHODS - In this multicentre, prospective cohort study, we included adult (≥18 years) medical or surgical ICU patients with respiratory failure, shock, or both as part of two parallel studies: the Bringing to Light the Risk Factors and Incidence of Neuropsychological Dysfunction in ICU Survivors (BRAIN-ICU) study, and the Delirium and Dementia in Veterans Surviving ICU Care (MIND-ICU) study. We assessed patients at least once a day for delirium using the Confusion Assessment Method-ICU and identified a priori-defined, non-mutually exclusive phenotypes of delirium per the presence of hypoxia, sepsis, sedative exposure, or metabolic (eg, renal or hepatic) dysfunction. We considered delirium in the absence of hypoxia, sepsis, sedation, and metabolic dysfunction to be unclassified. 3 and 12 months after discharge, we assessed cognition with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). We used multiple linear regression to separately analyse associations between the duration of each phenotype of delirium and RBANS global cognition scores at 3-month and 12-month follow-up, adjusting for potential confounders.
FINDINGS - Between March 14, 2007, and May 27, 2010, 1048 participants were enrolled, eight of whom could not be analysed. Of 1040 participants, 708 survived to 3 months of follow-up and 628 to 12 months. Delirium was common, affecting 740 (71%) of 1040 participants at some point during the study and occurring on 4187 (31%) of all 13 434 participant-days. A single delirium phenotype was present on only 1355 (32%) of all 4187 participant-delirium days, whereas two or more phenotypes were present during 2832 (68%) delirium days. Sedative-associated delirium was most common (present during 2634 [63%] delirium days), and a longer duration of sedative-associated delirium predicted a worse RBANS global cognition score 12 months later, after adjusting for covariates (difference in score comparing 3 days vs 0 days: -4·03, 95% CI -7·80 to -0·26). Similarly, longer durations of hypoxic delirium (-3·76, 95% CI -7·16 to -0·37), septic delirium (-3·67, -7·13 to -0·22), and unclassified delirium (-4·70, -7·16 to -2·25) also predicted worse cognitive function at 12 months, whereas duration of metabolic delirium did not (1·14, -0·12 to 3·01).
INTERPRETATION - Our findings suggest that clinicians should consider sedative-associated, hypoxic, and septic delirium, which often co-occur, as distinct indicators of acute brain injury and seek to identify all potential risk factors that may impact on long-term cognitive impairment, especially those that are iatrogenic and potentially modifiable such as sedation.
FUNDING - National Institutes of Health and the Department of Veterans Affairs.
Copyright © 2018 Elsevier Ltd. All rights reserved.
Computational protein design has been successful in modeling fixed backbone proteins in a single conformation. However, when modeling large ensembles of flexible proteins, current methods in protein design have been insufficient. Large barriers in the energy landscape are difficult to traverse while redesigning a protein sequence, and as a result current design methods only sample a fraction of available sequence space. We propose a new computational approach that combines traditional structure-based modeling using the Rosetta software suite with machine learning and integer linear programming to overcome limitations in the Rosetta sampling methods. We demonstrate the effectiveness of this method, which we call BROAD, by benchmarking the performance on increasing predicted breadth of anti-HIV antibodies. We use this novel method to increase predicted breadth of naturally-occurring antibody VRC23 against a panel of 180 divergent HIV viral strains and achieve 100% predicted binding against the panel. In addition, we compare the performance of this method to state-of-the-art multistate design in Rosetta and show that we can outperform the existing method significantly. We further demonstrate that sequences recovered by this method recover known binding motifs of broadly neutralizing anti-HIV antibodies. Finally, our approach is general and can be extended easily to other protein systems. Although our modeled antibodies were not tested in vitro, we predict that these variants would have greatly increased breadth compared to the wild-type antibody.
Genomic maps of local ancestry identify ancestry transitions - points on a chromosome where recent recombination events in admixed individuals have joined two different ancestral haplotypes. These events bring together alleles that evolved within separate continential populations, providing a unique opportunity to evaluate the joint effect of these alleles on health outcomes. In this work, we evaluate the impact of genetic variants in the context of nearby local ancestry transitions within a sample of nearly 10,000 adults of African ancestry with traits derived from electronic health records. Genetic data was located using the Metabochip, and used to derive local ancestry. We develop a model that captures the effect of both single variants and local ancestry, and use it to identify examples where local ancestry transitions significantly interact with nearby variants to influence metabolic traits. In our most compelling example, we find that the minor allele of rs16890640 occuring on a European background with a downstream local ancestry transition to African ancestry results in significantly lower mean corpuscular hemoglobin and volume. This finding represents a new way of discovering genetic interactions, and is supported by molecular data that suggest changes to local ancestry may impact local chromatin looping.
OBJECTIVE - To evaluate the relationship between genetic ancestry and uterine fibroid characteristics.
DESIGN - Cross-sectional study.
SETTING - Not applicable.
PATIENT(S) - A total of 609 African American participants with image- or surgery-confirmed fibroids in a biorepository at Vanderbilt University electronic health record biorepository and the Coronary Artery Risk Development in Young Adults studies were included.
INTERVENTION(S) - None.
MAIN OUTCOME MEASURE(S) - Outcome measures include fibroid number (single vs. multiple), volume of largest fibroid, and largest fibroid dimension of all fibroid measurements.
RESULT(S) - Global ancestry meta-analyses revealed a significant inverse association between percentage of European ancestry and risk of multiple fibroids (odds ratio: 0.78; 95% confidence interval 0.66, 0.93; P=6.05 × 10). Local ancestry meta-analyses revealed five suggestive (P<4.80 × 10) admixture mapping peaks in 2q14.3-2q21.1, 3p14.2-3p14.1, 7q32.2-7q33, 10q21.1, 14q24.2-14q24.3, for number of fibroids and one suggestive admixture mapping peak (P<1.97 × 10) in 10q24.1-10q24.32 for volume of largest fibroid. Single variant association meta-analyses of the strongest associated region from admixture mapping of fibroid number (10q21.1) revealed a strong association at single nucleotide polymorphism variant rs12219990 (odds ratio: 0.41; 95% confidence interval 0.28, 0.60; P=3.82 × 10) that was significant after correction for multiple testing.
CONCLUSION(S) - Increasing African ancestry is associated with multiple fibroids but not with fibroid size. Local ancestry analyses identified several novel genomic regions not previously associated with fibroid number and increasing volume. Future studies are needed to explore the genetic impact that ancestry plays into the development of fibroid characteristics.
Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
A subgroup of Parkinson's disease (PD) patients treated with dopaminergic therapy develop compulsive reward-driven behaviors, which can result in life-altering morbidity. The mesocorticolimbic dopamine network guides reward-motivated behavior; however, its role in this treatment-related behavioral phenotype is incompletely understood. Here, mesocorticolimbic network function in PD patients who develop impulsive and compulsive behaviors (ICB) in response to dopamine agonists was assessed using BOLD fMRI. The tested hypothesis was that network connectivity between the ventral striatum and the limbic cortex is elevated in patients with ICB and that reward-learning proficiency reflects the extent of mesocorticolimbic network connectivity. To evaluate this hypothesis, 3.0T BOLD-fMRI was applied to measure baseline functional connectivity on and off dopamine agonist therapy in age and sex-matched PD patients with (n = 19) or without (n = 18) ICB. An incentive-based task was administered to a subset of patients (n = 20) to quantify positively or negatively reinforced learning. Whole-brain voxelwise analyses and region-of-interest-based mixed linear effects modeling were performed. Elevated ventral striatal connectivity to the anterior cingulate gyrus (P = 0.013), orbitofrontal cortex (P = 0.034), insula (P = 0.044), putamen (P = 0.014), globus pallidus (P < 0.01), and thalamus (P < 0.01) was observed in patients with ICB. A strong trend for elevated amygdala-to-midbrain connectivity was found in ICB patients on dopamine agonist. Ventral striatum-to-subgenual cingulate connectivity correlated with reward learning (P < 0.01), but not with punishment-avoidance learning. These data indicate that PD-ICB patients have elevated network connectivity in the mesocorticolimbic network. Behaviorally, proficient reward-based learning is related to this enhanced limbic and ventral striatal connectivity. Hum Brain Mapp 39:509-521, 2018. © 2017 Wiley Periodicals, Inc.
© 2017 Wiley Periodicals, Inc.
BACKGROUND & AIMS - Cardiovascular disease (CVD) is the leading cause of death among patients with nonalcoholic fatty liver disease (NAFLD). Moderate drinking (vs abstinence) is associated with lower risk of CVD in the general population. We assessed whether alcohol use is associated with CVD risk in patients with NAFLD.
METHODS - We analyzed data from participants in the Coronary Artery Risk Development in Young Adults longitudinal cohort study of 5115 black and white young adults, 18-30 years old, recruited from 4 cities in the United States from 1985 through 1986. Participants self-reported alcohol use at study entry and then again after 15, 20, and 25 years. At year 25 (2010-2011), participants underwent computed tomography examination of the thorax and abdomen and tissue Doppler echocardiography with myocardial strain measured by speckle tracking. Coronary artery calcification was defined as an Agatston score above 0. NAFLD was defined as liver attenuation <51 Hounsfield Units after exclusions. Drinkers reported 1-21 (men) or 1-14 (women) standard drinks/week at years 15, 20, or 25. Nondrinkers reported no alcohol use at years 15, 20, and 25.
RESULTS - Of the 570 participants with NAFLD (mean age, 50 years; 54% black; 46% female), 332 (58%) were drinkers; significantly higher proportions of drinkers were white, male, and with higher levels of education compared with nondrinkers (P < .05 for all). Higher proportions of drinkers had obesity, diabetes, and metabolic syndrome compared with nondrinkers (P < .01). There was no difference in liver attenuation between groups (P = .12). After multivariable adjustment, there was no association between alcohol use and CVD risk factors (diabetes, hypertension, hyperlipidemia) or subclinical CVD measures (coronary artery calcification, early transmitral velocity/late (atrial) transmitral velocity (E/A) ratio, global longitudinal strain).
CONCLUSIONS - In a population-based sample of individuals with NAFLD in midlife, prospectively assessed alcohol use is not associated with significant differences in risk factors for CVD or markers of subclinical CVD. In contrast to general population findings, alcohol use may not reduce the risk of CVD in patients with NAFLD.
Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.
PURPOSE - To evaluate the magnitude of chemical exchange effects and R dispersion in muscle and their relationship to tissue sodium levels with aging.
METHODS - Seven healthy volunteers (aged 24 to 87years, median age 47) underwent MRI to assess tissue sodium levels and water T values at different spin-locking frequencies in calf muscles. T values at each locking field were computed based on a three-parameter mono-exponential model to fit signals obtained at different locking times, and R (=1/T) rates were compared at different locking fields. In particular, the dispersion of R (ΔR=R(0Hz)-R(500Hz)) was examined as a function of subject age. Muscle sodium content was calculated by comparing signal intensities between tissues and reference standards within the same image. The variations of ΔR with age and sodium were analyzed by linear regression.
RESULTS - T values and sodium content both increased with age. R dispersion also increased with age and showed a strong linear correlation (correlation coefficient r=0.98, P=0.000578) with sodium content.
CONCLUSION - ΔR reports on the contribution of labile protons such as hydroxyls which may be associated with macromolecule accumulation in the extracellular matrix (ECM). An increase of sodium signal suggests an enlarged ECM volume fraction and/or an increase in sodium concentration, which occurs during normal aging. The strong correlation between ΔR and sodium is likely the consequence of increased ECM and density of total charged sites within the matrix from molecules such as collagens and proteoglycans. The results from this study show the potential use of R dispersion and sodium imaging in the assessment of pathological changes in muscle such as fibrosis.
Copyright © 2017 Elsevier Inc. All rights reserved.
OBJECTIVES - This study sought to assess whether body mass index (BMI) was associated with subclinical left ventricular (LV) systolic dysfunction in African-American individuals.
BACKGROUND - Higher BMI is a risk factor for cardiovascular disease, including heart failure. Obesity disproportionately affects African Americans; however, the association between higher BMI and LV function in African Americans is not well understood.
METHODS - Peak systolic circumferential strain (ECC) was measured by tagged cardiac magnetic resonance in 1,652 adult African-American participants of the Jackson Heart Study between 2008 and 2012. We evaluated the association between BMI and ECC in multivariate linear regression and restricted cubic spline analyses adjusted for prevalent cardiovascular disease, conventional cardiovascular risk factors, LV mass, and ejection fraction. In exploratory analyses, we also examined whether inflammation, insulin resistance, or volume of visceral adipose tissue altered the association between BMI and ECC.
RESULTS - The proportions of female, nonsmokers, diabetic, and hypertensive participants rose with increase in BMI. In multivariate-adjusted models, higher BMI was associated with worse ECC (β = 0.052; 95% confidence interval: 0.028 to 0.075), even in the setting of preserved LV ejection fraction. Higher BMI was also associated with worse ECC when accounting for markers of inflammation (C-reactive protein, E-selection, and P-selectin), insulin resistance, and volume of visceral adipose tissue.
CONCLUSIONS - Higher BMI is significantly associated with subclinical LV dysfunction in African Americans, even in the setting of preserved LV ejection fraction.
Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
The aim of this work was to investigate possible sex differences in the patterns of sodium deposition between muscle and skin using sodium MRI. A total of 38 subjects were examined for comparisons: 20 males, aged 25-79years with a median age of 51; 18 females, aged 38-66years, median age 53. All subjects underwent sodium MRI scans of the calf muscles together with cross sections through four calibration standards containing known sodium contents (10mM, 20mM, 30mM, and 40mM). Tissue sodium concentrations (TSC) in muscle and skin were then calculated by comparing signal intensities between tissues and reference standards using a linear analysis. A Wilcoxon rank sum test was applied to the ΔTSC (=TSC-TSC) series of males and females to examine if they were significantly different. Finally, a multiple linear regression was utilized to account for the effects from two potential confounders, age and body mass index (BMI). We found that sodium content appears to be higher in skin than in muscle for men, however women tend to have higher muscle sodium than skin sodium. This sex-relevant sodium deposition is statistically significant (P=3.10×10) by the Wilcoxon rank sum test, and this difference in distribution seems to be more reliable with increasing age. In the multiple linear regression, gender still has a statistically significant effect (P<1.0×10) on the difference between sodium deposition in muscle and skin, while taking the effects of age and BMI into account.
Copyright © 2016 Elsevier Inc. All rights reserved.