Should regression calibration or multiple imputation be used when calibrating different devices in a longitudinal study?

In longitudinal studies, the devices used to measure exposures can change from visit to visit. Calibration studies, wherein a subset of participants is measured using both devices at follow-up, may be used to assess between-device differences (i.e., errors). Then, statistical methods are needed to adjust for between-device differences and the missing measurement data that often appear in calibration studies. Regression calibration and multiple imputation are two possible methods. We compared both methods in linear regression with a simulation study, considering various real-world scenarios for a longitudinal study of pulse wave velocity. Regression calibration and multiple imputation were both essentially unbiased, but correctly estimating the standard errors posed challenges. Multiple imputation with predicted mean matching produced close agreement with the empirical standard error. Fully stochastic multiple imputation underestimated the standard error by up to 50%, and regression calibration with bootstrapped standard errors performed slightly better than fully stochastic multiple imputation. Regression calibration was slightly more efficient than either multiple imputation method. The results suggest use of multiple imputation with predictive mean matching over fully stochastic imputation or regression calibration in longitudinal studies where a new device at follow-up might be error-prone compared to the device used at baseline.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association.

BACKGROUND: The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs). METHODS: The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy. RESULTS: Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics. CONCLUSIONS: The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Bending the Curve in Cardiovascular Disease Mortality: Bethesda + 40 and Beyond.

More than 40 years after the 1978 Bethesda Conference on the Declining Mortality from Coronary Heart Disease provided the scientific community with a blueprint for systematic analysis to understand declining rates of coronary heart disease, there are indications the decline has ended or even reversed despite advances in our knowledge about the condition and treatment. Recent data show a more complex situation, with mortality rates for overall cardiovascular disease, including coronary heart disease and stroke, decelerating, whereas those for heart failure are increasing. To mark the 40th anniversary of the Bethesda Conference, the National Heart, Lung, and Blood Institute and the American Heart Association cosponsored the "Bending the Curve in Cardiovascular Disease Mortality: Bethesda + 40" symposium. The objective was to examine the immediate and long-term outcomes of the 1978 conference and understand the current environment. Symposium themes included trends and future projections in cardiovascular disease (in the United States and internationally), the evolving obesity and diabetes epidemics, and harnessing emerging and innovative opportunities to preserve and promote cardiovascular health and prevent cardiovascular disease. In addition, participant-led discussion explored the challenges and barriers in promoting cardiovascular health across the lifespan and established a potential framework for observational research and interventions that would begin in early childhood (or ideally in utero). This report summarizes the relevant research, policy, and practice opportunities discussed at the symposium.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association.

BACKGROUND: The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs). METHODS: The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease. RESULTS: Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics. CONCLUSIONS: The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association.

BACKGROUND: The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs). METHODS: The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals. RESULTS: Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics. CONCLUSIONS: The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Incident Chronic Kidney Disease Risk among Hispanics/Latinos in the United States: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

BACKGROUND: Although Hispanics/Latinos in the United States are often considered a single ethnic group, they represent a heterogenous mixture of ancestries who can self-identify as any race defined by the U.S. Census. They have higher ESKD incidence compared with non-Hispanics, but little is known about the CKD incidence in this population. METHODS: We examined rates and risk factors of new-onset CKD using data from 8774 adults in the Hispanic Community Health Study/Study of Latinos. Incident CKD was defined as eGFR <60 ml/min per 1.73 m2 with eGFR decline ≥1 ml/min per 1.73 m2 per year, or urine albumin/creatinine ratio ≥30 mg/g. Rates and incidence rate ratios were estimated using Poisson regression with robust variance while accounting for the study's complex design. RESULTS: Mean age was 40.3 years at baseline and 51.6% were women. In 5.9 years of follow-up, 648 participants developed CKD (10.6 per 1000 person-years). The age- and sex-adjusted incidence rates ranged from 6.6 (other Hispanic/mixed background) to 15.0 (Puerto Ricans) per 1000 person-years. Compared with Mexican background, Puerto Rican background was associated with 79% increased risk for incident CKD (incidence rate ratios, 1.79; 95% confidence interval, 1.33 to 2.40), which was accounted for by differences in sociodemographics, acculturation, and clinical characteristics. In multivariable regression analysis, predictors of incident CKD included BP >140/90 mm Hg, higher glycated hemoglobin, lower baseline eGFR, and higher baseline urine albumin/creatinine ratio. CONCLUSIONS: CKD incidence varies by Hispanic/Latino heritage and this disparity may be in part attributed to differences in sociodemographic characteristics. Culturally tailored public heath interventions focusing on the prevention and control of risk factors might ameliorate the CKD burden in this population.

Low Utilization of Beta-Blockers Among Medicare Beneficiaries Hospitalized for Heart Failure With Reduced Ejection Fraction.

BACKGROUND: The evidence-based beta-blockers carvedilol, bisoprolol, and metoprolol succinate reduce mortality and hospitalizations among patients with heart failure with reduced ejection fraction (HFrEF). Use of these medications is not well described in the general population of patients with HFrEF, especially among patients with potential contraindications. OBJECTIVES: Our goal was to describe the patterns of prescription fills for carvedilol, bisoprolol, and metoprolol succinate among Medicare beneficiaries hospitalized for HFrEF, as well as to estimate the associations between specific contraindications for beta-blocker therapy and those patterns. METHODS AND RESULTS: With the use of the cohort of 15,205 Medicare beneficiaries hospitalized for HFrEF from 2007 to 2013 in the 5% Medicare random sample, we described prescription fills (30 days after discharge) and dosage patterns (1 year after discharge) for beta-blockers. By means of of Fine and Gray competing risk models, we estimated the associations between potential contraindications (hypotension, chronic obstructive pulmonary disease [COPD], asthma, and syncope) and prescription fill and dosing patterns while adjusting for demographics, comorbidities, and health care utilization. For beneficiaries who did not die or readmitted to the hospital, 38% of hospitalizations were followed by a prescription fill for an evidence-based beta-blocker within 30 days, 12% were followed by prescription fills for at least 50% of the recommended dose of an evidence-based beta-blocker within 1 year, and 9% were followed by a prescription fill for an up-titrated dose of an evidence-based beta-blocker within 1 year. The prevalence of the contraindications were 21% for hypotension, 48% for COPD, 15% for asthma, and 12% for syncope. Among beneficiaries who did not fill a prescription for an evidence-based beta-blocker within 30 days, 67% had at least 1 of these contraindications. Hypotension, COPD, and syncope were each associated with a ∼10% lower risk of filling a prescription for an evidence-based beta-blocker. CONCLUSIONS: Prescription fill and up-titration rates for evidence-based beta-blockers are low among Medicare beneficiaries with HFrEF, but contraindications explain only a minor part of these low rates.

Fine particulate matter and incident coronary heart disease in the REGARDS cohort.

Chronic exposure to fine particulate matter (PM2.5) is accepted as a causal risk factor for coronary heart disease (CHD). However, most of the evidence for this hypothesis is based upon cohort studies in whites, comprised of either only males or females who live in urban areas. It is possible that many estimates of the effect of chronic exposure to PM2.5 on risk for CHD do not generalize to more diverse samples. METHODS: Therefore, we estimated the relationship between chronic exposure to PM2.5 and risk for CHD in among participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort who were free from CHD at baseline (n=17,126). REGARDS is a sample of whites and blacks of both genders living across the continental United States. We fit Cox proportional hazards models for time to CHD to estimate the hazard ratio for baseline 1-year mean PM2.5 exposure, adjusting for environmental variables, demographics, and other risk factors for CHD including the Framingham Risk Score. RESULTS: The hazard ratio (95% CI) for a 2.7-µg/m3 increase (interquartile range) 1-year mean concentration of PM2.5 was 0.94 (0.83-1.06) for combined CHD death and nonfatal MI, 1.13 (0.92-1.40) for CHD death, and 0.85 (0.73-0.99) for nonfatal MI. We also did not find evidence that these associations depended upon overall CHD risk factor burden. CONCLUSIONS: Our results do not provide strong evidence for an association between PM2.5 and incident CHD in a heterogeneous cohort, and we conclude that the effects of chronic exposure to fine particulate matter on CHD require further evaluation.

Barriers to Beta-Blocker Use and Up-Titration Among Patients with Heart Failure with Reduced Ejection Fraction.

PURPOSE: For patients with heart failure with reduced ejection fraction (HFrEF), guidelines recommend use of beta-blockers with gradual up-titration. However, many patients with HFrEF do not use beta-blockers and up-titration is rare. Our purpose was to identify and rank barriers to beta-blocker use and up-titration from the perspective of primary care physicians. METHODS: We conducted 4 moderated, structured group discussions among 19 primary care physicians using the nominal group technique; 16 participants also completed a survey. Participants generated lists of barriers to beta-blocker use and up-titration among patients with HFrEF. Each participant had six votes with three votes assigned to the item ranked most important, two to the second most important item, and one to the third most important item. Investigators characterized items into themes. The percentage of available votes was calculated for each theme. RESULTS: Fifteen of 16 participating primary care physicians who completed the survey reported that management of beta-blockers was their responsibility. Treatment/side effects, particularly hypotension, were identified as the most important barrier for beta-blocker use (72% of available votes) followed by polypharmacy (11%), healthcare system barriers (10%), and comorbidities (6%). Barriers to up-titration included treatment/side effects (49% of available votes), patient communication/buy-in (21%), polypharmacy (13%), and healthcare system barriers (8%). CONCLUSIONS: Many barriers to guideline concordant use of beta-blockers among patients with HFrEF identified by primary care providers are not readily modifiable. Addressing these barriers may require development, testing, and dissemination of protocols for beta-blocker initiation and up-titration that are safe and appropriate in primary care.

Testing for clustering at many ranges inflates family-wise error rate (FWE).

BACKGROUND: Testing for clustering at multiple ranges within a single dataset is a common practice in spatial epidemiology. It is not documented whether this approach has an impact on the type 1 error rate. METHODS: We estimated the family-wise error rate (FWE) for the difference in Ripley's K functions test, when testing at an increasing number of ranges at an alpha-level of 0.05. Case and control locations were generated from a Cox process on a square area the size of the continental US (≈3,000,000 mi2). Two thousand Monte Carlo replicates were used to estimate the FWE with 95% confidence intervals when testing for clustering at one range, as well as 10, 50, and 100 equidistant ranges. RESULTS: The estimated FWE and 95% confidence intervals when testing 10, 50, and 100 ranges were 0.22 (0.20 - 0.24), 0.34 (0.31 - 0.36), and 0.36 (0.34 - 0.38), respectively. CONCLUSIONS: Testing for clustering at multiple ranges within a single dataset inflated the FWE above the nominal level of 0.05. Investigators should construct simultaneous critical envelopes (available in spatstat package in R), or use a test statistic that integrates the test statistics from each range, as suggested by the creators of the difference in Ripley's K functions test.

Alterations in zonal distribution and plasma membrane localization of hepatocyte bile acid transporters in patients with NAFLD.

BACKGROUND: NAFLD is highly prevalent with limited treatment options. Bile acids (BAs) increase in the systemic circulation and liver during NAFLD progression. Changes in plasma membrane localization and zonal distribution of BA transporters can influence transport function and BA homeostasis. However, a thorough characterization of how NAFLD influences these factors is currently lacking. This study aimed to evaluate the impact of NAFLD and the accompanying histologic features on the functional capacity of key hepatocyte BA transporters across zonal regions in human liver biopsies. METHODS: A novel machine learning image classification approach was used to quantify relative zonal abundance and plasma membrane localization of BA transporters (bile salt export pump [BSEP], sodium-taurocholate cotransporting polypeptide, organic anion transporting polypeptide [OATP] 1B1 and OATP1B3) in non-diseased (n = 10), NAFL (n = 9), and NASH (n = 11) liver biopsies. Based on these data, membrane-localized zonal abundance (MZA) measures were developed to estimate transporter functional capacity. RESULTS: NAFLD diagnosis and histologic scoring were associated with changes in transporter membrane localization and zonation. Increased periportal BSEPMZA (mean proportional difference compared to non-diseased liver of 0.090) and decreased pericentral BSEPMZA (-0.065) were observed with NASH and also in biopsies with higher histologic scores. Compared to Non-diseased Liver, periportal OATP1B3MZA was increased in NAFL (0.041) and NASH (0.047). Grade 2 steatosis (mean proportional difference of 0.043 when compared to grade 0) and grade 1 lobular inflammation (0.043) were associated with increased periportal OATP1B3MZA. CONCLUSIONS: These findings provide novel mechanistic insight into specific transporter alterations that impact BA homeostasis in NAFLD. Changes in BSEPMZA likely contribute to altered BA disposition and pericentral microcholestasis previously reported in some patients with NAFLD. BSEPMZA assessment could inform future development and optimization of NASH-related pharmacotherapies.

Dynamic and functional linkage between von Willebrand factor and ADAMTS-13 with aging: an Atherosclerosis Risk in Community study.

BACKGROUND: von Willebrand factor (VWF) is a multimeric glycoprotein critically involved in hemostasis, thrombosis, and inflammation. VWF function is regulated by its antigen levels, multimeric structures, and the state of enzymatic cleavage. Population studies in the past have focused almost exclusively on VWF antigen levels in cross-sectional study designs. OBJECTIVE: To identify subjects in the Atherosclerosis Risk in Community study who had persistently low and high VWF antigen over 10 years and to quantify longitudinal changes in the biological activities and cleavage of VWF in these subjects. METHODS: We measured VWF antigen, propeptide, adhesive activities, and cleavage by ADAMTS-13 quantified using a mass spectrometry method that detected the cleaved VWF peptide EQAPNLVY, as well as coagulation factor VIII activity. RESULTS: We determined the mean subject-specific increase in VWF to be 22.0 International Units (IU)/dL over 10 years, with 95% between -0.3 and 59.7 IU/dL. This aging-related increase was also detected in VWF propeptide levels, ristocetin cofactor activity, and VWF binding to collagen. We identified 4.1% and 25.0% of subjects as having persistently low (<50 IU/dL) and high (>200 IU/dL) VWF antigen, respectively. Subjects with persistently low VWF had enhanced ristocetin cofactor activity, whereas those with persistently high VWF had elevated levels of ADAMTS-13, resulting in a comparable rate of VWF cleavage between the 2 groups. CONCLUSIONS: These results provide new information about the effects of aging on VWF antigens and adhesive activity and identify a functional coordination between VWF and the rate of its cleavage by ADAMTS-13.

Perinatal Health Outcomes Across Rural and Nonrural Counties Within a Single Health System Catchment.

Background: Perinatal health outcomes are influenced by a variety of socioeconomic, behavioral, and economic factors that reduce access to health services. Despite these observations, rural communities continue to face barriers, including a lack of resources and the fragmentation of health services. Objective: To evaluate patterns in health outcomes, health behaviors, socioeconomic vulnerability, and sociodemographic characteristics across rural and nonrural counties within a single health system catchment area. Methods: Socioeconomic vulnerability metrics, health care access as determined by licensed provider metrics, and behavioral data were obtained from FlHealthCHARTS.gov and the County Health Rankings. County-level birth and health data were obtained from the Florida Department of Health. The University of Florida Health Perinatal Catchment Area (UFHPCA) was defined as all Florida counties where ≥5% of all infants were delivered at Shands Hospital between June 2011 and April 2017. Results: The UFHPCA included 3 nonrural and 10 rural counties that represented more than 64,000 deliveries. Nearly 1 in 3 infants resided in a rural county, and 7 out of 13 counties did not have a licensed obstetrician gynecologist. Maternal smoking rates (range 6.8%-24.8%) were above the statewide rate (6.2%). Except for Alachua County, breastfeeding initiation rates (range 54.9%-81.4%) and access to household computing devices (range 72.8%-86.4%) were below the statewide rate (82.9% and 87.9%, respectively). Finally, we found that childhood poverty rates (range 16.3%-36.9%) were above the statewide rate (18.5%). Furthermore, risk ratios suggested negative health outcomes for residents of counties within the UFHPCA for each measure, except for infant mortality and maternal deaths, which lacked sample sizes to adequately test. Conclusions: The health burden of the UFHPCA is characterized by rural counties with increased maternal death, neonatal death, and preterm birth, as well as adverse health behaviors that included increased smoking during pregnancy and lower levels of breastfeeding relative to nonrural counties. Understanding perinatal health outcomes across a single health system has potential to not only estimate community needs but also facilitate planning of health care initiatives and interventions in rural and low-resource communities.

Use of troponins in the classification of myocardial infarction from electronic health records. The Atherosclerosis Risk in Communities (ARIC) Study.

OBJECTIVE: Electronic health record (EHR) data are underutilized for abstracting classification criteria for heart disease. We compared extraction of EHR data on troponin I and T levels with human abstraction. METHODS: Using EHR for hospitalizations identified through the Atherosclerosis Risk in Communities (ARIC) Study in four US hospitals, we compared blood levels of troponins I and T extracted from EHR structured data elements with levels obtained through data abstraction by human abstractors to 3 decimal places. Observations were divided randomly 50/50 into training and validation sets. Bayesian multilevel logistic regression models were used to estimate agreement by hospital in first and maximum troponin levels, troponin assessment date, troponin upper limit of normal (ULN), and classification of troponin levels as normal (< ULN), equivocal (1-2× ULN), abnormal (>2× ULN), or missing. RESULTS: Estimated overall agreement in first measured troponin level in the validation data was 88.2% (95% credible interval: 65.0%-97.5%) and 95.5% (91.2-98.2%) for the maximum troponin level observed during hospitalization. The largest variation in probability of agreement was for first troponin measured, which ranged from 66.4% to 95.8% among hospitals. CONCLUSION: Extraction of maximum troponin values during a hospitalization from EHR structured data is feasible and accurate.

Use of Real-World Data and Physiologically-Based Pharmacokinetic Modeling to Characterize Enoxaparin Disposition in Children With Obesity.

Dosing guidance for children with obesity is often unknown despite the fact that nearly 20% of US children are classified as obese. Enoxaparin, a commonly prescribed low-molecular-weight heparin, is dosed based on body weight irrespective of obesity status to achieve maximum concentration within a narrow therapeutic or prophylactic target range. However, whether children with and without obesity experience equivalent enoxaparin exposure remains unclear. To address this clinical question, 2,825 anti-activated factor X (anti-Xa) surrogate concentrations were collected from the electronic health records of 596 children, including those with obesity. Using linear mixed-effects regression models, we observed that 4-hour anti-Xa concentrations were statistically significantly different in children with and without obesity, even for children with the same absolute dose (P = 0.004). To further mechanistically explore obesity-associated differences in anti-Xa concentration, a pediatric physiologically-based pharmacokinetic (PBPK) model was developed in adults, and then scaled to children with and without obesity. This PBPK model incorporated binding of enoxaparin to antithrombin to form anti-Xa and elimination via heparinase-mediated metabolism and glomerular filtration. Following scaling, the PBPK model predicted real-world pediatric concentrations well, with an average fold error (standard deviation of the fold error) of 0.82 (0.23) and 0.87 (0.26) in children with and without obesity, respectively. PBPK model simulations revealed that children with obesity have at most 20% higher 4-hour anti-Xa concentrations under recommended, total body weight-based dosing compared to children without obesity owing to reduced weight-normalized clearance. Enoxaparin exposure was better matched across age groups and obesity status using fat-free mass weight-based dosing.

Using Extracellular Vesicles Released by GDNF-Transfected Macrophages for Therapy of Parkinson Disease.

Extracellular vesicles (EVs) are cell-derived nanoparticles that facilitate transport of proteins, lipids, and genetic material, playing important roles in intracellular communication. They have remarkable potential as non-toxic and non-immunogenic nanocarriers for drug delivery to unreachable organs and tissues, in particular, the central nervous system (CNS). Herein, we developed a novel platform based on macrophage-derived EVs to treat Parkinson disease (PD). Specifically, we evaluated the therapeutic potential of EVs secreted by autologous macrophages that were transfected ex vivo to express glial-cell-line-derived neurotrophic factor (GDNF). EV-GDNF were collected from conditioned media of GDNF-transfected macrophages and characterized for GDNF content, size, charge, and expression of EV-specific proteins. The data revealed that, along with the encoded neurotrophic factor, EVs released by pre-transfected macrophages carry GDNF-encoding DNA. Four-month-old transgenic Parkin Q311(X)A mice were treated with EV-GDNF via intranasal administration, and the effect of this therapeutic intervention on locomotor functions was assessed over a year. Significant improvements in mobility, increases in neuronal survival, and decreases in neuroinflammation were found in PD mice treated with EV-GDNF. No offsite toxicity caused by EV-GDNF administration was detected. Overall, an EV-based approach can provide a versatile and potent therapeutic intervention for PD.

The Impact of Pregnancy on Antihypertensive Drug Metabolism and Pharmacokinetics: Current Status and Future Directions.

INTRODUCTION: Hypertensive disorders of pregnancy (HDP) are rising in prevalence, and increase risk of adverse maternal and fetal outcomes. Physiologic changes occur during pregnancy that alter drug pharmacokinetics. However, antihypertensive drugs lack pregnancy-specific dosing recommendations due to critical knowledge gaps surrounding the extent of gestational changes in antihypertensive drug pharmacokinetics and underlying mechanisms. AREAS COVERED: This review (1) summarizes currently recommended medications and dosing strategies for non-emergent HDP treatment, (2) reviews and synthesizes existing literature identified via a comprehensive PubMed search evaluating gestational changes in the maternal pharmacokinetics of commonly prescribed HDP drugs (notably labetalol and nifedipine), and (3) offers insight into the metabolism and clearance mechanisms underlying altered HDP drug pharmacokinetics during pregnancy. Remaining knowledge gaps and future research directions are summarized. EXPERT OPINION: A series of small pharmacokinetic studies illustrate higher oral clearance of labetalol and nifedipine during pregnancy. Pharmacokinetic modeling and preclinical studies suggest these effects are likely due to pregnancy-associated increases in hepatic UGT1A1- and CYP3A4-mediated first-pass metabolism and lower bioavailability. Accordingly, higher and/or more frequent doses may be needed to lower blood pressure during pregnancy. Future research is needed to address various evidence gaps and inform the development of more precise antihypertensive drug dosing strategies.

Trajectories of Depressive Symptoms, Neurocognitive Function, and Viral Suppression With Antiretroviral Therapy Among Youth With HIV Over 36 months.

BACKGROUND: Depression and neurocognitive impairment are highly prevalent among persons living with HIV and associated with poorer clinical outcomes; however, longitudinal studies of depression-neurocognition relationships in youth living with HIV (YLWH), and the role of antiretroviral therapy (ART), are lacking. This study tested whether (1) depressive symptomatology, across somatic, cognitive, and affective symptom domains, improved with ART and (2) more severe depressive symptoms at baseline were associated with poorer neurocognitive function and poorer HIV suppression. SETTING: Data were collected from 181 YLWH (18-24 years) who were treatment-naive, a subset of whom (n = 116) initiated ART. METHODS: Participants were categorized into elevated (DS) or nonelevated (non-DS) depressive symptom groups at entry (Beck Depression Inventory-II ≥14) and followed for 36 months. Neurocognition (5-domain battery) and depressive symptoms were repeatedly assessed. Longitudinal models examined depressive symptomatology, neurocognition, and odds of HIV nonsuppression by group. RESULTS: Greater improvements in depressive symptoms were observed in the DS group over 36 months [beta = -0.14, (-0.24 to -0.03)], particularly within cognitive and affective domains. Verbal learning performance increased in the DS group [beta = 0.13, (0.01 to 0.24)], whereas psychomotor function improved somewhat in the non-DS group [beta = -0.10, (-0.22 to 0.00)]. Adjusted for ART adherence, odds of HIV nonsuppression did not significantly differ by group [odds ratio = 0.22, (0.04 to 1.23)]; however, greater somatic symptoms at study entry were associated with an increased risk of nonsuppression over time [odds ratio = 2.33 (1.07 to 5.68)]. CONCLUSION: Depressive symptoms were associated with differential neurocognitive trajectories, and somatic depressive symptoms at baseline may predict poorer subsequent HIV suppression. Identifying and treating depressive symptoms at ART initiation may benefit neurocognitive and clinical outcomes in YLWH.

Evidence-based beta blocker use associated with lower heart failure readmission and mortality, but not all-cause readmission, among Medicare beneficiaries hospitalized for heart failure with reduced ejection fraction.

The beta blockers carvedilol, bisoprolol, and sustained-release metoprolol succinate reduce readmissions and mortality among patients with heart failure with reduced ejection fraction (HFrEF), based upon clinical trial and registry studies. Results from these studies may not generalize to the typical patient with HFrEF. We conducted a retrospective cohort study of beneficiaries in the Medicare 5% sample hospitalized for HFrEF between 2007 and 2013 and were discharged alive. We compared the 30-day and 365-day heart failure (HF) readmission, all-cause readmission, and mortality rates between beneficiaries who filled a prescription for an evidence-based beta blocker and those who did not after being hospitalized for HFrEF. Out of 12,127 beneficiaries hospitalized for HFrEF, 20% were readmitted for HF, 62% were readmitted for any cause, and 27% died within 365 days. In competing risk models adjusted for demographics, healthcare utilization, and comorbidities, beta blocker use was associated with a lower risk of HF readmission between 8-365 days post discharge (hazard ratio 0.79 [95% confidence interval 0.76, 0.82]), but was not significantly associated with all-cause readmission (1.02 [0.97-1.07]). In Cox models adjusted for the same covariates, beta blocker use was associated with lower mortality 8-365 days post discharge (0.65 [0.60-0.71]). Results were similar when follow up was truncated at 30 days post discharge. Increasing the use of beta blockers following HFrEF hospitalization may not decrease all-cause readmissions among Medicare beneficiaries, but may reduce HF-specific readmissions and mortality.