Emerging Concepts in Precision Medicine and Cardiovascular Diseases in Racial and Ethnic Minority Populations

Cardiovascular diseases remain the leading cause of mortality and a major contributor to preventable deaths worldwide. The dominant modifiable risk factors and the social and environmental determinants that increase cardiovascular risk are known, and collectively, are as important in racial and ethnic minority populations as they are in majority populations. Their prevention and treatment remain the foundation for cardiovascular health promotion and disease prevention. Genetic and epigenetic factors are increasingly recognized as important contributors to cardiovascular risk and provide an opportunity for advancing precision cardiovascular medicine. In this review, we explore emerging concepts at the interface of precision medicine and cardiovascular disease in racial and ethnic minority populations. Important among these are the lack of racial and ethnic diversity in genomics studies and biorepositories; the resulting misclassification of benign variants as pathogenic in minorities; and the importance of ensuring ancestry-matched controls in variant interpretation. We address the relevance of epigenetics, pharmacogenomics, genetic testing and counseling, and their social and cultural implications. We also examine the potential impact of precision medicine on racial and ethnic disparities. The National Institutes of Health's All of Us Research Program and the National Heart, Lung, and Blood Institute's Trans-Omics for Precision Medicine Initiative are presented as examples of research programs at the forefront of precision medicine and diversity to explore research implications in minorities. We conclude with an overview of implementation research challenges in precision medicine and the ethical implications in minority populations. Successful implementation of precision medicine in cardiovascular disease in minority populations will benefit from strategies that directly address diversity and inclusion in genomics research and go beyond race and ethnicity to explore ancestry-matched controls, as well as geographic, cultural, social, and environmental determinants of health.

Progress Toward Improved Cardiovascular Health in the United States

The Healthy People Initiative has served as the leading disease prevention and health promotion roadmap for the nation since its inception in 1979. Healthy People 2020 (HP2020), the initiative's current iteration, sets a national prevention agenda with health goals and objectives by identifying nationwide health improvement priorities and providing measurable objectives and targets from 2010 to 2020. Central to the overall mission and vision of Healthy People is an emphasis on achieving health equity, eliminating health disparities, and improving health for all population groups. The Heart Disease and Stroke (HDS) Work Group of the HP2020 Initiative aims to leverage advances in biomedical science and prevention research to improve cardiovascular health across the nation. The initiative provides a platform to foster partnerships and empower professional societies and nongovernmental organizations, governments at the local, state, and national levels, and healthcare professionals to strengthen policies and improve practices related to cardiovascular health. Disparities in cardiovascular disease burden are well recognized across, for example, race/ethnicity, sex, age, and geographic region, and improvements in cardiovascular health for the entire population are only possible if such disparities are addressed through efforts that target individuals, communities, and clinical and public health systems. This article summarizes criteria for creating and tracking the 50 HDS HP2020 objectives in 3 areas (prevention, morbidity/mortality, and systems of care), reports on progress toward the 2020 targets for these objectives based on the most recent data available, and showcases examples of relevant programs led by participating agencies. Although most of the measurable objectives have reached the 2020 targets ahead of time (n=14) or are on track to meet the targets (n=7), others may not achieve the decade's targets if the current trends continue, with 3 objectives moving away from the targets. This summary illustrates the utility of HP2020 in tracking measures of cardiovascular health that are of interest to federal agencies and policymakers, professional societies, and other nongovernmental organizations. With planning for Healthy People 2030 well underway, stakeholders such as healthcare professionals can embrace collaborative opportunities to leverage existing progress and emphasize areas for improvement to maximize the Healthy People initiative's positive impact on population-level health.

Building the Next Generation of Implementation Science Careers to Advance Health Equity

Rapid advancements in translational research have produced innovative clinical discoveries and evidence-based interventions that are ready for uptake in real-world settings, creating vast opportunities and challenges for implementation science. However, there is an inadequate research workforce to study effective strategies and delivery of implementation to advance the field. Novel career development initiatives will build scholars for the next generation of implementation science to bridge research to practice for diverse populations to advance health equity, specifically with a strategic focus on heart, lung, blood and sleep diseases and conditions. Along with traditional mentoring and curricula, research training includes state-of-the-art approaches using complex methods and multi-disciplinary collaborations between researchers, practice settings, and diverse communities. Implementation science scholars strive not only to decrease the lag time between the discovery of evidence-based interventions and successful implementation but also how to advance health equity and to reduce disparities for underserved populations that suffer disproportionally.

Genetic characterization of physical activity behaviours in university students enrolled in kinesiology degree programs

Studies of physical activity behaviours have increasingly shown the importance of heritable factors such as genetic variation. Nonsynonymous polymorphisms of alpha-actinin 3 (ACTN3) and the β-adrenergic receptors 1 and 3 (ADRB1 and ADRB3) have been previously associated with exercise capacity and cardiometabolic health. We thus hypothesized that these polymorphisms are also related to physical activity behaviours in young adults. To test this hypothesis we examined relationships between ACTN3 (R577X), ARDB1 (Arg389Gly), ADRB3 (Trp64Arg), and physical activity behaviours in university students. We stratified for student enrollment in kinesiology degree programs compared with nonmajors as we previously found this to be a predictor of physical activity. We did not identify novel associations between physical activity and ACTN3. However, the minor alleles of ADRB1 and ADRB3 were significantly underrepresented in kinesiology students compared with nonmajors. Furthermore, carriers of the ADRB1 minor allele reported reduced participation in moderate physical activity and increased afternoon fatigue compared with ancestral allele homozygotes. Together, these findings suggest that the heritability of physical activity behaviours in young adults may be linked to nonsynonymous polymorphisms within β-adrenergic receptors.

The science of sex and gender in human health: online courses to create a foundation for sex and gender accountability in biomedical research and treatment

BACKGROUND

Sex and gender differences play a significant role in the course and outcome of conditions that affect specific organ systems in the human body. Research on differences in the effects of medical intervention has helped scientists develop a number of sex- and gender-specific guidelines on the treatment and management of these conditions. An online series of courses, "The Science of Sex and Gender in Human Health," developed by the National Institutes of Health Office of Research on Women's Health and the U.S. Food and Drug Administration Office of Women's Health, examines sex and gender differences and their implications. Thus far, three online courses have been generated. The first course offers an overview of the scientific and biological basis for sex- and gender-related differences. The second course is focused on disease-specific sex and gender differences in health and behavior and their implications. Finally, the third course covers the influence of sex and gender on disease manifestation, treatment, and outcome.

METHODS

Data were obtained using website analytics and post-course surveys.

RESULTS

To date, over 1000 individuals have completed at least one course. Additionally, 600 users have received continuing education credit for completing a course in the series. Finally, the majority of respondents to the online course survey have indicated that the courses considerably enhanced their professional effectiveness.

CONCLUSIONS

"The Science of Sex and Gender in Human Health" online courses are freely available sources of information that provide healthcare providers and researchers with the resources to successfully account for sex and gender in their medical practice and research programs.

The ACTN3 R577X Polymorphism Is Associated with Cardiometabolic Fitness in Healthy Young Adults

Homozygosity for a premature stop codon (X) in the ACTN3 “sprinter” gene is common in humans despite the fact that it reduces muscle size, strength and power. Because of the close relationship between skeletal muscle function and cardiometabolic health we examined the influence of ACTN3 R577X polymorphism over cardiovascular and metabolic characteristics of young adults (n = 98 males, n = 102 females; 23 ± 4.2 years) from our Assessing Inherent Markers for Metabolic syndrome in the Young (AIMMY) study. Both males and females with the RR vs XX genotype achieved higher mean VO₂ peak scores (47.8 ± 1.5 vs 43.2 ±1.8 ml/O₂/min, p = 0.002) and exhibited higher resting systolic (115 ± 2 vs 105 ± mmHg, p = 0.027) and diastolic (69 ± 3 vs 59 ± 3 mmHg, p = 0.005) blood pressure suggesting a role for ACTN3 in the maintenance of vascular tone. We subsequently identified the expression of alpha-actinin 3 protein in pulmonary artery smooth muscle, which may explain the genotype-specific differences in cardiovascular adaptation to acute exercise. In addition, we utilized targeted serum metabolomics to distinguish between RR and XX genotypes, suggesting an additional role for the ACTN3 R577X polymorphism in human metabolism. Taken together, these results identify significant cardiometabolic effects associated with possessing one or more functional copies of the ACTN3 gene.

Examination of Lifestyle Behaviors and Cardiometabolic Risk Factors in University Students Enrolled in Kinesiology Degree Programs

Preventing physical inactivity and weight gain during college is critical in decreasing lifelong obesity and associated disease risk. As such, we sought to compare cardiometabolic risk factors and lifestyle behaviors between college students enrolled in kinesiology and non-kinesiology degree programs to assess whether health and exercise degree programs may influence health behaviors and associated disease risk outcomes. Anthropometrics, fasting blood glucose, insulin, lipid profiles and HbA1c%, blood pressure, and peak oxygen consumption (V[Combining Dot Above]O2peak) were assessed in 247 healthy college students. The homeostasis model assessment of insulin sensitivity (HOMA) was calculated using glucose and insulin levels. Self-reported physical activity from the Paffenbarger questionnaire was collected to estimate the average caloric expenditure due to different types of physical activities. Despite no significant differences in body mass index or waist circumference between groups, kinesiology majors presented with ∼20% lower fasting insulin levels and HOMA (p = 0.01; p < 0.01, respectively) relative to nonmajors. Kinesiology majors reported increased weekly participation in vigorous-intensity sport and leisure activities and, on average, engaged in >300 metabolic equivalent-h·wk, whereas non-kinesiology majors engaged in <300 MET-h wk (p = 0.01). Our data suggest that students enrolled in kinesiology degree programs display improved healthy behaviors and associated outcomes (parameters of glucose homeostasis). Practical outcomes of this research indicate that implementing components of a comprehensive kinesiology curriculum encourages improved health behaviors and associated cardiometabolic risk factors.

Situation awareness as a function of frame of reference, computer-graphics eyepoint elevation, and geometric field of view

The purpose of this study was to determine how 3 variables for the design of a "heads-down" spatial display--the frame of reference (pilot's eye vs. God's eye), geometric field of view, and elevation of the computer graphics eyepoint--influenced situation awareness. Thirteen flight-naive subjects each flew a simulated F-16 over a computer-generated flight environment to lock onto and intercept a series of sequentially appearing targets. The flight scene consisted of both an "out-the-window" view and a computer-generated heads-down spatial display showing an airplane symbol superimposed on a perspective view of the flight environment. During the interactive phase of the experiment, root mean square flight-path error, target lock-on time, and target acquisition time were measured. After the interactive phase of the study was completed, subjects were required to mark the location of the targets from memory on a computer-generated top-down view of the flight scene in an attempt to reconstruct the spatial mental model which subjects formed of the flight environment. The results for the interactive phase of the study indicated that performance was superior using the pilot's-eye display. However, for the spatial reconstruction task, performance was better using the God's-eye display. It was also shown that the ability to maintain the optimal flight-path using the more top-down view of the scene (600 eyepoint) was superior to the 300 eyepoint elevation. Implications of the results for the design of spatial instruments are discussed.

Relationship of factors affecting age of onset of independent ambulation

Despite the standard available pediatric developmental scales and popular lore that girls walk at an earlier age than boys, no large-scale evaluation of the age of onset of independent ambulation has been previously published. The purpose of this study was the prospective epidemiologic evaluation of a large heterogeneous group of normal children to determine the effect of gender, race, birth order, and socioeconomic status on the age of onset of independent ambulation. The study cohort consisted of 986 children (575 male, 471 female). A multivariable analysis of covariance model was used to examine the effects of race, gender, income, and birth order on age at ambulation. After controlling for the other variables in the model, race was the only statistically significant predictor of age at ambulation (p < 0.0001), with black children walking at a younger age (10.9 +/- 2.1 months) than white children (11.6 +/- 2.3 months). Overall, the independent variables included in the model were only able to explain 2.5% of the variance of age at ambulation.

Some virtual reality and telemedicine applications useful for long duration spaceflight from a systems engineering perspective

This paper presents a review of virtual reality, telemedicine, and systems engineering design concepts that relate to the human performance of mission tasks during long duration spaceflight. A Mini-Case Study of the MIR/Progress collision is discussed and serves to highlight some of the key issues. We review some physiologic changes which occur as a result of long duration spaceflight, discuss issues associated with performing required mission tasks, and integrate concepts from telemedicine and virtual reality as possible methods and technologies to alleviate some of the deleterious effects of extended space missions.

Cost consequences of implementation of an early obstetrical discharge programme in a military teaching hospital

We evaluate the cost consequence of a voluntary early obstetrical discharge programme in a military teaching hospital. The study involved a control group of routine obstetrical discharge patients with uncomplicated vaginal delivery from March 1 to August 31, 1994 and the study group of early obstetrical discharge (24-48 hours) patients with uncomplicated vaginal delivery from March 1 to August 31, 1996. There were 1,042 total control patients with routine vaginal delivery totalling 2,668 hospital days with a mean number of hospital days of 2.56 per patient. The study group of early obstetrical discharge patients with uncomplicated vaginal delivery encompassed 1,050 patients with 1,965 hospital days with mean hospital days of 1.87 per patient (p < 0.05) without an increase in postpartum clinic or emergency room visits. The total cost of admissions (cost calculation of $1,221 per hospital day) fell from $3,257,628 in the routine discharge group to $2,399,625 in the early discharge cohort showing a total cost savings of $858,003 over the 6-months study period. The average cost per obstetrical admission for routine vaginal delivery fell from $3,126 per day to $2,285 per day without an increase in the postpartum paediatric adverse outcomes. Maternal postpartum readmission rates were statistically significantly increased (p < 0.05) in the study group at 0.6% with an OR[2.32(2.17, 6.92)] but all readmissions fell outside the 48-hour early discharge window. This programme showed significant cost savings without concomitant increase in paediatric or maternal adverse outcomes.

Skilled performance on software as a function of domain expertise and program organization

As part of a study on the recall of skilled and novice programmers, 23 subjects each viewed a 25-line BASIC program organized in one of three ways, executable order, random chunks, and random lines. Subjects performed a perceptual task in which they recopied a 25-line BASIC program on an answer sheet while the program remained in plain view, and a memory task, in which they recalled the BASIC program after a 4-min. exposure to it. For the perceptual task, the number of glances and amount of time per glance between the answer sheet and stimulus material were used as indices of recall. For the memory task, the number of lines recalled as a function of program organization and level of programming skill measured performance. Analysis indicated that skilled programmers encoded more lines of a program per glance and also spent less time examining each line of code than novices when the program was presented in executable order or random chunks. Further, skilled programmers recalled more lines of code than novices when the program was presented in executable order or random chunks but not in random lines. Implication of the results for the design of human-computer interfaces is discussed.

Statistical analysis of accident severity on rural freeways

The growing concern about the possible safety-related impacts of Intelligent Transportation Systems (ITS) has focused attention on the need to develop new statistical approaches to predict accident severity. This paper presents a nested logit formulation as a means for determining accident severity given that an accident has occurred. Four levels of severity are considered: (1) property damage only, (2) possible injury, (3) evident injury, and (4) disabling injury or fatality. Using 5-year accident data from a 61 km section of rural interstate in Washington State (which has been selected as an ITS demonstration site), we estimate a nested logit model of accident severity. The estimation results provide valuable evidence on the effect that environmental conditions, highway design, accident type, driver characteristics and vehicle attributes have on accident severity. Our findings show that the nested logit formulation is a promising approach to evaluate the impact that ITS or other safety-related countermeasures may have on accident severities.

Spatial performance with perspective displays as a function of computer graphics eyepoint elevation and geometric field of view

The purpose of this study was to investigate the effect of varying the elevation of the computer graphics eyepoint and the geometric field of view on judgements of spatial information using a stereoscopic perspective display. Twelve subjects judged the elevation and azimuth angle separating two computer-generated objects viewed using an eyepoint elevation that ranged between -15 degrees and 45 degrees and a geometric field of view that ranged between 40 degrees and 80 degrees. The results of the study indicated that judgements of elevation were affected by the compression of the vertical axis resulting from the raised eyepoint elevation. Furthermore, azimuth judgements were influenced by both the eyepoint elevation and the geometric field of view. Implications of the results for the design of displays and for spatial performance using stereoscopic displays are discussed.

The importance of extreme prematurity and low birthweight to US neonatal mortality patterns: implications for prenatal care and women's health

OBJECTIVE

In order to frame the appropriateness of neonatal mortality reduction efforts that begin only after pregnancy is recognized, this study examined the relative contributions of different gestational age and birthweight groups to total neonatal mortality and to racial disparities in neonatal mortality in the United States.

METHODS

Using the national linked birth/infant death data set for the 1988 cohort, the relative contributions of different birthweight and gestational age groups to national neonatal mortality rates were calculated. The relative contributions of these groups to the racial disparity in neonatal mortality were also assessed.

RESULTS

Very low birthweight infants (< 1,500 g) accounted for 1.2% of all births, but 64.2% of all neonatal deaths. The very low birthweight rate for whites was 0.93%, while that for blacks was 2.79% with the contribution of this group to neonatal mortality higher for blacks than whites. Infants less than 1,000 g contributed more than 80% of the racial disparity in neonatal mortality.

CONCLUSION

Neonatal mortality patterns in the United States have become highly dependent on infants with gestational ages that approach the second trimester. Preventing neonatal mortality by enhancing care only after pregnancy has been recognized, therefore, may be limited. Strategies that link prenatal care to broader initiatives to improve the health of women regardless of pregnancy status may be more effective.

Effect of roadway geometrics and environmental factors on rural freeway accident frequencies

This paper explores the frequency of occurrence of highway accidents on the basis of a multivariate analysis of roadway geometrics (e.g. horizontal and vertical alignments), weather, and other seasonal effects. Based on accident data collected in the field, a negative binomial model of overall accident frequencies is estimated along with models of the frequency of specific accident types. Interactions between weather and geometric variables are proposed as part of the model specifications. The results of the analysis uncover important determinants of accident frequency. By studying the relationship between weather and geometric elements, this paper offers insight into potential measures to counter the adverse effects of weather on highway sections with challenging geometrics.

Judgments of azimuth and elevation as a function of monoscopic and binocular depth cues using a perspective display

The purpose of this study was to investigate the use of three-dimensional display formats for judgments of spatial information using an exocentric frame of reference. Eight subjects judged the azimuth and elevation that separated two computer-generated objects using either a perspective or stereoscopic display. Errors, which consisted of the difference in absolute value between the estimated and actual azimuth or elevation, were analyzed as the response variable. The data indicated that the stereoscopic display resulted in more accurate estimates of elevation, especially for images aligned approximately orthogonally to the viewing vector. However, estimates of relative azimuth direction were not improved by use of the stereoscopic display. Furthermore, it was shown that the effect of compression resulting from a 45-deg computer graphics eye point elevation produced a response bias that was symmetrical around the horizontal plane of the reference cube, and that the depth cue of binocular disparity provided by the stereoscopic display reduced the magnitude of the compression errors. Implications of the results for the design of spatial displays are discussed.

Effect of geometric parameters of perspective on judgements of spatial information

15 university students performed an exocentric judgement task in which they estimated the azimuth and elevation separating two computer-generated cubes, using a perspective display. The perspective displays were created by varying two geometric parameters of perspective, the geometric field of view and station-point distance. Further, the radial distance separating the computer-generated images was varied. Analysis indicated that azimuth errors varied as a function of geometric field of view, radial distance, and station-point distance, while elevation errors varied as a function of geometric field of view and radial distance.

Eccentricity, contrast, and angular extent as factors in the perception of peripheral apparent motion

Two experiments were performed to investigate the perception of peripherally presented apparent motion as a function of eccentricity of the stimulus, ambient illumination, sex, stimulus pattern, and angular extent of stimulus presentation. The experimental task for both studies was to judge the direction of apparent motion for a stimulus target lighter than the background and presented on a Braumbach perimeter. The results from Exps. 1 and 2 indicated main effects for subjects and eccentricity. The combined results of Exps. 1 and 2 indicated main effects for eccentricity and angular separation of the apparent motion, however, the interaction between the two was not significant.

Peripheral apparent motion as a function of location, contrast, and direction of stimulus motion

This study investigated the perception of the direction of peripheral apparent motion as a function of stimulus location in the peripheral visual field, stimulus contrast, and the direction of the apparent motion. Results indicated that each of these independent variables was significant as a main effect while the interactions were not.

Discriminating the structure of rotated three-dimensional figures

Visualizing the structure of transformed (by rotation) three-dimensional (3-D) figures is an important aspect of information processing for computer-graphics tasks. However, little research exists to establish the speed and accuracy in which subjects perform discrimination tasks for transformed images and the effects of rotation variables on perceiving transformed images. This research tests the effects of figural complexity, angles and axes of rotation on the speed and accuracy in which subjects discriminate the structure of rotated 3-D wireframe images. Results show that response times are affected more by angles than axes of rotation, the specific form of the image affects error rates, and the number of 90 degrees bends which determine the structure of an image may be an inadequate measure of form complexity for the task described here.