Cardiovascular disease in space: A systematic review.

BACKGROUND: With expanding commercial space programs, uncertainty remains about the cardiovascular effects of space environmental exposures including microgravity, confinement, isolation, space radiation, and altered bacterial virulence. Current limited data suggests additional health threats compared to Earth. METHODS: We systematically reviewed PubMed, CENTRAL, Web of Science, EMBASE and Cochrane databases for prospective studies on spaceflight and cardiovascular outcomes. Search terms combined cardiovascular disease topics with spaceflight concepts. No date or language restrictions were imposed. RESULTS: 35 studies representing 2696 space travelers met inclusion criteria. Studies were grouped into spaceflight associations with: atherosclerosis, mortality, cardiac function, orthostatic intolerance, and arrhythmias. Atherosclerosis evidence was limited, with animal studies linking space radiation to endothelial damage, oxidative stress, and inflammation. However, human data showed no significantly increased atherosclerotic disease in astronauts. Mortality studies demonstrated lower cardiovascular mortality in astronauts compared to the general population however there was conflicting data. Cardiac function studies revealed physiologic ventricular atrophy, increased arterial stiffness, and altered blood flow distribution attributed to microgravity exposure. Effects appeared transient and reversible post-flight. Orthostatic intolerance studies found astronauts experienced altered heart rate variability, baroreflex response, and blood pressure changes post-flight. Arrhythmia studies showed increased ventricular ectopy during spaceflight, but limited data on long term flights. CONCLUSIONS: Environmental space hazards impact the cardiovascular system through multiple mechanisms. Microgravity causes cardiac atrophy and orthostatic intolerance while space radiation may potentially accelerate atherosclerosis. Further research is needed, especially regarding long-term spaceflights.

Human Health during Space Travel: State-of-the-Art Review.

The field of human space travel is in the midst of a dramatic revolution. Upcoming missions are looking to push the boundaries of space travel, with plans to travel for longer distances and durations than ever before. Both the National Aeronautics and Space Administration (NASA) and several commercial space companies (e.g., Blue Origin, SpaceX, Virgin Galactic) have already started the process of preparing for long-distance, long-duration space exploration and currently plan to explore inner solar planets (e.g., Mars) by the 2030s. With the emergence of space tourism, space travel has materialized as a potential new, exciting frontier of business, hospitality, medicine, and technology in the coming years. However, current evidence regarding human health in space is very limited, particularly pertaining to short-term and long-term space travel. This review synthesizes developments across the continuum of space health including prior studies and unpublished data from NASA related to each individual organ system, and medical screening prior to space travel. We categorized the extraterrestrial environment into exogenous (e.g., space radiation and microgravity) and endogenous processes (e.g., alteration of humans' natural circadian rhythm and mental health due to confinement, isolation, immobilization, and lack of social interaction) and their various effects on human health. The aim of this review is to explore the potential health challenges associated with space travel and how they may be overcome in order to enable new paradigms for space health, as well as the use of emerging Artificial Intelligence based (AI) technology to propel future space health research.

The Legacy of the Wright State University Aerospace Medicine Residency Program.

INTRODUCTION: In the mid-1970s, NASA required a robust training program for physicians responsible for the medical needs of the Shuttle astronauts. Personnel at NASA worked closely with academicians and subject matter experts at Wright State University (WSU) to develop and establish a residency program in aerospace medicine. This academic training program was initiated in 1978 and closed in 2018. The objective of this historical piece is to catalog, for posterity, the impact this training program has had on national and international human spaceflight and aviation. METHODS: A thorough review of all available historical documents and oral histories provided by contemporaries were reviewed in detail, including a search of every available residents thesis and all available historical documents and reports at WSU and NASA Headquarters. RESULTS: Over the past 40 yr, WSU has graduated 172 individuals with an M.S. degree focused on aerospace medicine, of which 84 were residents. Nearly 50 of these residents have worked closely with NASA. Many others became integrated into academia, the aviation industry, or international space programs. DISCUSSION: With the growth in interest for government and commercial spaceflight, the field of aerospace medicine is poised to grow. Although it is not well known outside of the Aerospace Medicine community, the legacy of this pioneering, 40-yr civilian-based program is of significant value. If not recorded in an easily locatable and accessible manner, many of the challenges and outcomes from this residency could be lost until future generations have to spend the money, time, and effort to relearn them. Doarn CR, Shimada K, Shepanek M. The legacy of the Wright State University Aerospace Medicine Residency program. Aerosp Med Hum Perform. 2021; 92(9):744750.

A randomized placebo-controlled clinical trial of the effectiveness of thyroxine and triiodothyronine and short-term exposure to bright light in prevention of decrements in cognitive performance and mood during prolonged Antarctic residence.

OBJECTIVE: We examined the effects of a combined levothyroxine/liothyronine supplement and exposure to bright (10,000 lux) light in euthyroid men and women who spent the austral summer (n = 43) and/or winter (n = 42) in Antarctica. METHODS: Subjects were randomized to receive 64 nmol of levothyroxine and 16 nmol of liothyronine supplement or a placebo capsule for 93.2 +/- 3.0 days in summer and/or 149.5 +/- 2.2 days in winter. Subjects were further randomized to receive 10,000 lux bright white light or 50 lux dim red light for 14 days at the end of summer and/or winter. Cognitive performance and mood were assessed using the Automatic Neuropsychological Assessment Metric - Isolated and Confined Environments. RESULTS: In winter, bright light exposure was associated with a significantly greater reduction in TSH and anger (P < 0.05), a significantly greater increase in fT(3) (P < 0.05), and a significantly smaller increase in depressive symptoms (P < 0.001), when compared with dim light. The T4/T3 supplement also led to a significantly greater reduction in TSH (P < 0.05), but a greater reduction in cognitive task efficiency (P < 0.05) as well, when compared with placebo. CONCLUSION: Administration of bright light leads to a significant reduction in serum TSH and prevents increases in anger and depressive symptoms in winter. However, these associations were not observed in summer, suggesting a seasonal influence of photoperiod over temperature upon this intervention in the polar environment.

Promoting Tech Transfer Between Space and Global Mental Health.

INTRODUCTION: Numerous issues in mental health benefit from technological innovation. An example involves the mental health challenges of long-duration spaceflight (such as a Mars mission), including prolonged confinement, microgravity, and different sunlight exposure lengths. Persisting on Earth are global mental health challenges stemming from disease burdens, limited interview-based diagnostic systems, trial-and-error treatment approaches, and suboptimal access. There is potential for cross-pollinating solutions between these seemingly disparate challenges using a range of emerging technologies such as sensors, omics, and big data. In this review, we highlight the bidirectional value of mental health technology transfer aimed to address issues both on Earth and in space.METHODS: We prepared a systematic review of studies pertaining to mental health technological innovation and space medicine.RESULTS: For Earth mental health technologies translatable to long-duration space missions, we cite several example technologies, including device-based psychotherapy and social support, conversational agents aka chatbots, and nutritional and physical activity focused mental health. Space technologies translatable to Earth mental health include remote sensing devices, global navigation satellite systems, satellite communications, chronotherapies, and nutritional advances.DISCUSSION: There is a rich history of space technologies informing Earth technological trends, including general health care on Earth, and vice versa. To avoid the traditional happenstance approach that results in delays, missed opportunities, and increased cost, and to improve outcomes for both Earth and space utilization of these technologies, we propose increased dialogue and training opportunities to enhance innovation and outcomes.Chang DD, Storch EA, Black L, Berk M, Pellis N, Lavretsky H, Sutton J, Ternes K, Shepanek M, Smith E, Abbott R, Eyre HA. Promoting tech transfer between space and global mental health. Aerosp Med Hum Perform. 2020; 91(9):737745.

Health challenges including behavioral problems in long-duration spaceflight.

Over the past 60 years, our ability to live and work in space has evolved. From short sojourns in small spacecraft to landing on the moon and residing in an orbiting international space station, we have learned to adapt to an extreme environment and safely return home. Human missions to the Moon, Mars, and exploration of deep space are different. This paper summarizes the challenges of providing medical care, specifically mental health care during long-duration flights. Considerable information about challenges that crews bound for Mars will face is available. Literature regarding this issue is summarized. This manuscript provides a short historical summary of long-duration spaceflight to date; the challenges including limited communication with mission controllers on Earth; and, a summary of the behavioral impacts space flight has had on humans. A look at how the future autonomous systems might support physical and mental health when definitive care is millions of miles away, is also provided. Human spaceflight to Mars or other distant sites will require new approaches to mission preparedness and inflight medical support systems. Exploration class missions will be more autonomous than anything deployed until now. The concepts of telemedicine that have aptly supported crews from the 1960s to the present will no longer be in real-time. While communication between Earth and Mars is possible, it will be characterized by significant time delays. Mars-based crews will need to have systems onboard and on Mars to support all health and performance issues.

Environmental influences on hypothalamic-pituitary-thyroid function and behavior in Antarctica.

We examined the physiological and psychological status of men and women who spent the summer (n=100) and/or winter (n=85) seasons in Antarctica at McMurdo (latitude 78.48 S, elevation 12 m) and South Pole (latitude 90 S, elevation 3880 m) stations to determine whether there were any significant differences by severity of the stations' physical environment. Physiological measures (body mass index, blood pressure, heart rate, tympanic temperature), serum measures of thyroid hormones, cortisol, and lipids and plasma catecholamines were obtained at predeployment (Sep-Oct) and the beginning of the summer (November) and winter (Mar-Apr) seasons. Cognitive performance and mood were assessed using the Automatic Neuropsychological Assessment Metric - Isolated and Confined Environments (ANAM-ICE), a computerized test battery. South Pole residents had a lower body mass index (p<0.05) and body temperature (p<0.01) and higher levels of plasma norepinephrine (p<0.05) in summer and winter than McMurdo residents. Upon deployment from the United States and during the summer, South Pole residents experienced significantly higher thyroid hormone values (free and total T(3) and T(4)) (p<0.01) than McMurdo residents; in summer they also experienced lower levels of triglycerides (p<0.01) cortisol (p<0.05) and LDL (p<0.05). In winter, South Pole residents also experienced a 39% decrease in serum TSH compared with a 31.9% increase in McMurdo (p<0.05). South Pole residents also were significantly more accurate (p<0.05) and efficient (p<0.01) in performance of complex cognitive tasks in summer and winter. Higher thyroid hormone levels, combined with lower BMI and body temperature, may reflect increased metabolic and physiological responses to colder temperatures and/or higher altitude at South Pole with no apparent adverse effect on mood and cognition.

Human behavioral research in space: quandaries for research subjects and researchers.

With the advent of long-duration spaceflight on board the International Space Station (ISS) and possible future missions beyond low Earth orbit (LEO) such as Mars, it is critical that those at NASA have a realistic assessment of the challenges that will face individuals on long-duration missions so that they can develop preventive and real-time countermeasures to behavioral health issues. While space travellers are very interested in having countermeasures to the deleterious effects of space missions, they have a powerful disincentive to participate in this research if they feel it could in any way negatively affect their flight status. The behavioral issues of isolation and confinement for extended-duration space missions are reviewed. Areas of basic and clinical behavioral research are listed. And the classical clinical model for research is not considered appropriate for the current configuration of the space program. The use of analogue environments and advanced statistical analysis are suggested as ways to address the limited spaceflight research opportunities. The challenge of research subject or patient confidentiality vs. mission safety and issues of personal flight status are addressed.

Life, survival, and behavioral health in small closed communities: 10 years of studying isolated Antarctic groups.

In the late 1980s the Australian Antarctic Division collaborated with NASA to use the Australian National Antarctic Research Expeditions' (ANARE) stations to pursue research of benefit to both programs. This article outlines the data collection efforts, the development of analyses, and selected results, and describes some of the benefits for the aerospace, health, and environmental psychology communities. The Behavior and Performance Laboratory at Johnson Space Center developed a questionnaire to sample broadly the many aspects of life in extreme environments analogous to space missions. Data were collected from volunteers involved in various ANAREs conducted from 1994 to 2003. Pool-timed series regression, hierarchical models, and content analysis have all enhanced the understanding of the kinds of psychosocial variables relevant in extreme environments, and how these variables relate to each other; examples are given. Observations gathered over the last 10 yr comprise a unique, comprehensive, and advanced representation of psychosocial factors in this extreme environment and provide a strong base for future research and application.