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Progress in Cardiovascular Diseases 2023With expanding commercial space programs, uncertainty remains about the cardiovascular effects of space environmental exposures including microgravity, confinement,... (Review)
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.
Topics: Humans; Cardiovascular Diseases; Orthostatic Intolerance; Prospective Studies; Space Flight; Hemodynamics; Arrhythmias, Cardiac; Atherosclerosis; Atrophy
PubMed: 37531984
DOI: 10.1016/j.pcad.2023.07.009 -
Journal of Human Hypertension Dec 2023Worldwide, raised blood pressure (BP) or hypertension is the global leading risk factor for the development of cardiovascular diseases and all-cause mortality, with the... (Meta-Analysis)
Meta-Analysis Review
Worldwide, raised blood pressure (BP) or hypertension is the global leading risk factor for the development of cardiovascular diseases and all-cause mortality, with the highest prevalence found in Asian and African origin populations. Post-exercise hypotension (PEH), defined as a sustained reduction in BP after a single bout of exercise is an important physiological phenomenon in BP management. However, little is known about the hypotensive effect of a single bout of exercise in non-Caucasian populations. We systematically summarized the acute effects of a single bout of aerobic exercise on BP in a population of African or Asian origin. We searched the MEDLINE database identifying randomized controlled trials investigating the effect of a single bout of aerobic exercise on BP in African or Asian populations with optimal BP, high normal BP or hypertension published in a peer reviewed journal up to August 2021. A subsequent meta-analysis was performed using random-effect models fitted to estimate effect sizes. We identified 10 aerobic exercise trials performed in individuals of Asian origin (n = 136; mean age: 29.51 (21.2-69) years: 78% male; baseline systolic BP/diastolic BP: 118.9 ± 9.64/68.9 ± 2.69 mmHg) and 11 aerobic exercise trials involving individuals of African origin (n = 157; mean age: 41.05 (29.9-49) years; 59% male; baseline systolic BP/diastolic BP: 134.5 ± 8.65 mmHg/82.2 ± 3.24 mmHg). Non-significant reductions in office systolic BP and diastolic BP at 30 min post exercise (-2.25 [-6.38, 1.88] mmHg, p = 0.28/-1.02 [-2.51, 0.47] mmHg, p = 0.18) and 60 min post exercise (-2.80 [-7.90, 2.28], p = 0.27/-1.95, [-5.66, 1.75], p = 0.3) were observed compared to the control intervention. No statistically significant differences were found between both ethnic groups (p > 0.05). Ambulatory BP was reported only in a few African groups. No effect was found on 24h-systolic BP post exercise, but 24h-diastolic BP was statistically significantly reduced (-1.89 [-3.47, -0.31] mmHg, p < 0.01) after a bout of aerobic exercise compared to the control intervention. The available evidence is insufficient to recommend a single session of aerobic exercise as an efficient tool to lower BP in African and Asian populations. Though, the paucity of data in non-Caucasian populations underscores the need for additional efforts to establish the efficacy of single bouts of exercise, including isometric and dynamic resistance exercise, as a potential non-pharmacological adjunct to help lowering BP in the daily life of descendants of Asian or African origin.
Topics: Humans; Male; Adult; Female; Post-Exercise Hypotension; Randomized Controlled Trials as Topic; Hypertension; Blood Pressure; Hypotension
PubMed: 37468543
DOI: 10.1038/s41371-023-00844-8 -
American Journal of Therapeutics
Meta-Analysis
Topics: Humans; Midodrine; Syncope, Vasovagal
PubMed: 35703495
DOI: 10.1097/MJT.0000000000001513