Impact of moderate altitude exposure on cardiovascular risk

2021 ◽  
pp. 1-4
Author(s):  
Christopher Stremmel ◽  
Nikolay Vdovin ◽  
Antonia Kellnar ◽  
Wolfgang Hamm ◽  
Anna Strüven ◽  
...  
Keyword(s):  
Cardiovascular Risk ◽  
Moderate Altitude ◽  
Altitude Exposure

scholarly journals Differences in the prevalence of physical activity and cardiovascular risk factors between people living at low (<1,001 m) compared to moderate (1,001–2,000 m) altitude

2021 ◽  
Vol 8 (4) ◽  
pp. 624-635
Author(s):  
Martin Burtscher ◽  
◽  
Grégoire P Millet ◽  
Jeannette Klimont ◽  
Johannes Burtscher ◽  
...  
Keyword(s):  
Physical Activity ◽  
Risk Factors ◽  
Cardiovascular Risk ◽  
Cardiovascular Risk Factors ◽  
Ultra Violet ◽  
Mortality Data ◽  
Activity Levels ◽  
Moderate Altitude ◽  
Lifestyle Behavior ◽  
Climate Conditions

<abstract> <p>Living at moderate altitude (up to about 2,000 m) was shown to be associated with distinct health benefits, including lower mortality from cardiovascular diseases and certain cancers. However, it remains unclear, whether those benefits are mainly due to environmental conditions (e.g., hypoxia, temperature, solar ultra-violet radiation) or differences in lifestyle behavior, including regular physical activity levels. This study aims to compare altitude-related differences in levels of physical activity and the prevalence of cardiovascular risk factors such as obesity, hypertension, hypercholesterolemia, and diabetes in an Alpine country. We interrogated the Austrian Health Interview Survey (ATHIS) 2019, a nationally representative study of persons aged over 15 years living in private Austrian households. The results confirm a higher prevalence of hypertension (24.2% vs. 16.8%) in men living at low (&lt;1,001 m) compared to those at moderate (1,001 to 2,000 m) altitude. Women living above 1,000 m tend to have a lower prevalence of hypercholesterolemia (14.8% vs. 18.8%) and diabetes (3.2% vs. 5.6%) than their lower living peers. Both sexes have lower average body mass index (BMI) when residing at moderate altitude (men: 25.7, women: 23.9) compared to those living lower (26.6 and 25.2). Severe obesity (BMI &gt; 40) is almost exclusively restricted to low altitude dwellers. Only men report to be more physically active on average when living higher (1,453 vs. 1,113 weekly MET minutes). These novel findings confirm some distinct benefits of moderate altitude residence on heath. Beside climate conditions, differences in lifestyle behavior, i.e., physical activity, have to be considered when interpreting those health-related divergences, and consequently also mortality data, between people residing at low and moderate altitudes.</p> </abstract>

Is Syncope Related to Moderate Altitude Exposure?

JAMA ◽  
1992 ◽  
Vol 268 (7) ◽  
pp. 904 ◽  
Author(s):  
Richard Nicholas
Keyword(s):  
Moderate Altitude ◽  
Altitude Exposure

Is syncope related to moderate altitude exposure?

JAMA ◽  
1992 ◽  
Vol 268 (7) ◽  
pp. 904-906 ◽  
Author(s):  
R. Nicholas
Keyword(s):  
Moderate Altitude ◽  
Altitude Exposure

Hyperoxic Effects on Decompression Strain During Alternating High and Moderate Altitude Exposures

2021 ◽  
Vol 92 (4) ◽  
pp. 223-230
Author(s):  
Rickard nell ◽  
Mikael Grnkvist ◽  
Mikael Gennser ◽  
Ola Eiken
Keyword(s):  
Gas Exchange ◽  
Decompression Sickness ◽  
The Other ◽  
Moderate Altitude ◽  
Cardiac Ultrasound ◽  
Fighter Aircraft ◽  
Lower Altitude ◽  
Healthy Men ◽  
Altitude Exposure ◽  
Long Duration

INTRODUCTION: In fighter aircraft, long-duration high-altitude sorties are typically interrupted by refueling excursions to lower altitude. In normoxia, excursions to moderate cabin altitude may increase the occurrence of venous gas emboli (VGE) at high cabin altitude. The aim was to investigate the effect of hyperoxia on VGE and decompression sickness (DCS) during alternating high and moderate altitude exposure.METHODS: In an altitude chamber, 13 healthy men were exposed to three different conditions: A) 90 min at 24,000 ft (7315 m) breathing normoxic gas (54% O2; H-NOR); B) 90 min at 24,000 ft breathing hyperoxic gas (90% O2; H-HYP); and C) three 30-min exposures to 24,000 ft interspersed by two 30-min exposures to 18,000 ft (5486 m) breathing 90% O2 (ALT-HYP). VGE occurrence was evaluated from cardiac ultrasound imaging. DCS symptoms were rated using a scale.RESULTS: DCS occurred in all conditions and altogether in 6 of the 39 exposures. The prevalence of VGE was similar in H-NOR and H-HYP throughout the exposures. During the initial 30 min at 24,000 ft, the prevalence of VGE was similar in ALT-HYP as in the other two conditions, whereas, after the first excursion to 18,000 ft, the VGE score was lower in ALT-HYP than in H-NOR and H-HYP.DISCUSSION: Hyperoxic excursions from 24,000 to 18,000 ft reduces VGE occurrence, presumably by facilitating diffusive gas exchange across the bubble surfaces, increasing the share of bubble content contributed by oxygen. Still, the excursions did not abolish the DCS risk.nell R, Grnkvist M, Gennser M, Eiken O. Hyperoxic effects on decompression strain during alternating high and moderate altitude exposures. Aerosp Med Hum Perform. 2021; 92(4):223230.

Physiologic Response to Moderate Altitude Exposure among Infants and Young Children

2003 ◽  
Vol 4 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Michael Yaron ◽  
Susan Niermeyer ◽  
Kjell N. Lindgren ◽  
Benjamin Honigman ◽  
John D. Strain ◽  
...  
Keyword(s):  
Young Children ◽  
Moderate Altitude ◽  
Physiologic Response ◽  
Altitude Exposure ◽  
Infants And Young Children

scholarly journals Iron insufficiency diminishes the erythropoietic response to moderate altitude exposure

2019 ◽  
Vol 127 (6) ◽  
pp. 1569-1578
Author(s):  
Kazunobu Okazaki ◽  
James Stray-Gundersen ◽  
Robert F. Chapman ◽  
Benjamin D. Levine
Keyword(s):  
Retrospective Study ◽  
Iron Deficiency ◽  
Prospective Study ◽  
Sea Level ◽  
Athletic Performance ◽  
Iron Supplementation ◽  
Endurance Athletes ◽  
Altitude Training ◽  
Moderate Altitude ◽  
Altitude Exposure

The effects of iron stores and supplementation on erythropoietic responses to moderate altitude in endurance athletes were examined. In a retrospective study, red cell compartment volume (RCV) responses to 4 wk at 2,500 m were assessed in athletes with low ( n = 9, ≤20 and ≤30 ng/mL for women and men, respectively) and normal ( n = 10) serum ferritin levels ([Ferritin]) without iron supplementation. In a subsequent prospective study, the same responses were assessed in athletes ( n = 26) with a protocol designed to provide sufficient iron before and during identical altitude exposure. The responses to a 4-wk training camp at sea level were assessed in another group of athletes ( n = 13) as controls. RCV and maximal oxygen uptake (V̇o2max) were determined at sea level before and after intervention. In the retrospective study, athletes with low [Ferritin] did not increase RCV (27.0 ± 2.9 to 27.5 ± 3.8 mL/kg, mean ± SD, P = 0.65) or V̇o2max (60.2 ± 7.2 to 62.2 ± 7.5 mL·kg−1·min−1, P = 0.23) after 4 wk at altitude, whereas athletes with normal [Ferritin] increased both (RCV: 27.3 ± 3.1 to 29.8 ± 2.4 mL/kg, P = 0.002; V̇o2max: 62.0 ± 3.1 to 66.2 ± 3.7 mL·kg−1·min−1, P = 0.003). In the prospective study, iron supplementation normalized low [Ferritin] observed in athletes exposed to altitude ( n = 14) and sea level ( n = 6) before the altitude/sea-level camp and maintained [Ferritin] within normal range in all athletes during the camp. RCV and V̇o2max increased in the altitude group but remained unchanged in the sea-level group. Finally, the increase in RCV correlated with the increase in V̇o2max [( r = 0.368, 95% confidence interval (CI): 0.059–0.612, P = 0.022]. Thus, iron deficiency in athletes restrains erythropoiesis to altitude exposure and may preclude improvement in sea-level athletic performance. NEW & NOTEWORTHY Hypoxic exposure increases iron requirements and utilization for erythropoiesis in athletes. This study clearly demonstrates that iron deficiency in athletes inhibits accelerated erythropoiesis to a sojourn to moderate high altitude and may preclude a potential improvement in sea-level athletic performance with altitude training. Iron replacement therapy before and during altitude exposure is important to maximize performance gains after altitude training in endurance athletes.

Improved Race Performance in Elite Middle-Distance Runners After Cumulative Altitude Exposure

2009 ◽  
Vol 4 (1) ◽  
pp. 134-138 ◽  
Author(s):  
Philo U. Saunders ◽  
Richard D. Telford ◽  
David B. Pyne ◽  
Christopher J. Gore ◽  
Allan G. Hahn
Keyword(s):  
Altitude Training ◽  
Moderate Altitude ◽  
Confidence Limits ◽  
Simulated Altitude ◽  
Competitive Performance ◽  
Distance Runners ◽  
Altitude Exposure ◽  
Race Performance

We quantified the effect of an extended live high-train low (LHTL) simulated altitude exposure followed by a series of training camps at natural moderate altitude on competitive performance in seven elite middle-distance runners (Vo2max 71.4 ± 3.4 mL·min−1·kg−1, mean ± SD). Runners spent 44 ± 7 nights (mean ± SD) at a simulated altitude of 2846 ± 32 m, and a further 4 X 7- to 10-d training at natural moderate altitude (1700–2200 m) before racing. The combination of simulated LHTL and natural altitude training improved competitive performance by 1.9% (90% confidence limits, 1.3-2.5%). Middle-distance runners can confidently use a combination of simulated and natural altitude to stimulate adaptations responsible for improving performance.

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