All posts by Roberto Santos

Roberto Santos is an avid outdoorsman, prolific reader, writer and web developer currently stationed in the Colorado high country. Originally from the Northern Mariana Islands, his work, study and adventures have taken him from surfing across the Pacific, to climbing the highest peaks in Japan and Colorado.
Acclimation, Altitude Science, Exposure, Health, High Altitude, Technology

From Mountains to Mars: Why High-Altitude Research Matters for Mars Missions

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Thin Air

You step out of your car at roughly 9,000 feet in Frisco, Colorado, and the first thing you notice isn’t the mountain views –it’s your breath. It comes faster, deeper, almost as if your body knows something you don’t: the air pressure here is lower and each breath delivers ~28% fewer oxygen molecules than at sea level1. This “thin air” triggers the same hypoxic (low-oxygen) stress that Mars settlers will face, where every habitat and spacesuit must carefully control both pressure and oxygen1,2,7,8. On Mars, the atmospheric pressure is less than 1% of that on Earth.

Acclimatization

On your first hike, your heart pounds harder than usual. That’s your body’s rapid response: breathing quickens, heart rate rises, and oxygen delivery ramps up to keep the entire body going1,2,4. Within 24-48 hours, your kidneys release erythropoietin (EPO), signaling the bone marrow to make more red blood cells1,3. This raises hemoglobin levels, enhancing oxygen transport. Over the following weeks, blood volume and hemoglobin continue to rise1,2,4. This is acclimatization –which varies between individuals, an important consideration when selecting crew for long-duration Mars missions.

Sleep and Oxygen

At night, breathing becomes fragile. Many people develop “periodic breathing” –brief pauses that fragment sleep. Summit County residents often experience oxygen dips into the high 80% –lower than the ~90% seen in Denver; and far below the typical 96-98% at sea level1. These dips have real implications: hypoxia combined with sleep disruption can affect mood, stress, and cognitive performance, as seen in Antarctic “winter overs,” where low oxygen and isolation caused up to 20% drop in certain cognitive task speeds and increased mood disturbances. Altitude sleep data are useful for researchers to determine extra nighttime buffers and habitat controls. Predicting and mitigating these person-specific patterns is key for astronaut safety and performance4,5.

From Frisco to the Final Frontier

Frisco, Colorado is not just known for its scenic views. This mountain town serves as a “living laboratory”, allowing researchers to track oxygen saturation, breathing, heart rate, sleep, and exercise tolerance in residents and visitors. These insights can help engineers determine how much oxygen a Mars habitat should provide, and how quickly conditions can safely change after landing1,2,7,8. NASA spacecraft air pressures currently range from 8.2 – 14.7 psi, with oxygen comprising 21-32% of that air; parameters informed in part by high-altitude research7,8. At the 7th Chronic Hypoxia Symposium in La Paz, Bolivia at 12,000 feet elevation (3,640 m) the use of insights from high altitude populations to enable the exploration of Space was discussed. The sponsor and organizers were Drs. Gustavo Zubieta-Calleja and his daughter Natalia Zubieta De Urioste who run the Institute of High Altitude Pulmonology and Pathology there. Presenters and attendees came from 16 countries covering topics ranging from molecular biology to genetics.
A presentation on “BioSpaceForming”  identifies chronic hypoxia as a “fundamental tool” that “gives humans and other species an advantage on earth and beyond.” Dr Zubieta explained that the space station is engineered to have the barometric pressure (760 mmHg) and oxygen content of sea level. When the astronauts change into their space suits to work outside the ship they experience a pressure drop of over 200 mm Hg in a laborious process of donning the suit. Seeing that millions of inhabitants are healthy at 486 mm HG in Bolivia, he advocates that maintaining lower pressures and lower oxygen levels in the space station would be economical and promote the health of the astronauts. Several altitude scientists see this as a future that “uncouples biology and physics.

(Photo of Dr Gustavo in front of space slide)

Modeling Mars Conditions

Researchers combine data from high-altitude locations, Antarctic stations, Mars-analog habitats like HI-SEAS in Hawaii to build predictive models. These models provide guidelines for when oxygen supplementation or workload adjustments are needed to optimize safety while completing tasks 4-6,9. They also help develop “operations playbooks” for simulating life on Mars10; set habitat air pressure and oxygen guidelines7,8; define spacesuit safety limits4,6,11; and better understand how the human body responds to spaceflight and space living2,5,9,12,13. For example, extravehicular activity (EVA) suits –spacesuits used for work outside the spacecraft –typically operate at ~4.3 psi with 100% oxygen. While this allows astronauts to breathe in low-pressure environments, prolonged use can lead to overheating, dehydration, and higher risk of injuries11.

The gravitational pull is 38% of that on Earth. Solar and the more dangerous Galactic Cosmic Radiation of Alpha particles from distant supernovae is hundreds of times greater than on Earth, due to the lack of a magnetic field or protective atmosphere. A breeze on Mars could barely move a blade of grass. Global dust storms occur every few years and last months, devastating the surface.

At the 9th  Chronic Hypoxia and First International Space Physiology Symposium in La Paz, Bolivia in 2025 Dr. Akbar Hussain presented his Craterhab design for accommodations in austere high altitude environments and eventually on Mars.

(PHOTO akbar in front of slide with craterhub) 

Astronauts could be acclimatized before embarking on the long journey to distant space in facilities located at 5,000 meters near mines in the Andes.

(Photo of Dr Gustavo in front of space slide)

Limitations

Most high-altitude studies are conducted over weeks to months, while Mars missions could last years and require hundreds of participants to have the skills to be self-sustaining. Due to planetary rotations, travel to Mars is only feasible once every 26 months. Messages from Mars take 7 to 45 minutes to arrive on Earth. Individual differences in acclimatization, long-term cognitive effects, and combined stressors like radiation or microgravity are not fully captured. Longer-duration studies at high-altitudes, combined with simulated Martian habitats and spacesuit trials, are needed to refine safety parameters.

Conclusion

High-altitude research gives scientists a window into human maladaptive and adaptive responses to low-oxygen, low-pressure conditions on Earth, and is directly relevant to anticipating health risks and necessary countermeasures for human habitation on Mars.

References

  1. Ebert-Santos C. High-Altitude Pulmonary Edema in Mountain Community Residents. High Alt Med Biol. 2017 Sep;18(3):278-284. doi: 10.1089/ham.2016.0100. Epub 2017 Aug 28. PMID: 28846035.
  2. Le Roy B, Martin-Krumm C, Pinol N, Dutheil F, Trousselard M. Human challenges to adaptation to extreme professional environments: A systematic review. Neurosci Biobehav Rev. 2023;146:105054. doi:10.1016/j.neubiorev.2023.105054.
  3. Roach RC, Hackett PH. Frontiers of hypoxia research: acute mountain sickness. J Exp Biol. 2001 Sep;204(Pt 18):3161-70. doi: 10.1242/jeb.204.18.3161. PMID: 11581330.
  4. Mairesse O, MacDonald-Nethercott E, Neu D, et al. Preparing for Mars: Human sleep and performance during a 13-month stay in Antarctica. Sleep. 2019;42(1). doi:10.1093/sleep/zsy206.
  5. Pagel JI, Choukèr A. Effects of isolation and confinement on humans—Implications for manned space explorations. J Appl Physiol (1985). 2016;120(12):1449-1457. doi:10.1152/japplphysiol.00928.2015.
  6. Dunn Rosenberg J, Jannasch A, Binsted K, Landry S. Biobehavioral and psychosocial stress changes during three 8–12 month spaceflight analog missions with Mars-like conditions of isolation and confinement. Front Physiol. 2022;13:898841. doi:10.3389/fphys.2022.898841.
  7. Waligora JM, Horrigan DJ, Nicogossian A. The physiology of spacecraft and space suit atmosphere selection. Acta Astronaut. 1991;23:171-177. doi:10.1016/0094-5765(91)90116-M.
  8. Morgenthaler GW, Fester DA, Cooley CG. An assessment of habitat pressure, oxygen fraction, and EVA suit design for space operations. Acta Astronaut. 1994;32(1):39-49. doi:10.1016/0094-5765(94)90146-5.
  9. Sarma MS, Shelhamer M. The human biology of spaceflight. Am J Hum Biol. 2024;36(3):e24048. doi:10.1002/ajhb.24048.
  10. Lim DSS, Abercromby AFJ, Kobs Nawotniak SE, et al. The BASALT research program: Designing and developing mission elements in support of human scientific exploration of Mars. Astrobiology. 2019;19(3):245-259. doi:10.1089/ast.2018.1869.
  11. Stirling L, Arezes P, Anderson A. Implications of space suit injury risk for developing computational performance models. Aerosp Med Hum Perform. 2019;90(6):553-565. doi:10.3357/AMHP.5221.2019.
  12. Cassaro A, Pacelli C, Aureli L, et al. Antarctica as a reservoir of planetary analogue environments. Extremophiles. 2021;25(5-6):437-458. doi:10.1007/s00792-021-01245-w.
  13. Fairén AG, Davila AF, Lim D, et al. Astrobiology through the ages of Mars: The study of terrestrial analogues to understand the habitability of Mars. Astrobiology. 2010;10(8):821-843. doi:10.1089/ast.2009.0440.
  14. Akbar Hussain M, Ayaz Hussain M, Mehdi Hussain M, Fatima R, Carretero R, eds. Craterhab Technology: Adapting Martian Habitat Systems to Combat Chronic Hypoxia in High-Altitude Mining in the Andes – A White Paper. Mareekh Dynamics. Published June 3, 2024. Accessed August 15, 2025. https://www.mareekh.com/post/craterhab-technology-adapting-martian-habitat-systems-to-combat-chronic-hypoxia-in-high-altitude-mi
Acclimation, Altitude Science, Athletic Training, Health, High Altitude, High Altitude Training & Fitness

PORTRAIT OF A HIGH-ALTITUDE ATHLETE: THE ULTRA MOUNTAIN ATHLETE, 2.0

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Six years ago, I sat down with ultra mountain athlete Yuki Ikeda for the first time for an interview about his experience training, competing and recovering in the extreme altitudes of Colorado’s central Rocky Mountains. At the time, Yuki had only recently started competing in running races at over 10,000′ (3048m) since beginning his career as a cyclist in 2003, going pro in 2007.

In 2019, he managed to compete in his first Leadville Race Series, which included 50- and 100-mile MTB and trail run courses starting at above 10,000′ and rising to over 12,000′.

This summer, I had the pleasure of catching up with this extraordinary athlete and his wife Sayako, a dietitian and high-altitude runner herself who inspired Yuki to compete as a runner as well as a cyclist. The pair have been spending summers in the Colorado high country every year to train and compete before returning to their home in Japan to continue competing year-round, and between their experience training and racing and nutritional expertise, they make a formidable team.

Six years ago, we were all three of us in our thirties, and when I asked about what has changed about training and acclimating to the altitude since then, there was certainly a consensus about how it hasn’t gotten easier now that we are all in our forties. A significant part of their strategy for success has always been nutrition, and at this elevation, maximizing the delivery of oxygen throughout the body makes a huge difference. In our last interview, Yuki talked about incorporating foods rich in nitrates, which facilitate your body’s production of nitric oxide, like red bell peppers, arugula and beets, and these are still a big part of their diet.

Something they’ve been paying closer attention to lately is iron, also a critical component of blood. It’s dangerous for iron levels to be too high, but it can be a critical supplement for healthy circulation. In the case of long distance runners, blood vessels can take a considerable beating as feet hit ground over and over again for long periods of time. One food in particular that contains a high level of iron is clams. In Japan and the Pacific, asari, also known as Manila clam or Japanese cockle, is a regular part of cuisine and easy to find. Here in the middle of the Rockies, however, Yuki and Sayako have been buying canned clams to supplement their iron.

Every summer, the couple have come to the Colorado Rockies to train and compete. They’re full-time residence is in Tokyo, Japan, so each time they are traveling from sea-level, a dramatic and quick ascent to a high elevation. The decrease in available oxygen in the air at high altitude prompts a response in the body to create more red blood cells in order to carry more oxygen throughout the body. This requires more iron, which is vital for this process.

Additionally, the two athletes are paying special attention to nutrient absorption. Most of their diet is plant-based, and until recently, Yuki has been eating a completely vegan diet. Organic compounds found in plants called tannins and polyphenols — while beneficial — can inhibit your body’s absorption of nutrients you eat by up to 90%. So consuming something with these compounds along with your meal may dramatically decrease the benefits of nutrition in the food you’re eating. Coffee contains these compounds, so Sayako recommends waiting at least an hour after a meal to have a cup of coffee in order to maximize nutrient uptake. Even better, vitamin C can enable greater absorption, so consuming it (even in other foods such as a citrus) with a meal can be very helpful.

“… iron is also necessary for the hypoxia-inducible-factor (HIF) pathway, cellular energy production, myoglobin function (the muscle oxygen acceptor), and thyroid hormone function,” write DeLoughery and DeLoughery in a recent article for the Wilderness Medical Society. “The HIF pathway is the key regulator of the body’s response to hypoxia. Typically, the HIF-1 and HIF-2 proteins are rapidly degraded, but they are stabilized by hypoxic conditions when prolyl hydroxylase, which tags the HIFp roteins for degradation, is inhibited. When stabilized, the HIF proteins function as transcription factors that coordinate the synthesis of various proteins essential for the body’s response to hypoxia. Prolyl hydroxylase requires iron to function, and with a low iron level, this is less effective, leading to an exaggerated response to hypoxia.”

It is also important to note that, as Yuki and Sayako point out, it can take three to four weeks for anyone to experience noticeable results from any change in diet and nutrition. Keeping this in mind, it is advisable to increase iron intake weeks ahead of a trip to a high altitude environment, although further research may be needed to recommend just how much.

References

DeLoughery, MD, Emma P. Emma P. DeLoughery, MD and Thomas G. DeLoughery, MD, “Women, Iron, and Altitude — Path to the Peak”, Wilderness Medical Society 2025.

Acclimation, Altitude Science, Diabetes, Exposure, Genetics, Health, High Altitude

Living High and Testing Higher: Can Living at High Altitudes Skew Diagnostic Diabetes Tests? 

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by Hailey Garin PA-S

Diabetes is very prevalent in our society, with around 11% of the population in the United States diagnosed with this disease2. A key diagnostic test used in healthcare is the hemoglobin A1c (HbA1c) blood test. This blood test measures an individual’s average blood sugar over a 3-month period. A value of less than 5.7% is normal, 5.7%-6.4% is pre-diabetic range, and 6.5% and greater is a diagnosis of diabetes1. There are other blood tests that are used in the diagnoses of diabetes including fasting plasma glucose (FPG) and 2-hour postprandial glucose (2-h PG) testing. FPG testing measures blood sugar levels after 8 or more hours of fasting. A FPG value of 126 mg/dl or greater is diagnostic of diabetes. The 2-h PG test is a blood sugar reading 2 hours after eating a meal. A 2-h PG value of 200 mg/dl or higher is diagnostic of diabetes3. Currently the HbA1c blood test is the most used to diagnose diabetes, and many individuals around the world are diagnosed and placed on medications based off HbA1c results alone.

But is this appropriate for individuals living at altitude? 

A groundbreaking study completed in mainland China has begun to answer this question for us. Altitudes and Hemoglobin A1c Values: An Analysis Based on Two Nationwide Cross-sectional Studies by Zheng et al was published in 2024. In this study, 95,000 adults were examined by comparing HbA1c, fasting blood glucose, and 2-hour postprandial (after a meal) glucose levels between individuals living above and below 2,500 meters (8,200 feet)4. 

A key finding of this study was that individuals living above 2,500 meters had higher HbA1c levels but the same FPG and 2-h PG results as individuals below 2,500 meters4. The individuals at altitude may have HbA1c levels that are falsely elevated. This inaccuracy can lead to an inappropriate diagnosis of diabetes in individuals living at altitude. The researchers explained that oxygen levels at higher elevations are lower, and the body reacts to these low levels by increasing levels of red blood cells and the lifespan of red blood cells. When lifespan is increased, the hemoglobin is exposed to glucose in our blood stream for longer, eliciting a higher HbA1c result despite normal blood sugar levels4. 

Another study by Bazo-Alvarez et. al in 2017 sought to evaluate the relationship between HbA1c and FPG among individuals at sea level compared to those at high altitude.

The study analyzed data from 3613 Peruvian adults without diagnosed diabetes from both sea level and high altitude (>3000m). The mean values for hemoglobin, HbA1c, and FPG differed significantly between these populations. The correlation between HbA1c and FPG was quadratic at sea level but linear at high altitude, suggesting different glucose metabolism patterns. Additionally, for an HbA1c value of 48 mmol/mol (6.5%), corresponding mean FPG values were significantly different: 6.6 mmol/l at sea level versus 14.8 mmol/l at high altitude.

These studies show that one-size-fits all screening for diabetes may not work for everyone, especially those living at altitude. Ebert Family Clinic, at 2743m (9000 ft) in the Colorado Rocky Mountains, has been researching the effects of altitude on many aspects of health including examining HbA1c levels in our residents and thus far we have seen elevated HbA1c levels in our otherwise healthy, “thin”, and active patients despite implementing appropriate lifestyle interventions to lower blood sugar. This can lead to unnecessary health anxiety that we hope to avoid by determining if HbA1c will continue to be an appropriate diagnostic tool with our residents living well above 2,500 meters.

References

1. Centers for Disease Control and Prevention. (n.d.-a). A1C test for diabetes and Prediabetes. Centers for Disease Control and Prevention. https://www.cdc.gov/diabetes/diabetes-testing/prediabetes-a1c-test.html 

2. Centers for Disease Control and Prevention. (n.d.-b). National Diabetes Statistics Report. Centers for Disease Control and Prevention. https://www.cdc.gov/diabetes/php/data-research/index.html 

3. U.S. Department of Health and Human Services. (n.d.). Diabetes tests & diagnosis – NIDDK. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/diabetes/overview/tests-diagnosis 

4. Zheng, R., Xu, Y., Li, M., Wang, L., Lu, J., Wang, T., Xu, M., Zhao, Z., Zheng, J., Dai, M., Zhang, D., Chen, Y., Wang, S., Lin, H., Wang, W., Ning, G., & Bi, Y. (2024). Altitudes and hemoglobin A1C values: An analysis based on two nationwide cross-sectional studies. Diabetes Care, 47(2). https://doi.org/10.2337/dc23-1549 

Acclimation, Altitude Science, Anesthesia, Health, High Altitude, Medicine, Technology

Anesthesia and Altitude

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by Megan Wilson, NP-S

One of the last things anybody wants to go through is a surgical procedure, especially if you happen to be in the mountains on vacation. Unfortunately, life happens, and whether you’re a visitor to high-altitude or a permanent resident, there is a chance you may need surgical care. 

Anesthesia is a requirement for surgical procedures and there are varying levels of anesthetic available. General anesthesia, often referred to as “going off to sleep”, is where you are completely unconscious and anesthetic gases and medications keep you sedated while a machine breathes for you during your procedure. Monitored anesthesia care (MAC), also known as conscious sedation, is when the anesthesiologist keeps you comfortable with meds, but you are still able to breathe on your own. Medications given for surgery affect your ability to breathe, which is why your vital signs (oxygen levels, blood pressure, heart rate) are monitored through a machine by a doctor. 

How is this different at high altitude?

When you head to higher elevations, barometric pressure decreases and causes partial pressure of oxygen to decrease – this makes oxygen harder to effectively get into your lungs and causes hypoxemia/low oxygen levels (Leissner & Mahmood, 2009). This leads to a condition commonly known as altitude sickness, causing headaches and trouble breathing, and in more serious cases, it can also lead to high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). Much like oxygen, anesthetic gases are also affected by barometric pressures, impacting the effectiveness of inhaled anesthetics (Bebic et al., 2021). Additionally, equipment is affected by high altitude – meters on anesthesia machines that monitor gas/oxygen levels tend to under-read at higher elevations (Bebic et al., 2021; Leissner & Mahmood, 2009). Pulse oximetry, which measures your overall oxygen saturation (the percentage of oxygen in your blood) also has limited accuracy at high altitude (Bebic et al., 2021). Providers who practice at higher elevations should be aware of these nuances and treat accordingly. The most important treatment we have to help with the effects of partial pressure at high altitude is supplemental oxygen (Leissner & Mahmood, 2009).  

Unfortunately, there is limited research on the effects of high altitude and anesthesia, and even less on the effects of anesthetic drugs at high altitude vs. sea level (Bebic et al., 2021). With current published data, it is clear that surgical risks increase with elevation. Whether it’s the potential for equipment to malfunction, or novice providers new to high-altitude unaware of the subtleties in treatment, it is critical to be mindful of compromised respiratory status at elevation when considering which anesthetic agents to use for surgery. 

References

Bebic, Z., Brooks Peterson, M., & Polaner, D. M. (2021). Respiratory physiology at high altitude and considerations for pediatric patients. Pediatric Anesthesia, 32(2), 118-125.

https://doi.org/10.1111/pan.14380

Leissner, K. B., & Mahmood, F. U. (2009). Physiology and pathophysiology at high altitude:

Considerations for the anesthesiologist. Journal of Anesthesia, 23(4), 543-553.

https://doi.org/10.1007/s00540-009-0787-7

Altitude Science, Health, Hyperbaric Therapy, Medicine

WHEN OXYGEN IS TOXIC

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Why Too Much Oxygen Can Be Deadly: The Hidden Molecular Consequences of Hyperoxia

by Nic Rolph, PA-S

Oxygen keeps us alive—but in excess, it can quietly unravel critical cellular functions. A groundbreaking study by Baik et al. (2023) in Molecular Cell shines a light on why hyperoxia (too much oxygen) is toxic, and reveals a hidden mechanism behind its damaging effects.

The Mystery of Oxygen Toxicity

We’ve long known that both oxygen deprivation (hypoxia) and oxygen overload (hyperoxia) are harmful. While hypoxia research has led to major discoveries like the Nobel Prize-winning work on HIF (Hypoxia-Inducible Factors), hyperoxia has remained less understood—until now.

Baik and colleagues tackled a fundamental biological question: Why is oxygen toxic at the molecular level?

The Culprit: Fragile Iron-Sulfur Proteins

Using a combination of genome-wide CRISPR screening, proteomics, and in vivo experiments, the researchers identified a specific class of proteins highly vulnerable to excess oxygen: iron-sulfur cluster (Fe-S)-containing proteins.

These clusters act like tiny biochemical power stations inside proteins, but they’re extremely sensitive to oxidation. Under hyperoxic conditions, certain Fe-S proteins degrade, compromising several key cellular pathways:

  • Diphthamide synthesis – crucial for accurate protein translation.
  • De novo purine biosynthesis – needed for DNA and RNA building blocks.
  • Nucleotide excision repair (NER) – repairs damaged DNA.
  • Mitochondrial electron transport chain (ETC) – essential for energy production.

A Vicious Cycle of Oxygen Damage

Perhaps the most striking discovery was the feedback loop of cellular damage:

  1. Hyperoxia damages the ETC, lowering oxygen consumption;
  2. this increases local tissue oxygen levels even more,
  3. which leads to more damage—a self-amplifying loop Baik et al. called “cyclic oxygen toxicity.”

This cycle can explain why supplemental oxygen—while lifesaving—is also associated with complications in neonatal care, ICU patients, and chronic diseases.

From Petri Dishes to Lungs

The team validated their findings in human cells, mice, and even primary lung tissue. In a mouse model of hyperoxic lung injury, the same Fe-S proteins degraded rapidly—especially those in the ETC. Mice with preexisting ETC defects (like the Ndufs4 KO model) showed extreme sensitivity, confirming the ETC as the “weakest link” in the oxygen toxicity chain.

Bigger Picture: Aging, Disease, and Therapy

This study suggests that hyperoxia might contribute to a wide range of diseases—from premature infant lung injury and ischemia-reperfusion damage to neurodegenerative and mitochondrial disorders. It also offers a potential explanation for why antioxidant therapies have largely failed: superoxide isn’t the only villain—molecular oxygen itself may be enough to destabilize these proteins.

Rethinking Oxygen Therapy

Given these findings, clinicians may need to rethink how we use oxygen in medical settings. Rather than focusing solely on delivering “more oxygen,” we might need to tailor therapy to a patient’s oxygen-processing capacity—especially in those with mitochondrial or genetic vulnerabilities.

What’s Next?

Future research may explore:

  • Therapeutic hypoxia to interrupt the damage cycle.
  • Genetic screening to identify patients vulnerable to oxygen toxicity.
  • New drugs to stabilize Fe-S proteins in oxidative environments.

Takeaway

Oxygen is life-sustaining—but Baik et al. reveal it’s also a molecular saboteur under the wrong conditions. This landmark study not only explains the elusive biology of oxygen toxicity but opens new doors for safer therapies and deeper understanding of metabolic diseases.

Note from Dr. Christine Ebert-Santos, MD, MPS of Ebert Family Clinic in the Colorado Rocky Mountains at 9000’/2743m: newborns, children with respiratory infections or high altitude pulmonary edema, and people with sleep apnea are advised to use oxygen at high altitude. The level of oxygen saturation achieved with this treatment is well below normal sea-level values, so unlikely to cause any negative effects.

Acclimation, Altitude Science, Exposure, Health, High Altitude

ERUCTILE DYSFUNCTION AT ALTITUDE: Low Barometric Pressures Worsen Discomfort for Those Who Can’t Burp

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by Noor Pawar, PA-S


Retrograde Cricopharyngeus Dysfunction and the Impact of Altitude

Lucie Rosenthal’s journey, captured in her viral Reddit video, sheds light on a lesser-known condition: retrograde cricopharyngeus dysfunction, or “no-burp syndrome.” What makes her story particularly fascinating is the intersection of this medical condition with the effects of altitude—a factor that significantly influences our bodies and their functions.

In her video, Lucie joyfully discovers her ability to burp after a procedure that injects Botox into the upper esophageal muscle. However, her initial excitement turns into an uncontrollable experience that raises questions about the body’s mechanisms, especially in relation to altitude. As she recounts the bloating and discomfort that accompanied her condition, it echoes a broader issue faced by many individuals living in higher elevations, where changes in atmospheric pressure can exacerbate gastrointestinal symptoms.

The relationship between altitude and digestive health is an important consideration. At higher elevations, the reduced atmospheric pressure can lead to gas expansion in the stomach and intestines, intensifying feelings of bloating and discomfort. This is particularly relevant for individuals like Daryl Moody, who struggled with no-burp syndrome while also engaging in activities like skydiving. As he ascended, the altitude caused his stomach to inflate like a bag of chips, amplifying his discomfort and highlighting how altitude can complicate existing health issues.

The article emphasizes the growing awareness surrounding retrograde cricopharyngeus dysfunction, especially through online communities like the r/noburp subreddit. These platforms provide vital support for those affected, particularly in regions where altitude impacts digestive health. It’s a testament to how individuals can come together to share experiences and coping strategies, transforming personal struggles into a collective understanding of a shared condition.

The financial barriers mentioned in the article are further complicated for those living in high-altitude areas. With treatments often deemed “experimental” by insurance companies, individuals may face significant out-of-pocket expenses, particularly in regions where healthcare costs are already high.

Historically reports of individuals unable to burp date back centuries. The contemporary acknowledgment of retrograde cricopharyngeus dysfunction reflects an evolving understanding of how environmental factors, such as altitude, can play a crucial role in health. As we continue to learn more about this condition, the need for further research into the effects of altitude on digestive health becomes increasingly apparent.

In summary, Lucie Rosenthal’s story illustrates the complexities of retrograde cricopharyngeus dysfunction, particularly in relation to altitude. The interplay between physiological responses and environmental factors underscores the importance of patient advocacy and community support in addressing these issues. As we navigate our health, understanding how altitude can influence our bodies highlights the need for a comprehensive approach to medical care that considers all aspects of a patient’s environment.

Accessibility, Acclimation, Altitude Science, Athletic Training, Child Growth & Development, Exposure, Genetics, Health, High Altitude, Medicine, Postural Orthostatic Tachycardia Syndrome (POTS)

Thin Air Making You Lightheaded?

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by Joy Plutowski, PA-S2

Feeling lightheaded after going to a high altitude is a key symptom of acute mountain sickness (AMS)—a condition caused by the reduced oxygen available in thin mountain air. AMS often comes with other symptoms like headache, nausea, and fatigue, usually starting after a recent climb to higher elevations.

But what if it’s not just AMS? For people with conditions like postural orthostatic tachycardia syndrome (POTS), which affects blood flow and heart rate, lightheadedness at altitude could be a clue to an underlying issue. While AMS happens because of low oxygen, POTS is tied to a problem with how the nervous system regulates the body. In some cases, going to altitude might even uncover undiagnosed POTS, as symptoms can become more noticeable in these conditions.

Living With POTS

Living with POTS has been a journey of adaptation, requiring constant vigilance and adjustment to manage a complex array of symptoms. Each new environment brings its own challenges, demanding a personalized approach to maintaining stability. My recent clinical rotation in Frisco, Colorado, situated at 9,000 feet above sea level, provided an invaluable opportunity to observe firsthand how altitude influences the physiology of POTS. An overnight stay in Denver for partial acclimatization helped mitigate some initial altitude-related exacerbations, but the first few days at higher elevation were marked by pronounced symptoms, including lightheadedness, tachycardia, and insomnia. Physically demanding activities, such as snowboarding, pushed my body to its limits, resulting in extreme fatigue and heightened tachycardia. Despite these challenges, I observed gradual improvement; by the second week, I had returned to my baseline—if not better than during my time in the heat of Phoenix, Arizona. Interestingly, the colder temperatures of the region seemed to offer symptomatic relief, likely through vasoconstriction that may enhance circulation. These experiences have deepened my understanding of POTS as a highly individualized condition, emphasizing the critical importance of lifestyle modifications, environmental considerations, and a patient-specific approach to management. My journey underscores how adaptability and tailored interventions can significantly improve functionality and quality of life for those navigating the complexities of this syndrome.

What is POTS?

Postural Orthostatic Tachycardia Syndrome (POTS) is a chronic condition characterized by an abnormal increase in heart rate upon standing. It is a form of dysautonomia, involving dysregulation of the autonomic nervous system, which balances the sympathetic (“fight or flight”) and parasympathetic (“rest and digest”) systems. The autonomic nervous system regulates involuntary bodily functions such as heart rate, blood pressure, and digestion. POTS primarily affects women, with symptoms often appearing in their teens or twenties. It is estimated to affect between 1 to 3 million people in the United States, though it is likely underdiagnosed due to lack of awareness. Under normal conditions, standing triggers the body to constrict blood vessels and slightly increase heart rate to counteract gravity’s effects. In POTS, this response is impaired, leading to blood pooling in the lower extremities and reduced blood flow to the brain. The exact cause of POTS is not fully understood, but it is commonly linked to viral infections, autoimmune conditions, genetic predispositions, small fiber neuropathy, impaired norepinephrine regulation, or hypovolemia (low blood volume). Notably, long-COVID, a range of long-term symptoms and conditions resulting from an acute COVID infection, is linked to POTS. Approximately 1% of patients with an acute COVID-19 infection go on to develop orthostatic intolerance (Cheshire, 2024). Studies also show that keeping up with COVID-19 vaccinations can prevent long-COVID.

The hallmark symptom of POTS is an excessive increase in heart rate of over 30 bpm quickly after standing (WP, 2024). Common symptoms include tachycardia, palpitations, dizziness, and fainting (syncope or near-syncope), brain fog, headaches, lightheadedness, and severe fatigue. Less common symptoms include nausea, bloating, abdominal discomfort, shakiness, and exercise intolerance. POTS symptoms are often worsened by factors such as dehydration, heat, prolonged standing, illness, or physical stress. Diagnosing POTS involves a tilt-table test which monitors heart rate and blood pressure during positional changes. Treatment for POTS focuses on improving symptoms and quality of life through lifestyle adjustments. Key components include hydration, increased salt intake, compression garments, graded exercise therapy, and psychological support. Medications such as Fludrocortisone or Midodrine, that both increase blood pressure, may be added if the provider deems it fit. The course of POTS varies widely; some individuals experience significant improvement with treatment, others may have persistent symptoms. Early diagnosis and a multidisciplinary approach can lead to better outcomes.

The Effect of Altitude on the Autonomic Nervous System

Altitude significantly influences the autonomic nervous system due to reduced oxygen levels and atmospheric pressure, which challenge the body’s ability to maintain homeostasis. At higher elevations, the sympathetic nervous system becomes more active, increasing heart rate and blood pressure to compensate for lower oxygen availability. This is because hypoxia alters chemoreceptor and baroreceptor function, leading to increased sympathetic excitation and decreased parasympathetic tone.

During a study at 4300 m, urine norepinephrine levels—a marker of sympathetic activity—peaked 4–6 days after altitude exposure (Mazzeo, 1998). The study compared women in different hormonal phases when exposed to high altitude. The urinary norepinephrine levels heart rates both increased over time in both follicular and luteal phases. The differences between the two were not statistically significant, showing that women experience sympathetic increase at altitude regardless of what phase of their cycle. This was done in comparison to a previous study showing the same findings in men (Mazzeo, 1998). 

A line graph indicating the rise follicular and luteal heart rates in beats per minute as days at altitude increase.
A line graph indicating increasing amounts per 24 hours of urinary norepinephrine.

Other physiological responses include increased ventilation, cardiac output, and heart rate. However, with acclimatization, heart rate and cardiac output typically return to sea-level values within 9–12 days (Hainsworth et al., 2007). Over time, improved oxygen-carrying capacity enhances tolerance to orthostatic stress. All in all, orthostatic tolerance during hypobaric hypoxia involves three mechanisms: cardiovascular control of heart rate and cardiac output, cerebrovascular responses to hypocapnic hypoxia (due to hyperventilation), and elevated sympathetic activity (Blaber et al., 2003). 

For individuals with POTS, altitude-related stresses may exacerbate symptoms. Hypoxia and reduced barometric pressure can worsen fatigue, brain fog, and dizziness by increasing the body’s effort to oxygenate tissues. Reduced oxygen delivery to the brain and tissues may intensify lightheadedness and syncope— which is already common in POTS.

Although acclimatization typically occurs within 1–2 weeks at altitude in healthy individuals, research on acclimatization in POTS patients is limited. Further studies are needed to determine whether individuals with autonomic dysfunction can adapt as effectively as those without.

Living With POTS at Altitude 

Living with POTS at altitude presents unique challenges that require careful management, as patients may find it harder to adapt to the altitude-induced changes in blood oxygenation and pressure regulation. These challenges are compounded by the existing difficulties they face in maintaining autonomic stability. The reduced oxygen levels and increased demands on the cardiovascular system can amplify POTS symptoms, making daily activities more difficult. Patients with POTS generally understand their triggers and have a protocol that was formulated with their provider. Such strategies include staying well-hydrated, using compression garments, increasing salt intake, decreasing alcohol and caffeine consumption, and avoiding sudden changes in posture. Also, gradual exposure to altitude helps the body adapt to the reduced oxygen and barometric pressure, minimizing symptom flares. For individuals with POTS visiting high-altitude environments, strict adherence to their treatment regimen, including lifestyle modifications and potentially pharmacologic interventions, is paramount for managing their condition effectively.

References

Blaber AP, Hartley T, Pretorius PJ (2003) Effect of acute exposure to 3,660 m altitude on orthostatic responses and tolerance. J Appl Physiol 95:591–601

Cheshire WP. (2024) Postural tachycardia syndrome. UpToDate. 

Hainsworth, R., Drinkhill, M. J., & Rivera-Chira, M. (2007). The autonomic nervous system at high altitude. Clinical autonomic research : official journal of the Clinical Autonomic Research Society, 17(1), 13–19

Mazzeo RS, Child A, Butterfield GE, et al. (1998) Catecholamine response during 12  days of high-altitude exposure (4,300 m) in women. J Appl Physiol 84:1151–1157

Joy Plutowski is a second-year PA student born and raised in Arizona. She completed her undergraduate degree in biology at Arizona State University and is now pursuing her master’s at Midwestern University in Glendale, AZ. Before PA school, she worked as a medical scribe for an interventional cardiologist, a field she is interested in pursuing. Currently, she has the wonderful opportunity of completing her pediatrics rotation in Frisco, CO. In her free time, Joy enjoys exploring national parks, playing video games, dancing, and most recently, snowboarding. 

Acclimation, Altitude Science, Exposure, Genetics, Health, High Altitude

Boy Scouts and Skiers: Reducing the Risk of Developing Acute Mountain Sickness

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Thousands of boy scouts travel to Philmont Scout Ranch (PSR) in Cimarron, New Mexico each year in hopes of improving their wilderness survival skills by ascending its rugged, mountainous terrain. Elevations at PSR range from 2011 to 3792 m, in sharp contrast to the lower elevations the boy scouts are used to. Those with a history of daily headaches, gastrointestinal illnesses, and prior acute mountain sickness were found to be most at risk of developing altitude related illnesses while ascending PSR. The incidence of acute mountain sickness was 13.7% at PSR when participants ascended from base camp (2011 m) to 3000m+ as compared to up to 67% in other staged ascent studies [3]. Similarly to PSR, millions of people ascend the Colorado Rocky Mountains during ski season and face the same potential complications. This risk makes it abundantly important to investigate potential ways to prevent the development of altitude related illnesses.

Oxygen from inspired air (air breathed in) flows down its concentration gradient from the alveolar space into the blood, where it is carried primarily bound to hemoglobin and delivered to tissue. At high altitudes, oxygen availability and barometric pressure decrease remarkably, hindering the concentration gradient and increasing the risk of tissue hypoxia [2]. Progressive tissue hypoxia eventually leads to high altitude illnesses (HAI), which are cerebral and pulmonary syndromes resulting from rapid ascent. The likelihood of developing these disease processes can be greatly reduced if the body is given time to acclimate to the increased altitude. This is especially relevant during the holidays, when many are traveling from lower altitudes to higher altitudes abruptly for vacation or to visit with family.

This raises the question: should travelers spend the night in Denver before ascending into the mountains to allow for acclimatization and reduce the risk of HAI?

The rate of acclimatization, or the body’s ability to adjust to and accommodate increased oxygen requirement, is difficult to generalize given rate of ascension is not the only factor that influences the development of HAI. This process can take anywhere from days to potentially months depending on a number of factors including cardiopulmonary comorbidities, a history of HAI, genetics, certain medications, substance usage, and degree of physical exertion amongst others [5].

Despite the multifactorial nature of developing HAI, rate of ascent remains one of the primary risk factors. Studies have shown that spending time at moderate altitude before ascending to higher altitudes in a process called “staged ascent” decreases the likelihood of developing HAI in unacclimatized individuals [4]. A recent study conducted at the U.S. Army Research Institute of Environmental Medicine assessed incidence of acute mountain sickness (AMS, a subcategory of HAI), in unacclimatized individuals who were staged for 2 days at altitudes of 2500 m, 3000 m, and 3500 m respectively before ascending to 4300 m. Another group ascended directly to 4300 m without staging. Ultimately, the incidence of AMS was significantly lower in the staged groups than in the direct ascent group; AMS incidence in the staged groups was up to 67%, while AMS incidence in the direct ascent group was up to 83% [1].

Two graphs, A and B, illustrate the incidence of acute mountain sickness by percent at elevations of 2500m, 3000m, 3500m and a control group, as well as peak acute mountain sickness severity ranked from 0 to 2 for the same elevations and a control group.

Graphs A and B show that the incidence of AMS at 4300 m is reduced when unacclimatized individuals are staged at 2500 m, 3000 m, and 3500 m as compared to those who directly ascended to 4300 m [1].

Given the above information, unacclimatized individuals, skiers and boy scouts alike, may benefit from spending the night in Denver before coming to the mountains, as this mimics staged ascent and thus decreases the incidence of HAI.

Tall, snowy pines rise up out of powdery snow on a ski slope overlooking forests stretching out toward a range of white peaks in the distance under a sunny blue sky.
View from the top of Keystone Resort taken while snowboarding (elevation 3782 m)

References

[1] Beth A. Beidleman et al. “Acute Mountain Sickness is Reduced Following 2 Days of Staging During Subsequent Ascent to 4300m”. In: High Altitude Medicine & Biology 19.4 (2018). Published Online: 21 December 2018, pp. xxx–xxx. doi: 10.1089/ham.2018.0048. 

[2] Chris Imray et al. “Acute Mountain Sickness: Pathophysiology, Prevention, and Treatment”. In: Progress in Cardiovascular Diseases 52.6 (May 2010), pp. 467–484. doi: 10.1016/j.pcad.2009.11.003.

[3] Courtney LL Sharp et al. “Incidence of Acute Mountain Sickness in Adolescents Backpacking at Philmont Scout Ranch”. In: Wilderness and Environmental Medicine 35.4 (2024), pp. 403-408

[4] Andrew M. Luks, Erik R. Swenson, and Peter B¨artsch. “Acute high-altitude sickness”. In: European Respiratory Review 26.143 (Jan. 2017), p. 160096. doi: 10.1183/16000617.0096-2016.

[5] Michael Schneider et al. “Acute mountain sickness: influence of susceptibility, preexposure, and ascent rate”. In: Medicine & Science in Sports & Exercise 34.12 (Dec. 2002), pp. 1886–1891

Matison Miratsky is a physician assistant student who attends Midwestern University in Arizona with plans to go into OB/GYN. Before PA school, she grew up in Denver, Colorado and attended the University of Colorado at Boulder. She worked in an emergency department in Denver, then at a family medicine clinic in Arizona. Her personal interests include snowboarding, watching movies, spending time with family, and cooking.

Acclimation, Altitude Science, Backcountry, Backpacking, Health, High Altitude, Huts, Medicine, Mountaineering, Technology

New Use for Existing Technology and HAPE/HACE

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by Kaity Barker-Grasser, FNP

Ultrasound itself is not an unfamiliar technology to most, having been used in obstetrics and gynecology (OB/GYN) for many years. Newer research is now showing that ultrasound imaging may have good applicability in both high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE). Pulmonary edema (or fluid in the lungs) is identified as “B-lines” or “comet tails” and is easily distinguishable on ultrasound (Gargani, 2019).

Illustration of the rib cage and clavicle bones indicating different probe positions to scan the lung using Ultrasound, accompanied by two images of lung Ultrasounds where asterisks indicate shadows of the ribs and white arrows indicating the pleural line.
Gargani, 2019

Using ultrasound to measure the diameter of the optic nerve can also assist with a diagnosis of HACE, as an increased diameter indicates increased intercranial pressure from HACE (Shookahi et al., 2020). The advantages of ultrasound over traditional imaging include being highly portable and usable in austere environments (such as back country), no radiation like many other imaging techniques, accurate for diagnosing pulmonary edema and other conditions, and takes little time for providers to master. Ultrasound also has a significant cost savings as the machine itself is relatively inexpensive, does not require special construction like adding lead to an Xray room, and is applicable in many other diagnoses (including kidney disorders, gallbladder disease, pneumonia, trauma, muscular disorders, and gynecological complaints). Ultrasound also has the capability to differentiate types of pulmonary edema, as well as other lung disorders, and generally much faster than a traditional Xray as there is no radiographic lag between clinical onset and ultrasound changes.

Three x-ray images displaying different etiologies of B-lines: cardiogenic pulmonary edema, noncardiogenic pulmonary edema, and pulmonary fibrosis.
Pulmonary Edema on Xray, Mayo Clinic, 2024

Pulmonary Edema on Xray Mayo Clinic, 2024

In HAPE, an increase in the number of B-lines indicates an accumulation of fluid in the lungs. Healthy individuals acclimating to the altitude have been shown to have a physiologic increase in B-lines during the first 4 days of high-altitude exposure as well as pregnant individuals having an increase in their baseline b-line count. Keeping these differences in mind, an increase of B-lines of more than 3 in a lung field, in more than 2 lung fields indicates an increase in extravascular lung water (EVLW) and could support a diagnosis of HAPE. Correlating this with clinical signs and symptoms of altitude sickness (HA, dizziness, fatigue, shortness of breath, nausea/vomiting), as well as HAPE (hypoxia, cough, exercise intolerance) can support a more rapid diagnosis of HAPE as well as assist with deciding need for oxygen and/or altitude descent (Yang et al., 2018; Heldeweg et al., 2022). The provider can also use the ultrasound to monitor resolution of the pulmonary edema to help support decisions to discontinue oxygen or to encourage altitude descent. Those with comorbidities such as heart failure can also be monitored for early signs that their treatment plan is not adequately addressing their EVLW and can receive correction prior to needing hospitalization (Chiu et al., 2022).

Two x-ray images of the chest from the Mayo Clinic labelled cardiogenic and HAPE/noncardiogenic from left to right.

Pulmonary Edema on Xray Mayo Clinic, 2024

HACE, as a disorder including altered mental status, ataxia, headache, loss of consciousness, and seizures, is a serious complication of high altitude. As the symptoms suggest, rapid identification is key to reducing other problems, including death, from HACE. The use of ultrasound is relatively new in assisting with diagnosis, but an increase in optic nerve diameter on ultrasound above 5 millimeters indicates that there is a good chance of brain swelling (or cerebral edema) and subsequent increased intracranial pressure. Identifying this early allows for rapid decision making the descent to a lower altitude or using a more rapid evacuation method (helicopter or rapid ground transport). Increased intracranial pressure can also result from head injury or trauma and thus can be useful in settings where an injury may have occurred. This makes this a tool that could be invaluable in search and rescue operations or for first responders (Shookahi et al., 2020).

Four Ultrasound images of the lungs illustrating use as a densitometer: different ultrasound patterns for different levels of lung aeration. Below the images, a graph indicating lung air content from 100% on the left to 0% on the right.
Gargani, 2019

Keeping these benefits in mind, remember that diagnostic imaging is a support tool and not the complete answer to all health problems. Hopefully soon we will see this tool being used with more frequency to help aid our healthcare providers in determining a more accurate cause of symptoms!

References

Chiu, L., Jairam, M. P., Chow, R., Chiu, N., Shen, M., Alhassan, A., Lo, C.-H., Chen, A., Kennel, P. J., Poterucha, T. J., & Topkara, V. K. (2022). Meta-Analysis of Point-of-Care Lung Ultrasonography Versus Chest Radiography in Adults With Symptoms of Acute Decompensated Heart Failure. The American Journal of Cardiology, 174, 89–95. https://doi.org/10.1016/j.amjcard.2022.03.022

Gargani L. (2019). Ultrasound of the Lungs: More than a Room with a View. Heart Failure Clinics, 15(2), 297–303. https://doi.org/10.1016/j.hfc.2018.12.010

Heldeweg, M. L. A., Smit, M. R., Kramer-Elliott, S. R., Haaksma, M. E., Smit, J. M., Hagens, L. A., Heijnen, N. F. L., Jonkman, A. H., Paulus, F., Schultz, M. J., Girbes, A. R. J., Heunks, L. M. A., Bos, L. D. J., & Tuinman, P. R.. (2022). Lung Ultrasound Signs to Diagnose and Discriminate Interstitial Syndromes in ICU Patients: A Diagnostic Accuracy Study in Two Cohorts*. Critical Care Medicine, 50(11), 1607–1617. https://doi.org/10.1097/ccm.0000000000005620

Mayo Clinic (2024). Pulmonary Edema. Mayo Foundation for Medical Education and Research. Retrieved February 27, 2024 from https://www.mayoclinic.org/diseases-conditions/pulmonary- edema/symptoms-causes/syc-20377009

Shokoohi, H., Pyle, M., Kuhl, E., Loesche, M. A., Goyal, A., LeSaux, M. A., Boniface, K. S., & Taheri, M. R. (2020). Optic Nerve Sheath Diameter Measured by Point-of-Care Ultrasound and MRI. Journal of neuroimaging : official journal of the American Society of Neuroimaging, 30(6), 793–799. https://doi.org/10.1111/jon.12764

Yang, W., Wang, Y., Qiu, Z., Huang, X., Lv, M., Liu, B., Yang, D., Yang, Z., & Xie, T.. (2018). Lung Ultrasound Is Accurate for the Diagnosis of High-Altitude Pulmonary Edema: A Prospective Study. Canadian Respiratory Journal, 2018, 1–9. https://doi.org/10.1155/2018/5804942

Acclimation, Altitude Science, Child Growth & Development, Genetics, Health, High Altitude, Huts, Medicine, Summit Huts

Unveiling the Hidden Risks of Living at High Altitude on our Kidney Health, and What it Might Mean for Your Child

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The hallmark concern for the body living at high altitude is low oxygen. We breathe in less, and thus less is sent throughout our blood stream to our tissues. We are quick to think about how this affects our heart and lungs, but what about our kidneys? What are our kidneys even responsible for?

Kidneys filter, reabsorb, and excrete our blood in the form of urine. They connect our cardiovascular system with our genitourinary system. The flow through the kidneys also helps monitor and adjust our blood pressure. Their importance is truly undervalued. When they receive less oxygen than preferred (hypoxia), they will become injured. Specifically, the glomerulus (term for the filter) will become affected. When this happens, it is not efficient at filtration, and protein will spill out into our urine (proteinuria), a key feature of High Altitude Renal Syndrome (HARS).

Zooming further in below

And even further…

Another issue involves uric acid, the chemical at fault for causing gout. Due to the filter injury sustained from low oxygen, uric acid excretion is affected. It can thus build up in our musculoskeletal system and other tissues. It is famous for causing red, swollen, and painful joints. The enzyme that helps create uric acid (xanthine oxidase) is also turned on by reactive oxygen species during hypoxia. This then causes further uric acid crystal deposition in our body. This can present in patients from adolescent years through adulthood, ranging from fleeting pain to amputations from severe bone infections. We have found that for younger patients, diet plays a lesser part than genetic predisposition and hypoxia.

So how is this treated? We are still researching the best course of action. We can treat with drugs that work by inhibiting the previously specified enzyme: xanthine oxidase. These include oral allopurinol, febuxostat, and even IV pegloticase infusions. But we are primarily focused on prevention and holistic care here, so we would prefer to use supplemental oxygen therapy for those that struggle to maintain oxygen saturations in the healthy ranges. Acetazolamide is also helpful in cases. This medication works to increase our respiratory drive, helping us breathe off CO2 and breathe in more oxygen. Contact us to see what method might be right for you.

This research was brought to us by a stroke of luck. A stranger on an airplane, and a son’s coworker. This stranger happened to be a nephrologist (kidney doctor) who is studying how altitude affects the kidneys. In working with him and his team at University of Colorado Anschutz, the team at Ebert Family Clinic in Frisco, Colorado (9000′) have been ordering broader lab panels (including uric acid) for their patients and seeking those with questionable renal labs. Another patient seen by the Ebert Family Clinic team has been severely impacted by gout. With multiple amputations before the patient’s 30th birthday, this case has motivated the health care team to prevent this from happening to others in their high altitude community.

Screenshot

Carter Odean is a third-year medical student at Rocky Vista University. He was born and raised outside of Denver, Colorado before heading to Gonzaga University in Spokane, Washington where he studied biology and completed research on an invasive bee species there while playing club lacrosse. After graduating in 2019, he then came back to Denver to complete his Master’s in Biomedical Sciences at Regis University. After Regis, he started as a Clinical Research Coordinator at Anschutz Medical campus, working on multiple Diabetes Mellitus Type 2 research trials. He is in the Rural & Wilderness Track which is his favorite part about school. He plans to work as a rural Pediatrician or Family Medicine Physician. In his free time, you can find him dirt biking, fly fishing, skiing, and relaxing with friends and family. 

References

  1. Schoene, R.B. “High altitude renal syndrome: polycythemia, hyperuricemia, microalbuminuria, and hypertension.” High Alt Med Biol. 2002 Spring;3(1):65-73. doi: 10.1089/152702902753639371. PMID: 11949751.
  2. Bigham, A.W., Lee, F.S. “Tibetan and Andean patterns of adaptation to high-altitude hypoxia.” Hum Biol. 2014 Oct;86(4):321-37. doi: 10.3378/027.086.0401. PMID: 25700353; PMCID: PMC4438718.
  3. Beall, C.M., Cavalleri, G.L., Deng, L., et al. “Natural selection on EPAS1 (HIF2α) associated with low hemoglobin concentration in Tibetan highlanders.” Proc Natl Acad Sci U S A. 2010 Mar 9;107(25):11459-64. doi: 10.1073/pnas.1002443107. Epub 2010 Feb 22. PMID: 20176925; PMCID: PMC2895106.
  4. Simonson, T.S., Yang, Y., Huff, C.D., et al. “Genetic evidence for high-altitude adaptation in Tibet.” Science. 2010 Sep 10;329(5987):72-5. doi: 10.1126/science.1189406. PMID: 20616233; PMCID: PMC3490534.
  5. Schoene, R.B., Swenson, E.R. “Cobalt-Induced Chronic Mountain Sickness: Pathophysiological Mechanisms and Genetic Susceptibility.” High Alt Med Biol. 2017 Mar;18(1):1-5. doi: 10.1089/ham.2016.0106. PMID: 28145824.Baillie, J.K., Bates, M.G., Thompson, A.A., et al. “Endogenous urate production augments plasma antioxidant capacity in healthy lowland subjects exposed to high altitude.” Chest. 2007 Dec;132(6):S275. doi: 10.1378/chest.132.6.275. PMID: 18079246.
  6. Yu, K.H., Wu, Y.J., Tseng, W.C., et al. “Risk of end-stage renal disease associated with gout: a nationwide population study.” Arthritis Res Ther. 2012 Jun 27;14(3):R83. doi: 10.1186/ar3818. PMID: 22738152; PMCID: PMC3446515.
  7. Bhat, A., Deshmukh, A., Anand, S., et al. “Acute Myocardial Infarction due to Coronary Artery Embolism in a Patient with Severe Hyperuricemia.” J Assoc Physicians India. 2019 Nov;67(11):90-91. PMID: 31801335.
  8. Khanna, D., Khanna, P.P., Fitzgerald, J.D., et al. “2012 American College of Rheumatology guidelines for management of gout. Part 1: systematic nonpharmacologic and pharmacologic therapeutic approaches to hyperuricemia.” Arthritis Care Res (Hoboken). 2012 Oct;64(10):1431-46. doi: 10.1002/acr.21772. PMID: 23024028.
  9. Schoene, R.B., Swenson, E.R. “Treatment of Cobalt-Induced Chronic Mountain Sickness.” High Alt Med Biol. 2017 Mar;18(1):74-77. doi: 10.1089/ham.2016.0135. PMID: 28145823.
  10. Schoene, R.B., Hackett, P.H., Henderson, W.R., et al. “High Altitude Medicine and Physiology, Fourth Edition.” CRC Press, 2007.
  11. Burtscher, M., Mairer, K., Wille, M., et al. “Risk of acute mountain sickness in tourists ascending to 4360 meters by cable car.” High Alt Med Biol. 2004 Summer;5(2):141-6. doi: 10.1089/1527029041352154. PMID: 15265307.
  12. Baumgartner, R.W., Bärtsch, P. “Chronic mountain sickness and the heart.” Prog Cardiovasc Dis. 2010 May-Jun;52(6):540-9. doi: 10.1016/j.pcad.2010.02.009. PMID: 20417390.