Dr Christine Ebert-Santos presents to employees of the Town of Breckenridge. Contact Ebert Family Clinic if your organization or group is interested in learning more about living in our hypoxic environment admin@ebertfamilyclinic.com
Category Archives: Acclimation
What happens to your body’s physiology when you move between low and high elevations?
Rethinking Your Energy Supply
On May 27th 2017, Adrian Ballinger summited Mount Everest without supplemental oxygen. This is an accomplishment that less than 200 people have achieved and followed a failure to summit the previous May of 2016. The 41 year old seasoned climber attributed his failures to the cold, which could have been aided by more muscle and fat content, better insulated jacket and gloves, but he wondered why his climbing partner, Cory Richards so easily made it to the top. Ballinger came to realize it that wasn’t his gear or body composition, but it was that Richards had a different approach to training and nutrition that gave him the edge to summit. Richards trained with a organization called Uphill Athlete that trains its athletes to become a fat burners. After hearing of Richard’s training regimen Ballinger was determined to pursue the same for a another summit attempt in 2017. Ballinger was a carb burner, which means he was relying on burning carbohydrates for energy. When he attempted to summit Everest being a carb-burner, he simply ran out of energy to fuel his body through the last grueling stretch. This was due to depleted glycogen levels that a carb-burner relies on. The average human can only contain enough carbohydrates to supply glycogen stores for about 45 minutes. Once your glycogen stores are depleted, you need to refuel, which in Ballinger’s case, would mean pulling a hand out of a mit in the frigid Everest air to replenish his energy every 45 minutes. This is also known as “bunking,” which means completely exhausting your energy supply, which is what happened to Ballinger. Richards on the other hand, was a fat burner. With alterations in Ballinger’s nutrition and training regimen, he was successful in 2017.
But what is a fat burner?
A fat burner is an athlete that primarily uses fat for energy, and this metabolic process is called fat oxidation. When an athlete is exercising on a typical high carb and low fat diet, they are burning about a 50/50 mix of carbs and fats during steady exercise. If that athlete decides to sprint at full speed being a carb burner or a fat burner, they are primarily burning carbohydrates, known as glycogen. This is the body’s evolutionary design to have instant energy to run away from the tiger when it storms your cave. In Ballinger’s scenario, the high intensity of Everest climbing was like a sprint, depleting all of his glycogen stores causing him to “bunk”.
Why is a fat-burning diet better for climbing?
Being a fat burner for a long distance endurance athlete is beneficial because it eliminates the need to refuel every 45 minutes, which is bothersome. Ever wonder why there is a plethora of fancy sugary “sports” drinks, gummies, and energy bars at sporting stores? They are called “energy” foods, because they are loaded with simple carbohydrates and sugar. On the other hand, a fat burner does not need refueling foods or drinks during exercise, but relies on the extensive supply of fat throughout the body. Even the most elite athletes with very low body fat will have enough to supply the body energy for a event. Picture this, there is a giant fuel tanker truck cruising on I-70. The truck has its own fuel tank which sits below the cab of the truck, which will be depleted in a couple hours. What if the truck could access the large tank that it’s hauling? That would give the trucker a enough fuel to drive for days! In the context of nutrition and your body, the small tank is the your glycogen storage and the large tank is fat storage. This is why some people can fast for days without skipping a beat; they have tapped into their fat supply.
What does it take to become a fat burner?
To become a fat burner, it’s quite simple: cut the carbohydrates. Well, I guess some may think it’s not so easy. You have to cut out pizza, bread, candy, tortillas, and all that good tasty stuff. When a person limits their carbohydrate intake to less than 10% of caloric intake, and increase fat consumption to 70% of their intake, their body shifts into a different mode of creating energy, by burning fat instead of carbs. The by-products of fat oxidation are called ketones. When a person converts to being a fat burner, it is called being in ketosis. This process may take a few days to weeks, which varies from person to person.
Is there any research behind this crazy idea of eating all the bacon and butter you can handle?
Yes, yes there is!
In the research article by Volek et al. (2015), the authors wanted compare a low carbohydrate ketogenic diet and a typical high carbohydrate diet in 20 elite endurance athletes. The authors tested the athletes with a 180 minute, moderate intensity (64% VO2 max), treadmill run.
VO2 max is known as the capacity of your cardiovascular system and its ability to distribute oxygen throughout the body. Higher means a stronger cardiovascular system, so 64% of your maximum effort would be considered moderate exercise.
A 64% VO2 max to you or I would be a brisk walk or a slow hike up that beautiful 14’er, but for these Ironman athletes it was an easy run on a treadmill. The authors compared the rate of fat oxidation and carb oxidation between the two diets, as well as their ability to recover and replenish their glycogen stores. The authors found that the fat adapted athletes had 2.7 times the rate of fat oxidation than the high carb diet athletes. The low carb group also had fat oxidation at higher VO2 max, meaning they could go faster without tapping into their precious glycogen stores. The study also found that after the exercise, the athletes in both groups had similar glycogen level in their muscle. This is significant because the classic rule of thumb with exercising is that you need a post-workout shake with protein and carbs to replenish your muscles, or your exercising efforts are gone to waste …
WRONG!
It turns out your body has its own way of replenishing its glycogen stores without the post-workout carb load. That means after you climb that 14’er, you don’t necessarily have to stop at the local brewery for carb-tastic IPA, but I won’t judge you if you do.
In another research article by Hetlelid et al., they wanted to compare the levels of fat and carb oxidation levels between nine well-trained (WT) runners and nine recreationally-trained (RT) runners during a high-intensity interval training session (HIIT). There was no difference in diets amongst the participants in the study. The study found that the WT runners had a three times higher rate of fat oxidation than RT runners and increased performance with higher VO2 max. The author attributed the increased performance due to the higher rates of fat oxidation. These athletes were consuming a normal carb-ful diet, which makes me wonder what the difference would have been if they were fat adapted.
So, let’s get down to why all this mumbo-jumbo is important to your next trip to the high country. Many outdoor activities that we enjoy in the summer like hiking, biking, climbing, etc. all require significant energy to supply for all day fun. Take climbing a 14’er, for example. You will most likely be climbing for several hours, depleting your energy stores as you climb being on a high carb diet. You have to stop, refuel, start up climbing, stop and repeat. As a fat adapted climber, you could sail past your carb-comrades with ease, not depleting your glycogen stores all day, all while burning some of that winter Christmas cookie belly in the process. As we examined the two research articles, we also found that higher fat oxidation could mean higher VO2 max levels.
What does this mean for your next trip to high altitude?
That’s right, better usage of the less available oxygen in the high country and improving oxygen delivery throughout the body. If you want to be the best Balliger you can be on the mountains this summer, rethink your energy supply and consider life in the fat lane!
So, here are some personal tips to becoming fat adapted:
-Give your body at least 3 weeks to become adapted before any highly strenuous activity, like climbing a 14’er
-Hydrate, hydrate, hydrate with water, and balance it with electrolytes
-Consult with your physician before drastically changing your diet
-Choose foods high in natural fats (eggs, nuts, olive oils, avocados, meat, fish, dairy) and stay away from unhealthy trans fats
-Intermittent fasting can help you transition into ketosis faster (12-16 hrs)
References
Hetlelid, K. J., Plews, D. J., Herold, E., Laursen, P. B., & Seiler, S. (2015). Rethinking the role of fat oxidation: Substrate utilisation during high-intensity interval training in well-trained and recreationally trained runners. BMJ Open Sport & Exercise Medicine, 1(1). doi:10.1136/bmjsem-2015-000047
Volek, J. S., Freidenreich, D. J., Saenz, C., Kunces, L. J., Creighton, B. C., Bartley, J. M., . . . Phinney, S. D. (2016). Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism, 65(3), 100-110. doi:10.1016/j.metabol.2015.10.028
http://www.adrianballinger.com/about/
Mountains and Caffeine
Effects of Caffeine at High Altitude
Visitors travelling to high altitude destinations have been known to avoid coffee/caffeine intake in order to avoid the dreaded symptoms of acute mountain sickness. The theory is that caffeine leads to dehydration, which then predisposes the individual to acute mountain sickness. A few symptoms of dehydration include headache, lethargy, confusion, weakness, nausea and vomiting. Similarly, symptoms of acute mountain sickness include fatigue, headache, nausea, vomiting, shortness of breath and difficulty sleeping. Although the symptoms of dehydration and acute mountain sickness are very similar, there is no evidence to support this claim that dehydration predisposes an individual to acute mountain sickness.1 Thus, the diuretic effect of coffee and caffeine are often exaggerated. Individuals that are accustomed to drinking 12 oz. of coffee rarely suffer from the diuretic effect of the beverage.1
The condition of acute mountain sickness is a response to hypoxia in the brain’s vascular circulation that causes an increase in the release of a neurotransmitter called adenosine. Adenosine binds to adenosine receptors found on the inner lining of cerebral blood vessels, causing vasodilation of the blood vessels in an attempt to increase the flow of oxygen and nutrient-rich blood to the brain. This increase in cerebral blood flow, however, is painful and causes many of the above-mentioned symptoms of acute mountain sickness.
Caffeine, in contrast, counteracts these effects of adenosine in the brain’s circulation by causing vasoconstriction of those cerebral blood vessels, decreasing blood flow within the brain. Therefore, it is likely that caffeine can help prevent the onset of acute mountain sickness because of its ability to decrease cerebral vasodilation in response to hypoxia at high altitude.1 Caffeine is included in several over-the-counter headache medications, such as Excedrin Migraine, exactly for this purpose.
While there is no clinical data exhibiting that caffeine increases the rate at which individuals acclimate to living at high altitude from sea level, physiologic studies suggest that caffeine is helpful in increasing ventilation and decreasing hypoxia. Caffeine stimulates chemoreceptors in the brain and carotid arteries, altering the brainstem’s respiratory center in the medulla oblongata to become more sensitive to low blood oxygen saturation. As a result of this increased sensitivity to hypoxia, the lungs and respiratory muscles unconsciously increase their activity to increase resting ventilation rate and increase blood oxygen saturation.
My Experience
During my six weeks at the Ebert Family Clinic for my pediatric medicine rotation, I measured my blood oxygen levels before and after drinking 12 oz of coffee. My results can be found in Table 2.
Table 2. Six-week average blood oxygen saturation pre- and post-consumption of 12 oz. coffee
| Pre-coffee oxygen saturation average: | Post-coffee oxygen saturation average: |
| Week 1 | 91% | 94% |
| Week 2 | 90% | 92% |
| Week 3 | 91% | 93% |
| Week 4 | 92% | 94% |
| Week 5 | 92% | 93% |
| Week 6 | 91% | 93% |
While these results are an anecdotal summary of my own experience living at high altitude and drinking coffee for six-weeks, drinking 12 oz. of coffee showed an average increase of blood oxygenation of 2%.
Caffeine Study at Everest
One study conducted at the base camp of Mt. Everest (17,600 ft) studied the 24-hour effect of caffeine in black tea ingested by one study group compared to a placebo group that only drank water. Both groups ingested the same volumes of liquid in the 24 hours. The study found that both groups had identical urine amounts at the end of the study, suggesting that caffeine did not lead to dehydration. Additionally, the tea-drinking group reported less fatigue and better mood compared to the placebo group.1
Caffeine Withdrawal at High Altitude
Caffeine cessation in fear of dehydration while travelling to high altitude destinations often leads to an exacerbated withdrawal reaction from caffeine, mimicking the symptoms of acute mountain sickness. This is due to the up-regulation, of adenosine receptors in the brain that become uninhibited in the absence of caffeine. As a result, adenosine binds to the increased amount of adenosine receptors in the brain causing excessive cerebral vasodilation and subsequent headache, nausea, vomiting, weakness, lethargy and confusion. Therefore, regular coffee drinkers or any type of caffeine users should avoid abrupt cessation of caffeine intake while traveling from sea level to high altitude.1
Future Studies
The above mentioned studies have not studied the effects of caffeine in caffeine-tolerant vs. caffeine-naïve individuals, but a trial of caffeine in the form of either coffee, tea or pill would be worthwhile in otherwise healthy individuals suffering from symptoms of acute mountain sickness while visiting high altitude locations. Future studies would benefit from comparing the effects of caffeine on caffeine tolerant individuals and individuals who do not consume caffeine on a regular basis. However, individuals must always consult their health care provider to determine if it is safe to use caffeine prior to consumption of caffeine products.
Michael Peterson, PA-S
University of St. Francis, Physician Assistant Program
Summit v.s. Saipan: Running
When I lived on Saipan in the Pacific and visited my parents in Breckenridge I noted that my 10k times were just as good at 9000 ft with humidity around 27% and temperatures in the 70’s as at sea level with 80% humidity and temperatures in the 80’s. Last month I had the same experience, in reverse: living at high altitude and visiting Saipan. Reading our blog on asthma, I attribute that to the lower viscosity of air and lower air pressure in the mountains compared to the high density of water vapor in the islands. Both locations are beautiful and inspiring places to run!
Tatum Simonson and Altitude Adaption: Physiologic and Genetic
Tatum Simonson is a researcher at the University of California, San Diego who is interested in high altitude medicine: specifically, how high altitude adaptations can, over hundreds of generations, become part of our genes. I read one of her publications called Altitude Adaptation: A Glimpse Through Various Lenses. It delves into the research that has been done on physiologic and genomic changes of high altitude inhabitants and how these two factors coincide.
When looking at this information, it is important to remember that the reason high altitude is so much different from sea level or lower altitude is the oxygen in the air. It is not necessarily the percentage of the oxygen in the air, because the air is 20.9% oxygen at all altitudes. It is actually the lower air pressure that makes it feel like there is less oxygen. The air pressure comes from the weight of the air above us in the atmosphere. The further you go up, the less atmosphere there is above you to press down, and therefore less air pressure. Boyle’s law (whoa physics!) basically says that because of the lower pressure, in a given volume of air there are fewer molecules. Because there are fewer molecules of everything, the percentage of oxygen remains 20.9% but it feels like there is less oxygen in the air.
This is all to say that organisms have to adapt to this lower air pressure and less molecules in a given volume. Things that we know are affected include the saturation of oxygen of our blood. With less air pressure to drive the saturation of our blood with oxygen, sometimes it leads to low oxygen levels, or hypoxia. Hypoxia is detrimental because our body needs oxygen for our cells to function.
Simonson looks at 3 populations that have lived at high altitudes (3500m-4500m or 11,483ft-14,764ft) for hundreds of generations: Qinghai-Tibetan Plateau, Andean Altiplano, and Semien Plateau of Ethiopia (see map below). In her paper she goes further into the history of these populations and the uncertainty that exists with their timeline, but for our purposes just know that these populations have inhabited these high altitude areas for anywhere from 5,000-70,000 years.
Figure 1. Map with three locations where high-altitude adapted populations have lived for hundreds of generations. (Image modified from http://www.nasa.gov/topics/earth/features/20090629.html; low elevations are purple, medium elevations are greens and yellows, and high elevations are orange, red and white.) Tatum S. Simonson. High Alt Med Biol. 2015 Jun 1;16(2):125-137.
The first lens she looks through is physiologic, or how the body functions. There has been extensive research in this lens, summarized below.
- Increased common iliac blood flow into uterine arteries in Tibetan and Andeans leads to increased utero-placental oxygen delivery at altitude, allowing less growth restriction. In other words, Tibetan and Andean populations have increased the blood flow to the growing fetus to help it grow more like someone living at lower altitudes. Furthermore, some studies show that their babies are actually bigger.
- Tibetan and Amhara Ethiopian populations show the characteristic increase in hemoglobin levels that has long been associated with travelers to high altitude, but to a much lower extent than someone who has just traveled to altitude (i.e. native lowlander). This is in contrast even with Andean populations, who have higher hemoglobin levels than Tibetans. The Tibetan and Amhara Ethiopian populations don’t necessarily need a higher level of hemoglobin (molecule that carries oxygen) to get the oxygen that they need to their tissues.
- Differences in the control of breathing: the hypoxic ventilation response is an increase in ventilation that is induced by low oxygen levels. The research shows that Tibetans exhibit an elevated hypoxic ventilation response while Andeans exhibit a blunted response.
- Tibetan and Sherpa have been shown to have higher heart rates than lowlanders at altitude, as well as increased cardiac output, or blood that they are able to pump out of their hearts. There are also differences in the energy sources that some high altitude populations use for their heart to pump.
- There are certain adaptive changes in skeletal muscle that Sherpa populations have made as well. Specifically, increased small blood vessels and increased maximal oxygen consumption.
The second lens is genomic, or the evidence for different genes in highlanders that have allowed them to survive and thrive at higher altitudes. One theory is that the ancestors of modern day highlanders had specific genes that gave them traits that were favorable for surviving at high altitudes. By matter of Darwinian selection, these genetic variants were passed down favorably over generations.
- Many genes studies are involved in the hypoxia-inducible factor (HIF) pathway, which is involved in regulating various responses to hypoxia including making new blood vessels, making new red blood cells, iron regulation, and metabolism.
- Specific genes studied include EPAS1 – has been associated with low (within sea level range rather than elevated) hemoglobin in Tibetans at altitude discussed above. EGLN1 and PPARA have also been associated with hemoglobin concentration changes.
- There are many other specific genes that have been associated with specific adaptive changes for these high altitude populations.
It is important to realize the physiologic and genetic components of adaptation to high altitude environment. Simonson sums it up best herself:
“Understanding the associations between genetic and physiological variation in highlanders has additional application for understanding maladaptive and general responses to hypoxia, which remain an important biomedical component of hypoxia research. This is also of clinical value when considering distinct and shared hypoxia-associated genetic variants and combinations thereof may contribute to physiological responses in residents and visitors to the environmental hypoxia at altitude as well as chronic…or intermittent…states of hypoxia.”
I was happy to read this article and see how high altitude medicine may be affected by genomics in the not-so-distant future. Hopefully you learned something about hypoxia, physiologic and genetic adaptations!
Hannah Evans-Hamer, MD
Resources:
Simonson T. Altitude Adaptation: A Glimpse Through Various Lenses. High Alt Med Biol. 2015 Jun; 16(2):125-37. PMID: 26070057; PMCID: PMC4490743.
Reentry High Altitude Pulmonary Edema (HAPE) in High Altitude Residents!
When High Altitude Pulmonary Edema (HAPE) is diagnosed, one often thinks of the diagnosis in relation to patients who have lived long term in low/sea level altitudes coming to high altitudes for the first time. However, a new study conducted by Santosh Baniya based out of the Himalayas suggest there is a subset of HAPE in which long term high altitude residents can fall ill to HAPE upon reentry to high altitudes after even a brief stay at lower altitudes.
Baniya’s study is based off a case report of an otherwise healthy pediatric patient who was diagnosed with HAPE after returning to his village of Manag (3500m) after a winter in Besisahar (760m)- a trip that was done multiple times in his life time with no complications. One change surrounding this diagnosis was a recent construction of a road between the two villages that decreased the usual travel time from a span of several days to a single day. The pathophysiologic explanation behind this phenomenon is thought to be caused by the descent of high altitude residents to lower altitudes, leading to a decrease in the red cell mass and a compensatory rise in plasma volume, which then in turn predisposes an individual to pulmonary edema once they return to high altitudes. Had the patient taken the original route of travel- it is likely that the gradual ascent would’ve allowed his body to acclimate to the altitude change and the red cell mass and plasma levels would’ve adjusted accordingly. However, due to the decrease in overall travel time the excess plasma levels led to pulmonary edema. Manifestation of this included shortness of breath, respiratory distress, and hypoxia (an oxygen saturation of 44% in this case). Treatment included high-flow oxygen, dexamethasone to help with air way swelling, and descent to lower altitudes which resulted in immediate marked improvement.
The remarkable aspect of this case- and the reason it was published- is that the doctors in a high altitude community failed to recognize a condition familiar to medical providers in the mountains here in Colorado. More importantly the clinical symptoms that we describe here are also pertinent to Mountain Resident HAPE and Trauma Related HAPE, which is often misdiagnosed by experts in Denver and other lower altitude communities outside of Colorado. Understanding the prevalence of this phenomenon is of utmost importance as an incorrect diagnosis of influenza, pneumonia or asthma could lead to fatal consequences- as oxygen does not treat these conditions. Proper recognition, diagnosis and treatment with oxygen, rest, and if severe enough, descent into lower altitudes need to be carried out promptly for effective treatment.
Garkie Zhu, PA-S3
MCPHS PA Program
Reference:
Baniya, S. (2017). Reentry High Altitude Pulmonary Edema in the Himalayas. High Altitude Medicine & Biology,18(4), 425-427. Retrieved January 23, 2018.
Ebert-Santos, C. (2017). High-Altitude Pulmonary Edema in Mountain Community Residents. HIGH ALTITUDE MEDICINE & BIOLOGY, 18(3), 278-284. Retrieved February 2, 2018.
Chronic Mountain Sickness
Avinell Abdool
Chronic Mountain Sickness (CMS) is a pathological finding that is commonly found amongst individuals that have taken up permanent residence in high altitude environments (altitudes of over 8,200 feet)1. Clinical manifestations of CMS include but are not limited to the following1;
- HA
- Dizziness
- Tinnitus
- Breathlessness
- Palpitations
- Sleep Disturbances
- Fatigue
- Loss of appetite
- Confusion
- Cyanosis
- Dilation of veins
CMS is the outcome of progressive loss of ventilation rate, which subsequently results in hypoxemia and polycythemia2. Polycythemia is defined as by excessive erythrocytosis (EE; Hb >/= 19g/dL for women and Hb >/= 21 g/dL for men) which along with a hypoxic environment can result in pulmonary hypertension2. In advanced conditions of Chronic Mountain Sickness there can be cor-pulmonlae and congestive heart failure2 .
A study was conducted in the University of San Diego by Dr. Gabriel Haddad that researched the adaption of the Peruvian population in high altitude conditions3. It was found that CMS is highest in the Andeans (approximately 18 %), lesser in Tibetans (1%-11%) and completely absent in the Ethiopian population3. From these data points it appeared that there was was a genetic correlation between CMS sufferers and ethnicity3. In addition, this finding added another factor that mystified the conclusive pathogenesis of CMS3. By understanding exact pathogenesis of CMS, it would not only benefit those who are at potential risk for the disease but also those living at sea level, where hypoxia plays a role in certain pathology ( such as stroke, cardiac ischemia, Obstructive sleep apnea and Sickle Cell Disease)3 .
A cohort of 94 individuals were gathered and were equally categorized into CMS and non CMS subjects3. These individuals originated from Cerro de Pasco, which has an elevation of greater than 14,000 feet3. Genetic tools and a custom algorithm were utilized and the researchers identified 11 regions on the genome that contained 38 genes that proved to be statistically significant3. Nine of the eleven genes were tested in fruit flies in hypoxic experiments3. The experiment consisted of fruit flies that had these genes and ones that did not have the genes3. It was concluded that individuals with these molecular adaptions were better able to adapt to physiological stress such as hypoxia when compared to individuals that did not have this adaption3. The results of this study allowed researchers to better understand the correlation between genetics and individuals who strive in hypoxic environments3.
Figure 1- D.melanogaster (fruit fly)3
Figure 2-Cerro de Pasco3
Bibliography
- Villafuerte FC, Corante N. Chronic Mountain Sickness: Clinical Aspects, Etiology, Management, and Treatment. High Altitude Medicine & Biology. 2016;17(2):61-69. doi:10.1089/ham.2016.0031.
- Chronic mountain sickness and high altitude pulmonary hypertension. High Altitude Medicine and Physiology 5E. 2012:333-346. doi:10.1201/b13633-23.
- Stobdan T, Akbari A, Azad P, et al. New Insights into the Genetic Basis of Monges Disease and Adaptation to High-Altitude. Molecular Biology and Evolution. 2017. doi:10.1093/molbev/msx239.
Asthma and High Altitude: What You Need to Know
According to the Centers for Disease Control and Prevention: one in thirteen people suffer from
asthma—that’s 25 million people in the United States alone, seven million of which are children under the age of
eighteen. 1 With populations in high elevation towns growing each year, more individuals with asthma will be adjusting
to life “up in the clouds.” While asthma sufferers may be at increased risk of developing a high-altitude illness such as
high altitude pulmonary edema (HAPE), is it possible for them to experience any benefits living at or traveling to
higher elevation? Before we dig in, let us examine what Asthma is and its related symptoms.
Asthma is an obstructive lung disease, meaning airflow is limited due to airway narrowing brought on by
inflammation and bronchial hyperactivity. The vast majority of patients with asthma will develop symptoms of
coughing, wheezing, chest tightness, and difficulty breathing before the age of five. When these symptoms present
intermittently, they can be controlled by a short-acting bronchodilator like Albuterol. For those with more persistent
asthma, an inhaled corticosteroid and (or) a long-acting bronchodilator may be needed in addition to
Albuterol. Exercise, cold weather, upper respiratory illness, stress, air pollution, and dust mite allergens are all known
triggers of an acute asthma attack. Is it possible that high altitude can actually minimize the impact of any of these
triggers?
One of the benefits of living at high altitude is consistently breathing the clean alpine air. Significantly lower
levels of house dust mites and air pollutants are found at high elevations; great news for allergic asthma
sufferers. 2 However, if one does not fall into that category, do not worry! A study published in the European
Respiratory Journal in 2012 showed that high altitude has beneficial effects for all asthma-types, especially those
refractory to steroids. Participants in the study had improved asthma control, improved lung function, and fewer sino-
nasal symptoms after 12 weeks at an altitude of 1,600 meters. 3 Given that even those with nonallergic asthma
benefited from high altitude treatment, there has to be something other than low levels of allergens at play. Several
studies have reported increased levels of catecholamines and cortisol in the bloodstream within the first two weeks of
staying at high altitude. 4 These hormones contribute to decreasing both bronchial inflammation and bronchial
reactivity which helps in controlling asthma symptoms. Furthermore, the lower viscosity of the air and lower oxygen
pressure reduce the resistance of airflow with inspiration and expiration, making it easier to breath! 2 Mountain living
may also yield a less stressful lifestyle. 3 Lower stress equals lower levels of the stress hormones that typically elicit an
inflammatory response, thus keeping asthma symptoms in check.
So, who is at risk when climbing to higher elevations? Anyone with asthma that is not well controlled prior to
to traveling to elevations of 1,500 meters and above could be at greater risk for having an asthma exacerbation when
they arrive. 2 However, little research has been done to determine who is more susceptible to Acute Mountain
Sickness (AMS) or more perilous altitude illnesses like HAPE. A group of researchers studying the effects of high
altitude and cold air exposure on airway inflammation in patients with asthma did incidentally find that patients with
lower oxygen saturation levels during a hypoxic exercise test were more likely to suffer from AMS when climbing to
high altitude. 4
What have we learned? HIGH altitude equals a LOW trigger environment for asthma patients. That means
it’s time to take that desired mountain vacation or tell your loved ones that suffer from asthma to finally come visit you
in the mountains! Keep in mind, the cold, dry air often accompanied by high elevations can incite an inflammatory
response, in turn, worsening asthma symptoms for some. We recommend visiting in the summer months. This
adverse reaction to cold air can be thwarted by using a face mask or other protective gear that not only warms but
also humidifies inspired air. 5
Disclaimer: If you or a loved one with asthma plan on traveling to high altitude be sure to check in with your primary
care provider first. If your asthma is not well controlled you may want to avoid any travel as it could increase your risk
of an attack. Be prepared! Always carry your rescue inhaler and if you plan on going up in elevation be extra
cautious and bring inhaled or oral steroids as well.
Laura Greenberg, PAS-II
Midwestern University Physician Assistant Program
Clinical Rotation—September 2017
Resources
- Centers for Disease Control. Asthma. http://www.cdc.gov/asthma/default.htm. (retrieved September 24, 2017)
- Mendenhall, A.M. & Forest, C.P. (2017). Out of air: Is going to high altitude safe for your patient. JAAPA, 30(8), 10-15.
- Rijssenbeek-Nouwens, L.H., Fieten, K.B., Bron, A.O., Hashimoto, S., Bel, E.H., and Weersink, E.J. (2012). High-altitude treatment in atopic and nonatopic patients with severe asthma. Eur Respir J. 40(6): 1374-1380
- Seys, S.F., Daenen, M., Dilissen, E., Thienen, R.V., Bullens, D.M.V., Hespel, P., Dupont, L.J. (2013). Effects of high altitude and cold air exposure on airway inflammation in patients with asthma. Thorax BMJ. 68: 906-913
- Cogo, A., Fiorenzano, G. (2009). Bronchial Asthma: Advice for Patients Traveling to High Altitude. High Alt Med & Biol. 10(2): 117-121
- Vinnikov, D., Khafagy, A., Blanc, P.D., Brimkulov, N., Steinmaus, C. (2016). High-altitude alpine therapy and lung function in asthma: systematic review and meta-analysis. ERJ open research, DOI: 10.1183/23120541.00097-2015.
- Grissom, C.K., Jones, B.E. (2017). Respiratory Health Benefits and Risks of Living at Moderate Altitude. High Alt Med & Biol. 00(00): 1-7
Children’s Ears and Changes in Altitude
Children’s Ears and Changes in Altitude Changes
The middle ear is where problems originate during changes in altitude like flying in a plane or driving over mountain passes. The middle ear contains Eustachian tubes that open and expand/contract to accommodate for changing air pressures in the environment. Adults have the knowledge and ability to actively “pop” our ears with intention so the pressure doesn’t become too high. Children that are too young to understand this process are at a higher risk for developing problems related to pressure related changes in the middle ear. So if you have descended on a plane or over a mountain pass and your child has been screaming the whole time…this is probably why!!! Their Eustachian tubes are also narrower and shorter than adults putting them at higher risk for problems equalizing pressure changes. Descending is usually when the most intense pressure changes occur but it can become a concern at any point in a trip.
Things you can do to help your baby/children:
- Encouraging them to swallow (this will help the Eustachian tubes to expand)
- Giving them a pacifier (in babies and much younger children this sucking can mimic swallowing and help to expand the Eustachian tubes)
- Give them a bottle (this is even more effective than a pacifier at opening the Eustachian tubes)
- If they are old enough to chew gum this can be very helpful!
- If they are old enough to follow directions but don’t have the natural instinct to pop their ears then have them pinch their nostrils closed, fill their cheeks with air, and blow out with the mouth closed directing the air toward the ears. This may have to be repeated several times to achieve effect. (These directions seem to help with understanding the technique)
- NEVER EVER LET YOUR BABY SLEEP DURING THE DESCENT. Allowing the pressure to build up without relieving it for an entire descent can put your child at risk for an ear drum rupture, especially if they have been congested or have a cold already. You should keep your baby awake for any descent and follow the above advice for pacifier or bottle feeding during this time.
- Decongestants are okay to pre-medicate adults for altitude changes but not the best option for very young children or babies. If you are planning on traveling with a congested or sick baby and have concerns about altitude pressure changes in the plane or mountains, speak with your healthcare provider before administering any medications.
- If your baby or child remains fussy, irritable, congested, feverish, or is pulling at their ears they should see a healthcare provider to assess if there is an ear infection (this may be related or unrelated to the altitude changes)
American Academy of Otolargyngology. (2017). Ears and altitude. Retrieved from: http://www.entnet.org/content/ears-and-altitude
Tara Taylor RN, BSN, CEN, CCRN
tarat@ebertfamilyclinic.com
Tara Taylor is a Family Nurse Practitioner at Ebert Family Clinic where she provides adult patient care and participates in high altitude research. She is a passionate advocate for mental health, women’s health, and affordable health care.
P.L.A.Y. AT ALTITUDE CAMPAIGN
This summer, as part of my RN to BSN program with UCCS, I needed to complete a public health course with clinical. I decided on an unusual path by joining the team of pediatrician and public health activist, Dr. Ebert-Santos.
Dr. Ebert-Santos has been the primary care giver for my two boys, now 8 and 4 years old, since birth. I would venture to say that Dr. Chris, as we call her, is known by most families in Summit County. Not only are we a mountain community but we are a community committed to growing in mindful ways. A lot of thought goes into how we operate our community events and care for our families. Dr. Ebert-Santos has been very active on more community issues than I can address here. But, let’s include water quality, health insurance/coverage initiatives, and pretty much every community health walk for a cause, healthy community eating and garden initiatives, bike to work week, trail maintenance…you get the picture. For these reasons, I finagled my way into her office this summer.
Our community is one of the healthiest in the nation according to national statistics. We are one of the lowest on obesity, adult diabetes, and hypertension. For this reason, along with the beauty of the Rocky Mountains, we have a lot more people moving here than ever before. “Summit County has recently exceeded a permanent resident population of 30,000. This is a 28.7% increase in full-time residents since 2000” (Summit County Colorado, 2017).
One major health issue that Dr. Ebert-Santos is bringing to light with her current research shows that high altitude kids are often born at lower birth weights, catching up on the national growth charts within the first few years. These babies are not unhealthy by high altitude standards. The problem is that statewide and nationally, we have yet to set standards specific to high altitude children. Dr. Ebert-Santos is making a big push to address this.
Dr. Ebert-Santos is also the doctor most likely to check your newborn for wellness and release them home, safe and sound, following birth. Many of our mountain babies go home with an infant oxygen tank that you will see parents wearing as backpacks. Dr. Ebert-Santos has been collecting and analyzing data on high altitude kids for years now. At higher altitudes, we have lower air pressure and that means decreased bioavailable oxygen. While many people are aware that acute mountain sickness and high altitude pulmonary edema (HAPE) are potential obstacles to overcome when travelling up into the Rockies, many people do not know that our resident children, who haven’t even travelled down from altitude and back up, are also prone to these illnesses. High altitude pulmonary edema in children living at altitude can follow the sort of respiratory infections that kids are prone to catching as they make their way through school while their immune systems are developing. This is often entirely treatable with oxygen alone.
The problem Dr. Ebert-Santos has identified is that, assuming residents are acclimated and therefore unlikely to have HAPE, kids here are often diagnosed with pneumonia instead of HAPE. Treatment of pneumonia often involves a hospital stay with antibiotics and other medications on board. Dr. Ebert-Santos sees dozens of children each year who have what she would like others in the medical community to recognize as Mountain Resident HAPE. With proper diagnosis, these children can be treated with oxygen and improve within a matter of days. Awaiting recovery from pneumonia when there is no pneumonia present can be detrimental to children.
Dr. Ebert-Santos will have her research published this year in the Journal of High Altitude Medicine and Biology. I had the fortunate experience of working this summer, with Dr. Ebert-Santos and her dedicated team, to create a public health message relevant to her work. Office manager Meaghan Zeigler, who has a master’s in public health, was invaluable to my education there. I was happy to find that our local oxygen companies were ready to join in this effort to educate the public. Big thanks to Summit Oxygen Inc. in Frisco, AlpinAire in Breckenridge, and AeroCare in Silverthorne! Below you can see the acronym I created to help high altitude families recognize the signs and symptoms of high altitude illnesses, including HAPE and Mountain Resident HAPE.
Stay safe and keep breathing Summit County!
Juli Joyce, RN
