Category Archives: Acclimation

What happens to your body’s physiology when you move between low and high elevations?

Acclimation, Health, High Altitude, Medicine, Mountaineering

Closer to the Sun: The Dermatological Benefits and Consequences of Living at High Altitude

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As many of us know, high-altitude living goes hand-in-hand with a multitude of outdoor activities like biking, hiking, and skiing. But with all that outdoor activity comes an insidious risk: radiation from the sun. According to an article interviewing Kim Guthke PA-C, a Physician Assistant working in Dermatology in Boulder, CO, “living at a higher elevation exposes us to approximately 25 percent more ultraviolet radiation when compared to sea level” (Guthke 2018). This means that with all the outdoor activities we enjoy, we must also be proactive about protecting our skin from high altitude sun and the increased risks of long-term skin issues it brings. 

Using thick UV-protectant clothing, sunglasses, and sunscreen (and reapplying it) are great ways to protect our skin from the sun. However, some new research has argued that we are actually hurting our health by staying away from the sun. In a revelational article from Outside magazine called “Is Sunscreen the New Margarine?”, Rowan Jacobsen uncovered a novel study claiming only the sun can provide the vitamin D we need. He claims that we are trying and failing to supply vitamin D with pills alone, and the pills just aren’t good enough. Vitamin D is a vitamin required for calcium absorption whose levels, if low, can increase one’s risk of “cancer, diabetes, obesity, osteoporosis, heart attack, stroke, depression, cognitive impairment, autoimmune conditions, and more” (Jacobsen 2019). Thus healthcare workers have concluded that supplementing it will obviously decrease the risk of these diseases. 

Jacobsen reports that multiple different studies have proven that supplementation of vitamin D just isn’t enough to lower that risk. The studies reported that even if supplementation raised vitamin D levels, the general health of the patient did not improve. There was no correlation between high supplemented vitamin D levels and overall health.

So, why was this?

Jacobson claims that vitamin D is actually just a marker for overall health. In other words, raising vitamin D by artificial supplementation does not make one healthier; rather, to raise one’s vitamin D level one must live a healthy lifestyle outside in the sun. Jacobsen states, “…what made the people with high vitamin D levels so healthy was not the vitamin itself. … Their vitamin D levels were high because they were getting plenty of exposure to the thing that was really responsible for their good health — that big orange ball shining down from above” (Jacobsen 2019). 

Soaking up the Vitamin D on Lake Dillon.

So, what are the implications of this study? Does this mean we all need to stop using sunscreen in order to absorb the most natural form of vitamin D and subsequently decrease our risk of dangerous diseases? Well, yes and no.

Yes, in that the best way to absorb vitamin D is from the sun and sunscreen does inhibit that absorption.

No, in that one day of playing at the beach and getting horribly sunburnt is not going to raise your vitamin D levels enough to benefit your health.

Unfortunately, the answer is quite complicated. I believe the implication of this new information is that we all need to start getting outside every day, exercising, enjoying the mountain air, and absorbing small amounts of sunlight each day, rather than just enjoying a single session of baking our skin to blisters. Living at high-altitude, I hypothesize that we don’t need as much time to absorb the same amount of beneficial sunlight as we would at sea level, so I feel there is still a need for sunscreen and protective clothing, if outside for an extended period. We should all try to absorb the sun’s rays daily, but we need to do it in a healthy way.

Cooling down on the way up Uneva Peak off Vail pass.

I encourage everyone to read Jacobson’s article, as it has points both for and against protection from the UV rays of the sun. In the meantime, there is one point Jacobson makes that I would like to argue. 

In his article, Jacobsen admits that increasing sun exposure does increase the rate of skin cancer, but then claims this is ‘okay’ because, “Skin cancer kills surprisingly few people: less than 3 per 100,000 in the U.S. each year … People don’t realize this because several different diseases are lumped together under the term ‘skin cancer.’ The most common by far are basal-cell carcinomas (BCCs) and squamous-cell carcinomas (SCCs), which are almost never fatal” (Jacobsen 2019). The reason I’m disagreeing with this point is due to my direct experience with the “non-fatal” skin cancers. I spent 12 months working with a board-certified dermatological surgeon performing Mohs micrographic surgery, a delicate and precise surgical procedure to remove said cancers from the face, ears, scalp, fingers and toes. Although it’s true BCCs and SCCs are rarely fatal, they can cause significant damage to one’s image. Depending on the location and size of the cancer, a “non-fatal” SCC in-situ has the potential to cause extensive disfigurement of the face, ears, or eyes. I strongly believe this is not something to take lightly, and I fear that saying skin cancer is non-fatal creates a false sense of security. This can be especially dangerous in high-altitude where the sun’s rays are exceptionally stronger than the majority of the US. 

All in all, I do believe that the sun is incredibly beneficial to our health, though in moderate portions. Living in the Colorado mountains gives us more opportunities to enjoy the mountain air, along with the sun, and allows us to lead healthier lives in general. I don’t think I’m going to stop using sunscreen in the near future, but I do know I won’t be so afraid of the sun anymore. I definitely won’t be letting the sun keep me from enjoying my time here in Colorado!

Delaney Schara is a Physician Assistant student at Des Moines University in Des Moines, Iowa. She hails from Fergus Falls, Minnesota, and obtained her undergraduate degree in Chemistry at Augustana University in Sioux Falls, South Dakota. Delaney gained valuable experience in medicine by working as a medical scribe in Dermatology prior to beginning PA school. After completing her pediatrics rotation with Dr. Chris, Delaney will have rotations in multiple Midwestern states before her graduation in June 2020. Delaney is an avid musician who loves singing in choir, playing the flute, and playing acoustic guitar. She also enjoys tasting new blends of tea, exploring rural communities, and spending time with loved ones. 

References

Guthke, Kim. “Sun Protection at Higher Altitudes.” Boulder Medical Center, 29 August 

2018, www.bouldermedicalcenter.com/sun-protection-at-higher-altitudes/

Jacobsen, Rowan. “Is Sunscreen the New Margarine.” Outside Online, 6 June 2019

www.outsideonline.com/2380751/sunscreen-sun-exposure-skin-cancer-science?utm_source=pocket&utm_medium=email&utm_campaign=pockethits

Acclimation, High Altitude, High Altitude Training & Fitness, Mountaineering

Mt. Shavano & Tabeguache Peak

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This past weekend, we ended Dr. Chris’s birthday week celebration with an ascent up Mt. Shavano, at 14,229′ (4337 m). We didn’t make it to the summit of the neighboring Tabeguache Peak, but I’m including it in the title of this piece because it was very much a part of our experience on this particular trek.

The standard summer route up Shavano and Tabeguache starts at 9700′, outside of the town of Salida. Up to the summit of Shavano, there is a 4400′ elevation gain over about 4.2 miles. If this is hard for you to imagine, know that it is formidable. Additionally, the trail increases in difficulty the further you progress, and the last .6 mile to the top is one of the most challenging ascents I’ve ever done without a heavy pack. In a previous article, I mentioned anticipating an inner dialogue about turning around before summiting. This inner dialogue didn’t involve me turning around so much as just passing out on a rock and staying there forever. But I did manage to summit after a 5.5 hr ascent, which included a 2-mile detour past and then back to the very first sign indicating the trail, in the dark of the early morning, at the very beginning of the hike. As obvious as the sign should have been, I’m relieved to say we weren’t the only ones.

This is the wooden sign indicating the Colorado Trail and the trail to reach Mt. Shavano and Tabeguache Peak.
The sign, .1 mi from the trailhead, that we somehow missed in the dark of the early morning.

And this is precisely why you should bring several resources to help guide you. In spite of all the trail descriptions with mileage that we brought, the only sure indication we had passed the turn-off from the Colorado Trail were the actual GPS coordinates of the sign listed in one of our resources (14ers.com). Pro tip: you can enter GPS coordinates into your Google Maps app (assuming you have service); leaving off the capital letters for cardinal directions (N, S, E, W), the first number will be latitude, the second longitude (in our case, we entered “38.60218, -106.19594” to find the sign we had initially passed).

Another learning experience on this particular trek was regarding our camp site. We had chosen the Angel of Shavano camp site, close to the trailhead, which is outside the town of Maysville, past Salida (about two hours from Frisco). The site is right at the foot of the mountains in that area, quite small (20 spots, first-come-first-serve, $20 per night for two vehicles). I was expecting a lot of other hikers, going to bed earlier than us, to wake up and start their ascent earlier than us, with more expensive, specialized gear, but was surprised to find all our neighbors partying until hours after we had retired into our tents.

Icing these puppies in a beautiful river along the Angel of Shavano campground.

As it turns out, there is a Winter route up Shavano, and the trailhead for the standard Summer route was about a 30-minute drive back toward Salida from the Angel of Shavano campground. So that explains why we didn’t encounter any other early-risers there. The good news is that Angel of Shavano campground is gorgeous, right off the Colorado Trail, along a beautiful river that, this late in the summer, was flowing shallow and slow enough that I could set a chair in it and soak my feet in the icy water (before putting them through hell the next day).

A half-moon over Angel of Shavano campground.

We ended up at the trailhead for the Summer route the next morning at 5:15 am. Pitch black. Here’s another pro tip: if your headlamp is dim, it needs new batteries.

Be aware that this parking lot is referred to as the “Blanks Trailhead Parking Lot” on signs on the trail, and this sign is the only one that reads “Mount Shavano Tabeguache Peak Trailhead”.

Other than missing what would have been a very obvious sign in the daylight, the rest of the trail was pretty much straight up. Even the switchbacks were steep enough to make me think, “Would it be much steeper if we just went straight up?” If you’ve ever climbed Peak One in the Ten Mile Range above Frisco, it’s like that (or any portion of that) times a hundred.

The dawn breaking as we backtrack toward the sign we missed.

It’s also significant to note that this was the second time in my life I’d ever wished for hiking poles. The steep grade had me pushing off my own thighs constantly as I trudged up the incline, and my quads were burning the entire hour-and-a-half it took me to get back down. Yes: 5.5 hours up, 1.5 hours down.

The water in my Camel-bak was all I’d brought on the trail (after drinking from a couple Nalgene bottles I’d brought in the car), and I ran out just before getting back to the trailhead. One of us ran out of water in her Camel-bak on her way up to the summit. Fortunately, another one of us had packed an extra gallon of water.

As far as snacking went, we had plenty of jerky, pistachios, bananas, nut butter, and electrolytes between us. I may even have had a chocolate-covered Twinkie. But we didn’t finish all of that, and as I’d expected, my body didn’t really crave food so much as liquids, until I’d reached the end of the hike, at which point I promptly finished all traces of food in the car.

Dr. Chris taking a break on the saddle below the summit of Shavano.

All-in-all, I’d say that was a successful excursion, and even the mistakes we made affirmed that even experienced hikers should take extra care. My main takeaway: don’t rush the start of the trail. It is worth hours to be sure where you are headed, even if it means standing in one spot, double-checking all your resources, entering GPS coordinates for 20 minutes.

The treacherous terrain up the last .6 mi to the summit of Mt. Shavano.

Also notable: we started back on the right track toward the beginning of the hike just before 7 am, at which point it was already bright out, and I reached the summit at 11 am. By 11:15, all the distant clouds had amassed into huge thunderheads, and the first rumble of thunder had us packing up pretty quickly. And this isn’t the first time I’ve seen this. No matter how far away you think those clouds are, it takes mere minutes for them to travel. And as white and interspersed as clouds may seem, they can collect into large, grey, stormy masses very quickly. So, beer in hand, I started a quick descent from the peak. I’d already run for my life down a fourteener in a lightning storm once, and I don’t ever plan to do that again. Furthermore, the summit area of Mt. Shavano is little more than a huge pile of rough boulders, a type of terrain requiring your hands as well as your feet to navigate, called talus. The trail is neither clear nor safe, and there is no way you are running down it.

Do you see a trail here?
Neither did we.

Finally, the weather was the main reason we didn’t make it to the neighboring Tabeguache Peak. A local we talked to on the trail who had made the ascent numerous times advised us to budget at least an hour each way to and from Tabeguache. It’s only about a mile away, but it’s a rocky, narrow ridge. And sure enough, on our way down, it started hailing along with the thunder (and in my experience with fourteeners this time of year, it always does), rained lightly twice through the forest, and then poured torrential rain toward the bottom of the trail.

Would I recommend this trek? Definitely. It is a true test of fitness, and even more so, stamina. As with any other trek, and as I always strongly advise, be wise and pre-emptive about how far and how fast you go. Elevations above 8,000′ are when your body’s reaction to the altitude become exponentially more dramatic, so you can bet elevations above 10,000′ put you at much higher risk for all kinds of symptoms of altitude illness. The faster you ascend, the greater the risk. And remember, our party set out well before daylight at 5:30 am. In the future, should I plan to summit both of these beasts, I would certainly start no later than 4 am.

Other than that, do your homework and prepare accordingly, and you’ll be in for the time of your fitness-challenging, self-motivated lives! Happy Trails!

Beer and jerky time, 5.5 hours later, atop Mt. Shavano at 14,229′.
robert-ebert-santos
Roberto Santos on an epic powder day at the opening of The Beavers lift at Arapahoe Basin ski area.

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.

Acclimation, Child Growth & Development, Health, High Altitude, High Altitude Training & Fitness, Medicine, Mountaineering, Technology

What’s Going On in La Paz?

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The 7th Chronic Hypoxia Symposium was held this year in La Paz, Bolivia, in February and March. La Paz, sitting at 11,942 ft. (3640 m), is home to one of the world’s leading researchers of the effects of chronic hypoxia, Dr. Gustavo Zubieta-Calleja, with whom Colorado’s own Dr. Christine Ebert-Santos was able to meet with during her attendance of the symposium. You can refer to her previous article on the gathering of experts from over 16 countries for her own account of Dr. Zubieta-Calleja’s impressive work.

Below is the renowned Dr. Sanjay Gupta’s own account on video of his introduction to the experience of hypoxia and altitude with Dr. Zubieta-Calleja.

Always keep in mind, there are many physiological reactions going on when your body and brain are at altitude, and the higher the altitude, the more extreme the effects. Benefitting from a hypoxic environment isn’t as simple as staying hydrated. When we talk about chronic hypoxia, we are typically referring to a population who have spent many years in a high altitude environment.

robert-ebert-santos
Roberto Santos on an epic powder day at the opening of The Beavers lift at Arapahoe Basin ski area.

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.

Acclimation, Health, High Altitude, High Altitude Training & Fitness, Medicine, Mountaineering

Coloradans on the Annapurna Circuit

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One of our nearest and dearest, Shelbie Ebert, a certifiable high country local born at Vail Valley Hospital, has been an adventure guide for the last decade. She is currently working on her nursing degree, and is an Emergency Medical Technician. While she has done some multi-day backpacking in the past, she says her recent trip to Nepal was her “most ambitious journey to date.” I was able to sit down with her and her mother, Karen, and hear all about the literal ups and downs on the Annapurna Circuit, in the central mountain region of Nepal, where they reached the highest point at 17,769 ft (5416 m)! They were in Nepal from April 17th to May 17th.

This trek is of international fame, and there are many resources to inform those looking to embark on this historical, spiritual, mental, and physical adventure. All in all, they spent 14 days on the trail. But I was so curious what it was like for those more familiar with the unique challenges posed by Colorado’s high altitude environment.

Did you do anything different from others you observed on the trail?

Most people had porters; we decided not to do that. Even those who didn’t have porters hired a guide.

Having been born and raised at a higher elevation than most, did you notice a difference between your own process of acclimation and that of your colleagues?

I did get sick in Nepal, but it was mostly stomach sickness. No headaches or anything like that. Mom didn’t feel a headache until we got pretty high up. We noticed a lot of people dropping; a lot of people bused into Manang, and from there, it’s a two-day hike up to the base camp, and from there you cross the pass. They got on the trail from there. Manang is at about 10,000 ft. Those people definitely struggled more. 

A father and son hiked the trail side-by-side with us. They didn’t hire porters. Shortly after we got over [Thorung La Pass], the son got really, really sick. The pass tops out at about 17,200 ft. When we saw him at the top of the pass, his lips were bright blue. I think he started to get sick on the ascent. I think he was probably about my age, and he was a doctor. He had some drugs stocked up and he felt pretty confident about doing the hike. 

They started their hike at about 2600 ft. above sea level. In a matter of 10 days, they would climb to over 17,000 ft. over 70 miles.

How long did you take before you started hiking?

We flew into Kathmandu, spent two days there, then took a long bus to the city where we started hiking, and we started hiking as soon as we got off the bus. We did take an acclimation day in Manang, at 10,000 ft. We hiked to it, then we spent an extra day there, about 48 hours. 

What was the greatest challenge about this excursion?

How much constant up and down it was, with the altitude gain. The day that we went over the pass it felt like a good day to me, because it resembled hiking in Colorado. But those days of up and down prepared us well for the pass. 

Did you do any training in particular in preparation for this excursion?

No, absolutely not. I read a lot of blogs so I knew what to expect. I tried to have just a really good plan for what we could and couldn’t do, and when we got to Kathmandu, I stocked up on all kinds of drugs, because anyone can buy them. Diamox. I think I maybe only took one once on our ascension day, just to get ahead of the game. 

Did you change or adjust your diet at all to prepare for this excursion?

I thought I did. I looked up some Nepali food online and tried cooking it at home to prepare my stomach for the type of food that we would be eating, but I found it was nothing like actual Nepali lentils and rice. 

Learned some hard lessons about food. A lot of the lentils in Nepal made me sick. Luckily they have a lot of potato-based dishes. 

[There was a] surprising amount of good snacks available, [lots of pre-packaged cashews, nuts, cookies and snacks]. I would recommend for anybody to bring five or six cliff bars for the harder days.

Also kept some sugar on me: Snickers, chocolate, gummies … I forced Karen to eat some sugar when she wasn’t feeling well, and that seemed to improve her condition.

Karen did experience some symptoms of altitude sickness as they ascended the highest point of the trek, Thorung La.

In retrospect, is there anything you would have done differently in preparation and/or on the trail?

I would have packed a lot less. We had about 35 – 40 lbs. in our bags, and that was way too much — and totally unnecessary. Less is more on the trail. We did end up hiring a porter to carry my mom’s pack on our big day, and that was an excellent decision. 

Did you notice anything different upon your return to a much lower elevation?

I felt really strong! I was really grateful for my body. I think it was mostly a mental shift. I felt more capable doing most activities, whether it was mental or not. I started taking better care of myself. I started running in the mornings before school, which is something I never would have felt before. 

I thought, “I hiked 17,000 ft, I can probably run a mile and be okay in the morning.”

Any other advice you’d give in particular to other travelers intent on similar excursions?

You know what, go for it! It’s not as hard as you think. I came to a country I’d never been to before with a book in my hand, and we did it! I think anybody can really do it.

Shelbie is honored to have shared this experience with her wonderful, strong mother. And this isn’t the first or last adventure they will have been on together. True backcountry buffs, I can always find them on all types of gear on the snow, on the river, or on the trail.

Shelbie and Karen victorious at the height of Thorung La Pass.

If you’d like to read more details about their Annapurna Circuit Trek, Shelbie maintains a blog where you can find all kinds of tips and recommendations on backcountry gear at lahlahdesigns.com.

robert-ebert-santos
Roberto Santos on an epic powder day at the opening of The Beavers lift at Arapahoe Basin ski area.

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.







Acclimation, Doc Talk, Health, High Altitude, High Altitude Training & Fitness, Veterinary Medicine

Dogs at Altitude

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The mountain communities are home to more animals than people in Colorado. Every Spring, we’re likely to see everything from foxes to moose in our yards and on our streets. About a month ago, I watched a juvenile (but plenty large) black bear on an evening walk in front of the houses in our neighborhood, peeking into the garbage bins lined up for pick-up the following morning.

Claire Tinker with her Dachshund Baxter on Bierstadt.

Dogs are natural companions to many up here as well, with plenty of space to run around, smells to sniff, and communities that seem to welcome their company indoors as well as out. Having seen so many of our dog friends on trails all across the state, we’ve wondered how they might be coping with the altitude. 

Most recently, we ran into a German short-haired pointer named Moose on an ascent up Mt. Bierstadt, one of Colorado’s 14ers, sitting at 14,060 ft (4285 m). He and his human, Nick, moved to Colorado permanently about a year ago, after a two-week visit turned into several months. 

Moose is 13 years old, Nick tells me, “but you have to believe that my dog acts like he’s 6.” Nick and Moose have been enjoying a lot of time outdoors together since moving to Colorado, and Bierstadt was their first 14er together, which they did with some other friends from Louisiana, where they’re from. 

“It was awesome. Took [our friends] a long time to summit, but Moose did really well. He liked the breeze and the birds coasting right next to him. It would have been hard without a harness to [lead] him up to the top. He’s 65 lbs. Boulders weren’t too bad for him. Just have to be careful coming down, so he doesn’t slip and break a leg.” 

Moose and his Louisiana posse on their way up Mt. Bierstadt.

This is a very legitimate concern. Many hikers have found themselves carrying their canine counterparts: they get tired, the terrain is difficult for them to negotiate or too rough on their bare paws, etc. You definitely don’t want to have your hands full as you ascend or descend a 14er.

Dr. Danielle Jehr, who has been a veterinarian with Frisco Animal Hospital for years after studying and practicing in Nebraska, also recommends waiting to take your puppy on the longer, more strenuous hikes.

Dr. Danielle Jehn with hiking and car ride enthusiasts Libby and Liam.

“Unfortunately, we do not get a chance to discuss this with many owners unless there are new puppy owners. Usually, we just see the aftermath from a hike and help guide them for future incidences. I would love to be able to tell all new puppy owners that activity needs to be limited up until 6-8 months of age while they are experiencing enormous amounts of bone growth. This means no major hikes on uneven surfaces and no 10 mile runs while the owner mountain bikes. We just want the pups to grow normally without complications for them or the owners.”

And as you might have speculated, animals are also prone to certain risks at high altitudes, although, “In general, healthy animals do not function any different at high altitude,” says Dr. Jehn. “Animals and pets with known blood pressure, cardiac or respiratory disease can decompensate at higher altitudes, and we do see this in practice. Just as human hearts have a difficult time at altitude, so do cats, dogs and livestock!”

Ike, about 8 months old, seriously reconsidering his choices on his way up Mt. Bierstadt.

So how do you know if your furry buddy is struggling with acclimation?

“Most often, an owner will call and have a presenting complaint of their pet experiencing exercise intolerance while on a hike or constant panting/lethargy/anorexia since the pet has been up in Summit County. If a dog presents in any type of respiratory distress, we place them on supplemental oxygen, check their heart and lung sounds, heart rate, respiratory rate, blood pressure and ability to oxygenate. We do this by utilizing a tool in the clinic that measures the percentage of oxygen carried in the blood.” Sound familiar? “We always want to see a dog at over 92%. If the dog or cat cannot maintain that or better without being provided oxygen, we need to see other diagnostics for reasons why.

“Common canine ailments we see that are drastically exacerbated by altitude are: cardiac disease (heart murmur, pulmonary hypertension, congestive heart failure), general hypertension, lung disease (asthma, allergic bronchitis) or vascular volume abnormalities (i.e. anemia).”

The most common injuries Dr. Jehn sees, she tells me, are “lacerations and abrasions from the rough terrain. We also see exacerbated lameness after hikes that are too long for our canine friends that are not otherwise used to it (i.e. 14ers).”

Nick and Moose currently live in Boulder, at 5328 ft (1624 m), but they moved there from a house in Bailey, at about 7740 ft (2359 m). I ask Nick if Moose has ever had trouble with the altitude since they moved to Colorado. 

“Not at all. Not even when we first got here. He was ready to rock and roll. The only thing he didn’t like was the snow at first. Once he realized there were rabbits and stuff that went in the snow, he was about it.”

Being from Louisiana, one of Moose’s greatest challenges is the relative scarcity of water. Colorado doesn’t have as many lakes and ponds that Moose can cool off in and drink from, so Nick says he’s sure to carry water for him.

Nick also tells me that Moose is a pretty fit dog, and has never experienced any major health complications. He is careful, however, not to work him so hard that he’s limping the following day. I think it’s safe to say that’s something humans are wary of for themselves as well. If you’ve ever hiked a 14er, you already know. 

Dr. Chris with grand-dog Ike on their way up Mt. Bierstadt.

Another factor that affects Moose and people alike is exposure. “If there’s no shade or wind, it’s a lot harder on him,” Nick notes. We also relate over the challenge of descending a mountain, when the resistance of gravity is especially stressful on your knees and hips. Nick works for Sacred Genetics, a company that cultivates feminized hemp seeds, who are partners with a company, Verdant Formulas, that specializes in CBD products, utilitzing the relaxing, remedial properties of the oil from cannabis. Among other applications, balms and oils infused with CBD have grown in popularity as a naturopathic treatment for muscle soreness and inflammation. Incidentally, more and more similar products are being marketed for the same afflictions in dogs. Nick tells me it helps with his own post-adventure soreness.

My main takeaway from all this insightful doggo dialogue is that we are all the more similar. It certainly seems like the same precautions apply for avoiding a serious situation outdoors. And don’t forget, if anyone in your party is having trouble on your hike, it is not advisable to continue; you are only as strong as the weakest member of your team, whether that is a dog or a person. 

A last bit of advice from Dr. Jehn:

“I would also love to be able to tell all tourists to take it easy on their canine counterparts while visiting us in Summit County as well. Altitude sickness is real for humans and dogs, alike. Accomplishing a crazy hike with your dog should not be the first priority within the first few days at elevation. Dehydration and prior health conditions are real when experiencing altitude. If you know your dog has history of a heart or lung issue, especially, let them take it easy. We want you to enjoy Summit County for everything it has to offer….without the emergency visit!!”

Happy Trails, all you trailhounds and trail … hounds!

robert-ebert-santos
Roberto Santos on an epic powder day at the opening of The Beavers lift at Arapahoe Basin ski area.

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.

Acclimation, Health, High Altitude, Mountaineering

Muscle Atrophy in Visitors at High Altitude

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As many as 30 million people travel to the mountains in the western United States each year1 to enjoy the beauty and outdoor activities the terrain has to offer. Travelers may worry about altitude sickness upon arrival. However, another important side effect of high altitude exists: muscle atrophy. While it may not be noticeable during visitors’ short time at high altitude, it is still a remarkable effect the elevation has on human bodies.

Muscle atrophy is a scientific term for the loss of muscle mass2; essentially, the muscle fibers shrink due to loss of important contractile proteins and organelles, which are essential parts of muscle fibers3. This means that the muscle won’t be able to perform as well4, especially in terms of endurance and power; tasks that are normally easy, such as walking up a flight of stairs, may be significantly more tiresome or difficult.

An elevation is considered high altitude when the location is 2400 meters or more above sea level4. This is about 7,874 feet of elevation. Over 140 million people worldwide live at or above this altitude4, making the issue of altitude-induced muscle atrophy very relevant to many. 

Hypobaric hypoxia, which occurs at high altitudes, is a decreased barometric pressure in addition to a decrease in oxygen availability1. This is a double whammy for visitors for two reasons: a lower pressure won’t be able to push as much oxygen into tissues, and less availability of oxygen will diminish the amount that tissues receive1. These two conditions result in less oxygen getting to body systems1 that usually obtain a good amount. This is especially pertinent to muscles because of their prevalence in the human body.

Muscle atrophy is indicative of a disproportion between the process that builds protein and the process that breaks down protein in muscles2. Several studies have shown that when muscles receive less oxygen, such as in hypobaric hypoxic states, muscle protein degradation is boosted while muscle protein creation dwindles2,3,4,5. This results in an overall deficit of protein in the muscle, which is meaningful because muscles store the most protein compared to any other organ in the body3.

Currently there are no official guidelines for prevention of muscle atrophy due to hypobaric hypoxia. There are also no medications that currently counteract the loss of muscle3, although researchers are now turning their focus to ways of maintaining the balance of protein breakdown and building in muscle. 

Despite the fact that these measures are suggested for preventing high altitude illness, it may be beneficial in general to stay hydrated, ascend slowly to altitude, eat a balanced diet, and remain active1. Foods and herbal supplements rich in antioxidants may be helpful in preventing muscle wasting during exposure to hypobaric hypoxia4, although there is no direct evidence to support this theory yet. Overall, it would be beneficial to maintain good nutrition throughout the visit to the mountains. Moderate exercise may help visitors acclimatize, although overly spirited exercise can cause other altitude-related problems1.

How are people who live at altitude affected by muscle atrophy? At the moment, studies are geared more towards the effects that altitude has on people who visit from lower elevations. Once the body has acclimated to the altitude, oxygen utilization and distribution will improve greatly and will ensure that tissues receive more oxygen1. This may explain why people who live at high altitude for long periods of time are able to maintain and oftentimes increase their muscle mass. Even so, people who live at high altitude should still eat a healthy diet and drink a good amount of water to make sure their bodies can function optimally.

It is important to be aware of the side effects that altitude has on the bodies of sea-level visitors. There is still more research to be done regarding effective treatment options for this particular type of muscle atrophy. Knowing that high altitude causes muscle atrophy can help people be aware of their activity level and diet and may modify how people choose to ascend to the mountains. This consequence of high altitude should not prevent people from enjoying all that mountainous regions have to offer.

Grace Barrett is a Physician Assistant student at the University of St. Francis in Albuquerque, New Mexico. Born and raised in Grand Rapids, Michigan, Grace attended Michigan State University where she received degrees in both Physiology and Spanish. After completing her rotation in pediatrics with Dr. Chris, Grace will have rotations in New Mexico, Michigan, and California before graduating in April 2020. She is hoping to explore urology as her elective rotation. Grace enjoys baking cookies, being active, watching Chopped on the Food Network, spending time with family, and planning her wedding (in August 2020). 

References

1. Gallagher SA, Hackett P, Rosen JM. High altitude illness: Physiology, risk factors, and general prevention. UpToDate. https://www.uptodate.com/contents/high-altitude-illness-physiology-risk-factors-and-general-prevention. Published September 20, 2017. Accessed July 18, 2019.

2. McKinnell IW, Rudnicki MA. Molecular Mechanisms of Muscle Atrophy. Cell Press. 2004;119:907-910.

3. Bonaldo P, Sandri M. Cellular and molecular mechanisms of muscle atrophy. Disease Models & Mechanisms. 2013;6(1):25-39. doi:10.1242/dmm.010389.

4. Rathor R, Suryakumar G. Muscle Atrophy at High Altitude. Journal of Clinical and Molecular Endocrinology. 2016;1(3):1-2. doi:10.21767/2572-5432.10018.

5. Chaudhary P, Suryakumar G, Prasad R, Singh SN, Ali S, Ilavazhagan G. Effect of acute hypobaric hypoxia on skeletal muscle protein turnover. Al Ameen Journal of Medical Science. 2012;5(4):355-361.

Acclimation, Health, High Altitude, Medicine, Mountaineering

Altitude and the Brain

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Our brain is a highly demanding organ that requires a constant supply of oxygen, evidenced by how quickly a drowning victim loses consciousness. But apart from being under water, many other places on Earth expose our brains to the low oxygen levels that cause hypoxia, or lack of oxygenated blood flow to the brain. The most common of these places is that of high altitude (current studies in the US often define this as above 8,000 ft.). But how does long-term exposure to the low oxygen levels in these environments affect our brains?  Recent studies have revealed new dangers from exposure to extremely high altitudes (15,000+ ft.), and they suggest that our brains also feel the impact at less extreme elevations as well. As concerning as these findings may be, further studies are being done to increase our knowledge of these effects and luckily, methods to prevent and avoid them do exist. But in order to avoid them effectively, we must first understand the dangers that high altitude presents. 

Extremely high altitude locations are some of the most impressive and breath-taking places in the world. They often serve as bucket list checkpoints for travelers and mountaineers everywhere.  However, in a 2006 study by Fayed et al, a new risk for extremely high altitude hikers (15,000 ft+) was revealed1. MRI scans were performed on the brains of those returning from locations including Mt. Everest, Mt. Aconcagua, Mont Blanc and Mt. Kilimanjaro1.  Shockingly, almost every Mt. Everest climber returned with brain changes on their MRI scans. They revealed cortical atrophy and enlargement of their Virchow-Robin spaces, processes that are usually associated with aging1. The amateur of the group seemed to suffer the most permanent changes with subcortical lesions as well1. Where there had been one unaffected hiker in the Everest group, none returned from the Aconcagua expedition without brain changes. Four hikers also showed subcortical lesions1. Unfortunately, and even more concerning, most of these changes were still present on MRI scans several years afterward as well1. 

A follow up study in 2015 by Kottke et al. examined mountaineers before and after a 7,126m (23,373ft) ascent and found that none had subcortical lesions afterward2. However, there were increases in cerebral spinal fluid fractions and decreases in white matter fractions in several of the hikers. They also took it a step further and related it to the hypoxic levels and mountain sickness symptoms that the individuals suffered and were able to correlate these episodes with more significant brain changes2. 

More research must be done to determine what these brain changes mean and how they will impact the lives of these individuals later in life. However, researchers have also found ways to approach altitude that seemed to lessen these effects. The number one suggestion that professionals share to prevent the possibility of permanent brain changes is simple; ascend slowly1. The studies that found permanent brain changes in extreme altitude hikers seemed to find worsened effects in the amateurs that ascended too quickly versus the professionals that had ascended correctly, over time1. Oxygen supplementation and other methods to prevent acute mountain sickness during the climbs seemed to help as well1. 

For those of us that refrain from scaling some of the world’s tallest mountains, but frequently visit or reside in moderately high altitudes, our brains can also be affected.  Abrupt elevations in altitude from a low level environment have been shown to affect people’s memory storage and recall3. It has also caused impairments in concentration, aphasia and finger tapping speed temporarily3. In a 2016 study that examined young, healthy individuals living at altitudes of 3650 m (11,975 ft) for a minimum of three years, significant impairments in attention were revealed4. Early and late stages of attentional processes were impacted in this study group when compared with a control group4. These impairments were also made more significant when larger amounts of perceptual input, or distractions, were added4. 

In terms of the long-term high altitude group, attention span data did show impairment in early and late stages, but interestingly, changes in brain activation on brain scans were proposed as possible mechanisms to attempt to compensate for this4. Moreover, it was also found that later stages of attentional processes showed less brain activation in the high altitude group, but they found that this discrepancy lessened the longer that the individual lived at altitude, suggesting adaptation was occuring4. 

Rather than residing at moderately high altitudes, traveling to them can also affect the brain. The same advice of ascending slowly at extremely high altitudes is also applicable here. Giving the body time for appropriate acclimatization is key to preventing any physical symptoms as well as any confusion, sluggish thinking, or difficulty concentrating and focusing1. Proper hydration, nutrition and the occasional oxygen supplementation can lessen symptoms as well. 

In conclusion, more research is needed to study the effects of permanent brain changes from extremely high altitudes as well as to determine if there really is a danger toward our attention spans, or any other cognitive processes, from living at high altitude. Although it is important to be aware of these risks, very few residents and adventurers let it hold them back from visiting and living in some of the most incredible places in the world. As long as we approach with an understanding of the dangers, prepare appropriately and always ascend slowly, not even our brains can hold us back from the adventures to be had in these amazing locations. 

Jenna Bradfield is a Physician Assistant Student at the University of St. Francis in Albuquerque, New Mexico. Prior to PA school, she completed her undergraduate studies at Southern Utah University where she played collegiate volleyball as well. She is currently completing her third clinical rotation in Pediatrics at the Ebert Family Clinic. As she is originally from a small town in Utah, she has and will be completing several more rotations in her home state along with other rotations in New Mexico and Texas. She grew up loving the outdoors and sports, and also enjoys physical fitness, music, reading and spending time with friends and family.

References:

1: Fayed, N., Modrego, P. and Morales, H Evidence of brain damage after high-altitude climbing by means of magnetic resonance imaging. American Journal of Medicine. 2006. 119, 168.e1-168.e6. 

2: Kottke, R. Hefti, JP. Rummel, C. Hauf, M. Hefti, U. Merz, TM. Morphological brain changes after climbing to extreme altitudes – a prospective cohort study. PLoS One. 2015; 10(10): e0141097

3: Hombein, TF. Long term effects of high altitude on brain function. Int J Sports Med. 1992;(13) Supple 1:S43-5. 

4: Wang, Y. Ma, H. Fu, S. Guo, S. Yang, X. Luo, P. Han, B Long-term exposure to high altitude affects voluntary spatial attention at early and late processing stages. Scientific Reports. 2014; (4) 4443.

Acclimation, Health, High Altitude, Medicine

Altitude as Asthma Treatment

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Can high altitude climate therapy (HACT) result in long term benefits for adults with severe asthma?

How much do you know about asthma? Have you ever considered that the air we breath every day is often filled with environmental triggers that worsen asthma symptoms making it more difficult for asthmatics to breath? Did you realize that at elevation many of those environmental triggers such as air pollution and pollen are gone? The rumors are true, mountain air really is better and residents at altitude are truly lucky to be breathing in fresh, clean, crisp mountain air on a daily basis. 

Based on data collected by The Global Initiative for Asthma (GINA), as of 2004 it was estimated that 300 million people of all ages worldwide suffer from asthma. That number is projected to increase to 400 million by 2025! In 2010, the CDC documented that 1.8 million people in the US alone visited the emergency department for asthma related care and of that number at least one third of them had to be hospitalized for severe symptoms. 

Asthma is characterized by: 1) Chronic airway inflammation, 2) intermittent and reversible airway obstruction, and 3) bronchial hyper-responsiveness (the tendency of airways to narrow in response to a variety of triggers in the air that have little effect on people without any respiratory disease). Patients with asthma often complain of intermittent cough, shortness of breath (or difficulty breathing), and wheezing. This classic presentation is often worsened by triggers such as allergens, pollutants, tobacco, cockroaches, pollen, mold, stress, upper respiratory infections, weather and/or exercise. Symptoms are alleviated with bronchodilator medications, which act to open the airways making breathing easier. 

Dillon Reservoir, sitting at over 9,000 ft. Visitors from all over the state and world alike come to enjoy Colorado’s reputably pure water and air.

Asthma is conventionally treated in a step-wise fashion, meaning that treatment escalates with increasing severity of symptoms. Patients who suffer from severe asthma on a daily and nightly basis are often on multiple medications in an attempt to control their symptoms. These usually include an inhaled corticosteroid medication, a long-acting beta-2 agonist. Some start oral steroids and some even require biologic or immune modulating agents. Patients that fall into this category often suffer from a decreased quality of life, multiple doctor or emergency room visits and have difficulty controlling their symptoms on a regular basis. 

Recently, researchers have been investigating different avenues to provide relief for patients suffering from severe asthma symptoms. Studies published on high altitude climate therapy (HACT) are showing positive outcomes for adults with severe asthma that are refractory to conventional treatment. 

An article published in 2018 in The European Journal of Allergy and Clinical Immunology conducted a study to determine if HACT resulted in long term benefits for asthmatics even after returning to sea level. Patients included in this study had to fall into the category of an adult with severe uncontrolled asthma symptoms despite conventional treatment methods. These patients were enrolled in a 12 week multi-disciplinary treatment program with environmental trigger avoidance in an alpine climate at an altitude greater than 1500 m (4921.26 ft). After the conclusion of the program, patients were followed for one year with repeat evaluations every 3 months to assess the long term effects of this therapy on their asthma symptoms.

This is the first study to show a decrease in exacerbations and improvement in asthma control up to 12 months!! This was measured in the number of asthma exacerbations, hospitalizations, and oral corticosteroid use before and after HACT treatment. The study showed a decrease in all three categories, which correlates to a positive outcome following this treatment.

While “trigger avoidance” has always been an important aspect of the conventional asthma treatment regimen, it is amazing to see how patients benefit when this is carried out effectively. It is hypothesized that allergens work to continually stimulate and maintain the airway inflammation in asthmatics. When these triggers are removed for a sufficient amount of time, the bronchioles have a chance to recover and decrease the process of ongoing inflammation.

Another proposed mechanism by which this treatment is effective is the decrease in air viscosity at altitude, which benefits the patient by decreasing the thickness of airway mucosa and may even reverse airway modeling. This makes breathing easier for patients and acts to decrease asthma symptoms. 

So who can benefit from this treatment? Are all asthmatics created equally?

Scientists and clinicians alike have identified three different groups of asthma patients: 1) severe atopic asthma, 2) persistent eosinophilic asthma, and 3) asthma associated with morbid obesity. While classically these different patient populations respond differently to asthma treatments, it has been found in another study, “Predictors of benefit from high altitude climate therapy,” that HACT improves the quality of life and respiratory function in all patients suffering from severe asthma symptoms. This study sought to investigate if different factors such as age, blood eosinophils (a type of white blood cell), and degree of asthma control prior to admission could predict how much a patient would benefit from high-altitude climate therapy. While this study is making steps in the right direction, it was determined that further patient characterization is required to clearly identify which patients will benefit the most from HACT. 

Finally, in a systematic review and meta-analysis on HACT, it was determined that patients experience a statistically significant improvement in lung function following this treatment modality. This review wanted to analyze the quality of research studies completed so far on this topic and also proposed some limitations of the publications so far.

“Shinrinyoku” (森林浴) is the Japanese word for spending time in nature, literally meaning “deep forest bathing”. It is believed the body exchanges and balances its ions with the ions present in the forest.

Some things to consider that are still being evaluated include: What is the optimal altitude and duration of treatment in order to see the most benefit? Which patients will experience the most improvement from this treatment? How does this treatment method compare financially with others considering that it is a resource-intensive intervention? 

Overall, research on HACT is making exciting headway! So far we have learned that adults with severe asthma can benefit from alpine treatment in some way regardless of phenotype. In addition, many patients experienced lasting improvement for up to 12 months. Be on the lookout as more research is published on this topic. As always, if you are patient suffering from asthma, check in with your primary care provider prior to making a trip to altitude to ensure your asthma is well controlled before arrival. While HACT has been shown to decrease asthma symptoms long term, arriving at altitude unprepared with uncontrolled symptoms could put an asthmatic at higher risk for high altitude sickness. As discussed at the beginning of the article, cold air can be a trigger for asthmatics as well and with that in mind it would be best to visit the mountains during the summer months! Lastly, always be prepared and carry your rescue inhaler with you, especially when traveling to altitude.

Author and PA Student Sarah Gordon

Sarah Gordon is currently a Physician Assistant Student at Midwestern University located in Glendale, Arizona. She plans to complete a one year fellowship at Mayo Clinic in otolaryngology/ head and neck surgery after graduation. Throughout her clinical year she has had the opportunity to travel to Denver and Frisco, Colorado, along with completing rotations located throughout the greater Phoenix area in Arizona. When she is not studying, she enjoys cooking new recipes, spending time with friends and staying active through fitness and outdoor adventures. 

References:

“Asthma | CDC.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, www.cdc.gov/asthma/default.htm.

Fanta, Christopher H. “An Overview of Asthma Management.” UpToDate, Helen Hollingsworth, MD, www-uptodate-com.mwu.idm.oclc.org/contents/an-overview-of-asthma-management?search=asthma adult&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1.

Fanta, Christopher H. “Diagnosis of Asthma in Adolescents and Adults.” Www, Helen Hollingsworth, MD, www-uptodate-com.mwu.idm.oclc.org/contents/diagnosis-of-asthma-in-adolescents-and-adults?search=asthma definition§ionRank=1&usage_type=default&anchor=H2&source=machineLearning&selectedTitle=1~150&display_rank=1#H3.

Fieten, Karin B., et al. “Less Exacerbations and Sustained Asthma Control 12 Months after High Altitude Climate Treatment for Severe Asthma.” Allergy, vol. 74, no. 3, 14 Nov. 2018, doi:10.1111/all.13664.

Hashimoto, S., et al. “Predictors of Benefit from High-Altitude Climate Therapy in Adults with Severe Asthma.” The Netherlands Journal of Medicine, vol. 76, no. 5, July 2018, pp. 218–225.

Rijssenbeek-Nouwens, L. H., and E. H. Bel. “High-Altitude Treatment: a Therapeutic Option for Patients with Severe, Refractory Asthma?” Clinical & Experimental Allergy, vol. 41, no. 6, 2011, pp. 775–782., doi:10.1111/j.1365-2222.2011.03733.x.

Seys, Sven F, et al. “Effects of High Altitude and Cold Air Exposure on Airway Inflammation in Patients with Asthma.” Thorax, vol. 68, no. 10, 2013, pp. 906–913., doi:10.1136/thoraxjnl-2013-203280.

Vinnikov, Denis, et al. “High-Altitude Alpine Therapy and Lung Function in Asthma: Systematic Review and Meta-Analysis.” 6.2 Occupational and Environmental Health, 2016, doi:10.1183/13993003.congress-2016.pa4293.

Acclimation, Alcohol at Altitude, Child Growth & Development, Health, High Altitude, High Altitude Training & Fitness, Medicine, Mountaineering

Spring Recap 2019

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We’ve learned a lot in the high country this season! For example, it isn’t too late or too warm for a snowstorm. We’ve conducted several interviews with professional, high-altitude athletes, athletic and tourism organizations in Summit County, physicians, podcasters, interns, and a local brewer. They’ve shed so much light on fitness, health, child growth & development, and acclimation at elevation, it warrants a re-cap:

  1. 8,000 ft. seems to be the pivotal elevation at which the body starts to experience a significant deficit in the oxygen and water it needs to function, affecting everything from sleep to metabolism.
  2. A plant-based lifestyle has benefitted athletes under extreme training and competitive conditions at altitude.
  3. Training at altitude significantly reduces your ability to reach cardiovascular and strength goals, even while preparing your respiratory and circulatory systems for the severe decrease in oxygen. “Live High, Train Low” is an effective strategy more and more athletes are advocating for.
  4. Preparation for backcountry excursions is as much mental as physical.
  5. Foods high in nitrates (like red beets, red bell peppers and arugula) can facilitate acclimation and recovery.
  6. Oily foods may inhibit your body’s ability to cope with a significant increase in altitude.
  7. We metabolize and experience the effects of alcohol differently at altitude.
  8. Current research suggests some people suffering from Parkinsons disease may experience some relieve from symptoms at higher elevation.
  9. Increased muscle mass requires increased oxygen. Being an athlete does not necessarily mean you will have an easier time acclimating.
  10. As always, the best way to facilitate acclimation and deal with symptoms of altitude sickness is to drink plenty of water, allow yourself ample rest, and monitor your blood oxygen saturation levels with a pulse oximeter.

Be sure to subscribe to keep up with what this summer has in store for your elevated experiences at altitude! And if you have any questions or are eager to read more about a particular topic, let us know in a comment!

Acclimation, Child Growth & Development, Health, High Altitude, Medicine

Beneficial Effects of Chronic Hypoxia

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Living in Summit County, Colorado has its perks – residents are within a 20 to 40 minute drive to five world class ski resorts, and some of the most beautiful Rocky Mountain trail systems are accessible right out our back door. With the endless opportunities drawing residents outdoors to partake in physical activity, it comes as no surprise that Summit County is considered one of the healthiest communities in the country. However, there may be more than meets the eye when it comes to explaining this, as it also has something to do with the thin air.

As a Summit County native, you have likely heard the term “hypoxia” or “hypoxemia” mentioned a time or two. So what does this mean? Simply put, these words describe the physiological condition that occurs when there is a deficiency in the amount of oxygen in the blood, resulting in decreased oxygen supply to the body’s tissues. When this occurs in the acute setting, it may result in symptoms such as headache, fatigue, nausea, and vomiting. These are common symptoms experienced by those with altitude illness, also known as acute mountain sickness. While these symptoms can cause extreme discomfort and may put a huge damper on a mountain vacation, they are not usually life threatening. However, in a small number of people, development of more serious conditions such as a high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE) can occur. The treatment for all conditions related to altitude illness is oxygen, whether via return to lower elevations or by a portable oxygen concentrator that allows you to stay where you are. While altitude illness generally affects those who rapidly travel from sea level to our elevation, it has also been known to affect residents returning home to altitude, usually after a period of two or more weeks away. In a very small subset it can occur after a period of only a day or two. This generally occurs in those with a preexisting illness, where altitude exacerbates the condition.

While the acute effects of altitude can clearly have detrimental effects on one’s physical well-being, there is emerging research demonstrating that chronic hypoxia may actually come with several health benefits. Long time Summit County business owner and community pediatrician, Dr. Chris Ebert-Santos of Ebert Family Clinic in Frisco, has spent quite some time studying the effects of chronic high-altitude exposure, and recently attended and presented at the Chronic Hypoxia Symposium in La Paz, Bolivia, the highest capital city in the world.

It is important to first understand the adaptations that occur in our bodies as a result of long-term hypoxia. The ability to maintain oxygen balance is essential to our survival.

So how do those of us living in a place where each breath we take contains about ⅓ fewer oxygen molecules survive?

Simply put, we beef up our ability to transport oxygen throughout our body. To do this, our bodies, specifically the kidneys, lungs and brain increase their production of a hormone called erythropoietin, commonly known as EPO. This hormone signals the body to increase its production of red blood cells in the bone marrow. Red blood cells contain oxygen binding hemoglobin proteins that deliver oxygen to the body’s tissues. Thus, more red blood cells equal more oxygen-carrying capacity. In addition to increasing the ability to carry oxygen, our bodies also adapt on a cellular level by increasing the efficiency of energy-producing biochemical pathways, and by decreasing the use of oxygen consuming processes2. Furthermore, the response to chronic hypoxia stimulates the production of growth factors in the body that work to improve vascularization2, thus, increased ability for oxygenated blood to reach its destination. 

So, how can these things offer health benefit?

To start, it appears that adaptation to continuous hypoxia has cardio-protective effects, conferring defense against lethal myocardial injury caused by acute ischemia (lack of blood flow) and the subsequent injury caused by return of blood to the affected area3. The exact mechanism of how this occurs is not well understood, but it seems that heart tissue adapts to be better able to tolerate episodes of ischemia, making it more resistant to damage that could otherwise be done by decreased blood flow that occurs during what is commonly known as a heart attack. This same principle applied to ischemic brain damage when tested in rat subjects. Compared to their normoxic counterparts, rats pre-conditioned with hypoxia sustained less ischemic brain changes when subjected to carotid artery occlusion, suggesting neuroprotective effects of chronic hypoxia exposure4.

Additionally, it appears that altitude-adapted individuals may be better equipped to combat a pathological process known as endothelial dysfunction5. This process is a driving force in the development of atherosclerotic, coronary, and cerebrovascular artery disease. Altitude induces relative vasodilation of the body’s blood vessels compared to lowlanders2. A relaxing molecule known as nitric oxide, or NO, assists with causing this dilation, and in turn the resultant dilated blood vessels produce more of this compound5. The molecule has protective effects on the inner linings of blood vessels and helps to decrease the production of pro-inflammatory cytokines that damage the endothelium5. This damage is what kickstarts the cascade that leads to atherosclerosis in our arteries. Thus, a constant state of hypoxia-induced vasodilation may in fact decrease one’s risk of developing occlusive vascular disease. 

The topics mentioned above highlight a few of the proposed mechanisms by which chronic hypoxia may be beneficial to our health. However, do keep in mind that there are potential detrimental effects, including an increased incidence of pulmonary hypertension as well as exacerbation of preexisting conditions such as COPD, structural heart defects and sleep apnea, to name a few6. Research regarding the effects of chronic hypoxia on the human body is ongoing, and given its significance to those of us living at elevations of 9,000 feet and above, it is important to be aware of the impact our physical environment has on our health. Dr. Ebert-Santos is avidly involved in organizations dedicated to better understanding the health impacts of chronic hypoxia, and has several current research projects of her own that may help us to further understand the underlying science.

Kayla Gray is a medical student at Rocky Vista University in Parker, CO. She grew up in Breckenridge, CO, and spent her third year pediatric clinical rotation with Dr. Chris at Ebert Family Clinic. She plans to specialize in emergency medicine, and hopes to one day end up practicing again in a mountain community. She is an avid skier, backpacker, and traveler, and plans to incorporate global medicine into her future practice.

Citations

  1. Theodore, A. (2018). Oxygenation and mechanisms for hypoxemia. In G. Finlay (Ed.), UpToDate. Retrieved May 2, 2019, from https://www-uptodate-com.proxy.rvu.edu/ contents/oxygenation-and-mechanisms-of-hypoxemia?search=hypoxia&source=search_ result&selectedTitle=1~150&usage_type= default&display_rank=1#H467959
  2. Michiels C. (2004). Physiological and pathological responses to hypoxia. The American journal of pathology, 164(6), 1875–1882. doi:10.1016/S0002-9440(10)63747-9. Retrieved May 2, 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1615763/ 
  3. Kolar, F. (2019). Molecular mechanism underlying the cardioprotective effects conferred by adaptation to chronic continuous and intermittent hypoxia. 7th Chronic Hypoxia Symposium Abstracts. pg 4. Retrieved May 2, 2019. http://zuniv.net/symposium7/Abstracts7CHS.pdf
  4. Das, K., Biradar, M. (2019). Unilateral common carotid artery occlusion and brain histopathology in rats pre-conditioned with sub chronic hypoxia. 7th Chronic Hypoxia Symposium Abstracts. pg 5. Retrieved May 2, 2019. http://zuniv.net/symposium7/Abstracts7CHS.pdf
  5. Gerstein, W. (2019). Endothelial dysfunction at high altitude. 7th Chronic Hypoxia Symposium Abstracts. pg 11. Retrieved May 7, 2019. http://zuniv.net/symposium7/Abstracts7CHS.pdf
  6. Hypoxemia. Cleveland Clinic. Updated March 7, 2018. Retrieved May 9, 2019. https://my.clevelandclinic.org/health/diseases/17727-hypoxemia