Increased Risk of Breast Cancer at High Altitude?

Stacy has lived in the high country for a long time. She knows I am interested in research to understand our risks and benefits. So she asked me again when I passed her on the trail,  “is breast cancer more common in women who live at high elevations? ” She knows so many women who have been affected.
Public health stats show that people live longer up here and there is a lower incidence of cancer. I assume this corrects for people who move away for treatment or health conditions. Since cancer patients are treated in many different clinics outside the area, there hasn’t been any reports that we’ve seen. But we do have many friends affected. It’s a good question.

Adaptation v.s. Aclimatization

Why don’t babies in Nepal and La Paz need oxygen? IMG_2996Dr. Chris in La Paz with 20 year old Maria and her mother

Research comparing ethnic groups that have lived at high altitude for centuries, such as native Tibetans, and more recent immigrants such as the Han Chinese in Tibet, showed changes in adaptation. People living in the Andes, Himalayas and mountains of Ethiopia have higher lung volumes, more nitric oxide in the blood, high oxygen carrying hemoglobin levels and increased respiratory rates which are genetic.

Those of us living in the mountains of Colorado have been here at the most 150 years, not long enough to establish gene-based adaptation. We do acclimatize over weeks and months with changes in hemoglobin levels, respiratory rates and lung volumes but not to the extent of the above populations.

During my travels to La Paz Bolivia and Cuzco, Peru I noticed the people were smaller. At Ebert Family Clinic we analyzed over 10,000 pieces of growth data on children up to four years old from our electronic medical record. A high per cent are below the standard growth chart: seven percent compared to three percent. Most catch up by age two years.

 

How to keep oxygen on your young child

Both tourist and local children may need supplemental oxygen during illnesses at high altitude. There are excellent providers available 24 hours a day to set up tanks and concentrators so most don’t have to stay in the hospital, but can be comfortable at home with the family. It is a mistake to admit these children to the hospital just because they won’t keep the nasal cannula in their nose. Hospital guidelines make it difficult for nurses to implement adequate control measures over these fiesty little ones.

At Ebert Family Clinic we have found a very effective method: magazines. Tape a magazine around both child’s arms so that they cannot bend their elbows to pull off the cannula. After 30 minutes of not being able to use their arms, most children will accept the oxygen.

Mountain resident high altitude pulmonary edema (MR-HAPE)

For five years I have been writing about children who live above 2500 feet with no history of travel who present with a respiratory illness and hypoxia. Because they do not appear very sick (toxic is the word we use in medical terms), repond to oxygen only, and have inconsistent or poor response to asthma medications, I have decided this is a form of HAPE. Observations by other clinicians support this:

  • Anthony Durmowicz and Ed Noordeweir et al. in Journal of Pediatrics May 1997:
  • “Although no data exists to support or refute the speculation that the presence of an ongoing pulmonary inflammatory process at the time of ascent to high altitude may predispose for the development of HAPE, I have observed that many children visiting high altitude who had HAPE at presentation had evidence of a preexisting inflammation-producing illness, such as a viral URI, OM, or GAS pharyngitis, that had begun before their ascent to high altitude.”
  • “Also noteworthy, the theory of increased endothelial cell permeability in response to hypoxia along with an increase in epithelial cell permeability may result in clinical pulmonary edema and the development of spontaneous HAPE in high altitude residents who acquire relatively mild respiratory tract illnesses seem to support this speculation.”

Careful review of the clinical records for these patients has not shown any factor that can reliably differentiate HAPE from other respiratory diagnoses such as asthma or pneumonia. Physical findings, symptoms, x-ray changes all overlap. The distinguishing feature to me is the clinical picture of a nontoxic patient with a low oxygen at altitude. HAPE is associated with increased pressures in the lungs, which can be diagnosed on an echocardiogram.  I am trying to organize a study to help us understand the causes of hypoxia which will include measuring pulonary pressures during acute episodes.

Asthma and Altitude

She died on the Breckenridge bike path clutching her inhaler, I heard. For years I was reminded by a memorial along the path. Then another man called last week say he is selling his house located at 10,500 feet because his trouble breathing interferes with skiing and rock climbing. “I use my inhaler 50 times a day,” he told me. “The doctor said I have asthma.”  Recently two doctors in Summit County have started to question whether some people living at high altitude may have another cause of their breathing problems such at high altitude pulmonary edema or pulmonary hypertension.

I frequently see children in my office with a respiratory illness and low oxygen, with readings in the 80’s or below. They are not leaning forward, gasping for air, using their rib muscles to breathe, like a person with an asthma attack severe enough to cause low oxygen. They do not have wheezes heard with the stethoscope. We usually give a trial of albuterol, since the medicine has minimal side effects and asthma is a common condition, but it rarely makes a big difference. We also test peak flows on patients over 5 to try and measure airway resistance seen in asthmatics. Then we send them home on oxygen, the treatment for high altitude pulmonary edema, and they get better.

Many of the families whose children need oxygen during illnesses are evaluated by lung specialists at Colorado Children’s Hospital or National Jewish Hospital. They are all told they have asthma and treated with inhaled steroids and albuterol. Pulmonary testing in the older children suggests reversible airway disease in about half. Recently the pulmonologist told us he does not believe the child had HAPE and requested a chest x-ray at the time of any future episode.

“Fulminant cases of HAPE do show dramatic changes in the x-rays, such as a recent case of a six year old who returned from sea level and overnight his oxygen dropped into the 40’s. But when we see patients with milder illness they often have clear lungs and the chest x-ray will not be abnormal until a day or two later. I rarely orders x-rays to make the diagnoses.

Since the pulmonologists are skeptical about the occurrence of HAPE in residents at high altitude, Dr. Ebert-Santos is proposing the syndrome be called “Acute Hypoxia of High Altitude Residents” or AHHAR. We need to figure out what is going on with our lungs at altitude. I’m trying to organize research concerning these issues.

They “had” to move to lower altitude…

Mary told me about two of her daughter’s friends whose families had to move after the girls had recurrent high altitude pulmonary edema (HAPE). This is easy to recognize in it’s classic form: a tourist has trouble breathing during the first 48 hours at altitude. But these girls lived here, and got sick returning from visits to lower latitude, which we call “reentry” HAPE. Both forms are not common, probably less than one out of one thousand people are affected. Certain people are more susceptible. Luckily it is prevented by taking diamox (acetazolamide) before traveling.

For families who live here I recommend buying a home pulse oximeter for less than $50 at Walmart or Walgreens. The affect person can have oxygen ordered by their doctor and delivered to the home if readings are below 90% saturation. The good news is that it doesn’t happen every time they travel and they tend to outgrow reentry HAPE in the teen years.

High Blood Pressure? check your oxygen while you sleep at altitude.

We are active, exercising, skiing, hiking every day. We are lean. We eat healthy diets.Yet we get high blood pressure. Our doctors think it is our age, genetics, or whatever. Now we know it could be something else: hypoxia. Pat was on medicine to control her pressures when she had a life-threatening allergic reaction. Another drug gave her side effects. Then her cardiologist Dr. Warren Johnson did a sleep study and found she was hypoventilating at night. Immediately after starting to sleep on Oxygen her blood pressure is normal. “If hypoxia is doing that to your blood pressure, what is it doing to your brain heart, muscles, lungs…” Pat wonders. I also had my blood pressure problem cured by sleeping on oxygen. And guess what? It is as easy as putting on pajamas. Two small prongs enter your nose and you don’t even feel it after a few minutes.

The air is thinner up here!

More and more people of all ages travel to  and reside in the mountains. Scientists and health care providers are just beginning to discover the effect of high altitude on health.

I have practiced medicine in Frisco, Colorado at 9,100 feet since 2000. Before that I worked on Saipan at sea level for 20 years. The difference has made me aware of special considerations when caring for people from newborns to retirees at high altitude. Simple measures can be taken to save a vacation or preserve an active life style in the mountains.  All visitors who are not pregnant should consider taking Diamox (acetazolamide) starting two days before travel. Tourists and residents should buy an inexpensive home pulse oximeter to monitor oxygen levels.  Anyone staying for more than a week should pursue testing for night time hypoxia and pulmonary hypertension when experiencing difficulty sleeping, fatigue or trouble breathing

Read articles on the Ebert Family Clinic Website for more information. I will add new information, discuss symptoms and diagnoses, and respond to questions. We have a power point available to interested groups. Personal evaluations and consults can be scheduled at Ebert Family Clinic with myself for children and Laura Amedro FNP for adults or children

Hi altitude Conference- peoples final.