Blood pressure may rise during mountain visits
September 9, 2005
FRISCO – Almost all of the research concerning high elevation relates to one-time events, such as climbing Mount Everest, as opposed to long-term exposure to changes in elevation. So Dr. Jim Bachman decided to study people who lived at sea level for part of the year and in Summit County the other part.Bachman said the phenomenon of rising blood pressure for many patients exists in the real world but does not exist in text books, which is why he wanted to write about it. He said many patients take medication for high blood pressure at high elevation but do not need to at sea level.He coined the term “bi-landers” to describe second-home owners. He studied the monthly blood pressure fluctuations of 70 bi-landers for two years as they traveled from sea level to high elevation and back. He found that the total population had statistically higher mean arterial pressure at high elevation than at low (mean of 97.8 compared to 93.8). In other words, about 30 percent of the patients experienced an increase in blood pressure.
“These findings are in contrast to the current belief that high altitude causes a decrease in blood pressure over several months or years,” Bachman wrote in a letter to the editor of High Altitude Medicine & Biology. “However, that belief is based on people living full-time at high altitude. It is possible that bi-landers might not have the same response.”He found that a personal or family history of hypertension, or starting the study with a diastolic above 90, predicted an increase in blood pressure at high elevation. Patients with borderline high blood pressure at sea level usually had in an increase in blood pressure. Other patients without high blood pressure histories or higher sea level readings were not affected by elevation.Elevated blood pressure usually isn’t harmful in the short term, but it’s harmful in the long term, which can mean six months. It can cause heart attacks and strokes, but Bachman makes a distinction between high elevation and high blood pressure causing such events.”High altitude does not cause heart attacks,” he said. “People have more on cruises than on ski vacations. We have the same amount here as everywhere else.”Altitude sickness, men and Viagra
Bachman and Dr. Aris Sophocles studied 29 cases of high-altitude pulmonary edema (HAPE) in Summit County visitors. The condition, which doctors see hundreds of cases per year in Summit County alone, occurs when pressure in the head and lungs causes fluid to leak into the lungs and build up. It can be fatal if the patient does not return to a lower elevation. Annually, about one to three visitors in Summit County die from it, Bachman said.Results from the study suggested there are two varieties of the illness – one that affects visitors at 8,000 feet or higher, and, at elevations of up to 11,000 feet affects primarily men. The other affects residents of high altitudes when they descend to an elevation below 8,000 feet and then return to high altitude. This second type affects children predominantly, and boys and girls are affected almost equally.Bachman has found that men suffer from the edema condition at about 30 times the rate of women, though previous data had said men and women got the illness about equally. However, women and men get a milder form of altitude illness equally. Bachman has found that before puberty, girls and boys have an equal chance of getting the illness. He thinks this suggests hormonal changes may alter the body’s response in high elevation.”My best guess is that the female hormone estrogen helps you, but it could be that the male hormone hurts you,” he said. “Other research indicates that men may play harder or (ignore symptoms) and that women breathe deeper and faster.”
Older adults have a lower risk of developing altitude sickness. Headaches, nausea and fatigue are caused by a lack of oxygen, which causes a mild swelling of the brain. People’s brains shrink as they age, allowing more room for the swelling and thus less pressure.Another new finding in altitude sickness research involves Viagra. The drug, which helps blood move from one place to another, will most likely get FDA approval for use in treating a variation of altitude illness called pulmonary hypertension. The illness is seen mostly in babies born at high altitude, Bachman said.Currently, the only drug available is Diamox, which simply makes the patient urinate more and breathe deeper and faster. Oxygen, rest and ginkgo biloba – an over-the-counter herb – also helps, Bachman said.Vail, Colorado