The Hindu Business Line : Scaling the hypertension summit

THREE years after Erik Weihenmayer became the first blind man to reach Mt Everest's summit, the mountain is host to an expedition that challenges a common but feared medical condition.

Ryan Bendixen who suffers from high blood pressure began his journey to Mt Everest via the North Col on April 4. Reports on the Internet say his attempt to scale the 8,850-metre Everest is the first by such a person. A week ago, when the last update of his climb was posted on everestnews.com, Bendixen was on his way to Base Camp on the peak's Chinese side.

Climbing Mt Everest is not considered technically difficult in the world of mountaineering, but it remains physically daunting given the impact of strain at high altitude, where oxygen is less than at sea level. In turn, that can affect one's competence in climbing.

Almost 90 per cent of Everest climbers fail to reach the summit.

An active athlete with a passion for mountain climbing, Bendixen's real condition was diagnosed in 1990. Then, 20 years old and a member of an elite US Army infantry unit, his health was found to be so compromised that he was permanently discharged from the Army. At that time, nose-bleeds, occurring once a month during workouts, were the only clue to his blood pressure problem.

Reporting on Bendixen last December, Health Scout News noted that his blood pressure was 180/115 when the condition was diagnosed, putting him in the most severe category of hypertension. Optimal blood pressure is 120/80, and hypertension is defined as anything over 140/90, according to the US Centre for Disease Control Prevention.

In Bendixen's case, there was a suspicion of family weakness for this condition, his grandfather having died of a stroke while his mother and sister have hypertension.

Mumbai's Dr Milind Chitale has been associated with high-altitude medicine. He was a climbing doctor on a 1988 expedition to the 8,586-metre Mt Kanchenjunga, organised by city-based mountaineering club, Girivihar. The attempt, albeit unsuccessful, had the distinction of seeing Indian civilian climbers cross the haloed 8,000-metre mark for the first time.

According to Dr Chitale, people with no history of hypertension see their blood pressure go up on reaching high altitude. This even if they have not trekked or climbed to those heights. "The reasons are not well explained, it may have something to do with atmospheric pressure," he said, conceding alongside that it was surprising why blood pressure at altitude had not been studied in detail.

The effects of altitude on patients with high blood pressure have not been previously studied, and Bendixen's climb is hoped to provide a better understanding of the subject, everestnews.com, which hosts dispatches from the expedition, said.

In fact, given the grim emergencies under which its assistance is called for and the harsh environments in which it is administered, a certain lack of exactness is there in high altitude medicine. For example, Diamox (acetazolamide), a drug used to prevent high altitude sickness, was originally meant for ophthalmic application. Why it worked at high altitudes for a wholly different set of problems was explained after its entry into mountaineering's medicine kit, Dr Chitale said.

Bendixen will be tracking his blood pressure throughout the Everest climb, which is being sponsored by Novartis Pharmaceuticals Corporation, manufacturers of Diovan, the medicine he takes to manage his condition. The last dispatch from April 12 from Tibet put his blood pressure at 114/72. It compares with 110/70 that doctors increasingly view as normal in lieu of the traditional 120/80. "Today, 120/80 is seen as pre-hypertensive and handled without medication," Dr Chitale said.