Guest Editorial: Medical and commercial ethics in altitude trekking (p. 1)

Sadly there have been a number of instances where porters for high altitude expeditions, particularly in the Himalayas, have fallen ill and not been given the attention they deserve. This Guest Editorial by Küpper and colleagues discusses the issues and points out that changes of attitude are badly needed.

Sightings, Edited by John W. Severinghaus (p. 5)

Clinician's Corner, Edited by Andrew Luks

Refractive surgery safety at altitude

Climbers who have had corneal refractive surgery are liable to develop visual changes with altitude exposure and there have been some dramatic episodes as a result. Mader and White (p. 9) review this topic and offers guidelines.

Scientific Articles

Prevalence and determinants of hyperlipidemia in moderate altitude areas of the Yunnan-Kweichow Plateau in southwestern China

There has been a rapid increase in interest in high altitude medicine in China in the last few years. Here Deng and colleagues (p. 13) document a high prevalence of hyperlipidemia in a random study of 14,015 people at the moderate altitude of 1500 to 2500 m in southwestern China. The prevalence was higher in men than women and increased with age. Responsible factors were a high BMI, unhealthy living habits, and unsuitable diets.

Carbohydrate supplementation and exercise performance at high altitude: a randomized controlled trial

Although it is known that carbohydrate supplementation increases exercise capacity at sea level, whether this occurs in the field at high altitude is not known. Oliver and colleagues (p. 22) studied 41 members during a time trial at an altitude of 5192 m. The participants were randomized in a double blind design to receive either carbohydrate supplementation or a placebo. The group with supplementation completed the test significantly faster and reported lower ratings of perceived exertion.

The effect of the sleep high-train low regimen on the finger cold-induced vasodilation response

A great deal of research has been devoted to the sleep high-train low pattern in an attempt to improve exercise performance at low altitudes. The finger cold-induced vasodilation response is believed to be affected by the level of physical fitness and altitude acclimatization. Amon and colleagues (p. 32) studied 17 males in either experimental or control groups and found that the sleep high-train low regimen improved the finger response in both normoxic and hypoxic conditions.

Hypobaric versus normobaric hypoxia: same effects on postural stability?

Postural stability has been proposed as an index of acclimatization to high altitude. In this study Degache and co-workers (p. 40) tested whether postural stability was affected more by hypobaric than normobaric hypoxia at simulated altitudes of 1700 and 3000 m. The results suggested that hypobaria rather than hypoxia itself was responsible for the altered balance known to occur at high altitude.

Brief Reports

Body composition and somatotype of experienced mountain climbers

Body composition and somatotype of 10 experienced mountain climbers were assessed by Barbieri and colleagues (p. 46) from measurements such as body mass, height, girth, and skinfold thickness. The dominant body type was mesomorphic, which is common in athletes and refers to a hard body with well-defined muscles, rectangular shape, broad shoulders, and easily gains in muscle mass.

A tale of two climbers: hypothermia, death, and survival on Mount Everest

Hypothermia is a serious risk factor at extreme altitude. Moore and Semple (p. 51) analyze the meteorological and hypothermic risk factors in the spring 2006 Mt. Everest climbing season. They concentrated on two climbers, one of whom survived and the other did not, when they were forced to spend a night in exposed conditions near the summit. Wind chill temperature and facial frostbite time were very different for the two climbers. The authors suggest that the barometric pressure which is easily measured is a useful predictor of factors predisposing to hypothermia.

High-altitude medicine education in China: exploring a new medical education reform

Interest in high altitude medicine has burgeoned in China in the last few years partly because of the increasing development of Tibet. It could be argued that there is more experience of high altitude morbidity in China than any other country, and Chinese experience with high altitude illnesses is greater than anywhere else. Luoa and colleagues (p. 57) describe training methods used in that country.

Case Report

Cerebral venous sinus thrombosis at high altitude

Thrombotic events are a risk at high altitude. Cerebral venous sinus thrombosis is rare but potentially life threatening and an interesting case is described here by Shrestha (p. 60).

Meeting Report

The impact of hypoxia on cells, mice, and men

Gassmann and colleagues (p. 63) describe a meeting to discuss the biology of hypoxia on a broad basis. The attendees were limited to 100, and the report indicates that a large array of stimulating topics were discussed.

Letter to the Editor

Pre-hospital wrist block for digital frostbite injuries

Frostbite of the hands is a common feature of high altitude accidents. Pasquier and colleagues (p. 65) describe a novel technique of bilateral wrist block that was effective in relieving pain during rewarming.