Clinical trial NCT00685438: Ultraviolet Exposure, Antioxidant Use and Skin Erythema at Extreme High Altitude
Official title: Observational Study of Skin Erythema by Spectrophotometer, and UV Exposure With Viospore Ultraviolet Monitors at Extreme Altitude (Mt. Everest, North Side)
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Altitude
Ultraviolet Rays
Antioxidants
Oxidative Stress
Erythema
Keywords: Environmental Medicine
Altitude
Ultraviolet Rays
Antioxidants
Oxidative Stress
Erythema
Lead sponsor: Sunnybrook Health Sciences Centre
Sponsor class: OTHER
Collaborators: name: Ontario Centres of Excellence
First posted: 2008-05-28
Enrollment: 25
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: ECOLOGIC_OR_COMMUNITY
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: 9 Mountaineers with intention to summit Everest (1 American, 1 British, 1 German, 5 Australians, 1 Asian-Australian) 4 Trekkers with intention to go to 7000m (2 Americans, 1 Asian, 1 British) 12 climbing sherpas (11 Nepali and 1 Tibetan)

Brief summary: With the increasing tourism and adventure travel into extreme environments comes the need to reassess the required protection against ultraviolet (UV) radiation and possible other oxidative stresses. This is an observational study of UV radiation exposure and skin erythema while at extreme altitude (Mt. Everest). In addition to UV exposure, skin erythema, antioxidant use (such as vitamins C and E) will be measured.

Hypothesis:

1. UV radiation at extreme altitude has larger effects on the skin than at sea level; therefore requiring an adjustment of the antioxidant use for adequate protection.
2. The skin is an accurate reflection of UV and oxidative stress exposure
3. The efficacy of oxidatives stress is reflective of the ethnicity of the individual.

Detailed description: The literature widely acknowledges the deleterious effects of UV radiation on skin health, via production of oxidative free radicals. Consequently, there have been numerous studies on the potential dermatological/anti-carcinogenic benefits of anti-oxidants, such as vitamins C and E, melatonin, green tea, zinc, and selenium. There is, however, a limited amount of literature on the quantity of UV exposure in high-risk settings, such as extreme altitude and equatorial zones. Currently, there is no literature on UV exposure on Mount Everest. Additionally, the efficacy of antioxidants (topical or systemic) has not yet been established in this environment.

This will be an observational study where the principal investigator will collect accumulated ultraviolet exposure at different extreme altitudes during a 6 week period of a summit expedition on the north side of Mt. Everest. Included in the data collection will be patient demographics, time, altitude, temperature, use of anti-oxidants, sunscreen (weighed), and skin erythema (spectophotometer).

Eligibility criteria: Inclusion Criteria:

* Participants part of the expedition who are willing to wear the monitor, and disclose information of diet/antioxidant supplements and topical sunblock.

Exclusion Criteria:

* Participants who are unwilling to carry the UV monitor or disclose their demographics

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
city: Kathmandu
country: Nepal
facility: Mount Everest, North side
Study officials:
affiliation: Sunnybrook Hospital Emergency Department
name: Ivy S Cheng, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Ontario Cancer Institute
name: Lothar D Lilge, PhD
role: PRINCIPAL_INVESTIGATOR
References:
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citation: Cheng I, Kiss A, Lilge L. An observational study of personal ultraviolet dosimetry and acute diffuse reflectance skin changes at extreme altitude. Wilderness Environ Med. 2013 Dec;24(4):390-6. doi: 10.1016/j.wem.2013.05.007. Epub 2013 Sep 25.