High altitude trekking risky for travellers with asthma
6 December 2002
Young adults with mild to moderate asthma are at risk of worsening symptoms when they travel overseas, especially if they go on high-altitude treks, Israeli researchers have warned.
The researchers' study found that people were at particular risk if they had used their bronchodilator (reliever medication) three or more times a week over the previous year. Combining excessive bronchodilator use with high-altitude treks further increased travellers' risk of worsening asthma.
These findings prompted the researchers to recommend that all people with asthma have optimal asthma control before travelling.
People who used inhaled bronchodilators three or more times a week during the previous year should be advised to postpone travel until better control was achieved, the researchers said.
From their clinicians travellers should be aware of optimal management of their asthma, how to recognise deteriorating asthma and how to follow a clear individual crisis plan, they wrote (Archives of Internal Medicine 2002; 162: 2421-26).
The researchers looked at 203 travellers diagnosed with asthma, who were an average of 24 years old and who were travelling overseas on holiday for a median 13 weeks. More than half of the travellers went high-altitude trekking.
Some 88 people had an asthma attack while away. Of these, 45 per cent said their asthma had worsened, 37 per cent experienced the worst attack of their life, and 11 per cent experienced a life-threatening attack.
Excessive bronchodilator use was linked to a 3-fold increased risk of asthma attack compared with infrequent bronchodilator users, and people participating in intensive physical activity during treks were twice as likely as those doing less vigorous exercise to have an attack.
Combining heavy bronchodilator use with trekking resulted in a 5-fold increased risk of an attack.
Most trekkers had mild to moderate asthma, as those with severe asthma were less likely to participate in rigorous travel activities. There was no link between asthma during travel and a history of exercise induced asthma or a positive exercise test.
(A 'positive' exercise test means that during a supervised exercise test the airways narrow in response to physical exercise.)
High altitude, cold dry air and exposure to new allergens (any substances that the body regards as foreign and against which it produces antibodies) could trigger asthma attacks during physically demanding trekking, the researchers said.
Last Reviewed: 06 December 2002
- 1. Medical Observer Weekly 06/12/02
