Background

Allergens and pollution are reduced at high altitude. We investigated the effect of asthma rehabilitation at high altitude (HA, 3100 m) compared to low altitude (LA, 760 m) on exhaled nitric oxide (FeNO) and on specific IgE levels for house dust mites (HDM,d1) and common pollen (sx1).

Methods

For this randomized controlled trial adult asthmatics living <1000 m were randomly assigned to a 3-week in-hospital-rehabilitation (education, physical- and breathing-exercises) at either LA or HA. Changes in FeNO, d1 and sx1 from baseline to end-rehabilitation were measured.

Results

50 asthmatics (34 females) were randomized [mean ± standard deviation LA: n = 25, 44 ± 11 years, total IgE 267 ± 365kU/l; HA: n = 25, 43 ± 13 years, total IgE 350 ± 445kU/l]. FeNO significantly improved at HA from 69 ± 56 ppb at baseline to the first day at altitude 23 ± 19 ppb and remained decreased until end-rehabilitation with 37 ± 23 ppb, mean difference 95%CI -31(-50 to −13, p = 0.001) whereas at LA FeNO did not change. A significant decrease in d1 and sx1 at end-rehabilitation was observed in the LA-group [mean difference 95%CI -10.2 kUA/l (−18.9 to −1.4) for d1 and -4.95 kUA/l(-9.69 to −0.21) for sx1] but not in the HA-group. No significant difference between groups [d1 5.9 kUA/l(-4.2 to 16.2) and sx1 4.4 kUA/l(-3.5 to 12.4)] was found.

Conclusion

Rehabilitation at HA led to significant FeNO reduction starting from the first day until end-rehabilitation despite unchanged levels of specific IgE. The significant decrease in d1 and sx1 at end-rehabilitation in the LA group might be explained by less HDM in the hospital and/or reduced seasonal pollen, as this decrease was not observed at HA.

中文翻译：

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高海拔与低海拔的哮喘康复及其对呼出的一氧化氮和敏化模式的影响：随机平行分组试验。

背景

高海拔地区减少了过敏原和污染。我们调查了高海拔（HA，3100 m）与低海拔（LA，760 m）哮喘康复对呼出气一氧化氮（FeNO）以及屋尘螨（HDM，d1）和普通花粉特定IgE水平的影响（sx1）。

方法

对于该随机对照试验，将生活在1000 m以下的成年哮喘患者随机分配到LA或HA进行为期3周的院内康复（教育，体育锻炼和呼吸运动）。测量了从基线到最终康复期间FeNO，d1和sx1的变化。

结果

50名哮喘患者（34名女性）被随机分配[平均±标准差LA：n = 25、44±11岁，总IgE 267±365kU / l；HA：n = 25，43±13岁，总IgE 350±445kU / l]。FeNO在HA时从基线时的69±56 ppb显着改善，到海拔23±19 ppb的第一天，并一直降低，直到恢复至37±23 ppb为止，平均差异为95％CI -31（-50至-13，p = 0.001），而在LA FeNO不变。在LA组中，康复末期的d1和sx1显着下降[d1和-4.95 kUA / l的平均差异95％CI -10.2 kUA / l（-18.9至-1.4）（-9.69至-0.21） ）（对于sx1]），但不在HA组中。组之间没有显着差异[d1 5.9 kUA / l（-4.2至16.2）和sx1 4.4 kUA / l（-3.5至12.4）]。

结论

尽管特异性IgE水平未发生变化，但从第一天开始直至终末修复，HA的修复导致FeNO大量减少。LA组在最终康复时d1和sx1的显着下降可能是由于医院的HDM减少和/或季节花粉减少，因为在HA中未观察到这种下降。