Asthma rehabilitation at high vs. low altitude: randomized parallel-group trial

Abstract

Background To investigate the effect of asthma rehabilitation at high altitude (3100 m, HA) compared to low altitude (760 m, LA). Methods For this randomized parallel-group trial insufficiently controlled asthmatics (Asthma Control Questionnaire (ACQ) > 0.75) were randomly assigned to 3-week in-hospital rehabilitation comprising education, physical-&breathing-exercises at LA or HA. Co-primary outcomes assessed at 760 m were between group changes in peak expiratory flow (PEF)-variability, and ACQ) from baseline to end-rehabilitation and 3 months thereafter. Results 50 asthmatics were randomized [median (quartiles) LA: ACQ 2.7(1.7;3.2), PEF-variability 19%(14;33); HA: ACQ 2.0(1.6;3.0), PEF-variability 17%(12;32)]. The LA-group improved PEF-variability by median(95%CI) -7%(− 14 to 0, p = 0.033), ACQ − 1.4(− 2.2 to − 0.9, p < 0.001), and after 3 months by − 3%(− 18 to 2, p = 0.103) and − 0.9(− 1.3 to − 0.3, p = 0.002). The HA-group improved PEF-variability by − 10%(− 21 to − 3, p = 0.004), ACQ − 1.1(− 1.3 to − 0.7, p < 0.001), and after 3 months by − 9%(− 10 to − 3, p = 0.003) and − 0.2(− 0.9 to 0.4, p = 0.177). The additive effect of HA vs. LA directly after the rehabilitation on PEF-variability was − 6%(− 14 to 2), on ACQ 0.3(− 0.4 to 1.1) and after 3 months − 5%(− 14 to 5) respectively 0.4(− 0.4 to 1.1), all p = NS. Conclusion Asthma rehabilitation is highly effective in improving asthma control in terms of PEF-variability and symptoms, both at LA and HA similarly. Trial registration Clinicaltrials.gov: NCT02741583 , Registered April 18, 2016. Electronic supplementary material The online version of this article (10.1186/s12890-019-0890-y) contains supplementary material, which is available to authorized users.

The Oxygen Transport Triad in High-Altitude Pulmonary Edema: A Perspective from the High Andes

“…Chronic hypoxia is not deleterious but rather beneficial under many circumstances. It gives us significant advantages: extended longevity [ 9 ], less mortality from several diseases [ 68 , 69 ], paradoxically greater tolerance to hypoxia as one goes higher [ 43 ], a form of human plasticity with lower incidence of cardiac diseases [ 70 ], less obesity, less asthma [ 9 , 71 ], fewer hypertension problems in the Andeans [ 72 , 73 ], less lung cancer incidence [ 74 , 75 ], and even less COVID-19 incidence and lower Case Fatality Rate, as we had first correctly predicted before the arrival of the pandemic to Bolivia, later also confirmed by others [ 25 , 76 , 77 , 78 ]. This was also observed in the questions above, because there is misconception among some of the sea level high altitude experts, (due of their biased understanding), that life at high altitude is always “deleterious”.…”

“…Chronic hypoxia is not deleterious but rather beneficial under many circumstance It gives us significant advantages: extended longevity [9], less mortality from several di eases [68,69], paradoxically greater tolerance to hypoxia as one goes higher [43], a form human plasticity with lower incidence of cardiac diseases [70], less obesity, less asthm [9,71], fewer hypertension problems in the Andeans [72,73], less lung cancer inciden…”

Physical Activity: A Missing Link in Asthma Care

“…To date, 10 randomised controlled trials (RCTs) have collectively reported benefits of supervised aerobic exercise training on a range of outcomes in adult patients with asthma such as exercise capacity, airway inflammation, disease exacerbation, clinical control, health-care use, psychosocial symptoms and asthma-related quality of life [30,[77][78][79][80][81][82][83][84][85][86]. In the largest and most recent RTC including 89 subjects with mild or moderate asthma, aerobic exercise at least three times a week for ≥ 30 minutes plus muscle training, and stretching, improved asthma control measured by the Asthma Control Test questionnaire and reduced shortness of breath [78].…”

“…Decreased air density at altitude also reduces airway resistance, which might increase exercise capacity [98]. A recent RCT found that a three-week comprehensive rehabilitation program with endurance training was highly effective in improving asthma control in patients with poorly controlled asthma-a benefit which was preserved after three months [83]. High-altitude training also led to better improvement in PEFR-variability, exercise capacity and airway inflammation as assessed by FeNO compared to low-altitude training [83].…”

Defining a role for exercise training in the management of asthma

“…Effects of exercise on symptom scores, quality of life and psychosocial morbidity in adults with asthma Studies in adults have demonstrated improvements in symptom scores with exercise interventions, as assessed by the ACQ or Asthma Control Test scores [11,42,49,51,52], with a recent Cochrane review suggesting that physical training improves asthma control [52].…”