Does climate therapy at moderate altitudes improve pulmonary function in asthma patients? A systematic review

Histopathologic features of chronic rhinosinusitis with nasal polyps in patients from high-altitude Xizang region

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous inflammatory disease with varying patterns across regions.

OBJECTIVE

This study aims to investigate the clinical and histopathological features of CRSwNP in Xizang, a high-altitude region in China.

MATERIALS AND METHODS

We retrospectively analyzed the histopathological features of CRSwNP patients from Shanghai and Xizang who underwent functional endoscopic sinus surgery (FESS) between 2017 and 2024. Polyp tissue samples were assessed, and statistical analyses compared features between the two regions in CRSwNP, eosinophilic CRSwNP (eCRSwNP), and noneosinophilic CRSwNP (neCRSwNP) patients.

RESULTS

Twenty-eight patients from Xizang and 35 from Shanghai were analyzed. All Shanghai patients were Han Chinese, and all Xizang patients were Tibetan. Compared to Shanghai, Tibetan patients had significantly lower rates of smoking and asthma. Overall inflammation levels in Xizang were lower, while eosinophil counts were lower in eCRSwNP patients. Neutrophil infiltration, mucosal ulceration, and squamous metaplasia were higher in Xizang patients, while neCRSwNP patients exhibited more neutrophil infiltration and less subepithelial edema.

CONCLUSIONS

The study revealed that Tibetan patients with CRSwNP have lower eosinophilic inflammation but higher neutrophil infiltration and squamous metaplasia compared to Shanghai patients, indicating the impact of high-altitude environments on inflammatory patterns.

Pediatric asthma and altitude: a complex interplay between different environmental factors

Asthma is one of the most common non-communicable diseases, and its prevalence and morbidity are influenced by a wide array of factors that are only partially understood. In addition to individual predisposition linked to genetic background and early life infections, environmental factors are crucial in determining the impact of asthma both on an individual patient and on a population level.Several studies have examined the role of the environment where asthmatic subjects live in the pathogenesis of asthma. This review aims to investigate the differences in the prevalence and characteristics of asthma between the pediatric population residing at higher altitudes and children living at lower altitudes, trying to define factors that potentially determine such differences. For this purpose, we reviewed articles from the literature concerning observational studies assessing the prevalence of pediatric asthma in these populations and its characteristics, such as spirometric and laboratory parameters and associated sensitization to aeroallergens.Despite the heterogeneity of the environments examined, the hypothesis of a beneficial effect of residing at a higher altitude on the prevalence of pediatric asthma could be confirmed, as well as a good profile on airway inflammation in asthmatic children. However, the possibility of a higher hospitalization risk for asthma in children living at higher altitudes was demonstrated. Moreover, a positive association between residing at a higher altitude and sensitization to pollens and between lower altitude and sensitization to house dust mites could be confirmed in some pediatric patients, even if the results are not homogeneous, probably due to the different geographical and climatic regions considered. Nonetheless, further studies, e.g., extensive and international works, need to be conducted to better understand the complex interplay between different environmental factors, such as altitude, and the pathogenesis of asthma and how its prevalence and characteristics could vary due to climate change.

Is altitude a determinant of the health benefits of nature exposure? A systematic review and meta-analysis

Introduction

Nature exposure is a widely accepted option for promoting public health owing to the recent surge of scientific evidence. However, the actual settings to facilitate this initiative is yet to be extensively reviewed. In this systematic review, we have aimed to provide an up-to-date summary of interventional studies investigating the psycho-physiological effects of forests and urban forests, including details on their physical settings, and investigate an effect-modifying role of altitude and summarize data on the magnitude and shape of the association.

Methods

A keyword search using five electronic academic databases (PubMed, Embase, PsycINFO, Web of Science, and Scopus) was conducted to identify relevant articles published in English from the inception year to the end of February 2022. The methodological quality was evaluated using the ROBINS-I or ROB2 tool, depending on the study design. Meta-regression and random effects model were jointly used to examine the relationship between altitude and health outcomes.

Results

We included 27 eligible studies and 31 cases extracted from 19 studies were used for the meta-analysis. In the meta-regression, we observed a non-linear association between altitude and psycho-physiological effects. Altitude had a positive quadratic association with anxiety (p < 0.000, adjusted R ² = 96.79%), depression (p < 0.000, adjusted R ² = 98.78%), and fatigue (p < 0.000, adjusted R ² = 64.74%) alleviating effects. Conversely, altitude demonstrated a negative non-linear association with the blood pressure-lowering effect (p = 0.009, adjusted R ² = 32.83%). Additionally, the thermal index (THI) and illuminance (lx) levels were significantly associated with effect sizes of psychological restoration.

Discussion

This review provides moderate-certainty evidence for an effect-modifying role of altitude. The meta-regression results suggested the optimal and minimal altitude ranges for psychological restoration and physiological relaxation, respectively. Despite some limitations, the study findings provide a significant basis for utilizing altitude, which is easily accessible and simple, to promote the health benefits of nature-based initiatives.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022310894, identifier: CRD42022310894.

Climatotherapy for asthma: Research progress and prospect

Asthma affects over 300 million people globally and is a cause of substantial burden of disease, including both premature death and reduced quality of life in people of all ages. Although both genetic and environmental factors play an important role in the pathogenesis of asthma, the rising trend of asthma and other allergic diseases over recent decades is thought to be largely caused by alteration in environmental conditions. Thus, a considerable amount of attention has been paid to environmental modification for the treatment and management of asthma, including household allergen reduction and/or irritant removal. More advanced environmental modification strategies (e.g., health resort medical rehabilitation, high-altitude climate therapy and multiple-hit interventions) have also been suggested. Research advances have been made over the past decades, but major challenges and opportunities coexist in this emerging field. Concerted efforts are required to tackle these formidable challenges.

A positive effect of a short period stay in Alpine environment on lung function in asthmatic children

Lung function is a central issue in diagnosis and determination of asthma severity and asthma control has been previously reported to improve after a stay in mountain environment for at least 2 weeks. No data are available for shorter periods of stay, in particular for small airways during a stay at altitude. The aim of this study is to focus on changes in respiratory function, regarding both the central airways and the peripheral airways in the first 2 weeks of stay in a mountain environment in asthmatic children. In this study, 66 asthmatic children (age: 14 ± 2.8 years) were evaluated through spirometric and oscillometric tests at the time of arrival at the Istituto Pio XII, Misurina (BL), Italy, 1756 m above sea level (T0), after 24 h (T1), and 168 h (T2) of stay. FEV1%, FEF25%-75%, and FEV1/FVC increased significantly from T0 value both at T1 and T2 (respectively, p = 0.0002, p < 0.0001, p = 0.0002). Oscillometry showed a significant improvement in R5, R20, and R5-20 at both T1 and T2 as compared to T0 (respectively, p = 0.0001, p = 0.0002, and p = 0.049). Reactance at 5 Hz (X5) improved significantly at T2 versus T0, p = 0.0022. The area under reactance curve between Fres and 5 Hz (AX) was significantly reduced (p = 0.0001) both at T1 and T2 as compared to T0. This study shows an improvement in respiratory indices as soon as after 24 h of stay at altitude, persisting in the following week.

Alpine altitude climate treatment for severe and uncontrolled asthma: An EAACI position paper

Currently available European Alpine Altitude Climate Treatment (AACT) programs combine the physical characteristics of altitude with the avoidance of environmental triggers in the alpine climate and a personalized multidisciplinary pulmonary rehabilitation approach. The reduced barometric pressure, oxygen pressure, and air density, the relatively low temperature and humidity, and the increased UV radiation at moderate altitude induce several physiological and immunological adaptation responses. The environmental characteristics of the alpine climate include reduced aeroallergens such as house dust mites (HDM), pollen, fungi, and less air pollution. These combined factors seem to have immunomodulatory effects controlling pathogenic inflammatory responses and favoring less neuro‐immune stress in patients with different asthma phenotypes. The extensive multidisciplinary treatment program may further contribute to the observed clinical improvement by AACT in asthma control and quality of life, fewer exacerbations and hospitalizations, reduced need for oral corticosteroids (OCS), improved lung function, decreased airway hyperresponsiveness (AHR), improved exercise tolerance, and improved sinonasal outcomes. Based on observational studies and expert opinion, AACT represents a valuable therapy for those patients irrespective of their asthma phenotype, who cannot achieve optimal control of their complex condition despite all the advances in medical science and treatment according to guidelines, and therefore run the risk of falling into a downward spiral of loss of physical and mental health. In the light of the observed rapid decrease in inflammation and immunomodulatory effects, AACT can be considered as a natural treatment that targets biological pathways.

Factors Associated with Severe Acute Respiratory Infections Due to Rhinovirus/Enterovirus Complex in Children and Their Comparison with Those of Respiratory Syncytial Virus

Background: Acute respiratory tract infections (ARTIs) are one of the main causes of morbidity and mortality in children under the age of five worldwide. Objectives: The objective of this research was to describe the main characteristics of hospitalized patients with ARTI caused by the rhinovirus/enterovirus (RV/EV) complex and the risk factors associated with severe infection. Methods: This was a retrospective descriptive study in patients from one month to 18-years-old who had been hospitalized for ARTI between October 2015 and December 2019 at Fundación Cardioinfantil in Bogotá, Colombia, and had had an RT-PCR viral panel during their hospitalization. Rhinovirus/enterovirus infection was characterized to identify factors associated with disease severity as compared to respiratory syncytial virus (RSV). A multivariate analysis was performed, controlling for confounding factors, to identify groups at risk of developing associated acute respiratory distress syndrome (ARDS). Results: During the study period, 645 RT-PCRs were performed, with the two main etiological agents identified being RV/EV (n = 224) and RSV (n = 68). The median age of patients with the RV/EV complex was 27 months (IQR: 8 - 70), and seven months for those with RSV (IQR: 2 - 11). Severe RV/EV complex infections required more transfers to intensive care (47% vs. 11%), showed more viral coinfection (OR: 2.13, 95% CI: 1.42 - 4.64), and had less bacterial coinfection (OR: 0.55, 95% CI: 0.31 - 0.98) than RSV infections. The RV/EV group had a higher risk of developing ARDS (OR: 3.6, 95% CI: 1.07 - 12:18), especially in premature infants (P: 0.05; exp(B), 2.99; 95% CI = 1.01 - 8.82), those with heart disease (P: 0.047; exp(B), 2.99; 95% CI = 1.01 - 8.82), and those with inborn errors of metabolism (P: 0.032; exp(B), 5 - 01; 95% CI = 1.15 - 21.81). A total of 13 patients from both study groups died (4.5%), with no differences found between the groups (RV/EV 54% vs. RSV 46%; P = 0.3). Conclusions: Respiratory infection due to RV/EV in children can frequently be severe, requiring management with intensive care therapy. When compared to RSV, this complex is more frequently associated with the development of ARDS, especially in risk groups such as those with prematurity, heart disease, or inborn errors of metabolism.

The Effects of Climate Therapy on Cardiorespiratory Fitness and Exercise-Induced Bronchoconstriction in Children with Asthma

We investigated whether a 1-week stay in the mountains may have a positive impact on Exercise-Induced Bronchoconstriction (EIB) and cardiorespiratory endurance in asthmatic children from an urban area. Spirometry was performed before and 10 min after a 20 m shuttle run test (20mSRT) on the first and seventh day of a summer asthma camp in the Italian Alps at 900 m of altitude. Spirometry z-scores were derived from the Global Lung Initiative 2012 prediction equations, and percentiles of the 20mSRT performance were assigned according to De Miguel-Etayo’s and Tomkinson’s predictive equations. A FEV1 decrease ≥10% after the exercise was defined as EIB. Particulate matter pollution was monitored during the camp and in the urban area of provenience. Twenty-four subjects (age range 7–16 years) were included. Frequency of EIB decreased from 58% (14/24) at day-1 to 33% (8/24) at the end of the camp (p = 0.08). Most subjects with a 20mSRT in the lowest quartile at day 1 had EIB (9/11). The proportion of children with a 20mSRT <25° percentile decreased from 45% (11/24) at day-1 to 16% (4/24) at day-7 (p = 0.02). Conclusion: One-week climate therapy in the mountains improved both bronchial hyperreactivity and cardiorespiratory endurance in our cohort of asthmatic children.

Effectiveness of pulmonary rehabilitation at high-altitude compared to sea-level in adults with severe refractory asthma

BACKGROUND

Beneficial effects of pulmonary rehabilitation at high-altitude (HAPR) in patients with severe refractory asthma have been reported earlier, but evidence for the effectiveness is limited.

AIM

To investigate the effectiveness of high-altitude pulmonary rehabilitation to comparable treatment at sea-level (LAPR) on patient outcome parameters.

METHODS

Adults with severe refractory asthma living in The Netherlands were included. Treatment consisted of a 12-week personalized multidisciplinary rehabilitation program either at high-altitude (Davos Switzerland) (n = 93) or in a tertiary lung center at sea-level in The Netherlands (n = 45). At baseline, after treatment, and during 12 months follow-up asthma related quality of life (AQLQ), asthma control (ACQ), pulmonary function and OCS-dose were assessed. Patients could not be randomized resulting in different asthma populations. Groups were compared using linear regression analysis (ANCOVA) adjusted for baseline values, in addition to age, atopy, smoking history, BMI and gender.

RESULTS

After treatment, and at 12 months follow-up, improved AQLQ(0.92,p < 0.001 and 0.82,p = 0.001, respectively), ACQ(-0.87,p < 0.001 and -0.69,p = 0.008, respectively) and lower maintenance OCS dose (Unadjusted linear regression analysis-5.29 mg, p = 0.003 and Crude Odds Ratio-1.67, p = 0.003, respectively) were observed in the HAPR-group compared to the LAPR group. Patients receiving HAPR also had less asthma exacerbations (≥1 exacerbation: 20% vs 60%,p < 0.001) and showed improvement in lung function (%predFEV₁ 3.4%,p = 0.014) compared to the LAPR group, but at 12 months no differences between groups were observed.

CONCLUSION

HAPR resulted in a larger improvement in patient outcome parameters compared to LAPR, on the long run the improvement in patient reported symptoms and lower maintenance OCS-dose persists. Underlying factors that explain this observed effect need to be investigated.

Hotspot detection and socio-ecological factor analysis of asthma hospitalization rate in Guangxi, China

BACKGROUND

Asthma is a major public health concern throughout the world. Numerous researches have shown that the spatial-temporal patterns of asthma are inconsistent, leading to the suggestion that these patterns are determined by multiple factors. This study aims to detect spatial-temporal clusters of asthma and analyze socio-ecological factors associated with the asthma hospitalization rate in Guangxi, China.

METHODS

Asthma hospitalization and socio-ecological data for 88 counties/municipal districts in Guangxi, China in 2015 was collected. Space-time scan statistics were applied to identify the high-risk periods and areas of asthma hospital admissions. We further used GeoDetector and Spearman correlation coefficient to investigate the socio-ecological factors associated with the asthma hospitalization rates.

RESULTS

There were a total of 7804 asthma admissions in 2015. The high-risk period was from April to June. The age groups of 0-4 and ≥65 years were both at the highest risk, with hospital admission rates of 45.0/10⁵ and 46.5/10⁵, respectively. High-risk areas were found in central and western Guangxi with relative risk (RR) values of asthma hospitalizations greater than 2.0. GDP per capita and altitude were positively associated with asthma hospitalizations, while air pressure and wind speed had a negative association. The explanatory powers of these factors (i.e., GDP per capita, altitude, air pressure, wind speed) were 22%, 20%, 14% and 10%, respectively.

CONCLUSIONS

The GDP per capita appears to have the strongest correlation with asthma hospitalization rates. High-risk areas were identified in central and western Guangxi characterized by high GDP per capita. These findings may be helpful for authorities developing targeted asthma prevention policies for high-risk areas and vulnerable populations, especially during high-risk periods.

Altitude above 1500 m is a major determinant of asthma incidence. An ecological study

BACKGROUND

Previous studies suggest an inverse correlation between asthma and altitude. In the present work, we performed an in-depth analysis of asthma incidence in the 758 Mexican counties covered by the largest medical institution in the country (∼37.5 million insured subjects), and evaluated its relationships with altitude and other factors.

METHODS

Asthma incidence in each county was calculated from new cases diagnosed by family physicians. Other variables in the same counties, including selected diseases, geographical variables, and socioeconomic factors, were also obtained and their association with asthma was evaluated through bivariate and multivariate analyses.

RESULTS

Median asthma incidence was 296.2 × 100,000 insured subjects, but tended to be higher in those counties located on or near the coast. When asthma incidence was plotted against altitude, a two-stage pattern was evident: asthma rates were relatively stable in counties located below an altitude of ∼1500 m, while these rates progressively decreased as altitude increased beyond this level (r_S = -0.51, p < .001). Multivariate analysis showed that, once each variable was adjusted by the potential influence of the others, asthma incidence was inversely correlated with altitude (standardized β coefficient, -0.577), helminthiasis (-0.173), pulmonary tuberculosis (-0.130), and latitude (-0.126), and was positively correlated with acute respiratory tract infection (0.382), pneumonia (0.289), type 2 diabetes (0.138), population (0.108), and pharyngotonsillitis (0.088), all with a p ≤ .001.

CONCLUSION

Our study showed that altitude higher than ∼1500 m comprises a major factor in determining asthma incidence, with the risk of new-onset asthma decreasing as altitude increases. Other less influential conditions were also identified.

[The application of climatic therapy in the health resorts of the Black Sea coast of the Caucasus: the current state-of-the-art and the prospects for the further development]

The present review summarizes the data published in the domestic and foreign literature concerning the history of climatic therapy, the current concepts of the mechanisms of action of the climatic and weather factors on the human body, the modern therapeutic modalities and technologies for health promotion. We consider not only the achievements but also the problems arising from insufficient knowledge of the impacts of current climate and extreme weather conditions on the state of human health and some disputable issues of the new methods and technologies of climatic therapy.

IN CONCLUSION

the promising areas of further research and developments pertaining to climatic therapy as practiced under conditions of the Black Sea coast resorts.

High-altitude alpine therapy and lung function in asthma: systematic review and meta-analysis

We used meta-analysis to measure the effect of high-altitude climate therapy (HACT) on lung function outcomes in asthma, and systematically searched PubMed, Embase and www.elibrary.ru for publications appearing from 1970 to mid-2015. We included studies carried out with children or adults with an exposure of up to 12 weeks at an altitude of ≥1500 m above sea level. Changes in forced expiratory volume in 1 s (FEV₁), FEV₁/vital capacity ratio or peak expiratory flow rate as the HACT intervention outcomes were analysed. We included data for 907 participants (age range 4–58 years) from 21 studies, altogether including 28 substrata based on asthma type or severity. Only three of 21 included studies had high quality, whereas 93% of substudies reported lung function improvement with an overall pooled standardised mean difference (SMD) of 0.53 (95% CI 0.43–0.62). The measured effect of HACT was greater in adults (SMD 0.75, 95% CI 0.63–0.88, n=14) than in children (SMD 0.24, 95% CI 0.09–0.38, n=14). Studies at altitude >2000 m above sea level yielded the same effect as those at lower altitude. Based on a cut-point of a 0.50 change in SMD to define a meaningful clinical difference, HACT appears to have efficacy as an intervention. This extent of benefit appears to be limited to adults with asthma.

High-altitude alpine therapy may be an effective intervention to improve lung function in patients with asthmahttp://ow.ly/u3i23008vU5