Asthma Prevalence and Phenotyping in the General Population: The LEAD (Lung, hEart, sociAl, boDy) Study

Abstract

Background

Asthma is a chronic heterogeneous respiratory disease involving differential pathophysiological pathways and consequently distinct asthma phenotypes.

Objective and Methods

In the LEAD Study, a general population cohort (n=11.423) in Vienna ranging from 6–82 years of age, we addressed the prevalence of asthma and explored inflammatory asthma phenotypes that included allergic and non-allergic asthma, and within these phenotypes, an eosinophilic (eosinophils ≥300 cells/µL, or ≥150 cells/µL in the presence of ICS medication) or non-eosinophilic (eosinophils <300 cells/µL, or <150 cells/µL in the presence of ICS) phenotype. In addition, we compared various factors related to biomarkers, body composition, lung function, and symptoms in control subjects versus subjects with current asthma (current doctor’s diagnosis of asthma).

Results

An overall prevalence of 4.6% was observed for current asthma. Furthermore, an age-dependent shift from allergic to non-allergic asthma was found. The non-eosinophilic phenotype was more prominent. Obesity was a prevalent condition, and body composition including visceral adipose tissue (VAT), is affected in current asthma versus controls.

Conclusion

This broad-aged and large general population cohort identified differential patterns of inflammatory asthma phenotypes that were age-dependent. The presence of eosinophilia was associated with worse asthma control, increased asthma medication, increased VAT, and lower lung function, the opposite was found for the presence of an allergic asthma.

Keywords:

• asthma
• prevalence
• phenotyping
• pulmonary function testing
• spirometry
• general population
• body composition

Abbreviation

LEAD Study, Lung, Heart, Social, Body Study; FEV1, Forced expiratory volume in 1 second; FVC, Forced vital capacity; GLI, Global Lung Initiative; DXA, Dual-energy X-ray absorptiometry; SES, Socioeconomic status; SHS, secondhand smoking; MS, Maternal smoking; FMI, Fat mass index; LMI, Lean mass index; VAT, visceral adipose tissue; SHS, Second-hand smoking; BMI, Body mass index; BD, bronchodilation; Th2, T helper 2; COPD, Chronic obstructive pulmonary disease; ACT, Asthma Control Test; GINA, Global Initiative for Asthma; ICS, inhaled corticosteroids; SABA, short-acting beta agonist; LABA, long-acting beta agonist; SAMA, short-acting muscarinic antagonist; LAMA, long-acting muscarinic antagonist.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

Prof. Dr. Roland Buhl reports grants from Boehringer Ingelheim, GlaxoSmithKline, Novartis, Roche; personal fees from AstraZeneca, Berlin-Chemie, Boehringer Ingelheim, Chiesi, Cipla, GlaxoSmithKline, Novartis, Sanofi, Roche, Teva, outside the submitted work. Prof. Dr. Wolfgang Pohl reports personal fees from AstraZeneca, Chiesi, Sanofi; grants, personal fees from GSK, outside the submitted work. Prof. Dr. Charles G Irvin reports Scientific Advisory Board for Medical Graphics Corp that manufactures PFT equipment. Dr Sylvia Hartl reports grants, personal fees from GSK, Astra zeneca, Chiesi Fatma, Menarini Pharma; personal fees from MSD and Roche, outside the submitted work. The authors declare no other conflicts of interest in this work.

Additional information

Funding

The Austrian LEAD Study is supported by the Ludwig Boltzmann Society, the Municipal Department of Health and Environment of Vienna, the Federal State Governmental Department of Health of Lower Austria, and unrestricted scientific grants from AstraZeneca, Böhringer Ingelheim, Chiesi Pharma, Glaxo Smith Kline and Menarini Pharma. None of the supporting parties had any participation in the data, nor did they contribute to the design or the content of the present manuscript.