Clinical implications of airway obstruction with normal or low FEV1 in childhood and adolescence

Hans Jacob Lohne Koefoed; Gang Wang; Ulrike Gehring; Sandra Ekstrom; Inger Kull; Roel Vermeulen; Jolanda M A Boer; Anna Bergstrom; Gerard H Koppelman; Erik Melén; Judith M Vonk; Jenny Hallberg

doi:10.1136/thorax-2023-220952

Clinical implications of airway obstruction with normal or low FEV₁ in childhood and adolescence

Thorax. 2024 Mar 21:thorax-2023-220952. doi: 10.1136/thorax-2023-220952. Online ahead of print.

Authors

Hans Jacob Lohne Koefoed^{1

2

3}, Gang Wang^{4

5

6

7}, Ulrike Gehring⁸, Sandra Ekstrom^{4

6

9}, Inger Kull^{4

10}, Roel Vermeulen⁸, Jolanda M A Boer¹¹, Anna Bergstrom^{6

9}, Gerard H Koppelman^{2

3}, Erik Melén^{4

10}, Judith M Vonk^{3

12}, Jenny Hallberg^{4

10}

Affiliations

¹ Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institute, Stockholm, Sweden h.j.l.koefoed@umcg.nl.
² Beatrix Children's Hospital, Department of Pediatric Pulmonology and Pediatric Allergology, University Medical Center Groningen, Groningen, The Netherlands.
³ Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, Groningen, The Netherlands.
⁴ Department of Clinical Science and Education, Sodersjukhuset, Karolinska Institute, Stockholm, Sweden.
⁵ Department of Integrated Traditional Chinese and Western Medicine, Sichuan University West China Hospital, Chengdu, Sichuan, China.
⁶ Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
⁷ West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, People's Republic of China.
⁸ Institute for Risk Assessment Sciences, University Medical Center Utrecht, Utrecht, The Netherlands.
⁹ Centre for Occupational and Environmental Medicine, Region Stockholm, Stockholm, Sweden.
¹⁰ Pediatrics, Sachs' Children's Hospital, Stockholm, Sweden.
¹¹ Center for Nutrition, Prevention, and Health Services, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
¹² Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.

PMID: 38514183
DOI: 10.1136/thorax-2023-220952

Abstract

Background: Airway obstruction is defined by spirometry as a low forced expiratory volume in 1 s (FEV₁) to forced vital capacity (FVC) ratio. This impaired ratio may originate from a low FEV₁ (classic) or a normal FEV₁ in combination with a large FVC (dysanaptic). The clinical implications of dysanaptic obstruction during childhood and adolescence in the general population remain unclear.

Aims: To investigate the association between airway obstruction with a low or normal FEV₁ in childhood and adolescence, and asthma, wheezing and bronchial hyperresponsiveness (BHR).

Methods: In the BAMSE (Barn/Child, Allergy, Milieu, Stockholm, Epidemiology; Sweden) and PIAMA (Prevention and Incidence of Asthma and Mite Allergy; the Netherlands) birth cohorts, obstruction (FEV₁:FVC ratio less than the lower limit of normal, LLN) at ages 8, 12 (PIAMA only) or 16 years was classified as classic (FEV₁ <LLN) or dysanaptic (FEV₁ ≥LLN) obstruction. Cross-sectional and longitudinal associations between these two types of obstruction and respiratory health outcomes were estimated by cohort-adjusted logistic regression on pooled data.

Results: The prevalence of classic obstruction at ages 8, 12 and 16 in the two cohorts was 1.5%, 1.1% and 1.5%, respectively. Dysanaptic obstruction was slightly more prevalent: 3.9%, 2.5% and 4.6%, respectively. Obstruction, regardless of FEV₁, was consistently associated with higher odds of asthma (dysanaptic obstruction: OR 2.29, 95% CI 1.40 to 3.74), wheezing, asthma medication use and BHR compared with the normal lung function group. Approximately one-third of the subjects with dysanaptic obstruction in childhood remained dysanaptic during adolescence.

Clinical implications: Children and adolescents with airway obstruction had, regardless of their FEV₁ level, a higher prevalence of asthma and wheezing. Follow-up and treatment at these ages should be guided by the presence of airway obstruction.

Keywords: Asthma; Asthma Epidemiology; Asthma Guidelines; Clinical Epidemiology; Lung Physiology; Paediatric asthma.