Affiliations 

  • 1 National Heart and Lung Institute, Imperial College London, 1B Manresa Road, London, SW3 6LR, UK. [email protected]
  • 2 National Heart and Lung Institute, Imperial College London, 1B Manresa Road, London, SW3 6LR, UK
  • 3 The Epidemiological Laboratory (Epilab), Khartoum, Sudan
  • 4 Dept. of Medicine, UWI, Mona, Jamaica
  • 5 Faculdade de Medicina, Instituto de Saúde Ambiental, Universidade de Lisboa, Lisbon, Portugal
  • 6 Oregon Health & Science University, Portland, OR, USA
  • 7 Dept of Pneumology, Faculty of Medicine Annaba, University Badji Mokhtar of Annaba, Annaba, Algeria
  • 8 Faculté de Médecine Dentaire de Monastir, Université de Monastir, Avenue Avicenne, Monastir, Tunisia
  • 9 Department of Respiratory Medicine, Faculty of Medicine, Mohammed Ben Abdellah University, University Hospital, Fes, Morocco
  • 10 Obafemi Awolowo University, Ile-Ife, Osun, Nigeria
  • 11 Department of Respiratory Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands
  • 12 King Abdullah International Medical Research Centre, King Saud Bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs, Riyadh, Saudi Arabia
  • 13 Department of Sleep, Landspitali University Hospital, Reykjavik, Iceland
  • 14 Department of Medical Sciences: Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden
  • 15 Department of Chest Diseases, Cukurova University School of Medicine, Adana, Turkey
  • 16 University of Kentucky, Lexington, KY, USA
  • 17 Woolcock Institute of Medical Research, Sydney, NSW, Australia
  • 18 University of Cambridge, Cambridge, UK
  • 19 Department of Community Health Sciences, Aga Khan University, Karachi, Pakistan
  • 20 Philippine College of Chest Physicians, Quezon City, Philippines
  • 21 RCSI & UCD Malaysia Campus, Penang, Malaysia
  • 22 Pulmocare Research and Education (PURE) Foundation, Pune, India
  • 23 Faculty of Medical Sciences, University of the West Indies, St Augustine, Trinidad and Tobago
  • 24 University Clinic for Pneumology, Paracelsus Medical University Salzburg, Salzburg, Austria
  • 25 Centre for Heart Lung Innovation, University of British Columbia, Vancouver, BC, Canada
  • 26 Ludwig Boltzmann Institute for Lung Health, Vienna, Austria
Respir Res, 2023 May 23;24(1):137.
PMID: 37221593 DOI: 10.1186/s12931-023-02450-1

Abstract

BACKGROUND: Spirometric small airways obstruction (SAO) is common in the general population. Whether spirometric SAO is associated with respiratory symptoms, cardiometabolic diseases, and quality of life (QoL) is unknown.

METHODS: Using data from the Burden of Obstructive Lung Disease study (N = 21,594), we defined spirometric SAO as the mean forced expiratory flow rate between 25 and 75% of the FVC (FEF25-75) less than the lower limit of normal (LLN) or the forced expiratory volume in 3 s to FVC ratio (FEV3/FVC) less than the LLN. We analysed data on respiratory symptoms, cardiometabolic diseases, and QoL collected using standardised questionnaires. We assessed the associations with spirometric SAO using multivariable regression models, and pooled site estimates using random effects meta-analysis. We conducted identical analyses for isolated spirometric SAO (i.e. with FEV1/FVC ≥ LLN).

RESULTS: Almost a fifth of the participants had spirometric SAO (19% for FEF25-75; 17% for FEV3/FVC). Using FEF25-75, spirometric SAO was associated with dyspnoea (OR = 2.16, 95% CI 1.77-2.70), chronic cough (OR = 2.56, 95% CI 2.08-3.15), chronic phlegm (OR = 2.29, 95% CI 1.77-4.05), wheeze (OR = 2.87, 95% CI 2.50-3.40) and cardiovascular disease (OR = 1.30, 95% CI 1.11-1.52), but not hypertension or diabetes. Spirometric SAO was associated with worse physical and mental QoL. These associations were similar for FEV3/FVC. Isolated spirometric SAO (10% for FEF25-75; 6% for FEV3/FVC), was also associated with respiratory symptoms and cardiovascular disease.

CONCLUSION: Spirometric SAO is associated with respiratory symptoms, cardiovascular disease, and QoL. Consideration should be given to the measurement of FEF25-75 and FEV3/FVC, in addition to traditional spirometry parameters.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.