Isolated small airways obstruction predicts future chronic airflow obstruction: a multinational longitudinal study

BACKGROUND

Chronic airflow obstruction is a key characteristic of chronic obstructive pulmonary disease. We investigated whether isolated small airways obstruction is associated with chronic airflow obstruction later in life.

METHODS

We used longitudinal data from 3957 participants of the multinational Burden of Obstructive Lung Disease study. We defined isolated small airways obstruction using the prebronchodilator mean forced expiratory flow rate between 25% and 75% of the forced vital capacity (FVC) (FEF25-75) if a result was less than the lower limit of normal (

RESULTS

Median follow-up time was 8.3 years. Chronic airflow obstruction was more likely to develop in participants with isolated small airways obstruction at baseline (FEF25-75 less than the LLN, OR: 2.95, 95% CI 1.02 to 8.54; FEV3/FVC less than the LLN, OR: 1.94, 95% CI 1.05 to 3.62). FEF25-75 was better than the FEV3/FVC ratio to discriminate future chronic airflow obstruction (AUC: 0.764 vs 0.692). Results were similar among participants of the UK Biobank study.

CONCLUSION

Measurements of small airways obstruction can be used as early markers of future obstructive lung disease.

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Key Words

• COPD epidemiology
• Lung Physiology

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MESH Headings

• Humans
• Longitudinal Studies
• Pulmonary Disease, Chronic Obstructive/complications
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Airway Obstruction/diagnosis
• Airway Obstruction/etiology
• Vital Capacity
• Forced Expiratory Volume

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Grants

• Wellcome Trust
• 085790/Z/08/Z Wellcome Trust
• MR/R011192/1 Medical Research Council
• AstraZeneca
• UK Biobank

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Affiliation(s)

Ben Knox-Brown National Heart and Lung Institute, Imperial College London, London, UK
James Potts National Heart and Lung Institute, Imperial College London, London, UK
Valentina Quintero Santofimio National Heart and Lung Institute, Imperial College London, London, UK
Cosetta Minelli National Heart and Lung Institute, Imperial College London, London, UK NIHR Imperial Biomedical Research Centre, London, UK
Jaymini Patel National Heart and Lung Institute, Imperial College London, London, UK
Najlaa Mohammed Abass College of Medicine, Alshaab Teaching Hospital, Bahri University, Khartoum, Sudan
Dhiraj Agarwal Vadu Rural Health Program, KEM Hospital Pune Research Centre, Pune, India
Rana Ahmed The Epidemiological Laboratory, Khartoum, Sudan
Padukudru Anand Mahesh Respiratory Medicine, JSS Medical College, Mysore, Karnataka, India
Jayaraj Bs Respiratory Medicine, JSS Medical College, Mysore, Karnataka, India
Meriam Denguezli Faculte de Medecine de Sousse, Universite de Sousse, Sousse, Tunisia
Frits Franssen Respiratory medicine, Maastricht University Medical Centre+, Maastricht, Netherlands Research and Education, CIRO, Horn, Netherlands
Thorarinn Gislason Department of Sleep, Landspitali University Hospital, Reykjavik, Iceland Faculty of Medicine, University of Iceland, Reykjavik, Iceland
Christer Janson Department of Medical Sciences Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden
Sanjay K Juvekar Vadu Rural Health Program, KEM Hospital Pune Research Centre, Pune, India
Parvaiz Koul Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
Andrei Malinovschi Department of Medical Sciences Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden
Asaad Ahmed Nafees Department of Community Health Sciences, The Aga Khan University, Karachi, Sindh, Pakistan
Rune Nielsen Department of Thoracic Medicine, University of Bergen, Bergen, Hordaland, Norway
Stefanni Nonna M Paraguas Philippine College of Chest Physicians, Quezon City, Philippines Philippine Heart Center, Quezon City, Manila, Philippines
Sonia Buist Oregon Health & Science University, Portland, Oregon, USA
Peter Gj Burney National Heart and Lung Institute, Imperial College London, London, UK
Andre F S Amaral National Heart and Lung Institute, Imperial College London, London, UK

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Evaluation for airway obstruction in adult patients with stable ischemic heart disease

Background

Ischemic heart disease (IHD) and chronic airway disease (COPD and Asthma) are major epidemics accounting for significant mortality and morbidity. The combination presents many diagnostic challenges. Clinical symptoms and signs frequently overlap. There is a need for airway evaluation in these patients to plan appropriate management.

Methods

Consecutive stable IHD patients attending the cardiology OPD in a tertiary care centre were interviewed for collecting basic demographic information, brief medical, occupational, personal history and risk factors for coronary artery disease and airway disease, modified medical research centre (MMRC) grade for dyspnea, quality of life-St. George respiratory questionnaire (SGRQ), spirometry and six-min walk tests. Patients with chronic airway obstruction were treated as per guidelines and were followed up at 3rd month with spirometry, six-minute walk test and SGRQ.

Results

One hundred fourteen consecutive patients with stable cardiac disease were included (Males-88, Females-26). Mean age was 58.89 ± 12.24 years, 53.50% were smokers, 31.56% were alcoholics, 40.35% diabetics, 47.36% hypertensive. Twenty five patients had airway obstruction on spirometry (COPD-13 and Asthma-12) and none were on treatment. Thirty-one patients had cough and 48 patients had dyspnea. Patients with abnormal spirometry had higher symptoms, lower exercise tolerance and quality of life. Treatment with appropriate respiratory medications resulted in increase in lung function, quality of life and exercise tolerance at 3rd month.

Conclusion

Chronic respiratory disease in patients with stable IHD is frequent but often missed due to overlap of symptoms. Spirometry is a simple tool to recognize the underlying pulmonary condition and patients respond favorably with appropriate treatment