0
Correspondence |

Isolated Reduction of the FEV3/FVC Ratio as an Indicator of Mild Airflow ObstructionFEV3/FVC Ratio in Mild Airflow Obstruction FREE TO VIEW

Karan Madan, MD, DM, FCCP; Vijay Hadda, MD, FCCP; Gopi C. Khilnani, MD, FCCP; Randeep Guleria, MD, DM
Author and Funding Information

From the Department of Pulmonary Medicine and Sleep Disorders, All India Institute of Medical Sciences.

Correspondence to: Karan Madan, MD, DM, FCCP, Department of Pulmonary Medicine and Sleep Disorders, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India 110029; e-mail: drkaranmadan@gmail.com


Editor’s Note: Authors are invited to respond to Correspondence that cites their previously published work. Those responses appear after the related letter. In cases where there is no response, the author of the original article declined to respond or did not reply to our invitation.

Financial/nonfinancial disclosures: The authors have reported to CHEST that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.


Chest. 2014;145(3):662. doi:10.1378/chest.13-2435
Text Size: A A A
Published online
To the Editor:

We read with keen interest the recent article by Morris et al1 in CHEST (October 2013) in which they describe the use of the FEV3/FVC ratio in diagnosis of early airflow obstruction (termed as mild lung injury by the authors). However, certain important issues need to be highlighted. It is important to interpret these observations in concert with clinical and radiologic features to ascertain whether reduction in FEV3/FVC ratio translates into clinically relevant patient outcomes.

Age-related changes in the respiratory function of healthy adults are important factors to be considered. With increasing age, there is a reduction in lung elastic recoil and respiratory muscle strength, which results in increased residual volume (RV). RV increases by approximately 50% between the ages of 20 and 70 years.2 Total lung capacity remains relatively unchanged with increasing age.3 Therefore, the ratio of RV to total lung capacity increases with age. Observations in the present study regarding the FEV3/FVC ratio are similar to age-related changes in lung function. It has also been observed that the utility of FEV1/FVC ratio in the diagnosis of airflow obstruction, especially in older individuals, is limited and can lead to overdiagnosis of COPD.4 The mean age of patients with isolated FEV3/FVC reduction in the present study was 61.2 ± 12.3 years. Therefore, calculating the sensitivity and specificity of the FEV3/FVC ratio using the FEV1/FVC ratio as the gold standard for airway obstruction may be inappropriate in older patients.

Whether the reduction in FEV3/FVC ratio is just an age-related phenomenon that subsequently evolves into FEV1/FVC ratio reduction without any clinically significant impact is a critical question. Inappropriate use of this ratio in the absence of clinical data might lead to overdiagnosis of obstructive airway disease. If the FEV3/FVC ratio is eventually recognized as a clinically relevant parameter for early airflow obstruction that translates into clinically significant patient outcomes, the global burden of patients with obstructive airway disease across the globe will increase dramatically. Use of the term mild lung injury in the title is misleading. The term lung injury is conventionally used with reference to patients with ARDS so use of another term, like early airway obstruction or early air trapping, will be more appropriate.

References

Morris ZQ, Coz A, Starosta D. An isolated reduction of the FEV3/FVC ratio is an indicator of mild lung injury. Chest. 2013;144(4):1117-1123. [CrossRef] [PubMed]
 
Janssens JP. Aging of the respiratory system: impact on pulmonary function tests and adaptation to exertion. Clin Chest Med. 2005;26(3):469-484. [CrossRef] [PubMed]
 
Sharma G, Goodwin J. Effect of aging on respiratory system physiology and immunology. Clin Interv Aging. 2006;1(3):253-260. [CrossRef] [PubMed]
 
Hardie JA, Buist AS, Vollmer WM, Ellingsen I, Bakke PS, Mørkve O. Risk of over-diagnosis of COPD in asymptomatic elderly never-smokers. Eur Respir J. 2002;20(5):1117-1122. [CrossRef] [PubMed]
 

Figures

Tables

References

Morris ZQ, Coz A, Starosta D. An isolated reduction of the FEV3/FVC ratio is an indicator of mild lung injury. Chest. 2013;144(4):1117-1123. [CrossRef] [PubMed]
 
Janssens JP. Aging of the respiratory system: impact on pulmonary function tests and adaptation to exertion. Clin Chest Med. 2005;26(3):469-484. [CrossRef] [PubMed]
 
Sharma G, Goodwin J. Effect of aging on respiratory system physiology and immunology. Clin Interv Aging. 2006;1(3):253-260. [CrossRef] [PubMed]
 
Hardie JA, Buist AS, Vollmer WM, Ellingsen I, Bakke PS, Mørkve O. Risk of over-diagnosis of COPD in asymptomatic elderly never-smokers. Eur Respir J. 2002;20(5):1117-1122. [CrossRef] [PubMed]
 
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543