Prediction equations for single breath diffusing capacity (dlco) in a middle aged caucasian population

¹ Allergy, Immunology and Respiratory Medicine, The Alfred Hospital, Australia
² Menzies Research Institute, University of Tasmania, Australia
³ Department of Epidemiology and Preventive Medicine, Monash University, Australia

^* To whom correspondence should be addressed. E-mail: b.thompson{at}alfred.org.au.

Accepted 16 March 2008

	Abstract

Rationale: There are many reference equations for the measurement of DLCO. However the testing methodologies vary and there are no well-documented studies that develop reference equations for DLCO and alveolar volume (VA) in middle aged and older populations.

Objectives: 1. Develop reference equations for DLCO in a middle aged population using the current ATS/ERS guidelines; 2. Compare the equations with those commonly used in laboratories around the world.

Methods: Healthy subjects (498 male and 474 female) aged 45 to 71 years were recruited as part of a larger epidemiological study. All participants completed a respiratory questionnaire and had spirometry and single breath DLCO (corrected for haemoglobin) measurements following ATS/ERS guidelines.

Results: The mean age was 58 years for males and 57 years for females. For males, factors that predicted DLCO were: Height, Age and Age * Height interaction and being an ex-smoker. For females, factors that predicted DLCO were: Height, Age, Weight and an Age * Height interaction.

Conclusion: We have described new prediction equations for DLCO in a middle-aged population that require validation in other populations.