Adult reference values for spirometry, body plethysmography and diffusing capacity adjusted for sex, age, weight,...

Area of Science:

• Pulmonary Physiology
• Respiratory Medicine
• Clinical Diagnostics

Background:

• Existing lung function reference values may not accurately reflect current populations.
• The Global Lung Function Initiative (GLI) and European Community for Coal and Steel (ECCS) provide widely used reference equations.
• Accurate reference values are crucial for diagnosing and managing respiratory diseases.

Purpose of the Study:

• To establish new national reference values for dynamic and static lung volumes and carbon monoxide diffusing capacity in Denmark.
• To compare these new values with existing GLI and ECCS reference values.
• To develop reference values for lung function based on arm span and post-bronchodilator spirometry.

Main Methods:

• 908 healthy non-smokers (aged 18-97) underwent spirometry, body plethysmography, and single-breath diffusion capacity testing.
• Multiple regression analysis incorporating sex, age, weight, and height (or arm span) was used.
• Quality control followed ATS/ERS standards, with comparisons to GLI and ECCS predicted values.

Main Results:

• Sex-specific reference equations for 29 lung function parameters were established.
• New reference values differed clinically significantly from GLI and ECCS, particularly in females and for flow/volume parameters.
• Bronchodilator response reference values, including z-scores, were also determined.

Conclusions:

• The newly developed Danish lung function reference values (DALFUMAT) show significant differences from current international standards (GLI, ECCS).
• These discrepancies necessitate a re-evaluation of diagnostic thresholds in the Danish population.
• Nationwide adoption of the DALFUMAT reference values is recommended for improved accuracy in lung function assessment.