Evolving Standards: Implementing GLI 2021 in the Diverse Asia-Pacific Landscape

Accurate interpretation of lung function is very important for managing respiratory diseases. Diagnosis and classification of the severity of abnormal lung function tests depend on the reference equations used. The Global Lung Function Initiative (GLI) 2021 reference equations were derived from a large representative sample across the entire age range and different ethnic groups using updated standardized techniques of lung function measurements. However, for the Asia-Pacific region—characterized by immensly different genetic, race, environmental, lifespan and varying healthcare infrastructures—using GLI 2021 reference equations presents diagnostic challenges. Implementation of GLI 2021 in Asian populations requires careful validation against existing "Asian-specific" norms. Research indicates that the application of universal equations can alter the "Lower Limit of Normal" (LLN), potentially impacting the diagnosis of restrictive or obstructive patterns or the impairement of lung diffusion capacity in airways and interstitial lung diseases. The GLI 2021 do not include individual data from all populations in the Asia-Pacific region and do not explicitly consider the factors that may contribute to the observed differences in lung function between populations. GLI DLCO equations and GLI static lung volumes are currently based on measurements predominantly from individuals of European ancestry due to insufficient reference data from other populations. In addition, some institutions in the Asia-Pacific region continue using the old models of lung function tests, which are not suitable for GLI 2021. This presentation will highlight some challenges and potential pitfalls when implementing GLI 2021 in the diverse Asia-Pacific region.