How to account for Inuit ancestry in lung function prediction

Area of Science:

• Pulmonary Medicine
• Anthropometry
• Public Health

Background:

• Lung function prediction equations are crucial for diagnosing respiratory diseases.
• Existing equations, like the Global Lung Function Initiative (GLI) for Europeans, may not accurately represent diverse populations such as the Inuit.
• There is a lack of specific lung function prediction equations for the Inuit population.

Purpose of the Study:

• To evaluate the accuracy of Global Lung Function Initiative (GLI) European-based equations for predicting lung function in the Inuit population.
• To determine if modifying standing height based on known Inuit standing-to-sitting height ratio (SHR) differences improves prediction accuracy.
• To establish reliable lung function prediction methods for Inuit individuals.

Main Methods:

• Spirometry data from 351 Inuit and 29 individuals of other ancestry were analyzed.
• Lung function predictions were initially made using standard GLI equations with recorded standing height.
• Predictions were re-evaluated using Inuit standing height adjusted for known differences in SHR.

Main Results:

• Using recorded standing height, Inuit participants showed significantly higher predicted FVC and FEV1 z-scores compared to predicted values.
• After adjusting height for SHR, Inuit FVC and FEV1 z-scores were no longer significantly different from predicted values.
• Inuit FEV1/FVC z-scores were not significantly different from non-Inuit, and modification for SHR yielded similar results.

Conclusions:

• Standard GLI equations with unadjusted standing height overestimate lung function in the Inuit.
• Adjusting standing height for the known Inuit standing-to-sitting height ratio (SHR) allows for representative lung function predictions using GLI equations.
• This modified approach provides a more accurate method for assessing Inuit lung function.