Reference spirometric values for healthy lifetime nonsmokers in Thailand.

Area of Science:

• Pulmonary Medicine
• Clinical Physiology
• Respiratory Health

Background:

• Spirometric reference values are essential for diagnosing lung diseases.
• Existing spirometric equations are often based on Caucasian populations, potentially leading to misdiagnosis in diverse ethnic groups.
• There is a lack of established normal spirometric reference values specifically for the Thai population.

Purpose of the Study:

• To establish standard spirometric prediction equations for Thai individuals aged 10 years and above.
• To provide accurate reference values for pulmonary function testing in Thailand.
• To facilitate better diagnosis and management of respiratory conditions in the Thai population.

Main Methods:

• A cross-sectional study involving 2299 women and 1655 men from the Thai population.
• Strict inclusion criteria ensured a healthy, non-smoking cohort without history of cardiopulmonary disease.
• Spirometry was performed using Cosmed 'Pony graphic' spirometers meeting ATS recommendations.
• Regression analysis incorporating sex, height, and age was used to derive prediction equations.

Main Results:

• New spirometric prediction equations for Forced Vital Capacity (FVC) and Forced Expiratory Volume in 1 second (FEV1) were developed for Thai adults.
• The established FVC and FEV1 values for Thai individuals are comparable to Chinese populations but approximately 8-20% lower than Caucasian populations.
• The study provides a robust dataset for normal spirometric values in Thailand.

Conclusions:

• The developed spirometric equations are recommended for use as reference values in the Thai population.
• These equations will aid in the accurate interpretation of spirometry results for Thai patients.
• This research addresses a critical gap in respiratory health assessment for Thailand.