Prediction equations for diffusing capacity (transfer factor) of lung for North Indians.

Area of Science:

• Pulmonary Physiology
• Respiratory Medicine
• Clinical Diagnostics

Background:

• Current lung function prediction equations lack standardization for the Indian population.
• This study addresses the need for population-specific equations for diffusing capacity of lung for carbon monoxide (DLCO) and alveolar volume (VA).

Purpose of the Study:

• To develop and validate prediction equations for DLCO, VA, and their ratio (DLCO/VA) in North Indian adults.
• To investigate ethnic variations in lung function predictions.

Main Methods:

• DLCO and VA were measured using standardized single-breath techniques in 357 healthy North Indian adults.
• Multiple linear regression was employed to develop prediction equations, with data randomly split into training and testing sets for validation.

Main Results:

• Validated prediction equations for DLCO and VA were established for both males and females. A reliable equation for DLCO/VA in females was not obtained and was computed indirectly.
• Indian DLCO predictions were lower than Caucasian but higher than Chinese predictions in males.
• Ethnic variations in DLCO and VA predictions were observed, with Caucasian equations generally yielding higher values.

Conclusions:

• Validated prediction equations for DLCO, VA, and DLCO/VA are now available for North Indian adults.
• Significant ethnic diversity exists in lung function parameters, highlighting the importance of population-specific equations.
• Indian DLCO/VA predictions were slightly higher than those from other ethnic groups.