Change in pulmonary diffusion capacity in a general population sample over 9 years

Area of Science:

• Pulmonary Medicine
• Respiratory Physiology
• Epidemiology

Background:

• Limited data exist on longitudinal changes in the diffusion capacity of the lung for carbon monoxide (DLCO).
• Understanding DLCO decline is crucial for assessing respiratory health over time.

Purpose of the Study:

• To investigate the change in DLCO (ΔDLCO) over a 9-year period in a community sample.
• To identify predictors of DLCO decline.

Main Methods:

• A Norwegian community cohort (n=830) with baseline and 9-year follow-up measurements of DLCO.
• DLCO measured using the single breath-holding technique.
• Generalized estimating equations used to analyze ΔDLCO in relation to baseline covariables.

Main Results:

• Mean ΔDLCO was -0.24 (SD 1.31) mmol·min(-1)·kPa(-1) over 9 years.
• Negative associations found between ΔDLCO and baseline age, current smoking, pack years, and baseline DLCO.
• Positive association found between ΔDLCO and baseline FEV1 and weight.

Conclusions:

• Accelerated DLCO decline is associated with older age, current smoking, cumulative smoking exposure (pack years), higher weight, and lower FEV1 at baseline.
• Sex, occupational exposure, and educational level did not predict ΔDLCO in this cohort.