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

摘要

RationaleData on the change in diffusion capacity of the lung for carbon monoxide (DL_(CO)) over time are limited. We aimed to examine change in DL_(CO) (ΔDL_(CO)) over a 9-year period and its predictors.MethodsA Norwegian community sample comprising 1,152 subjects aged 18–73 years was examined in 1987 and 1988. Of the 1,109 subjects still alive, 830 (75%) were re-examined in 1996/97. DL_(CO) was measured with the single breath-holding technique. Covariables recorded at baseline included sex, age, height, weight, smoking status, pack years, occupational exposure, educational level, and spirometry. Generalized estimating equations analyses were performed to examine relations between ΔDL_(CO) and the covariables.ResultsAt baseline, mean [standard deviation (SD)] DL_(CO) was 10.8 (2.4) and 7.8 (1.6) mmol·min~(?1)·kPa~(?1) in men and women, respectively. Mean (SD) ΔDL_(CO) was ?0.24 (1.31) mmol·min~(?1)·kPa~(?1). ΔDL_(CO) was negatively related to baseline age, DL_(CO), current smoking, and pack years, and positively related to forced expiratory volume in 1 second (FEV_(1)) and weight. Sex, occupational exposure, and educational level were not related to ΔDL_(CO).ConclusionsIn a community sample, more rapid decline in DL_(CO) during 9 years of observation time was related to higher age, baseline current smoking, more pack years, larger weight, and lower FEV_(1).