Lung diffusing capacity in adult bronchiectasis: a longitudinal study.
BACKGROUND
Recent studies described a progressive decline in lung volumes in adult bronchiectasis. Interstitial lung disease is also a feature of bronchiectasis, but whether this is associated with a decline in lung diffusing capacity (measured as the diffusing capacity of the lung for carbon monoxide [D(LCO)]) is not well known.


OBJECTIVE
To assess longitudinal decline in diffusing capacity of the lung for carbon monoxide (D(LCO)) in adult bronchiectasis.


METHODS
Sixty-one subjects had a detailed baseline clinical and laboratory assessment, then were followed regularly with clinical and lung-function assessment for a median 7 years.


RESULTS
Baseline spirometry demonstrated mild obstructive lung disease, with a mean FEV(1) of 72% of predicted, mean forced vital capacity 87% of predicted, and normal D(LCO) (mean D(LCO) 88% of predicted, and mean D(LCO) adjusted for alveolar volume [D(LCO)/V(A)] 100% of predicted). There was an accelerated decline in D(LCO) and D(LCO)/V(A) over the 7-year period. The median D(LCO) decline was 2.9% of predicted per year (95% CI 2.3-4.1% of predicted per year). The median D(LCO)/V(A) decline was 2.4% of predicted per year (95% CI 2.1-4.0% of predicted per year). There was a significant relationship between D(LCO) decline and age and decline in FEV(1).


CONCLUSIONS
In our cohort of patients with bronchiectasis there was a progressive D(LCO) decline.
Department of Respiratory and Sleep Medicine, Monash Medical Centre, 246 Clayton Road, Clayton, Melbourne 3168, Australia. paul.king@med.monash.edu.au
Paul T
PT
King
Stephen R
SR
Holdsworth
Nicholas J
NJ
Freezer
Elmer
E
Villanueva
Michael W
MW
Farmer
Paul
P
Guy
Peter W
PW
Holmes
D000328:Adult; D000367:Age Factors; D000368:Aged; D001987:Bronchiectasis / Q000150:complications* / Q000378:metabolism / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011653:Pulmonary Diffusing Capacity / Q000502:physiology*; D013147:Spirometry; D013997:Time Factors; D014797:Vital Capacity / Q000502:physiology