Matrix metalloproteinase-9 predicts pulmonary status declines in α1-antitrypsin deficiency

Respiratory Research

Table 3 Change in pulmonary status measurements over the entire study period

	Annualized change in measurements over study period
	Mean (95% CI)*	P-value*
Spirometry^†
FEV₁, ml	-36 (-67 to -5)	0.025
FVC, ml	-6 (-113 to +102)	0.92
FEV₁/FVC ratio	-1% (-2% to -0.02%)	0.046
Total Lung Capacity, ml^†	-48 (-152 to +56)	0.36
Transfer Factor (TLco), mmol/min/kpa^†	-0.2 (-0.34 to -0.08)	0.002
CT Densitometry
Adjusted Lung Density^‡	-1.8 (-2.4 to -1.1)	<0.001
Resting Oxygenation Saturation (room air)	0.2% (-0.3% to +0.6%)	0.43
Incremental Shuttle Walk Test
Distance Walked, meters	-8 (-23 to +6)	0.26

*95% confidence interval (CI) and P-value were calculated using the paired t-test, which determined the 95% CI of the observed changes in each measurement over the study period and tested whether these changes were different than 0.
^†Change in pulmonary function testing (PFT) measurements, which for the purposes of this study were measured over a 9 month period, are presented after extrapolation to an annualized (12 month) basis.
^‡Measured in Hounsfield Units at the 15^th percentile.

ISSN: 1465-993X