Table 1. Cross-sectional associations between HAA and serum biomarkers of lung injury, extracellular matrix remodeling and inflammation at the MESA baseline exam stratified by smoking status.

	Overall		Ever-smokers		Never-smokers		P for smoking interaction
	Percent change in biomarker*	P value	Percent change in biomarker*	P value	Percent change in biomarker*	P value
MMP-7, ng/mL	6.26 (1.29 to 11.47)	0.01	15.45 (7.91 to 23.53)	<0.001	1.39 (-5.36 to 8.62)	0.69	<0.001
SP-A, ng/mL	2.36 (-6.28 to 11.80)	0.60	8.60 (-3.52 to 22.30)	0.17	0.61 (-11.95 to 14.97)	0.93	0.14
CRP, mg/L	-2.73 (-8.82 to 3.76)	0.40	4.18 (-5.16 to 14.45)	0.39	-6.03 (-14.16 to 2.86)	0.18	0.88
IL-6, pg/mL	8.78 (4.77 to 12.95)	<0.001	17.70 (11.38 to 24.38)	<0.001	2.88 (-2.34 to 8.39)	0.28	0.11

HAA = high attenuation areas; MMP-7 = matrix metalloproteinase-7; SP-A = surfactant protein-A, CRP = c-reactive protein; IL-6 = interleukin-6 For MMP-7 and SP-A, n=908 (341 cases defined as having HAA>9% and a randomly selected subcohort of 600 MESA participants; 33 participants in the subcohort also met case definition); for CRP, n=6761; for IL-6, n=6621.

^*Adjusted for age, gender, race/ethnicity, educational attainment, height, BMI, waist circumference, smoking status, cigarette pack-years, glomerular filtration rate (GFR), study site, mA dose, total volume of imaged lung and percent emphysema. Adjustment for smoking status and pack-years was excluded from smoking-stratified models. All covariates measured at baseline examination in 2000 to 2002. Percent change is reported per 2-fold increase in HAA.