Table 2.

Associations of cigarette smoke exposure with radiographic pulmonary vascular measures

	TBV		BV5		BV5/TBV
	Difference (95% CI) (ml)	P Value	Difference (95% CI) (ml)	P Value	Difference (95% CI) (pp)	P Value
Pack-years of smoking (per 10 pack-years)	1.5 (0.9 to 2.0)	<0.001	0.6 (0.4 to 0.9)	<0.001	0.04 (−0.04 to 0.1)	0.3
Adjusted for smoking status	0.6 (−0.1 to 1.3)	0.1	0.2 (−0.1 to 0.5)	0.2	−0.02 (−0.1 to 0.08)	0.7
Ever vs. never-smoking status	4.6 (2.9 to 6.3)	<0.001	2.1 (1.3 to 2.9)	<0.001	0.28 (0.03 to 0.52)	0.03
Adjusted for pack-years	3.1 (1.0 to 5.2)	0.004	1.5 (0.6 to 2.4)	0.002	0.28 (−0.02 to 0.58)	0.07
Smoking status
Former vs. never	3.8 (2.1 to 5.6)	<0.001	1.8 (1.0 to 2.5)	<0.001	0.27 (0.01 to 0.52)	0.04
Current vs. never	9.0 (5.7 to 12.3)	<0.001	4.0 (2.6 to 5.5)	<0.001	0.32 (−0.15 to 0.79)	0.2
Smoking status, adjusted for pack-years
Former vs. never	3.0 (0.9 to 5.1)	0.005	1.4 (0.5 to 2.4)	0.002	0.28 (−0.02 to 0.58)	0.07
Current vs. never	7.2 (3.2 to 11.3)	<0.001	3.4 (1.6 to 5.2)	<0.001	0.40 (−0.18 to 0.98)	0.2
Second-hand smoke exposure	0.3 (−1.7 to 2.2)	0.8	0.5 (−0.3 to 1.4)	0.2	0.31 (0.03 to 0.58)	0.03
Adjusted for pack-years and smoking status	−1.5 (−3.5 to 0.5)	0.1	−0.2 (−1.0 to 0.7)	0.7	0.31 (0.02 to 0.59)	0.03
Among never-smokers only	−1.7 (−4.9 to 1.6)	0.3	0.1 (−1.3 to 1.6)	0.8	0.57 (0.11 to 1.02)	0.01

Definition of abbreviations: BV5 = blood volume of smaller peripheral vessels, defined as cross-sectional area <5 mm²; CI = confidence interval; pp = percentage-point; TBV = total blood volume.

Results of linear regression models with adjustment for age, sex, height, weight, personal educational attainment, occupation category, quartiles of census tract median neighborhood income, and Framingham Heart Study cohort (Offspring vs. Third Generation).