Table 1.

Characteristics of 2,513 Participants From the Multi-Detector Computed Tomography Study^a, Boston, Massachusetts, 2002–2005.

Characteristics	No. of Participants	%	Mean (SD)
Offspring Study cohort	1,024	40.8
Age at the time of MDCT scan, years			52.6 (11.9)
Women	1,323	52.7
Alcohol consumption, drinks/weekb			3.8 (4.6)
Current cigarette smoker	307	12.2
Former cigarette smoker	952	37.9
Education
High school or less	580	23.1
Some college	813	32.4
College graduate	1,120	44.6
Antihypertensive medication use	474	18.9
Statins use	314	12.5
Cardiovascular disease	174	6.9
Diabetes	146	5.8
Liver-to-phantom ratio			0.36 (0.05)
Hepatic steatosisc	436	17.4
Annual average PM2.5 concentration (2003), μg/m3			10.6 (1.4)
Distance to major roadways, md			271 (253)
Category of distance to major roadways, md
<50.0	514	20.5
50.0–99.9	213	8.5
100.0–199.9	396	15.8
200.0–399.9	518	20.6
400.0–999.9	589	23.4

Abbreviations: MDCT, multidetector computed tomography; PM_2.5, particulate matter having an aerodynamic diameter of ≤2.5 μm; SD, standard deviation.

^a All MDCT scans were conducted between 2002 and 2005. Age and cardiovascular events were updated to the date of MDCT scans; other baseline covariates were collected during 1998–2001 for participants from the Framingham Offspring Study examination 7 and during 2002–2005 for those from the Third Generation Cohort examination 1.

^b Standardized to 0.5 oz (15 mL) of alcohol per drink.

^c Defined as having a liver-to-phantom ratio of ≤0.33.

^d We excluded 283 participants who lived more than 1,000 m from major roadways.