Table 1.

Baseline Characteristics of Participants With Carotid Intima-Media Thickness Measurements, by Residential Distance to Major Roadways, Jackson Heart Study, 2004

Characteristic	Residential Distance to Major Roadwaysa
	All (n = 4,800)b		<150 m (n = 103)		150–300 m (n = 158)		>300 m (n = 4,539)
	Mean (SD)	%	Mean (SD)	%	Mean (SD)	%	Mean (SD)	%
Age, years	55.5 (12.7)		55.4 (12.9)		59.1 (12.5)		55.4 (12.7)
Female sex		63.7		68.0		63.8		63.6
Body mass indexc	31.6 (7.2)		32.9 (8.4)		30.8 (6.7)		31.6 (7.1)
Education
High school or less		38.0		43.1		38.0		38.0
College or vocational school		29.1		30.4		24.1		29.2
Graduate school		32.9		26.5		37.9		32.8
Household income
Low		15.1		20.0		8.4		15.2
Lower middle		24.1		24.0		25.2		24.0
Upper middle		29.9		21.3		29.8		30.1
High		30.9		34.7		36.6		30.7
Alcohol consumption		45.6		40.8		38.2		46.0
Ever smoking
Never smoker		68.2		66.0		75.3		68.0
Past smoker		18.9		13.6		15.8		19.0
Current smoker		12.9		20.4		8.9		12.8
Hypertension		62.6		56.4		67.7		62.5
Diabetes mellitus		21.6		16.5		21.8		21.7
Hyperlipidemia		54.7		60.2		58.9		54.4
History of CHD, stroke, or MI		5.3		7.8		3.2		5.3
No. of fast-food outlets per square mile	1.6 (2.5)		1.7 (2.4)		1.9 (2.6)		1.5 (2.5)
No. of grocery stores per square mile	2.7 (4.3)		4.0 (5.3)		3.9 (5.1)		2.6 (4.2)
Carotid intima-media thickness, mm	0.8 (0.2)		0.7 (0.2)		0.8 (0.3)		0.8 (0.2)

Abbreviations: CHD, coronary heart disease; MI, myocardial infarction; SD, standard deviation.

^a Major roadways were defined as US Census Feature Class Code A1 or A2 roads.

^b Missing data: body mass index, n = 5; education, n = 17; household income, n = 742; alcohol consumption, n = 16; ever smoking, n = 32; hypertension, n = 42; diabetes, n = 52.

^c Weight (kg)/height (m)².