Common carotid arterial interadventitial distance (diameter) as an indicator of the damaging effects of age and atherosclerosis, a cross-sectional study of the Atherosclerosis Risk in Community Cohort Limited Access Data (ARICLAD), 1987–89

Table 2 Beta coefficients and 95% confidence intervals (CI) for multivariable linear regression models with CCA diameter as the outcome after adjustment for basic covariates and after adding atherosclerotic risk factors.* Both models included interaction terms allowing determination of effects of age in subsets of varying atherosclerosis severity^†, the Atherosclerosis Risk in Communities (ARIC) Limited Data Set, 1987–1989

	Basic Model N = 8163		Full Model N = 8163
	Beta (95% CI)	p-value	Beta (95% CI)	p-value
Main effects
Male gender	0.492 (0.439, 0.545)^‡	<0.0001	0.435 (0.384, 0.486)^‡	<0.0001
Black race/ethnicity	0.190 (0.149, 0.231)^‡	<0.0001	0.087 (0.044, 0.130)^‡	<0.0001
Height (cm)	0.020 (0.018, 0.022)^‡	<0.0001	0.023 (0.021, 0.025)^‡	<0.0001
Current smoking	-		0.154 (0.107, 0.201)^‡	<0.0001
Current drinking	-		-0.038 (-0.075, -0.001)^‡	0.0485
Cigarette years of smoking (in 100's)	-		0.019 (0.015, 0.023)^‡	<0.0001
Ethanol (100 grams/week)	-		0.039 (0.021, 0.057)^‡	<0.0001
BMI	-		0.025 (0.021, 0.029)^‡	<0.0001
Systolic BP	-		0.017 (0.015, 0.019)^‡	<0.0001
Diastolic BP	-		-0.013 (-0.015, -0.011)^‡	<0.0001
Fibrinogen	-		0.0002 (0.0000, 0,0004)^‡	0.0335
Age (1 year of age)	0.028 (0.020, 0.036)^†	<0.0001	0.017 (0.009, 0.025)^†	<0.0001
Additional diameter increase per year of age
Among Diseased Subset	0.018 (0.004, 0.032)^§	0.0139	0.013 (-0.001, 0.027)^§	0.0611
Among Risk Factor Subset	0.011 (0.003, 0.019)^§§	0.0096	0.011 (0.003, 0.019)^§§	0.0101

* Basic model independent variables = age, race, gender, height, dummy variables for disease severity, and interaction terms between age-disease severity dummy variables. Full model added variables = BMI, systolic and diastolic blood pressures, current smoker status, cigarette years of smoking in hundreds, current drinker status and grams of ethanol usually consumed per week in 100 g, fibrinogen value.
^‡Beta indicates the expected difference in millimeters of CCA diameter associated with the presence of each categorical variable and for each unit increase of continuous variables.
^†Beta indicates the expected difference in millimeters of CCA diameter for each year of older age in the low risk subset.
^§-§§Betasindicate the expected difference in millimeters of CCA diameter associated with each year of age among the diseased (^§) and risk factor or high risk (^§§) subsets.

ISSN: 1476-7120