Table 4.

Summary of the Carotid Intima-Media Thickness (cIMT) Protocols and Traditional Risk Factors Contributions in Selected Population-Based Studies (listed alphabetically)

Study	Carotid segment measured	cIMT definition	Inclusion of plaque in cIMT measurements	Risk factors associated with IMT (and their contribution if available)

ARIC [2]	CCA, ICA, Bifurcation; Far wall	Mean IMT	Yes	age, LDL, HDL cholesterol, hypertension, smoking, diabetes

CHS [14]	CCA, ICA, Carotid bulb; Near and far wall	Max IMT	No	CCA IMT 18%
CHS [14]	CCA, ICA, Carotid bulb; Near and far wall	Max IMT	No	ICA IMT 17% from age, male sex, hypertension, diabetes, cholesterol levels, cigarette smoking

Epidemiological survey in Mexico City [32]	CCA, ICA; Near and far wall	Max IMT	No	CCA IMT: age, sex, triglycerides, TC, diabetes, HDL cholesterol, and SBP (all together 28 %)
Epidemiological survey in Mexico City [32]	CCA, ICA; Near and far wall	Max IMT	No	ICA IMT: age, sex, triglycerides, TC, smoking, diabetes, and SBP (all together 12 %)

Framingham offspring cohort [31]	CCA, ICA, Carotid bulb; Far wall	Max IMT	Yes	CCA IMT: Total: 28.6%: age (19.4%), gender (4.1%), systolic BP (1.9%), HDL cholesterol (1.2%), smoking (0.9%), diabetes (0.8%), hypertension treatment (0.3%), and total cholesterol (0.002%).
Framingham offspring cohort [31]	CCA, ICA, Carotid bulb; Far wall	Max IMT	Yes	ICA IMT: Total 27.5%: age (18.5%), gender (4%), smoking (1.6%), hypertension treatment (1.1%), systolic BP (0.8%), diabetes (0.8%), HDL cholesterol (0.6%), and total cholesterol (0.1%).

INVEST [27]	CCA, ICA, Bifurcation; Near and far wall	Mean IMT	No	Cumulative periodontal burden associated with IMT

NOMAS [23]	CCA, ICA, Bif; Near and far wall	Mean IMT	No	Stromelysin-1 (MMP3), Interleukin-6 (IL6). Hepatic lipase (HL) (each 19%)

CCA indicates common carotid artery; Bif, carotid bifurcation; ICA, internal carotid artery