Risk factors for subclinical carotid atherosclerosis in healthy men

Ultrasound-detected carotid artery intima-media thickness (IMT) is regarded as a valid index of atherosclerosis. Cross-sectional studies have been helpful in establishing determinants of IMT, but the long-term relationship between cardiovascular risk factors and subclinical atherosclerosis in a low-risk population has not been thoroughly evaluated.

A cohort of 483 military aviators, officially considered as fit for flying and therefore normotensive, was included in the study. All subjects underwent baseline examination with measurement of cardiovascular risk factors (body mass index, blood pressure, physical working capacity, cigarette smoking, and levels of cholesterol, high-density lipoprotein cholesterol, triglycerides, and gamma-glutamyltransferase) and carotid ultrasonography at the end point after 10 years of follow-up.

Age, cigarette smoking, and blood pressure were independent long-term predictors of IMT. After adjustment for age, cigarettes smoked daily at baseline, categorized in units of five cigarettes each (regression coefficient in mm, 0.057 [95% CI: 0.029 to 0.085]; p < 0.0001), and systolic blood pressure (regression coefficient in mm, 0.007 [95% CI: 0.003 to 0.010], p < 0.0001) were the only predictors of IMT. Physical working capacity was not associated with IMT.

Even in normotensive individuals, systolic blood pressure is a strong predictor of early carotid atherosclerosis.