Prevalence of and risk factors associated with carotid artery stenosis: the Tromsø Study

To assess prevalence, distribution, ultrasound characteristics and determinants of carotid artery stenosis in a large, population-based study of both women and men.

A total of 6,727 persons aged 25-84 years were screened for extracranial stenosis with Duplex ultrasound of the right carotid artery. Risk factors were compared in 225 persons with stenosis and 5,514 persons without.

The prevalence of carotid stenosis was higher in men than in women, where 3.8% (95% CI, 3.2-4.6%) had carotid stenosis, compared to 2.7% (95% CI, 2.2-3.3%) in women (p = 0.001). The prevalence gradually increased by age in both genders. Cholesterol, HDL cholesterol, fibrinogen, systolic blood pressure levels and current smoking were independently associated with carotid artery stenosis in both women and men. The presence of carotid stenosis was significantly associated with a history of cerebrovascular disease, coronary heart disease and peripheral artery disease. For each 10% increase in the degree of carotid stenosis, the risk of having had a cerebrovascular event increased by 26%.

The prevalence of carotid stenosis in the general population, as measured by ultrasound, is low. Age, male gender, smoking, total cholesterol, HDL cholesterol (inverse), fibrinogen and systolic blood pressure are all independent predictors of carotid artery stenosis.