Age and sex differences in the relationship between inherited and lifestyle risk factors and subclinical carotid atherosclerosis: the Tromsø study

Background: Ultrasound measurement of carotid artery intima-media thickness (IMT) is regarded as a valid index of atherosclerosis. Age and sex differences in the distribution of, and risk factors for, IMT have not been investigated thoroughly. Methods: In 1994–1995 a total of 6408 men and women aged 25–84 years living in the municipality of Tromsø, Norway, underwent ultrasound examination of carotid artery IMT and measurements of cardiovascular risk factors. Results: Age, systolic blood pressure, total cholesterol, HDL cholesterol, body mass index, and smoking were independent predictors of IMT in both sexes. Fibrinogen levels and physical activity were associated with IMT in men only, whereas triglyceride levels were associated with IMT independently of HDL cholesterol in women only. A family history of cardiovascular disease (CVD) was an independent predictor of IMT in both sexes, also when controlling for traditional CVD risk factors. The magnitude of the association between most risk factors and IMT did not differ depending on age, but the effects of physical activity and triglycerides were more pronounced at higher age. Conclusion: These data suggest that there are significant age and sex differences in the distribution and the determinants of subclinical atherosclerosis.