Breast arterial calcification and risk of carotid atherosclerosis: focusing on the preferentially affected layer of the vessel wall.

OBJECTIVE To assess the relationship between breast arterial calcification (BAC) detected on screening mammography and atherosclerosis of carotid arteries considering the most likely involved layer of the arterial wall. MATERIALS AND METHODS A total of 537 consecutive women who underwent screening mammography were enrolled in this study. Seventy-nine subjects having BAC, aged 46-75 years, and 125 age-matched controls from those without BAC were selected for ultrasound examination of carotid arteries assessing intima-media thickness (IMT) and plaque presence. Participants were divided into three groups of risk including, low-risk: IMT<0.6mm without plaque, medium-risk: 0.6mm≤IMT≤0.8mm without plaque and high-risk: IMT>0.8mm and/or plaque. Risk factors for atherosclerosis were obtained from medical records for independent effects. RESULTS BAC was present in 14.7% of mammograms. According to multivariable logistic regression analyses, significant association was identified between the carotid atherosclerosis risk and presence of BAC. Compared to women with IMT<0.6mm, those with 0.6mm≤IMT≤0.8mm and IMT>0.8mm had OR (95% CI) of 4.88 (1.47-16.16) and 23.36 (4.54-120.14), respectively. The OR (95% CI) for carotid plaque was 3.13 (1.3-7.57). There was no interaction between IMT category and plaque. Significant associations were also detected with postmenopausal duration (P=0.02) and hypertension (P=0.004). CONCLUSION The risk of carotid atherosclerosis increases with the presence of BAC. Women with BAC are more likely to have thicker IMT than plaque, which could be attributed to the preferentially similar affected layer of media causing thick IMT rather than plaque.