Purpose: To determine the relationship between breast arterial calcification, diabetes mellitus, and subsequent cardiovascular and noncardiovascular mortality.
Materials and methods: A prospective cohort study was carried out in 12,239 women aged 50-68 years who participated in a breast cancer screening program. The screening mammograms were coded for the presence of breast arterial calcification. Diabetes (n = 442) was defined as use of insulin or oral hypoglycemic agents, use of a restricted diet for diabetes, or the presence of glucosuria. Data were available from questionnaires and urine glucose tests. Hazard ratios, which were adjusted for age, smoking, parity, and obesity, were calculated from mortality data after 16-19 years of follow-up.
Results: Breast arterial calcification was seen in 9.0% (1,107 of 12,239) of all women and in 15.4% (68 of 442) of the diabetic women. An excess cardiovascular mortality of 40% (hazard ratio = 1.4; 95% confidence interval = 1.1, 1.8) was found for all women with breast arterial calcification. In diabetic women, the presence of breast arterial calcification was associated with a 90% (hazard ratio = 1.9; 95% confidence interval = 1.1, 3.2) increase in cardiovascular mortality.
Conclusion: Breast arterial calcification represents an independent risk factor for cardiovascular mortality in women over 50 years of age, especially in those with diabetes.