No Association Between Bone Mineral Density and Breast Arterial Calcification Among Postmenopausal Women

CONTEXT: The association between bone mineral density (BMD) and breast arterial calcification (BAC) remains poorly understood and controversial. OBJECTIVE: The objective of this article is to examine the association between BMD and BAC in a large cohort of postmenopausal women undergoing routine mammography. DESIGN: A cross-sectional analysis of baseline data from a multiethnic cohort was performed. SETTING: The setting for this analysis is an integrated health care delivery system in Northern California in the United States. PATIENTS: A total of 1273 women age 60 to 79 years (mean age, 67 years) were recruited within 12 months of screening mammography. MAIN OUTCOME MEASURE: A BAC score (mg) was obtained from digital mammograms using a novel densitometry method. BAC presence was defined as a BAC score greater than 0 mg, and severe BAC as a BAC score greater than 20 mg. RESULTS: Overall, 53% of women had osteopenia and 21% had osteoporosis. The prevalence of BAC greater than 0 mg was 29%, 30%, and 29% among women with normal BMD, osteopenia, and osteoporosis, respectively (P = 0.98). The prevalence of BAC greater than 20 mg was 5%, 3%, and 5% among women with normal BMD, osteopenia and osteoporosis, respectively (P = .65). The odds ratios (ORs) of BAC greater than 0 mg vs BAC = 0 mg after multivariable adjustment were 1.09 (95% CI, 0.81-1.48; P = .54) for osteopenia and 0.99 (95% CI, 0.69-1.48; P = .98) for osteoporosis. The adjusted ORs for BAC greater than 20 mg vs BAC 20 mg or less were 1.03 (95% CI, 0.52-2.01; P = .93) for osteopenia and 1.89 (95 CI, 0.81-4.47; P = .14) for osteoporosis. CONCLUSION: Our findings do not support an association of either osteopenia or osteoporosis with BAC presence or severity among postmenopausal women.