Abstract Body: Decreased bone mineral density (BMD) is associated with atherosclerosis in postmenopausal women and older men. Limited research has explored this relationship in middle-aged men. Aortic calcification (AC) is a novel biomarker for aortic atherosclerosis. This study aimed to examine whether baseline BMD is associated with the progression of AC in an international multi-ethnic cohort of middle-aged men participating in the ERA-JUMP Study (The Electron-Beam Tomography Risk Factor Assessment Among Japanese and U.S. Men in the Post-World War II Birth Cohort). We hypothesized that higher BMD at baseline would be associated with less progression of AC.
This analysis included participants who completed two visits an average of 5.69 years apart. Participants (mean age: 45.3 + 2.9) were recruited from population-based samples in the United States (Pennsylvania and Hawaii) and Japan (Shiga). All participants were free of clinical cardiovascular disease at baseline. BMD was measured via electron-beam tomography images of the T12 to L4 vertebrae. AC was evaluated from the aortic arch to the iliac bifurcation with computed tomography and scored via the Agatston Scoring Method. Incidence of AC was defined as an AC score <100 at baseline and ≥ 100 at follow-up. Linear regression was employed to assess the association between baseline BMD and changes in AC (Visit 2 – Visit 1). Model 1 adjusted for follow-up time, age, and race/ethnicity. Model 2 was further adjusted for cardiovascular risk factors: hypertension, diabetes, LDL-C, HDL-C, and lipid medication. Model 3 additionally adjusted for BMI and smoking status. Logistic regression, with the same models, was used to assess the association between baseline BMD and incident AC at Visit 2.
At baseline, the average BMD was 173.1 HU (+ 37.1), and the median AC score was 3.0. The median change in AC score was 39.76 (IQR: 0- 220.3). There were 159 incident cases of AC in the cohort. Baseline BMD was inversely associated with the change in AC in Models 1, 2 (p<0.05) and Model 3 (p<0.1). Similarly, baseline BMD was inversely associated with incident AC in Models 1, 2 (p<0.05), and Model 3 (p=0.10).
Our findings suggest that skeletal and cardiovascular health may be linked in middle-aged healthy men. Higher baseline BMD appears to be associated with reduced progression and lower incidence of AC. These results underscore the need for further longitudinal studies to confirm this relationship and explore its clinical implications.