Lower Bone Mineral Density in the Femoral Neck Is Associated with Greater Abdominal Aortic Calcification and Rate Pressure Product in Healthy Older Australians

Presentation Number: OR07-6
Date of Presentation: April 2nd, 2017

Alexander Joseph Rodriguez*1, David Scott2, Allison Hodge3, Dallas English4, Graham G. Giles3 and Peter R Ebeling2
1Monash University, Melbourne, AUSTRALIA, 2Monash University, Australia, 3Cancer Council Victoria, 4University of Melbourne

Abstract

Introduction:Osteoporosis is associated with risk factors for cardiovascular disease including aortic calcification, which increases cardiac workload and subsequent risk of cardiovascular events and death. We aimed to determine whether there is an association between lower bone mineral density (BMD) and increased cardiac workload in older men and women, and if this association was influenced by aortic calcification.

Design: Cross-sectional study of a 2010 subset of the Melbourne Collaborative Cohort Study [1] in Australia involving individuals with either low [<500mg/day] or high [≥1300mg/day] dietary calcium intake.

Methods: Three hundred and thirty-seven participants [61% female] of mean±SD age =70±5years and mean BMI =28±5kg/m2, had BMD determined by dual-energy x-ray absorptiometry and AAC determined by radiography. Aortic calcification score (ACS) was determined visually in the L1-L4 vertebrae (range: 0-24). Systolic blood pressure (SBP) and heart rate (HR) were measured by automated oscillometry. The rate pressure product (RPP), a cardiac workload measure, was determined by multiplying SBP and HR.

Results: Two hundred and five (62%) participants had AAC. Mean±SD RPP (9120±1823; range= 5424-18537) was low, indicating good cardiac health. In all participants, ACS was positively associated with RPP [β=0.011; 95%CI: 0.006, 0.016; p<0.001] and severe calcification was positively associated with RPP [β=0.083; 95%CI: 0.026, 0.140; p=0.004 relative to no calcification]. In sex-specific analyses, these associations were significant in females only. Lower odds of having any AAC were observed per 1g/cm2increment in femoral neck BMD [OR=0.08, 95% CI 0.01, 0.95]. A similar trend was evident in women [OR=0.05; 95% CI: 0.00, 1.17]. In all participants, femoral neck [β= -0.20; 95%CI: -0.39, -0.01; p=0.04] and total hip BMD [β= -0.17; 95%CI: -0.33, -0.01; p=0.04] were inversely associated with RPP after multivariable adjustment for important cardiovascular risk factors including dietary calcium intake, physical activity levels and smoking status. Adjusting additionally for AAC reduced the strength of the association in femoral neck (β= -0.19; 95%CI: -0.40, 0.11; p=0.51) but not in total hip BMD (β= -0.16; 95%CI: -0.33, -0.01; p=0.049).

Conclusion: Lower bone density was associated with increased cardiac workload, and this relationship was attenuated by aortic calcification. These associations were present in women but not men, possibly suggesting a role for sex steroids in bone loss and cardiovascular disease. Overall, these data suggest that older adults with osteoporosis may have an increased risk for cardiovascular disease and events.

 

Nothing to Disclose: AJR, DS, AH, DE, GGG, PRE