P149Measures of bone quality are associated with aortic distensibility

Abstract

Introduction and Purpose Osteoporosis and cardiovascular disease share some common risk factors and more recently have been linked mechanistically. There is a paucity of studies comparing detailed imaging parameters of bone and cardiovascular health. We present a large cross-sectional study of the relationship between quantitative ultrasound measures of bone health with clinical and cardiovascular magnetic resonance (CMR) markers of cardiovascular health using data from UK Biobank. Methods: Analysis is of the first 5,065 individuals to complete the UK Biobank imaging protocol. We defined cardiovascular disease as history of ischaemic or non-ischaemic heart disease, ischaemic stroke, peripheral vascular disease, aortic disease, ventricular arrhythmias or history of cardiac arrest. Clinical data were derived from self-report, Hospital Episode Statistics and UK Biobank algorithms for ischaemic stroke and myocardial infarction. Broadband ultrasound attenuation (BUA) and estimated bone mineral density (eBMD) were obtained from Quantitative Ultrasound of the calcaneus. Average values were used when bilateral measurements were taken. Bone indices were compared in individuals with and without cardiovascular disease using two sample t-test. Multivariate linear regression models were used to assess associations of eBMD and BUA with selected CMR parameters (LVEF, LVEDV/BSA, LVM/BSA, LVSV/BSA, circumferential strain, end systolic torsion, aortic distensibility), whilst controlling for age, sex and smoking history. The number of missing data points from CMR variables ranged from 172 to 826 reflecting omissions after quality control and sanity checks. Results: Mean age was 62 ± 7.6 years, 47% were male and 97% were Caucasian. Level of comorbidity was low (diabetes 5%; hypertension 33%; hypercholesterolaemia 28%; cardiovascular disease 6.1%). Quantitative ultrasound measures were available for 5,064 individuals. Mean BUA was 79 ± 19dB/MHz. Mean eBMD was 0.56 ± 0.13g/cm2. Greater aortic distensibility in the ascending aorta was associated with both higher BUA (β coef. 9.4 × 102dB/MHz/mmHg-1; 95% CI: 45, 1.8 × 103; p = 0.04) and eBMD (β coef. 8.2 g/cm2/mmHg-1; 95% CI: -1.8, 14.7; p = 0.01). There were no significant differences in eBMD (81 ± 19dB/MHz vs 79 ± 19dB/MHz; 95% CI: -0.02, 0.008; p = 0.36) or BUA (0.56 ± 0.14g/cm2vs 0.56 ± 0.13g/cm2; 95% CI: -4.4, 0.042; p = 0.054) between individuals with or without cardiovascular disease. Conclusions: Our findings demonstrate significant positive correlations between great bone mass and quality and aortic distensibility, a marker of bioelastic function of the aorta and a pathogenic marker of early arterial disease. Our population was a relatively healthy cohort, with low burden of cardiac and bone disease; this may have precluded detection of a clinical association. Longitudinal studies would be of interest to explore poor bone health as a predictor of adverse cardiovascular outcomes and vice versa.