Cardiovascular calcification and subcortical bone demineralization in hypertension

The present study investigated cardiovascular calcification, peripheral bone mineral density (BMD), and lab indices in hypertensive patients aged 55-74 years without severe kidney dysfunction. Cardiovascular calcification was investigated by ultrasound examinations at eight sites: aortic valve, left and right common carotid artery, left and right carotid artery bifurcation, left and right internal carotid artery, and abdominal aorta. The presence/absence of calcification at each site was coded as 1/0, respectively, for the calculation of a cumulative score. Peripheral bone mineral density was assessed by forearm quantitative computed tomography (pQCT) and was defined as low if the T-score was <-1. Lab work-up included plasma creatinine, calcium, phosphorus, parathyroid hormone and 25-(OH) vitamin D measurements. Ninety-one patients were studied. The range was 2-8 for the calcification score and 229-492 mg cm(-3) for bone mineral density. The prevalence of low bone densitometry was 83.5%. The calcification score and bone densitometry were inversely correlated in a non-adjusted analysis (R=-0.297, P= 0.004) and in multivariable regression (beta=-0.335, P= 0.003). The association was significant for subcortical bone (beta=-0.302, P= 0.007) but not for cortical bone or trabecular bone (P=0.194 in both cases). The calcification score was associated with a low prevalence of bone densitometry in the non-adjusted analysis (odds ratio=2.53, 95% CI= 1.41/4.54, P= 0.002) and in the multivariable logistic regression (odds ratio=2.46, 95% CI= 1.25/4.81, P= 0.009). Cardiovascular calcification was independently associated with peripheral bone densitometry in hypertensive patients. The data support the hypothesis that vascular calcification and low bone densitometry share some determinants in hypertensive patients.