Markers of Mineral Metabolism Are Not Associated With Aortic Pulse Wave Velocity in Community-Living Elderly Persons: The Health Aging and Body Composition Study

Abstract

Disorders in mineral metabolism are associated with risk for cardiovascular disease (CVD) events in patients with kidney disease as well as in the general population. This risk is thought to be mediated, in part, through the mechanism of stiffening of the arteries. The objective of this study was to evaluate the relationships between serum calcium, phosphorus, intact parathyroid hormone (iPTH), and 25-hydroxyvitamin D levels and arterial pulse wave velocity (aPWV) among 2,229 community-dwelling elderly persons participating in the Health Aging and Body Composition (Health ABC) study. The mean age of the participants was 72 years; 52% were woman, 39% were black, and 17% had chronic kidney disease (CKD) (estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2)). In parallel unadjusted analyses, the following associations were observed: 2.86% greater aPWV per 12 ng/ml (s.d.) lower 25-hydroxyvitamin D (95% confidence interval -4.38%, -1.31%), 3.04% greater aPWV per 28 pg/ml (s.d.) higher iPTH (95% confidence interval 1.42-4.68%), and 2.37% lower aPWV per 0.5 mg/dl (s.d.) higher phosphorus (95% confidence interval -3.90% to - 0.81%). Except for phosphorus, these associations were attenuated and rendered no longer statistically significant after adjustment for demographic risk factors, clinical site, season, medications and other CVD risk factors. The results were similar in men and women and were not dependent on the presence of CKD. Among well-functioning community-dwelling elderly persons, only serum phosphorus was associated with aPWV; and this association was in the opposite direction of the one hypothesized. Factors other than vascular stiffening may mediate the relationship between disordered mineral metabolism and CVD events in community-living elders.