This Article Full Text Full Text (PDF) All Versions of this Article: 93/5/2009    most recent Author Manuscript (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Google Scholar Articles by Bakhireva, L. N. Articles by Barrett-Connor, E. PubMed PubMed Citation Articles by Bakhireva, L. N. Articles by Barrett-Connor, E. Related Collections Calcium and Bone Metabolism Cardiovascular Endocrinology

Does Osteoprotegerin or Receptor Activator of Nuclear Factor-B Ligand Mediate the Association between Bone and Coronary Artery Calcification?

Division of Pharmacy Practice College of Pharmacy and Department of Family and Community Medicine, (L.N.B.), University of New Mexico, Albuquerque, New Mexico 87131; and Department Family and Preventive Medicine (G.A.L., R.B., E.B.-C.), University of California, San Diego, La Jolla, California 92093

Address all correspondence and requests for reprints to: Gail A. Laughlin, Ph.D., Family and Preventive Medicine, University of California, San Diego, 9500 Gilman Drive, 0631C, La Jolla, California 92093. E-mail: glaughlin{at}ucsd.edu.

Context: Accumulating evidence indicates that vascular and bone mineralization may be related, although the exact mechanism remains unknown.

Objective: Our objective was to investigate whether an observed inverse association between bone mineral density (BMD) and coronary artery calcification (CAC) in postmenopausal women currently taking estrogen therapy is mediated by osteoprotegerin (OPG) or receptor activator of nuclear factor-B ligand (RANKL).

Design: Participants were 92 postmenopausal women (aged 58–81 yr) taking estrogen therapy who had hip and spine BMD assessed by dual-energy x-ray absorptiometry and CAC measured by electron-beam computed tomography in 1998–2002 and serum RANKL and OPG levels measured in samples collected in 1997–1999. Total CAC score was dichotomized as none/minimal (10) vs. some (>10).

Results: OPG serum levels were higher in women who had some CAC compared with those who had none/minimal (126.8 ± 1.08 vs. 102.9 ± 1.07 pg/ml, respectively, P = 0.03); these differences became nonsignificant after adjustment for age and other risk factors (P = 0.51). A 1 SD increase in hip BMD was associated with significantly lower odds of having CAC > 10 (odds ratio = 0.52; 95% confidence interval = 0.29–0.93) independent of age, fat-free mass, high-density lipoprotein cholesterol, current smoking, and use of cholesterol-lowering medications. Other skeletal sites demonstrated a similar pattern. Addition of RANKL and/or OPG to the model had minimal effect on the magnitude or statistical significance of the BMD-CAC association. Additionally, a test of interaction indicated that RANKL and OPG are not significant effect modifiers.

Conclusions: Serum OPG and RANKL do not account for the observed association between bone and coronary artery calcification among postmenopausal women using hormone therapy.