Coronary artery calcium and bone mineral density by serial CTA: Does menopausal hormone therapy modify the association?

Abstract

IntroductionBoth osteoporosis and cardiovascular disease (CVD) increase in women after menopause. Estrogen deficiency is thought to be an underlying mechanism for both these conditions. MethodsHealthy menopausal women (n = 374, age 42–58 years) underwent cardiac CT scans over four years as participants in the Kronos Early Estrogen Prevention Study (KEEPS), a randomized, controlled trial to Women randomized to either oral conjugated equine estrogens (o-CEE, n = 104), transdermal 17β-estradiol (t-E2, n = 119) or placebo (n-115). CAC (Agatston units, AU), and BMD (mg/cm3) were measured from thoracic vertebrae at baseline and at the 4 years of the study using validated software. ANOVA and multiple linear regression analyzed the association between incident CAC or progression of CAC and BMD among the treatment groups. ResultsAt baseline 374 women, 40 participants with CAC >0 had greater decrements in BMD than the 334 participants with CAC = 0 at baseline, The average change in BMD in o-CEE group with CAC was −9.6 ± 13.3 versus −3.1 ± 19.5 in those with zero CAC, p = 0.0018. With t-E2, BMD changed by −11.7 ± 26.2 in those with CAC versus +5.7 ± 26.2 in the zero CAC group, p ≤ 0. 0001. Similarly in the 66 participants that showed progression of CAC >1, had more BMD loss, than those with stable CAC regardless of the treatment. ConclusionProgression of bone loss is reduced among women treated with o-CEE or t-E2. Progression of CAC is associated with greater BMD loss, a relationship that is differentially modified by t-E2 and o-CEE.