Abstract TH871: High Lipoprotein (a) Associated with Decreased Bone Mineral Density in Post-Menopausal Women

Introduction: Cardiovascular markers, including lipoprotein(a) (Lp(a)), are hypothesized to be associated with skeletal bone health because of an association between oxidative stress and bone marrow adiposity, but the US does not routinely test Lp(a) levels. This study evaluates whether high Lp(a) levels are linked to lower bone mineral density among post-menopausal women. Methods: This hypothesis was tested using data from the Study of Women' s Health Across the Nation (SWAN), a longitudinal study of women who were initially pre-menopausal or early perimenopausal and who reached menopause at visit 7, within 7 years of baseline (n=1357). High Lp(a) was defined as greater than or equal to 100 mg/dl. Spine bone mineral density was assessed at visit 10 utilizing Dual-energy X-ray absorptiometry (DEXA) scan, and coded as decreased if BMD decreased by 10% or more between visits 7 and 10. We analyzed the data using chi-square tests of association and Poisson multivariate regression adjusting for confounding variables measured at baseline: age, race, smoking status, BMI, LDL cholesterol, calcium and vitamin D supplements, HDL cholesterol, and physical activity. Results: Women with high Lp(a) were 35.4% more likely to have decreased bone mineral density than women with low Lp(a). Individuals with high Lp(a) levels were more likely to smoke, have higher BMI, LDL levels, and total cholesterol; they were also less likely to regularly exercise, take calcium supplements, and have high HDL. Women with high Lp(a) were 84.3% more likely to have decreased bone mineral density than women with low Lp(a), controlling for confounders. Conclusion: Our study provides suggests benefits to assessing Lp(a) levels in individuals at risk for cardiovascular mortality and declining bone health including women prior to the menopausal transition. Early detection of elevated Lp(a) levels could allow the possibility to offset the effects of elevated Lp(a) through management of more easily modifiable cardiovascular markers such as low-density lipoproteins. Novel Lp(a) lowering medications may also help protect skeletal bone health in individuals who are at risk of declining bone health.