Associations between bone mineral density and coronary artery calcification: a systematic review and meta-analysis

BACKGROUND: The studies about the correlation between bone mineral density (BMD) and coronary arterial calcification (CAC) were still controversial. The aim of this study was to conduct a meta-analysis to evaluate the association between BMD and CAC. METHODS: We systematically searched PubMed, Embase, Google scholar and Cochrane library for observational studies. We pooled odds ratio (OR) or correlation coefficient, and 95% confidence interval (CI) of the studies. Continuous data were pooled by mean difference (MD). Sub-group analysis was applied to investigate sources of heterogeneity. Funnel plots for publication bias was also performed. RESULTS: Seventeen studies met the inclusion criteria. Pooled ORs for the prevalence of CAC in patients with low BMD versus patients with normal BMD was 2.11 (95% CI: 1.11 - 4.02, P = 0.02). The data pooled for comparing CAC score of low BMD and normal BMD patients is 33.77 (95% CI: 23.77 - 43.77, p = 0.000). The pooled ORs of multivariate logistic regression to predict the association were 1.00 (95% CI: 0.92 - 1.10, p = 0.95, age-adjusted), and 0.95 (95% CI: 0.86 - 1.05, p = 0.33, multivariable-adjusted). Cohort category and BMD assessment method were the main sources of heterogeneity. CONCLUSIONS: Low BMD is associated with higher prevalence and severity of CAC, especially in postmenopausal women. But the relation is not significant after adjusting age and other confounding variables. Low BMD and CAC may be two independent processes with aging. More large-scale studies with high-quality design are still needed to increase the understanding of them.