The bone mineral density (BMD) loss is closely related to coronary heart disease (CAD). The BMD measured at different locations differ in BMD values, the risk to CAD, and the capability to identify CAD. An average BMD of the right and left femoral neck being below - 1.70 has the ability to indicate risk of CAD.
Purpose: Previous studies have reported that low bone mineral density (BMD) is closely related to coronary artery disease (CAD); however, it is not clear that the BMD loss at which location to what extent has the greatest effect in identifying risk of CAD. This study aimed to evaluate the ability of different measurement sites of BMD in identifying CAD and analyze the best measurement sites and the optimal cut-off of BMD for CAD.
Methods: This was a cross-sectional study in which 180 of 817 participants were diagnosed with CAD. All participants in the study were measured by dual-energy X-ray absorptiometry (DEXA) for BMD at 8 locations, and following measurements were derived: the average BMD of lumbar spine (L1-L4), femoral neck (left and right), and total proximal femur (left and right). The association between BMD at different locations and CAD was analyzed using logistic regression. The receiver operating characteristic (ROC) curve was used to select the optimal measurement location and cut-off value of the BMD for identifying CAD.
Results: There were significant differences in BMD at 3 different measurement locations. Higher BMD is a protective factor against CAD, which is more pronounced in the femoral neck and total proximal femur (ORs = 0.47 ~ 0.66, P < 0.001) than in the lumbar spine (ORs = 0.74 ~ 0.79, P < 0.001). The optimal site for predicting the risk of CAD by BMD is the femoral neck, with the AUC (area under the ROC curve) is 0.72 (95% CI: 0.67 ~ 0.76) and the cut-off is - 1.70.
Conclusion: The BMD below particular cut-off of the femoral neck rather than of the lumbar spine may have certain further research value for revealing the risk of CAD.
Keywords: Bone mineral density; Coronary artery disease; Dual-energy X-ray absorptiometry; Measurement location.