Sex- and age-related differences in bone microarchitecture in men relative to women assessed by high-resolution peripheral quantitative computed tomography

Abstract

The trabecular and cortical compartments of bone each contributes to bone strength. Until recently, assessment of trabecular and cortical microstructure has required a bone biopsy. Now, trabecular and cortical microstructure of peripheral bone sites can be determined noninvasively using high-resolution peripheral quantitative computed tomography (HR-pQCT). Studies that have used HR-pQCT to evaluate cohorts of both men and women have provided novel insights into the changes in bone microarchitecture that occur with age between the sexes, which may help to explain the lower fracture incidence in older men relative to women. This review will highlight observations from these studies on both the sex- and age-related differences in trabecular and cortical microstructure that may underlie the differences in bone strength, and thereby fracture risk, between men and women.

Figure 1

(a) Radiograph showing the site of imaging by HR-pQCT at the distal radius. The white line indicated the proximal level of the joint space, and the red lines indicate the section of bone over which images are acquired. (b) Representative cross-sectional images from the stack of CT slices. (c) Representative 3D image. Images were obtained using the initial prototype of the HR-pQCT scanner (Figure is reprinted with permission from Khosla et al. [8]  ^©2006 American Society for Bone and Mineral Research).

Figure 2

Representative reconstructions of high-resolution peripheral quantitative computed tomography images from young, middle-aged, and elderly men (left) and women (right). Values for trabecular microstructural variables for each subject are also provided. The arrow indicates the prominent plate-like trabeculae in the young man, which are less prominent or absent in the other images. Images were obtained using the initial prototype of the HR-pQCT scanner. (Figure is reprinted with permission from Khosla et al. [8] ^©2006 American Society for Bone and Mineral Research).