Effects of silicone breast prostheses on the assessment of body composition by dual-energy X-ray absorptiometry.

We examined the influence of silicone breast prostheses on body composition as assessed by dual-energy X-ray absorptiometry (DXA). Eighteen women were measured with and without a pair of silicone breast prostheses placed on the upper part of the trunk simulating endogenous implants. Bone area, bone mineral content (BMC), areal bone mineral density (BMD), lean tissue mass (LTM) and fat tissue mass (FTM) of the total body and of the subregions of the body, i.e. the head, trunk, arms and legs, were measured by a Norland XR-36 DXA scanner. After application of the silicone prostheses, bone area, BMC and BMD of the total body significantly increased by an average of 3.7, 6.6 and 3.4% (P<0.0001), respectively. Total body LTM and FTM were not affected. In the trunk region, changes were more pronounced. Trunk BMC, for example, was overestimated by 17.9% (P<0. 0001). The prostheses also influenced measurements of truncal soft tissue composition, with a small but statistically significant overestimation of both LTM (1.1%) and FTM (2.1%) (P<0.05). No changes in bone mass and soft tissue composition were seen in the head, arms and legs. Activation of a high-density detection software utility provided by the manufacturer had no influence on any of the measurements. We conclude that silicone breast prostheses affect the assessment of body composition by DXA.