For more data about these techniques, contact Mac Buchowski; Ph.D..
Body composition: the Core uses Dual energy x-ray absorptiometry (DXA) for measuring body fat, lean (muscle), and bone masses. DXA produces a full-body scan via photons at two different energy levels, 40 and 70 KeV. The photons pass through tissues and attenuate at rates related to elemental composition. Bone mineral, with highly attenuating calcium and phosphorous, is readily distinguished from soft tissues. The different elemental profiles of fat and bone-mineral free lean allows for the analysis of soft tissue fat content, so that bone mineral, fat, and bone mineral fat-free lean components may be resolved. As we have reported previously, we have a DXA scanner (Lunar Prodigy, GE Medical, Madison WI) with adult and pediatric software for the DRTC investigators. For applications that DXA is inappropriate (repeated measures in children, or subjects over 300 lbs), we offer the BOD POD air displacement system (Life Measurements Instruments, Concord, CA). Total body composition can be assessed non-invasively and within 10 minutes.