TY - JOUR
T1 - Chemical versus dual energy x-ray absorptiometry for detecting age- associated body compositional changes in male rats
AU - Feely, Rebecca S.
AU - Larkin, Lisa M.
AU - Halter, Jeffrey B.
AU - Dengel, Donald R.
PY - 2000/5
Y1 - 2000/5
N2 - Aging is associated with increases in body mass and fat mass (FM), whereas fat-free mass (FFM) either decreases or remains unchanged. The purpose of this study was to determine whether dual-energy X-ray absorptiometry (DXA) accurately detects age-associated changes in male Fischer 344 x Brown-Norway rats ages 8, 18, and 28 months. Eviscerated animal carcasses were first examined via the Lunar DPX-IQ DXA (small animal software version 1.0; HiRes (0.6 x 1.2 mm) medium mode). Eviscerated carcasses were then weighed, autoclaved, homogenized, and fat isolated from aliquots of homogenate via methanol/chloroform extraction. In both chemical (CHEM) and DXA analysis, carcass mass (CM), FM, and % fat were significantly higher (P < 0.0001) in the 18 and 28 versus 8-month-old rats. CHEM showed greater FFM in the 18 versus 8 months-old rats but not the 28 months-old animals. DXA was unable to detect the age-associated changes in FFM. Regression analysis showed a strong correlation between CHEM and DXA methods for CM (r = 0.98, P < 0.0001) and FM (r = 0.97, P < 0.0001), but less strong for FFM (r = 0.59, P = 0.0002). In conclusion, compared to CHEM, DXA consistently overestimated CM and FM across the age groups by 9% and 77%, respectively, and underestimated FFM by 5%. (C) 2000 Elsevier Science Inc.
AB - Aging is associated with increases in body mass and fat mass (FM), whereas fat-free mass (FFM) either decreases or remains unchanged. The purpose of this study was to determine whether dual-energy X-ray absorptiometry (DXA) accurately detects age-associated changes in male Fischer 344 x Brown-Norway rats ages 8, 18, and 28 months. Eviscerated animal carcasses were first examined via the Lunar DPX-IQ DXA (small animal software version 1.0; HiRes (0.6 x 1.2 mm) medium mode). Eviscerated carcasses were then weighed, autoclaved, homogenized, and fat isolated from aliquots of homogenate via methanol/chloroform extraction. In both chemical (CHEM) and DXA analysis, carcass mass (CM), FM, and % fat were significantly higher (P < 0.0001) in the 18 and 28 versus 8-month-old rats. CHEM showed greater FFM in the 18 versus 8 months-old rats but not the 28 months-old animals. DXA was unable to detect the age-associated changes in FFM. Regression analysis showed a strong correlation between CHEM and DXA methods for CM (r = 0.98, P < 0.0001) and FM (r = 0.97, P < 0.0001), but less strong for FFM (r = 0.59, P = 0.0002). In conclusion, compared to CHEM, DXA consistently overestimated CM and FM across the age groups by 9% and 77%, respectively, and underestimated FFM by 5%. (C) 2000 Elsevier Science Inc.
KW - Dual-energy x-ray absorptiometry
KW - Fat free mass
KW - Fat mass
KW - Lean body mass
UR - http://www.scopus.com/inward/record.url?scp=0034110088&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034110088&partnerID=8YFLogxK
U2 - 10.1016/S0531-5565(00)00095-4
DO - 10.1016/S0531-5565(00)00095-4
M3 - Article
C2 - 10832061
AN - SCOPUS:0034110088
SN - 0531-5565
VL - 35
SP - 417
EP - 427
JO - Experimental Gerontology
JF - Experimental Gerontology
IS - 3
ER -