Intramuscular and liver triglycerides are increased in the elderly.
Magnetic resonance spectroscopy studies have shown that intramyocellular lipids (IMCL) and liver fat (LFAT) levels vary with insulin sensitivity and obesity, which are common in the elderly. Thus, magnetic resonance spectroscopy was used to investigate the hypothesis that IMCL and LFAT are increased in the elderly. IMCL and LFAT in young (aged 20-32 yr) and elderly (aged 65-74 yr) were measured fasted, and glucose, insulin, total free fatty acids levels, and free fatty acids profiles were measured during a 2-h oral glucose tolerance test. Body fat percentage was determined with dual x-ray absorptiometry. The elderly had significantly greater IMCL (0.12 +/- 0.01 vs. 0.08 +/- 0.01, mean +/- sem; P = 0.01) and LFAT (0.28 +/- 0.06 vs. 0.08 +/- 0.01; P = 0.004; expressed as ratios to Intralipid standard) than the young. The elderly had increased insulin resistance as calculated by the Matsuda model compared with the young (5.1 +/- 0.9 vs. 9.9 +/- 1.4; P = 0.02). Regression analysis of all subjects indicated that the increases in IMCL and LFAT were correlated with insulin sensitivity, glycosylated hemoglobin, plasma lipids, and body fat. Furthermore, the correlation between insulin sensitivity and IMCL and LFAT remained significant, after accounting for the effect of body fat. Increases of IMCL and LFAT occur in elderly individuals and may be related to insulin resistance.
Department of Surgery, The University of Texas Medical Branch and Shriners Hospitals for Children, Galveston, Texas 77550, USA.
Melanie G
MG
Cree
Bradley R
BR
Newcomer
Christos S
CS
Katsanos
Melinda
M
Sheffield-Moore
David
D
Chinkes
Asle
A
Aarsland
Randall
R
Urban
Robert R
RR
Wolfe
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood / Q000378:metabolism* / Q000502:physiology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008099:Liver / Q000000981:diagnostic imaging / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D012044:Regression Analysis; D014280:Triglycerides / Q000378:metabolism*
D006442:Glycated Hemoglobin; D008055:Lipids; D014280:Triglycerides