Intramuscular and Liver Triglycerides Are Increased in the Elderly

• Published in: The journal of clinical endocrinology and metabolism 2004-08, Vol.89 (8), p.3864-3871
• Main Authors: Cree, Melanie G., Newcomer, Bradley R., Katsanos, Christos S., Sheffield-Moore, Melinda, Chinkes, David, Aarsland, Asle, Urban, Randall, Wolfe, Robert R.
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Adipose Tissue - diagnostic imaging; Adult; Aged; Aging - blood; Aging - metabolism; Aging - physiology; Biological and medical sciences; Endocrinopathies; Female; Fundamental and applied biological sciences. Psychology; Glycated Hemoglobin A - metabolism; Humans; Insulin Resistance; Lipids - blood; Liver - diagnostic imaging; Liver - metabolism; Magnetic Resonance Spectroscopy; Male; Medical sciences; Middle Aged; Muscle, Skeletal - metabolism; Regression Analysis; Space life sciences; Triglycerides - metabolism; Vertebrates: endocrinology
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2003-031986

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.