Intramuscular and liver triglycerides are increased in the elderly.

Department of Surgery, The University of Texas Medical Branch and Shriners Hospitals for Children, Galveston, Texas 77550, USA.
Journal of Clinical Endocrinology &amp Metabolism (Impact Factor: 6.31). 09/2004; 89(8):3864-71. DOI: 10.1210/jc.2003-031986
Source: PubMed

ABSTRACT 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.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Perivascular multipotent cells, pericytes, contribute to the generation and repair of various tissues in response to injury. They are heterogeneous in their morphology, distribution, origin and markers, and elucidating their molecular and cellular differences may inform novel treatments for disorders in which tissue regeneration is either impaired or excessive. Moreover, these discoveries offer novel cellular targets for therapeutic approaches to many diseases. This review discusses recent studies that support the concept that pericyte subtypes play a distinctive role in myogenesis, neurogenesis, adipogenesis, fibrogenesis and angiogenesis.
    Clinical Science 01/2015; 128(2):81-93. · 5.63 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Obesity among the elderly is a growing public health concern. Among the various factors that may contribute to the current rates of obesity is the rewarding aspect of highly palatable foods and beverages, which may lead to overconsumption and excess caloric intake. The present review describes recent research supporting the hypothesis that, for some individuals, the consumption these highly palatable foods and beverages may lead to the development of addictive-like behaviors. In particular, the authors consider the relevance of this hypothesis to the ageing population.
    Ageing Research Reviews 10/2014; · 7.63 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aging is generally accompanied by a progressive loss of skeletal muscle mass and impairments in metabolic function. Even a few days of muscle disuse (such as that occurring during injury or illness) leads to considerable loss of muscle mass and strength. It has been speculated that short, successive periods of muscle disuse throughout the lifespan may be largely responsible for the age-related loss of muscle mass. However, it remains unknown whether such short periods of disuse also induce impairments in metabolic function within the skeletal muscle. Here, we investigated the effects of a five day period of muscle disuse on intramyocellular triacylglycerol (IMTG) content, muscle oxidative capacity, and the expression of key genes that regulate oxidative metabolism in healthy young and elderly men. Muscle biopsies were collected from healthy, young (n=12; 23±1y) and elderly (n=12; 70±1y) men prior to and immediately after a five day period of one-legged knee immobilization by way of a full leg cast. At baseline, elderly men had a greater IMTG content when compared with the young (56.2±5.1 and 34.8±7.3μmol·g(-1), respectively; P<0.05) with no changes in either group following immobilization (53.4±5.0 and 35.7±5.0μmol·g(-1), respectively; P>0.05). In line, five days of disuse did not lower citrate synthase, β-HAD or cytochrome C oxidase activity in the skeletal muscle tissue. Pyruvate dehydrogenase activity increased following immobilization in the older subjects only, from 0.39±0.06 to 0.55 0.05μmol·g(-1)·min(-1) (71±33%; P<0.01). The skeletal muscle mRNA expression of PGC1α and citrate synthase both declined following immobilization in both the young and elderly subjects. We conclude that five days of muscle disuse does not increase intramuscular lipid deposition or reduce the maximal activity of key mitochondrial enzymes within the skeletal muscle of young or older men. Copyright © 2014. Published by Elsevier Inc.
    Experimental Gerontology 11/2014; 61. · 3.53 Impact Factor

Full-text (2 Sources)

Available from
Jun 3, 2014