title: Effects of chronic high-fat feeding on skeletal muscle mass and function in middle-aged mice.
abstract: OBJECTIVE
  Increased adipose tissue may promote catabolic events in skeletal muscle. The aim of this study was to test whether high-fat diet (HFD)-induced obesity would accelerate the onset of muscle wasting in middle-aged mice.
  
  
  METHODS
  Muscle was collected from C57BL/6 mice at 9 months of age (baseline) and 14 months of age after consuming a control (C) or HFD. Mice in C and HFD were also subjected to evaluations of body composition and function before and after their respective diets.
  
  
  RESULTS
  HFD demonstrated significant (p < 0.05) losses of grip strength (-15 %) and sensorimotor coordination (-11 %), whereas C did not. Lean mass decreased to a greater degree in HFD although not significantly (C: -20.69 ± 7.94 vs. HFD: -31.14 ± 5.49 %, p > 0.05). Gastrocnemius, quadriceps, and hamstrings mass in C and HFD were significantly reduced from baseline (-27 to 43 and -39 to 47 %, respectively, p < 0.05) with no differences between the two; however, soleus mass was lower only in HFD (-24 %, p = 0.03). Myofiber area, satellite cells, and myonuclei of the gastrocnemius were lower only in HFD (-23, -19, and -16 %, respectively, p < 0.05) compared to baseline.
  
  
  CONCLUSIONS
  HFD-induced obesity adversely affected function in middle-aged mice. Atrophy of the soleus in HFD but not C suggests sensitivity of oxidative muscle to HFD-dependent catabolism more so than aging. In the muscles containing fast/mixed fibers, aging effects may have concealed the catabolic nature of HFD; however, morphological changes in the gastrocnemius including decreased fiber area, satellite cells, and myonuclei are consistent with an atrophic phenotype related to HFD.
authors: Department of Health and Sport Sciences, The University of Memphis, Memphis, TN, USA.
authors: Sang-Rok
authors: SR
authors: Lee
authors: Andy V
authors: AV
authors: Khamoui
authors: Edward
authors: E
authors: Jo
authors: Bong-Sup
authors: BS
authors: Park
authors: Michael C
authors: MC
authors: Zourdos
authors: Lynn B
authors: LB
authors: Panton
authors: Michael J
authors: MJ
authors: Ormsbee
authors: Jeong-Su
authors: JS
authors: Kim
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism / Q000473:pathology; D000818:Animals; D001823:Body Composition; D059305:Diet, High-Fat / Q000009:adverse effects*; D004195:Disease Models, Animal; D008297:Male; D008660:Metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000473:pathology / Q000502:physiology; D009133:Muscular Atrophy / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D009765:Obesity / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D009929:Organ Size; D010084:Oxidation-Reduction