Sarcopenia and increased adipose tissue infiltration of muscle in elderly African American women.
BACKGROUND
Aging is associated with metabolic, physiologic, and functional impairments, in part through age-related changes in body composition. During the later adult years, skeletal muscle mass decreases and body fat becomes centralized.


OBJECTIVE
The goal of the study was to investigate body composition over time ( +/- SD: 2.04 +/- 0.6 y) in healthy, ambulatory, elderly African American women. The hypothesis that a reduction in total-body skeletal muscle (SM) and increases in visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) are ongoing in healthy, weight-stable elderly was tested.


METHODS
The study was a longitudinal evaluation of 26 women (age at baseline: 75.5 +/- 5.1 y) with a body mass index (in kg/m(2)) of 27.0 +/- 4.0. Body composition was measured by using whole-body magnetic resonance imaging for the quantification of SM, total adipose tissue (TAT), VAT, SAT, and IMAT.


RESULTS
SM (P < 0.001) and bone (P < 0.05) masses decreased, and regional analyses showed a decrease in dual-energy X-ray absorptiometry-derived leg SM (P < 0.05). VAT (P = 0.011) and IMAT (P < 0.001) increased. No changes occurred in TAT (P = 0.45), SAT (P = 0.96), physical function, or food intake.


CONCLUSIONS
These data show an age-related remodeling of body composition with reductions in SM and corresponding increases in VAT and IMAT. Changes in the previously unstudied depot of IMAT may be involved in the deterioration of metabolic values frequently observed during aging.
Song
Mi-Yeon
MY
Department of Medicine, Obesity Research Center, St Luke's-Roosevelt Hospital, 1090 Amsterdam Avenue, New York, NY 10025, USA.
Ruts
Else
E
Kim
Jaehee
J
Janumala
Isaiah
I
Heymsfield
Steven
S
Gallagher
Dympna
D
D015502:Absorptiometry, Photon / Q000379:methods; D000273:Adipose Tissue / Q000033:anatomy & histology / Q000378:metabolism*; D000368:Aged; D000375:Aging / Q000378:metabolism / Q000502:physiology*; D044383:Black People; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism*; D004032:Diet; D005260:Female; D005500:Follow-Up Studies; D005684:Gait; D018737:Hand Strength; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000378:metabolism; D011795:Surveys and Questionnaires; D014781:Viscera; D001741:Black or African American