title: Muscle tissue changes with aging.
abstract: OBJECTIVE
  This review article focuses on the changes that occur in muscle with age, specifically the involuntary loss of muscle mass, strength and function, termed sarcopenia. Particular emphasis is given to the metabolic alterations that characterize sarcopenia, and to the potentially treatable causes of this condition, including age-related endocrine and nutritional changes, and inactivity.
  
  
  RESULTS
  Recent data reported include those regarding the potential role of insulin resistance in the development of sarcopenia, the potential role of androgens and growth hormone in the treatment of this condition, the usefulness of exercise including both resistance and aerobic training to improve muscle growth and function, and, finally, the possible use of nutritional manipulations to improve muscle mass.
  
  
  CONCLUSIONS
  Sarcopenia is likely a multifactorial condition that impairs physical function and predisposes to disability. It may be prevented or treated with lifestyle interventions and pharmacological treatment. Further long-term investigations are needed, however, to ascertain what type and combinations of interventions are the most efficacious in improving muscle mass and function in older people.
authors.affiliation: Division of Endocrinology and Diabetes, Department of Medicine, University of Southern California, Los Angeles, California, USA. volpi@usc.edu
authors.forename: Elena
authors.initials: E
authors.lastname: Volpi
authors.forename: Reza
authors.initials: R
authors.lastname: Nazemi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujita
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology / Q000502:physiology*; D005081:Exercise Therapy; D013006:Growth Hormone / Q000627:therapeutic use; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D009133:Muscular Atrophy / Q000209:etiology / Q000473:pathology* / Q000517:prevention & control; D009752:Nutritional Status
chemical_list: D013006:Growth Hormone