title: Effects of aging on Type II muscle fibers: a systematic review of the literature.
abstract: The authors conducted a systematic review of the literature for scientific articles in selected databases to determine the effects of aging on Type II muscle fibers in human skeletal muscles. They found that aging of Type II muscle fibers is primarily associated with a loss of fibers and a decrease in fiber size. Morphological changes with increasing age particularly included Type II fiber grouping. There is conflicting evidence regarding the change of proportion of Type II fibers. Type II muscle fibers seem to play an important role in the aging process of human skeletal muscles. According to this literature review, loss of fibers, decrease in size, and fiber-type grouping represent major quantitative changes. Because the process of aging involves various complex phenomena such as fiber-type coexpression, however, it seems difficult to assign those changes solely to a specific fiber type.
authors.affiliation: Dept. of Physical Medicine and Rheumatology, Orthopedic University Hospital Balgrist, Zurich, Switzerland.
authors.forename: Florian
authors.initials: F
authors.lastname: Brunner
authors.forename: Annina
authors.initials: A
authors.lastname: Schmid
authors.forename: Ali
authors.initials: A
authors.lastname: Sheikhzadeh
authors.forename: Margareta
authors.initials: M
authors.lastname: Nordin
authors.forename: Jangwhon
authors.initials: J
authors.lastname: Yoon
authors.forename: Victor
authors.initials: V
authors.lastname: Frankel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D018656:Muscle Fibers, Fast-Twitch / Q000502:physiology*