Muscle weakness during aging: a deficiency state involving declining angiogenesis

Area of Science:

• Gerontology
• Vascular Biology
• Muscle Physiology

Background:

• Sarcopenia, or muscle weakness in old age, is a significant health concern.
• Reduced capillary density (CD) has been observed in aged muscles, brains, kidneys, and hearts of humans and animals.
• Angiogenic factors, which regulate CD, also decline with aging.

Purpose of the Study:

• To propose that reduced muscle capillary density is a primary cause of sarcopenia.
• To explore the potential of therapeutic angiogenesis as a treatment for age-related physical and cognitive decline.

Main Methods:

• Review of 9 reports documenting reduced capillary density in aged individuals and animals.
• Review of 7 studies showing declining angiogenic factors in aging muscles.
• Synthesis of evidence on reduced CD in various organs of aged subjects.

Main Results:

• Reduced capillary density (CD) is a widespread phenomenon in aged tissues, including muscles.
• Declining levels of angiogenic factors contribute to reduced CD during aging.
• Waning angiogenesis may significantly contribute to age-related physical and cognitive impairments.

Conclusions:

• Age-related muscle weakness (sarcopenia) is strongly linked to diminished capillary density.
• Therapeutic angiogenesis, using available recombinant factors, offers a potential treatment strategy for age-related deficiencies.
• Aging can be viewed as a deficiency state correctable by targeted therapies like angiogenesis.