Hormone May Reduce
Effects of Aging
Stimulating the production of growth hormone (GH) in
healthy older men and women can reduce body fat and restore hormone levels to amounts
found in younger adults, according to a study.
The research, which is being conducted at the
University of Washington and the Veterans Affairs Puget Sound Health Care System in
Seattle, shows that the use of GH-releasing hormone (GHRH), a GH stimulator, may increase
production of GH in healthy men and women over age 65.
Secretion of GH, which is responsible for growth in
childhood, also plays an important role in adults. According to the researchers, GH
regulates body fat, increases muscle mass and capacity for aerobic exercise and may be
responsible for normal mood and cognition.
Hormones such as GH maintain muscle strength and
energy. According to researchers, these hormones could help older adults remain
independent longer because the loss of strength associated with aging makes it difficult
for the elderly to complete tasks that were once a part of their daily independent living.
Stimulating GH production also could help lessen the
aging effects the University of Washington researchers attribute to a natural decrease in
GH secretion: reduced strength and energy; increased body fat, especially around the
abdomen; and psychological changes, possibly including changes in sleep.
For the preliminary section of this study, 60 healthy
older adults gave themselves nightly injections of GHRH or a placebo for five months.
Compared with the levels of those in the placebo group, GHRH boosted the nighttime
secretion of GH by about 35 percent. In both men and women, body fat was reduced by about
Effects on sleep and physical capacity are still being
evaluated in the study.
Preliminary results from this study were presented
June 12 in San Diego at the annual meeting of the Endocrine Society.