Many
of the body’s systems that function tomaintain optimal health and well-being
decline withadvancing
age. Aerobic capacity, muscle mass, andstrength all progressively decline with
age. This loss ofmuscle
mass, or sarcopenia, and the accompanyingreduction in strength increase the risk
of falls and theircomplications, and
for many individuals the associatedloss
of physical functional capacity leads to increasingdifficulty
in living independently. Complaints of poorsleep
are common in older populations. Insomniareduces quality of life and is often
a factor in decisions toseek
health care. Sleep complaints often lead to over-medication
and sedation of the elderly, with the numer-ous
potential attendant problems, including increasedmorbidity
and mortality. Finally, cognition also declineswith advancing age, particularly
those cognitive functionsthat
involve novel problem solving and psychomotorprocessing
speed, with its own related impact on theolder
individual’s ability to function independently.Interventions
that could at least stabilize or possiblyimprove
functional capacity, sleep quality, and cognitivefunction theoretically have the potential
to prolong anolder
individual’s ability to live independently, and inter-est in their possible utility is growing
rapidly. There isincreasing
evidence that the functioning of many of thesesystems
may be improved through stimulation of the“somatotrophic” or
growth hormone (GH)–insulinlikegrowth
factor–I (IGF-I) axis. Levels of GH and IGF-I riserapidly at puberty, remain high
during early adulthood,and
then decline progressively with aging. It has been sug-gested that with age there is a “somatopause” of
GH-2
2 9Treating
age-related changes insomatotrophic
hormones, sleep, and cognitionMichael
V. Vitiello, PhD; Robert S. Schwartz, MD; Karen
E. Moe, PhD;Giuliana
Mazzoni, PhD; George R. Merriam, MDAuthor
affiliations: Department of Psychiatry and Behavioral Sciences,
University of Washington, Seattle, Wash (Michael V. Vitiello, Karen E. Moe); Department
of Medicine, University of Washington, Seattle, Wash (George R. Merriam); Veterans
Affairs Puget Sound Health Care System, Seattle, Wash (George R. Merriam); Department
of Medicine, University of Colorado, Denver, Co (Robert S. Schwartz); Department
of Psychology, Seton Hall University, South Orange, NJ, USA (Giuliana Mazzoni)
F r e e
p a p e rKeywords:
aging; cognition; growth hormone–releasing hormone (GHRH);
chronic GHRH treatment; sleep; somatotrophic hormoneAddress for correspondence: Michael V. Vitiello,
PhD, Psychiatry and Behavioral Sciences, Box 356560, University of Washington,
Seattle, WA 98195-6560, USA (e-mail: vitiello@u.washington.edu) Many of the body’s systems that
function to maintainoptimal
health and well-being decline with advancingage.
Aerobic capacity, muscle mass, and strength all pro-gressively
decline. Significant sleep disturbances are asso-ciated
with increases in morbidity and mortality. Cogni-tion
declines, impacting an older individual’s ability tofunction independently. Interventions
that could at leaststabilize
or possibly improve functional capacity, sleepquality,
and cognitive function have the theoreticalpotential to prolong an older individual’s
ability to liveindependently,
and interest in their possible utility isgrowing
rapidly. One such intervention may be stimula-tion
of the “somatotrophic” axis via growth
hor-mone–releasing
hormone (GHRH). Here we review theevidence
for such somatotrophic interventions. We alsoreport
preliminary findings on the effects of chronicGHRH
treatment on the somatotrophic hormones, bodycomposition,
functional status, sleep, and cognitive func-tion
of healthy older men and women from two majorGHRH
intervention studies, one recently completed andthe
other ongoing.
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