There are 3 general approaches to hormone therapy. Hormones
can be given to replace a deficiency, hormones can be
given to raise the concentration above the normal value, and
agents can be given to block hormone action by either reducing
the rate of secretion or blocking their action. All approaches may
have a role in maintaining or increasing muscle mass. Replacement
of testosterone in hypogonadal elderly men has successfully
increased both muscle mass and strength (28). Administration
of insulin at rates sufficient to raise plasma concentrations
above the naturally occurring value has been shown to have an
anabolic effect on muscle in severely burned patients (52). In the
stressed state, the catabolic hormones cortisol and epinephrine
are counterregulatory hormones, the effects of which can be
minimized by either blocking receptors, in the case of epinephrine
(53), or blocking secretion, in the case of cortisol (54). Thus,
there clearly is a role for hormone therapy in maintaining and
increasing muscle mass and function. New advances in synthetic
hormones provide promise for expanded applications in the future.
For example, the synthetic steroid oxandralone stimulates
muscle growth, possibly without the same magnitude of androgenizing
effects of testosterone (55). At the same time, there are
limits and dangers of hormonal therapy caused by unexpected,
unwanted, and often unrecognized complications. For example,
it is well known that large doses of testosterone increase muscle
mass and function, particularly when given in conjunction with
exercise training. However, many undesirable side effects may
accompany the use of testosterone or any of its many synthetic
analogues, thereby limiting its clinical use on a widespread or
unsupervised basis.