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TESTOSTERONE AND THE METABOLIC SYNDROME
Saad,F.
Schering AG, Male Health Care, 13342 Berlin, Germany
The Metabolic Syndrome is a complex disorder involving numerous disturbances
in body composition and metabolic parameters but also
hormonal dysbalances. Abdominal obesity, dyslipidemia,
insulin resistance and other factors contribute to
a symptomatology which progressively leads into the
manifestation of cardiovascular diseases and type
2 diabetes. Cross-sectional and longitudinal epidemiological
studies, animal experiments, studies in patients with
prostate cancer undergoing androgen deprivation treatment,
studies in obese men, and in men with diabetes are
reviewed. An overview of intervention trials using
testosterone is given. Epidemiological studies have
shown associations between plasma levels of total
testosterone and risk factors for the Metabolic Syndrome.
Low testosterone levels are more common in patients
with the Metabolic Syndrome, cardiovascular dieseases,
or diabetes type 2 than in the normal population.
Particularly in angina and diabetes patients, up to
50 % of men are hypogonadal. Observations in prostate
cancer patients receiving GnRH analogues as androgen
deprivation therapy show an increased risk not only
of osteoporosis but also of insulin resistance. Studies
in obese men reveal that obese men in good or impaired
health have lower testosterone levels than normal-weight
controls. Their risk of developing the Metabolic Syndrome
and consequently diabetes and cardiovascular diseases
is significantly higher than in non-obese men. Studies
in diabetic men demonstrate that many of the risk
factors for diabetes correlate with levels of total
and free testosterone. Several intervention studies
in patients with visceral obesity, cardiovascular
diseases, and diabetes type 2 suggest that the normalisation
of testosterone levels in patients reduces fat mass,
increases lean body mass and shows an overall improvement
of the well-defined risk factors for the Metabolic
Syndrome and its consecutive diseases. Hormones play
a central role in the Metabolic Syndrome. The hypothesis
developed by Björntorp's group in Gothenburg, Sweden,
indicates a balance between fat accumulating and mobilizing
hormones. Recent data suggest that a restoration of
this balance by administering testosterone may be
beneficial for patients suffering from or being at
risk of developing the Metabolic Syndrome. Further
long-term studies are urgently needed to confirm these
results as well as to provide information whether
androgen treatment may delay the progression of the
Metabolic Syndrome to cardiovascular diseases and
diabetes type 2.
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