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Obesity
The majority of clinical trials investigating the effect of DHEA on
weight or fat loss, as well as on obesity, support its use for this purpose.
Metabolic Syndrome
Metabolic Syndrome is characterized by several conditions that are all
associated with elevated risk for heart disease, including increased insulin
resistance, obesity, and abnormal cholesterol levels. In metabolic syndrome,
these individual risk factors act synergistically, raising the risk of heart
disease higher than their individual risk levels alone. Although research is
still continuing, scientists have linked elevated cholesterol to lower DHEA
levels. Long-term DHEA supplementation improves insulin sensitivity by 30%,
raises high-density lipoprotein cholesterol by 12%, and lowers low-density
lipoprotein cholesterol by 11% and triglycerides by 20%. The lowering of low
density lipoproteins (LDL) by DHEA has an antioxidant effect, which could
have
anti-atherogenic consequences. DHEA also decreases abdominal fat, an
important characteristic of metabolic syndrome.
Clinical Studies
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The P. Diamond group of Quebec, Canada
performed a 12 month study with 15 60-70 year old women, using a 10% DHEA
cream applied to the skin. A 3.8% increase (P< 0.05) in femoral fat and a
3.5% increase (P < 0.05) in femoral muscular areas were observed at 12
months. These changes in body fat and muscular mass were associated with
a 11% decrease (P < 0.05) in fasting plasma glucose and a 17% decrease (P
< 0.05) in fasting insulin levels.
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A randomized, double-blind, placebo-controlled
trial conducted in a US university-based research centre (Washington
University School of Medicine) from June 2001 to February 2004.
Participants: Fifty-six elderly persons (28 women and 28 men aged 71
years; range, 65-78 years) with age-related decrease in DHEA level.
Participants were randomly assigned to receive 50 mg/day of DHEA or
matching placebo for six months. The primary outcome measures were
six-month change in visceral and subcutaneous abdominal fat measured by
magnetic resonance imaging and glucose and insulin responses to an oral
glucose tolerance test (OGTT). Of the 56 men and women enrolled, 52
underwent follow-up evaluations. Compliance with the intervention was 97%
in the DHEA group and 95% in the placebo group. Based on
intention-to-treat analyses, DHEA therapy compared with placebo induced
significant decreases in visceral fat area
(-13 cm2 vs. +3 cm2,
respectively; P=0.001) and subcutaneous fat (-13 cm2 vs. +2 cm2, P=0.003).
The insulin area under the curve (AUC) during the OGTT was significantly
reduced after six months of DHEA therapy compared with placebo (-1119
µU/ml per 2 h vs. +818 µU/ml per 2 h, P=0.007). Despite the lower insulin
levels, the glucose AUC was unchanged, resulting in a significant increase
in an insulin sensitivity index in response to DHEA compared with placebo
(+1.4 vs. -0.7, P=0.005). DHEA replacement could play a role in prevention
and treatment of the metabolic syndrome associated with abdominal obesity.
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