Trial Information

The Effect of Dihydrotestosterone (DHT) on Prostate Tissue Androgen Concentrations and Inflammation in Normal Men

In this study, we will examine the in vivo effects of DHT supplementation on the prostate
and serum inflammatory markers at the molecular level. We hypothesize that increases in
serum DHT will not increase intraprostatic DHT or prostate epithelial proliferation, and
will be associated with decreases in markers of systemic inflammation. Normal, healthy,
male study volunteers will be treated with either placebo gel (Group 1) or DHT gel (Group 2)
for one month. Serum hormonal and inflammatory measurements will be assessed before,
during, and after treatment, and the relationship between hormones and inflammatory markers
associated with cardiovascular risk will be determined. Prostate biopsies will be taken
after one month of treatment. Prostate tissue will be analyzed for changes in
intraprostatic hormone levels as well as gene expression following treatment.

SPECIFIC AIMS:

1. To determine the effect of increases in serum DHT, without concomitant increases in
serum T or estrogen, on intraprostatic androgen levels.

2. To determine the effect of increases in serum DHT, without concomitant increases in
serum T or estrogen, on prostate epithelial gene expression.

3. To determine the effect of increases in serum DHT, without concomitant increases in
serum T or estrogen, on serum lipids and inflammatory markers including C-Reactive
Protein [CRP], Tumor necrosis factor-alpha [TNFα], Interleukin-6 [IL-6], adiponectin,
plasminogen activator inhibitor [PAI-I], and leptin.

We will test the hypothesis in normal men (rather than hypogonadal men) as a "proof of
principle" investigation. A normal hypothalamic-pituitary-testicular axis and regulation,
circulating T and DHT levels and intraprostatic androgen concentrations in healthy, normal
men will permit optimal testing of the hypothesis. Exogenous DHT administration in normal
men is expected to suppress endogenous gonadotropin and testosterone secretion, compared to
more variable effects in hypogonadal men that depend on the degree of hypogonadism in these
men and whether they have primary (testicular) or secondary (hypothalamic-pituitary)
hypogonadism. Furthermore, intraprostatic T and DHT concentrations and 5 alpha-reductase
activity (that is androgen-dependent) is expected to be more variable in hypogonadal men,
depending on the degree of androgen deficiency and circulating T and DHT levels. If results
in normal men support the hypothesis, subsequent studies could be performed in hypogonadal
men. Because of the larger variability in circulating and probably intraprostatic androgen
concentrations in hypogonadal men, these studies will require much larger numbers of
subjects.