Dr. Ron’s Research Review – December 1, 2010

This week’s research review contains excerpts from articles on the testosterone-to-dihydrotestosterone ratio.

Dihydrotestosterone/Testosterone Ratio

A higher testosterone-to-dihydrotestosterone ratio was associated with a 42% decreased risk of benign prostatic hyperplasia when comparing the top 3 quartiles to the first quartile (OR 0.58, 95% CI 0.35-0.97, p = 0.04). (Parsons, Palazzi-Churas et al. 2010)

The dihydrotestosterone/testosterone ratio may be an important factor in the expression of androgenic activity, especially in the prostate. (Starka, Pospisilova et al. 2009)

One study examined dihydrotestosterone and testosterone levels in men screened for prostate cancer. The testosterone/DHT ratio tended to be higher in patients with more advanced tumors. There was an inverse relationship between tumor volume, as defined by PSA level, and 5 alpha-reductase activity, as defined by DHT level, and the testosterone/DHT ratio. This trend was most obvious with T-stage. (Gustafsson, Norming et al. 1996)

Testosterone Replacement Therapy

A recent study found that plasma 5alpha-dihydrotestosterone (DHT) levels declined upon testosterone administration to elderly men with subnormal plasma testosterone and high DHT levels. (Gooren, Saad et al. 2008)

Dr. Ron


References

Gooren, L. J., F. Saad, et al. (2008). "Decline of plasma 5alpha-dihydrotestosterone (DHT) levels upon testosterone administration to elderly men with subnormal plasma testosterone and high DHT levels." Andrologia 40(5): 298-302.

Gustafsson, O., U. Norming, et al. (1996). "Dihydrotestosterone and testosterone levels in men screened for prostate cancer: a study of a randomized population." Br J Urol 77(3): 433-40.

Parsons, J. K., K. Palazzi-Churas, et al. (2010). "Prospective study of serum dihydrotestosterone and subsequent risk of benign prostatic hyperplasia in community dwelling men: the Rancho Bernardo Study." J Urol 184(3): 1040-4.

Starka, L., H. Pospisilova, et al. (2009). "Free testosterone and free dihydrotestosterone throughout the life span of men." J Steroid Biochem Mol Biol 116(1-2): 118-20.