Androgen abuse in athletes

Shehzad Basaria
CLINICAL REVIEW:Androgen Abuse in Athletes: Detection and Consequences
J Clin Endocrinol Metab 2010 95: 1533-1543

I liked this article for several reasons:

1. Interesting and timely topic. Not only as it relates to professional sports, but also office consultations from non-professional athletes who have gotten involved in performance enhancement, knowingly or unknowingly through "supplements".

2. Nice mini-review of androgen synthesis and degradation and how this relates to detection

3. Interesting biochemistry for the assays. I love the genetic engineering of yeast to contain androgen receptors which can then activate the firefly gene luciferase to glow in the presence of androgen. See figure 4 for that.

Naturally you can check out the article as a pdf at Google docs through goodreader. By the way I downloaded Apple's Pages and am looking into a keyboard for the iPad now. This article comparing keyboards was helpful.

Hypogonadism and Diabetes

I recently had to review a paper on the topic of hypogonadism an diabetes and came across an entire topic that I was not aware of. There has been extensive research done looking at the association between testosterone (free and total), SHBG, and the development of diabetes.

A number of things affect both SHBG as well as testosterone. Age, exercise, obesity just to name a few. However, insulin also affects SHBG levels. Hyperinsulinemia is associated with a reduction in SHBG concentration and SHBG concentration is positively associated with insulin sensitivity. SHBG concentration is also negatively correlated with insulin resistance, insulin levels and glucose concentration. Both insulin and insulin-like growth factor 1 have inhibitory effects on SHBG secretion by Hep G2 cells in vitro. Insulin also suppresses hepatic SHBG synthesis.

Because of this relationship, many papers are studying whether SHBG levels can be predictive of the development of diabetes. Because SHBG binds to its receptor and actually has some actions through g-protein/cAMP pathway, there are studies also looking at whether low levels of SHBG may actually lead to diabetes. If this pans out, perhaps SHBG may be a target in the future for something else we have to raise.

Further Reading:

1. Stellato RK, Feldman HA, Hamdy O, Horton ES, McKinlay JB. Testosterone, sex hormone-binding globulin, and the development of type 2 diabetes in middle-aged men: prospective results from the Massachusetts male aging study. Diabetes Care. 2000;23(4):490-494.

This article shows that there is a Odds ratio of 1.89 of developing diabetes with a 1SD reduction in SHBG concentration.

2. Nair KS, Rizza RA, O'Brien P, et al. DHEA in Elderly Women and DHEA or Testosterone in Elderly Men. N Engl J Med. 2006;355(16):1647-1659.

From the WFMC...this article shows what little effect treating the elderly with DHEA in women or testosterone in men had on inuslin sensitivity.

3. Betancourt-Albrecht M, Cunningham GR. Hypogonadism and diabetes. Int. J. Impot. Res. 2003;15 Suppl 4:S14-20.

A pretty good review article on the topic.