NIH Testosterone Trial for Men Over 65

hormones_men_thmb.jpgThoughtful doctors have been prescribing testosterone for older men for decades, and now, finally, the government’s National Institutes of Health (NIH) is conducting a clinical trial to find out if testosterone replacement in men aged 65 and older will help their walking, vitality, sexual function, memory, blood count, and cardiovascular risk.

The Testosterone Trial, or TTrial, will include 800 men in 12 cities across the United States. The men will be given either a testosterone gel or a placebo gel for one year.

The good news about the Testosterone Trial is that the men will be given bioidentical testosterone in the form of AndroGel. The bad news is that they are being given a mega-dose of 75 mg daily, which is virtually guaranteed to cause unwanted side effects. A normal man in his twenties will make 3 to 5 mg of testosterone daily. Thus, the 75 mg dose is 15 times higher than the upper end of a normal dose of testosterone for a healthy young man.

The Benefits of Testosterone
Past clinical trials of testosterone supplementation in men have yielded inconsistent results, due to the use of synthetic testosterones, widely varying doses and delivery systems, and different ways of measuring hormone levels.

There is little argument that as men age their testosterone levels gradually drop, and that men with the lowest testosterone levels tend to suffer from more depression, foggy thinking, low libido, erectile dysfunction, low muscle mass, and an increased risk of heart disease. The famous 1999 Rancho Bernardo study found that older men with clinical depression had 17% lower bioavailable testosterone than those who were not depressed. A 2002 study done at the University of Pittsburgh found that older men with the highest bioavailable testosterone levels had the best cognitive function.

What Doctors May Not Know about Testing Testosterone Levels
Overdosing of hormones, including testosterone, has been created by a misunderstanding of hormone testing. A blood, urine or saliva test will accurately measure hormones made by the testicles, but this is not the same as measuring hormones delivered with a gel or patch.

When hormones are delivered orally (pill), 60 to 90 percent of the dose will be dumped by the liver, and only 10 to 40 percent ends up in the blood and tissues of the body. This is why oral dosing requires a much higher dose of a hormone to achieve normal levels.

When hormones are delivered through the skin, as with a hormone gel, almost 100 percent of the dose winds up in the bloodstream, yet it shows up little to not at all in conventional blood tests. When delivered through the skin, the hormones simply aren’t in the part of the blood that is measured in conventional testing, which is taken from a vein and measured in plasma, the watery part of the blood. Doctors give higher and higher doses of hormones, trying to get “normal” results with a blood test, without understanding that it’s never going to show up there with that delivery system!

On the other hand, a saliva test will show higher levels than are actually in the blood and tissues, so saliva tests need to be calibrated accordingly; only a few testing labs make these types of recalibrations.

Capillary blood spot hormone testing, which requires only a finger stick and can be done at home, is a newer form of hormone testing that accurately measures hormones delivered with a cream.

Should the TTrial doctors choose to test hormone levels with capillary blood spot or (accurate) saliva testing in men who are being given 75 mg of AndroGel daily, they will find them to be grossly overdosed, and will undoubtedly be showing signs of testosterone overdose such as irritability (“testiness”), impulsiveness, violence and excessive libido. Excess testosterone also tends to negate the benefits of testosterone supplementation, which include better mood, increased energy, clearer thinking, increased muscle mass and improved heart disease and diabetes markers.


References/Sources

The Testosterone Trial or TTrial Website
http://rt5.cceb.upenn.edu/portal/page/portal/T-Trial%20Portal/T-TrialPublicPageMain

Clinical Trials.gov
http://www.clinicaltrials.gov/ct2/show/NCT00799617?term=testosterone+aging&rank=40

NIH News
http://www.nih.gov/news/health/nov2009/nia-02.htm

Barrett-Connor E, von Muhlen DG, Kritz-Silverstein D, “Bioavailable Testosterone and Depressed Mood in Older Men: The Rancho Bernardo Study,” The Journal of Clinical Endocrinology & Metabolism 1999: Vol. 84, No. 2 573-577.

Emmelot-Vonk MH, Verhaar HJ, Nakhai Pour HR “Effect of testosterone supplementation on functional mobility, cognition, and other parameters in older men: a randomized controlled trial,” JAMA 2008 Jan 2;299(1):39-52.

Krause W, Mueller U, Mazur A “Testosterone supplementation in the aging male: which questions have been answered? Aging Male 2005 Mar;8(1):31-8.

Yaffe K, Lui LY, Zmuda J, Cauley J “Sex hormones and cognitive function in older men,” J Am Geriatr Soc 2002 Apr;50(4):707-12.