Understanding testosterone

Testosterone, in correct quantities, is just great. This hormone is the primary driver for masculinity, virility and athletic performance. So, it’s no surprise that testosterone and its derivatives are banned by elite sports governing bodies.

The normal range for men is between 8.4-28.7nmol per litre of blood. This is a measurement of total testosterone, and from its peak will decline by between 0.4-0.8% per year. A decline then, appears to be normal.

It may seem paradoxical, but testosterone levels are dictated by the hormone oestradiol (or oestrogen, aka the female hormone). Women produce testosterone, too, albeit in much lesser amounts.

Testosterone is converted to oestradiol by an enzyme called aromatase.  As body fat deposits increase, so too does aromatase. More fat equals more of the female hormone oestradiol –  which promotes female fat distribution patterns – and less testosterone.  Man boobs and love handles, anyone?

This state of low testosterone levels is a progressive cycle of increased abdominal fat with an attendant increase of aromatase activity – thus more oestradiol conversion – resulting in further decreased testosterone production. Wash and repeat. Ageing, poor health and disease are also contributing factors to low testosterone. It’s called hypogonadism.

Not a pretty word, is it? Although, it’s not to be confused with small genitals. Other more accurate descriptions are low testosterone or androgen deficiency, which may negatively affect multiple organ function and quality of life. Concerned that your testosterone may be low?

Signs and symptoms of low testosterone

These include inadequate erections, loss of sex drive and sexual performance. And that’s not all. There’s increased body fat, gynaecomastia (bitch tits), and a decline in muscle mass and strength, and mood changes. If that’s not grim enough, poor concentration, energy, bone density and reduced testicular mass round things off nicely. Sorry.

You can check out your clinical symptoms on the ADAM (androgen deficiency in the ageing male) questionnaire – the Vitruvian Man website has a free downloadable version

Essentially, there are two types of hypogonadism:
Primary – where the testes are the primary cause of failure to produce testosterone.
Secondary – where signaling hormones from the brain are low, due to a defect, resulting in significantly reduced testosterone output by the testes.

Testing testing

Determining the cause of hypogonadism requires around eight tests to establish a full androgen (hormone) profile. Looking at luteinising hormone (LH) and follicle stimulating hormone (FSH) levels, for example, is very informative*, as they instruct the testes to do their job. If they’re low, the cause of testosterone deficiency is secondary – the root cause being in the brain. The traffic lights are out, there’s no green light stimulating the flow, and nothing’s moving. If they’re high, the problem is primary and therefore testicular in origin. The lights are glowing bright and stuck on green, but your bollock-mobile has stalled. Two different causes same end result – low testosterone.

It is always important to include sex hormone binding globulin SHBG* in any androgen profiling, as some men can have a total testosterone level within a normal range, but a raised SHBG. This effectively lowers the amount of bioavailable testosterone, also resulting in hypogonadal symptoms.

How annoyed would you be if you were struggling to make ends meet, yet your bank account looked quite healthy? All that much-needed cash was tied up in some saving scheme but was inaccessible. The bank was happy, but you had to struggle on. Quite aggrieved, I expect. I would be. Tsk, banks…

Having an elevated level of SHBG can be very similar to dodgy bankers. It takes your hard earned testosterone, locks it away and only pays out far less than the usual 2% interest rate. This interest is all you have available to spend at any time.

So despite a normal total testosterone value, your available testosterone is significantly reduced. This can cause the same symptoms of hypogonadism (low testosterone), such as lack of libido, depression and fatigue. What’s worse, a cursory look at only the total testosterone levels will overlook the hypogonadism completely! It does look normal, after all. This can prevent a correct diagnosis and render the patient ineligible for testosterone replacement therapy. It is always important to have the correct tests performed to see the correct picture.

Vitruvian Man provide a private and confidential blood testing service.
Contact: Aaron Carnahan at Vitruvian Man; vitruvianman.org.uk.

*These hypogonadism diagnostic tests are inappropriate for those currently using (or have recently used) any anabolic steroids.