The trouble with men

The trouble with men

Tim Perkins isn't nearly so grumpy these days. His wife readily testifies to this. Since partaking in a diabetes prevention research trial earlier this year and losing 8½ kilograms, the 67-year-old feels much more energetic and motivated.

What he doesn't know is how much of his improved vigour is due to his weight loss and healthier lifestyle, or how much is due to improved testosterone levels.

Are unhealthy habits robbing men of testosterone?

Are unhealthy habits robbing men of testosterone?Credit:Getty

''I had no idea testosterone levels could affect your weight or risk of diabetes,'' says Perkins, of Adelaide. ''I thought it was only related to sexual function.''

Body builders have long exploited the ''king'' of steroids for its muscle-building effects. Only relatively recently have researchers started joining the dots and discovering clear associations between blood testosterone and chronic diseases such as diabetes, obesity and metabolic syndrome.


A 2008 study of 580 Australian men with type 2 diabetes, for example, found 43 per cent had low testosterone levels. Similarly, excess body fat around the waist is associated with low testosterone.

Such associations are more than coincidental, it seems, with evidence of a two-way relationship.

''Testosterone increases muscle mass and reduces body fat by 'instructing' stem cells [undifferentiated cells that haven't yet decided their fate] to become muscle cells,'' says endocrinologist Dr Mathis Grossmann, of Austin Health in Melbourne.

Low testosterone levels therefore predispose a man to gaining excess body fat. Conversely, carrying excess body fat lowers testosterone levels.

Low testosterone levels also appear to indirectly reduce the effectiveness of insulin - a hormone that regulates blood glucose levels - via these body composition changes, thus predisposing to diabetes as well.

What comes first - low testosterone or poor health? This is an increasingly common question practitioners grapple with when deciding treatment options.

''If you ask endocrinologists, some believe prescribing testosterone is not the right thing to do; you should lose weight first. Others say testosterone is the right thing to do. This debate will go on until we sort it out,'' says Professor Gary Wittert, the head of medicine at the University of Adelaide and chair of a national, double-blind randomised controlled trial designed to find answers.

''The trial examines whether men treated with testosterone combined with a healthy lifestyle program do better than with lifestyle treatment alone,'' Wittert says. ''As well as its effects on body composition and prevention of diabetes, we are interested to see if testosterone increases men's motivation to change their lifestyle.''

Testosterone or androgen deficiency is the most common hormonal deficiency in males, affecting one in 200 men under 60 years of age, and about one in 10 men aged over 60, according to Andrology Australia. It's usually caused by genetic disorders, such as Klinefelter syndrome, damage to the testes or a lack of hormone produced by the brain.

The decline that typically occurs with age, of about 10 per cent a decade after age 30, may well be due to chronic disease rather than age per se. A study involving 325 Australian men 40 and older found men who keep very good health can maintain normal blood testosterone levels into old age.

Our prevailing unhealthy lifestyles may be robbing not only individual men but generations of younger men of their vigour. Trends over the past 10 to 20 years show an intergenerational drop in testosterone levels. ''We don't know all the causes but at least some component relates to increased obesity levels,'' Grossmann says.

As well as playing a key role in the development of male reproductive and sexual functions, testosterone affects mood, aspects of mental ability and bone and muscle growth. In adult men, signs of deficiency include mood changes, poor concentration, low energy, reduced muscle strength, osteoporosis and low interest in sex.

Deficiency is typically underdiagnosed, says Dr Carolyn Allan, the medical advisor for Andrology Australia.

''Irrespective of age, if you have clinically proven low levels of testosterone, we treat you,'' Allan says, ''except if you want to start a family. Giving men testosterone is like giving women the pill. It reduces sperm production and can take months to resume function after treatment. And if you are overweight with an unhealthy lifestyle, I'll say … 'In terms of lifestyle changes, there are no downsides. Let's do that first, and see what happens.'''

So how hard must you work to boost testosterone through healthy living alone? ''A weight loss of up to 10 per cent of body weight achieved by lifestyle changes, increases testosterone by three to four nanomoles per litre [nmol/L],'' Grossmann says. ''This means if you have moderately low testosterone levels, you can normalise them through lifestyle alone.'' The normal range for men varies but generally greater than 12 nmol/L is considered normal, less than eight is low and between eight and 12 is a grey area, Grossmann says.

''The fatter you are, the younger you are and the more weight you lose, the better hormonal recovery,'' Grossman says, ''but older men can benefit, too.''

The testosterone for diabetes mellitus trial

Now recruiting overweight men, aged 50-74, showing signs of abnormal blood glucose metabolism with testosterone levels of 13 nanomoles (nmol) a litre or less - a level below which there's a marked increase in the incidence of type 2 diabetes. What's involved? Joining a Weight Watchers program or Weight Watchers plus three-monthly testosterone injections. To join, visit

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