October 30, 2008 -- Doctors have drawn up plans to screen older men for the male menopause, amid concerns that as many as one in five of the over-65s may be affected.

The existence of a male equivalent to the menopause is still controversial, but most experts agree some men experience a crash in testosterone that can leave them tired, depressed and lacking in libido.

The so-called "andropause" has also been linked to diabetes and obesity, and in some cases can be treated with testosterone injections.

Medical associations, including the European Association of Urology, have issued guidelines recommending that men with type 2 diabetes and symptoms of testosterone deficiency be tested.

"It is going to pick up a lot of men with low testosterone who previously would have been sat at home without their doctor investigating it," said Hugh Jones, professor of andrology at Sheffield University.

Unlike the menopause in women, not all men experience the andropause and scientists say that only those showing clear symptoms should be offered testosterone injections.

Eberhard Nieschlag, who worked on the guidelines at the University of Münster in Germany, told the New Scientist magazine that testosterone injections could be used to kickstart weight loss or alleviate the symptoms of diabetes.

Doctors should be more aware of the effects low testosterone can have, he said.