Mention osteoporosis and most people automatically assume it is something from which women suffer.

But although one in three women are generally affected by the condition, there are still two million men in Britain with the disease.

Osteoporosis can lead to vertebral deformities, frequent fractures, considerable pain and, in extreme cases, death.

Some men in their 30s start developing osteoporosis and, for most of them, there are usually reasons why they have exposed themselves to the risk.

These include using steroids, alcohol and smoking.

However, for one third of patients, there is no obvious cause and this is known as Male Idiopathic Osteoporosis.

Identifying the best course of treatment for these relatively young sufferers and assessing those at risk is difficult.

Horsham-based medical charity Action Research has found that some men who develop osteoporosis in their 30s or 40s have a defect in a receptor in their bones.

This receptor recognises the hormone oestrogen in the body and regulates what the bones' cells do in response to the hormone.

Bones are continuously being broken down and then rebuilt by the body to facilitate growth and repair.

These processes were thought to be controlled by the sex hormones oestrogen in women and testosterone in men.

Men, however, also synthesise low levels of oestrogen which, according to recent research, may be equally important for their bones.

A research team is now investigating whether osteoporosis in men is affected by the way their body reacts to the oestrogen.

Action Research chief executive Simon Moore said: "Osteoporosis affects so many people in this country and can be devastating so it's very exciting to find such a promising area of inquiry.

"This suggests that modifications of oestrogen-related drugs could be an effective way of managing the condition in men."

Brian Murray is 65 and has had a bad back for 20 years. He was diagnosed with osteoporosis ten years ago.

He said: "I couldn't believe it when they told me it was osteoporosis. I thought: 'What am I doing with that? it's a women's thing.'

"I was diagnosed after they took a sample of my thigh bone which confirmed it was osteoporosis. I remember there were more men in the ward than women.

"I am lucky in that I haven't had any fractures, which lots of people have, although I have lost two inches in height.

"There is a dull pain in my lower back all of the time but I try not to let it stop me doing anything."

For more details about osteoporosis, call the National Osteoporosis Society helpline on 0800 0566810.