A couple cuddle on a park bench in Beijing, oblivious of a worker pulling a cart past them. A survey shows more than 50 percent of Chinese men over 40 suffer from varying degrees of impotence.

More than 50 percent of Chinese men over 40 suffer from varying degrees of impotence and most delay seeking treatment because they are too embarrassed, according to a nationwide survey.

The six-month study of 1,000 people in major Chinese cities suggested 52.5 percent of men over 40 suffer from erectile dysfunction to some extent and 90 percent of those afflicted said their sex lives were badly affected.

The investigation is the country's first authoritative and systematic survey of men's sexual health, Xinhua news agency said.

Conducted by Jiang Hui, deputy director of the reproductive centre at the Beijing People's Hospital, it showed embarrassment and shyness deterred most sufferers from seeking medical help.

Patients on a national average only saw a doctor 22 months after the first symptoms occurred, compared to the average six months in the West, the report said.

Those in big cities delay treatment even longer. Beijing men wait 34.3 months while Shanghai men wait 30.4 months before seeking professional help.

"The unnecessary delay misses the best time for treatment and allows the disease to deteriorate," Jiang was quoted as saying.

Wang Yixin, professor with the Shanghai Andrology Research Centre, said 90 percent of affected patients do not seek help because of shyness, feelings of humiliation and worries over confidentiality.

He said 80 percent of impotence cases in China stemmed from physical problems while the rest related to psychological issues, such as tension, anxiety and depression.

"The idea that erectile dysfunction is incurable is totally wrong," Wang said. "Most patients can enjoy normal sex lives after appropriate treatments."

He said expensive treatment drugs was another "major barrier" to Chinese patients.

Viagra, a product of US manufacturer Pfizer Inc, costs nearly 100 yuan (12 dollars) for each tablet.

Earlier this month, Chinese media reports said 17 pharmaceutical companies would jointly produce a local variant of Viagra that would cost half the price of the US product.

(Agencies September 1, 2004)