More than half of Chinese middle-aged men show symptoms of depression, irascibility, aching joints, excessive sweating as well as a fading interest in sex because of a lack of testosterone, a recent health survey suggested.

The online survey released on Thursday found that 52 percent of men between 30 and 40 years old have a waning interest in sex and 60 percent of them say their physical strength and resistance is on the decline.

The survey was conducted by the Beijing University center for men's health and Nanjing Organ on Pharmaceutical Co. Ltd, a subsidiary of Fortune 500 company Akzo Nobel.

More than 2,000 netizens took part in the survey.

Testosterone decreases in men's bodies after the age of 30, triggering the symptoms above and impacting men's quality of life, said Guo Yinglu, director of the center and an academic from the Chinese Academy of Engineering.

Chronic diseases, bad living habits and environmental factors also contribute to low testosterone levels, said Guo.

Guo called for awareness of the problem and early diagnosis, prevention and treatment.

Only 40 percent of the people surveyed knew about declining testosterone levels and few people bothered to go to hospital for treatment in a survey conducted in east China's Shanghai municipality, Jiangsu and Anhui provinces in 2002.

Besides fostering good living habits, men should receive testosterone supplements if they have undesirable symptoms, said Guo.

Editor: Donald