The same research team first reported in 2004 the presence of low testosterone levels - known as hypogonadism - in obese, type 2 diabetic adult males and confirmed it in 2010 in more than 2,000 obese men, both diabetic and non-diabetic.
The study's first author Dr Paresh Dandona, Distinguished Professor in the Department of Medicine, said: ‘We were surprised to observe a 50 per cent reduction in testosterone in this paediatric study because these obese males were young and were not diabetic.
‘The implications of our findings are, frankly, horrendous because these boys are potentially impotent and infertile. The message is a grim one with massive epidemiological implications.'
In 2009, 20 per cent of 11 to 15-year-olds boys in the UK were recorded as obese.
The study included 25 obese and 25 lean youths and was controlled for age and level of sexual maturity. Concentrations of total and free testosterone and estradiol, an oestrogen hormone, were measured in morning fasting blood samples.
Dr Dandona said the results need to be confirmed with a larger number of subjects.
