A world expert in sleep disorders will warn obese people of the potential dangers of getting behind the wheel because of a condition that disrupts breathing during the night.

Obstructive sleep apnoea (OSA) occurs when soft tissue in the back of the airway collapses and blocks it, causing interruption in breathing lasting 10 seconds or more.

Being overweight is a major risk factor of the condition.

British medic, Dr Bertrand De Silva, will suggest to delegates at an obesity conference in London the problem can double the risk of road accidents.

Dr De Silva, who is medical director of American Sleep Medicine in California, will say: "Far from being regarded as a minor condition with irritating snoring, research has now identified Obstructive Sleep Apnoea as a fatal disease.

"This means that the condition and its consequences are now recognised as yet another co-morbidity of obesity along with type two diabetes, heart disease and some cancers.

"We predict that only 15% of suffering patients have been diagnosed, so despite the dangers, the majority are oblivious that they even suffer from the condition.

"It is known that OSA, which causes daytime sleepiness, doubles the risk of road accidents."

Dr De Silva, who will give his speech to the National Obesity Forum's seventh annual conference tomorrow, will inform the audience that the condition has been the subject of numerous new US research studies.

"Healthcare professionals and patients need to be mindful that OSA deserves its new-found place in the limelight as we also know that it increases the risk of heart conditions by 30%, dramatically increases hypertension, affects 58% of diabetic patients (90% if obese), impacts glucose intolerance and insulin resistance and is the second leading cause of erectile dysfunction," he will say.