A simple urine test based on colour can help detect dangerous types of snoring in children, according to a recent US study.

Previous studies have established that children who snore are at risk for dangerous snoring, known as obstructive sleep apnoea (OSA).

But the recent finding brings hope to parents who would otherwise have to worry about their children's health.

Children at risk for OSA process increased levels of three proteins: urocortin 3, orosomucoid, and uromodulin.

The children also exhibited lowered levels of a fourth protein.

Because the proteins are more concentrated in the children's urine, they provide an excellent way of measuring children's risk of OSA.

For the purposes of the study, the research team observed 90 children who had already entered a sleep clinic for possible risk of OSA.

About 3% of all children may have problems with dangerous snoring.

Using fluorescent dyes, the researchers tested samples of the children's morning urine.

They also tested the urine of 30 children who did not seem to have any risk of OSA.

Lead researcher David Gozal said that he had not expected that the urine tests would allow his team to detect OSA risk factors.

He said that he thinks researchers would soon be able to screen for OSA without needing to keep them in a sleeping clinic.

Ian Balfour, a respiratory consultant at Royal Brompton Hospital, said that OSA was a big problem in children with large tonsils or who were obese. 

Paul Gringras, a consultant for Evelina Children's Hospital, said that there were very few specialist centres that could accurately identify true cases of OSA.

He said he believed that the researchers should further simplify their biochemical tests.