Snoring may run in families, a study by US scientists says.
Children born to parents who snore have a higher risk of snoring
Researchers at Cincinnati Children's Hospital found children whose parents snore have a three-fold increased risk of being noisy sleepers themselves.
But UK experts said the link was likely to be related to families being obese - half of snoring is related to weight.
The study, based on interviews with 681 families and published in the Chest journal, also suggested a link between snoring and allergies.
Researchers found children who tested positive for atopy, an earlier indicator for the development of asthma and allergies, were twice as likely to snore as those who did not.
Parents were questioned about the extent to which both they and their children snored.
Habitual snoring was reported in 15% of the children, and allergy sensitivity in 29%.
Among the parents, 20% of mothers and 46% of fathers were habitual snorers.
An increased risk of snoring occurred in 21.5% of children who were sensitive to allergy triggers compared with 13% of those who were not prone to allergies.
The same trend was seen in 21.8% of children with a parental history of habitual snoring.
Only 7.7% of children without a snoring parent turned out to be frequent snorers.
The researchers said it was likely allergy-related respiratory diseases were causing the snoring.
Lead researcher Dr Maninder Kalra said that by knowing potential risk factors for sleep-disordered breathing in children, clinicians could identify high-risk groups and educate parents and families on how to modify risk factors.
And she added: "We would like to know how the snoring progresses as the child ages. Does it stop, continue or escalate? We will continue to follow these children through age five years to answer these questions."
The researchers also said although snoring was often seen as a joke, it could have serious implications.
Studies of older children and adults have linked snoring to behavioural problems, mental impairment, and heart and metabolic disease.
Professor Jim Horne, director of the Loughborough Sleep Research Centre, suggested that it was possible the link between family snoring behaviour was because of obesity.
"Half of snoring is caused by being overweight, so it is likely that this could explain why this pattern has emerged."