Obese teens getting gallstones

Among boys the link was weaker: the extremely obese had triple the chance of developing them and the obese were at almost double the risk.

Children who were overweight, but not obese, also had a higher incidence of gallstones. Among boys, being overweight increased the risk by almost 50 per cent, while it almost tripled the risk in girls.

Four out of five gallstones are caused by unusually high levels of cholesterol in the gallbladder, according to the NHS Choices website. This excess cholesterol “gradually solidifies to form a stone”. A minority are caused by high levels of bilirubin - broken down red blood cells. They can be as big as golf balls, although most are much smaller.

Symptoms can include recurrent abdominal pain and nausea. They can block the passage of bile into the intestine, which can cause severe damage or infection in the gallbladder, liver, or pancreas. If left untreated, the condition can be fatal.

It is well known that being an obese adult markedly increases the risk of gallstones, but Corinna Koebnick, lead author of the study, said the fact they were appearing in children was of concern.

She said: “Although gallstones are relatively common in obese adults, gallstones in children and adolescents have been historically rare.

“These findings add to an alarming trend - youth who are obese or extremely obese are more likely to have diseases we normally think of as adult conditions."

She went on: "We are also seeing more and more frequently among adolescents is diabetes, hypertension and high cholesterol."

And she warned: "Hypertension [high blood pressure] is not just something that causes problems in the future; we are seeing children with hypertension who already have organ damage - such as heart conditions usually seen in 40-year-olds."

George Longstreth, senior study author, from Kaiser Permanente’s San Diego Medical Centre, added: “The high rate of gallstones in obese children and adolescents may surprise paediatricians because gallstone disease is generally regarded as an adult disorder.

“Since obesity is so common, paediatricians must learn to recognize the characteristic symptoms of gallstones.

"With childhood obesity on the rise, pediatricians can expect to diagnose and treat an increasing number of children affected by gallstone disease. It is important to identify other factors that increase risk as well."

They found being on the contraceptive pill, known to be a risk factor for gallstones, doubled the chance of developing them, irrespective of weight.

Nick Markham, a consultant surgeon at North Devon and District Hospital, who has a specialist interest in gallstones, said: "From my own point of view and from talking to colleagues I would say that there are now more youngsters presenting with gallstones in Britain, and my gut feeling is that it's due to an increase in childhood obesity.

"However, I don't have any hard evidence to back that up."

Fatter people probably got gallstones more because they had a greater intake of cholesterol, he said, although he noted thin people got them too.

"While we know a lot about the things that predispose people to greater incidence of gallstones, we don't really know why they develop in one individual and not another," he said.