FRIDAY, July 9 (HealthDay News) -- Obese older children are at increased risk for developing the painful digestive disease known as gastroesophageal reflux disease (GERD), researchers from Kaiser Permanente in California report.

In fact, extremely obese children have up to a 40 percent higher risk of GERD, while those who are moderately obese have up to a 30 percent higher risk of developing it, compared with normal weight children, researchers say.

"Although we know that childhood obesity, especially extreme obesity, comes with risks for serious health conditions, such as diabetes, cardiovascular disease and cancer, our study adds yet another condition to the list, which is GERD," said study lead author Corinna Koebnick, a research scientist at Kaiser Permanente Southern California's Department of Research and Evaluation in Pasadena.

While the causes of the chronic digestive disease are not known, obesity appears to be one of them, she noted. "With the increasing epidemic of childhood obesity, GERD may become more and more of an issue," she added.

GERD can undermine quality of life, Koebnick said, noting that the disease can cause chronic heartburn, nausea and the potential for respiratory problems such as persistent cough, inflammation of the larynx and asthma.

GERD has already been linked to obesity in adults, many of whom are familiar with its intermittent heartburn resulting from liquid containing stomach acid that backs up into the esophagus. Untreated, GERD can result in chronic inflammation of the lining of the esophagus and, more rarely, to lasting damage, including ulcers and scarring.

About 10 percent of GERD patients also go on to develop a precancerous condition known as Barrett's esophagus, which in a small minority will develop into cancer. Kaiser researchers noted that GERD that persists through adulthood increases the risk for esophageal cancer later in life.

Cancer of the esophagus is the fastest growing cancer in the United States, and is expected to double in frequency over the next 20 years. This increase may be partly due to the obesity epidemic, Koebnick said.

The report is published in the July 9 online edition of the International Journal of Pediatric Obesity.

For the Kaiser study, Koebnick's team collected data on more than 690,000 children aged 2 to 19 years old. These children were members of the Kaiser Permanente Southern California integrated health plan in 2007 and 2008.

The researchers found 1.5 percent of boys and 1.8 percent of girls suffered from GERD. Among these children, obese children were much more likely to have GERD compared with normal-weight children.

This finding held true for those children 6 to 11 years old and those 12 to 19, but not for children 2 to 5, the researchers noted. The study did not find an association between GERD and BMI in young children.

The association between obesity and GERD remained even after taking race and ethnic background into account, Koebnick's group found.

Across the United States, gastroesophageal reflux disease may affect 2 percent to 10 percent of children, according to other studies, and in one school-based study, 40 percent of teens 14 to 18 reported at least one symptom of esophageal GERD.

"Knowing that GERD is associated with obesity in children, pediatricians can counsel those children to report symptoms of GERD and make lifestyle changes that target not only obesity, but target GERD," Koebnick said.

These changes include eating smaller meals, which will help reduce acid reflux, Koebnick said. "Whether losing weight will help isn't known, "but we can guess that it will," she said.

Dr. Aymin Delgado, assistant professor of pediatric gastroenterology at the University of Miami Miller School, said that "the findings confirm what we in pediatric gastroenterology have been suspecting, because it is what we see."

Obesity affects every organ system, Delgado said. "Obesity poses clear risks for the future health of children," she said. "Many of these risks are ones that occur later in life, and it is hard to show that they are real. However, this study, shows that they are and shows that we need to identify these risks and monitor overweight and obese children and to manage them appropriately."

Delgado said the key is prevention. "We need to take the risk of overweight and obesity seriously and we need to do something about it now," she said. "We need to keep the future health risks in mind when we see obese children."

More information

For more information on childhood obesity, visit the U.S. National Library of Medicine.