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TUESDAY, July 1, 2003 (HealthDayNews) -- People who are overweight or obese may be up to six times more likely to have gastroesophageal reflux disease (GERD) than people who are of normal body weight.
The association was strongest among heavy, premenopausal women and women who have used hormone therapy, suggesting that estrogen may play a role in the development of the stomach disorder.
The Scandinavian study outlining these findings appears in the July 2 issue of the Journal of the American Medical Association and was partially funded by AstraZeneca, the company which makes Prilosec, a drug for GERD.
Although the study does not prove a cause-and-effect relationship, the findings do appear to be significant.
"I was surprised by the strength of the associations," says Dr. Magnus Nilsson, lead author of the paper and a consultant in the upper gastrointestinal surgery team at the Karolinska Institute in Stockholm, Sweden. "I definitely think that we have established a new and significant etiologic pathway in GERD. This is by far the largest study so far on reflux etiology."
"It's extremely well-designed and based on a very large population," adds Dr. Ali Serdar Karakurum, chief of the division of gastroenterology at Nassau University Medical Center in East Meadow, N.Y. "We knew that the obesity and body mass index (BMI) and reflux association was there, but this actually showed that it was more striking than we ever knew."
"The study reopens a very controversial issue, which has been a debate about the relation between obesity and reflux disease," says Dr. David A. Johnson, chief of gastroenterology at Eastern Virginia School of Medicine in Norfolk and secretary of the American College of Gastroenterology. "It also reopens the issue about weight reduction as a potential facilitator of improvement of reflux symptoms, and it opens the question of use of hormonal therapy as potentially aggravating patients with reflux disease."
People who lost weight seemed to have a reduction in their symptoms.
People in the Western hemisphere are getting heavier and more are developing the uncomfortable symptoms of GERD. Both obesity and GERD raise the risk of developing esophageal adenocarcinoma, the incidence of which has also been on the rise in the last few years.
GERD occurs when the valve between the stomach and the esophagus doesn't close properly and lets the contents of the stomach (including stomach acid) spill up into the esophagus. The symptoms are continuing heartburn and acid regurgitation but can also include chest pain, difficulty swallowing and hoarseness in the morning. No one is sure what causes the disorder, although certain conditions may predispose a person.
This study compared 3,113 individuals who had symptoms of severe GERD with 39,872 people who did not have any symptoms of the disorder. All of the people had participated in a large public health survey in Norway between 1995 and 1997 and had completed a detailed, written questionnaire on symptoms of GERD, diseases, lifestyle factors, behavioral habits, work and employment information, medication use and more. Each participant also had a physical exam, including having their body weight, height and BMI measured.
The researchers used World Health Organization values for BMI, with 25 to 30 being overweight, more than 30 classified as obese and more than 35 considered severely obese. Less than 25 was considered normal.
In this group of people, the higher the BMI, the worse the reflux symptoms for both men and women, although the association was stronger in women. Severely obese men were 3.3 times as likely to have reflux symptoms compared with men of normal weight. Severely obese women were 6.3 times as likely to have these symptoms than women of normal weight.
Severely obese premenopausal women had the highest risk, being 6.8 times more likely to have GERD than normal women, while severely obese postmenopausal women were 4.2 times more likely to have reflux symptoms.
Most startling were the results showing that, "in severely obese women who had ever had hormone therapy, the risk of reflux is 16 times increased compared to normal-weight, never-treated women," Nilsson says. "Moreover, severely obese women who had estrogen-only therapy had 33 times increased risk of reflux compared to normal-weight never-treated women, pointing to estrogens as opposed to gestagens as the important hormonal factor."
Estrogen may predispose heavy women to reflux disease because it stimulates the production of nitrous oxide, which relaxes smooth muscles, something you definitely don't want in GERD, Karakurum says.
Even though the study does not close the book on whether obesity causes GERD, the results are striking.
"It does not definitively resolve the question, as there are still some potential bias issues due to the way the data was accumulated, issues of diet or physical changes due to patients trying to lose weight, as well as perhaps more frequent physician or health-care provider interactions," Johnson says. Nevertheless, he adds, "it's a very important study because it reopens the question."
More information
For more on GERD, visit the National Institute of Diabetes and Digestive and Kidney Disorders or the American College of Gastroenterology.
