For 500,000 people in the city, the cause is not heart trouble but a bad diet, a study claims Some 500,000 people in Hong Kong suffer chest pain because of eating habits rather than heart disease, it was revealed yesterday. A study by gastroenterologists at the University of Hong Kong estimated that 1.36 million people in the city had suffered chest pain in the past year. But 70 per cent of these did not have heart disease. Most non-cardiac chest pain is instead caused by gastro-oesophageal reflux disease, or Gerd, where contents of the stomach go back up into the oesophagus resulting in heartburn and acid regurgitation, said Benjamin Wong Chun-yu, associate professor at the department of medicine. He estimated half a million people in the city suffered from Gerd. The disease is more prevalent in men than in women. In more than half the instances, the cases are mild, with most episodes occurring once a month. Risk factors include obesity, lack of exercise, smoking, stress and poor eating patterns. 'Habits including overeating, eating irritating food, alcohol and having midnight snacks [are bad] because if you sleep or lie down shortly after eating the stomach and the oesophagus will be on a horizontal line that will promote reflux,' Professor Wong said. He said such pains were often misinterpreted as heart disease 'So people should avoid having snacks and should extend the time between dinner and going to bed. Patients often delay the access to appropriate treatment.' The study was based on a telephone interview of 2,209 people. In a second study, published in yesterday's issue of the international journal Archives of Internal Medicine, the same team analysed reports published worldwide and found that a common family of drugs called proton pump inhibitors, or PPIs, could treat reflux disease. They work by reducing the production of acid. PPI, which is included in the standard drugs formulary of the Hospital Authority, was not commonly available in doctors' clinics however, Professor Wong said. The study also found that a PPI test was a better diagnostic tool than having patients undergo 24-hour monitoring of the acid content of their oesophagus or filling out a questionnaire. One man, a retired construction worker, said he had been suffering chest pain for six years. In 2001, he went to see a cardiologist who administered a battery of tests and examinations, including an electrocardiogram and an exercise stress test. After a cardiac test, the doctor excluded the possibility of heart disease. It was only after an endoscopy and a 24-hour monitor for acidity that the doctor confirmed the pain was caused by reflux disease. The patient received a short course of PPI treatment and then recovered.