By Pippa Wysong
TORONTO (Reuters Health) – Asthmatics may have a slightly increased risk of developing irritable bowel syndrome (IBS) compared with the general population. However, those who use oral corticosteroids appear to have slight protection against developing the latter disease, researchers reported here Monday.
The finding comes from a study using data from the General Practice Research Database (GPRD) in the UK. The GPRD is a national computerized database of patient records from general practice. It contains more than 35 million patient-years of data and contains long-term information that can be used by researchers.
In short, the study findings suggest that asthmatics are 1.3 times more likely to develop IBS than non-asthmatics. A link between the two diseases has been suggested in studies in the past.
The results were presented in a poster by researchers from the Centro Espaסol Investigaciףn Farmacoepidemiolףgica in Madrid, Spain, at the 17th annual meeting of the International Conference on Pharmacoepidemiology here. The prinicipal investigator was Dr. Consuela Huerta.
The researchers used information from a random sample of 50,000 database subjects who had a diagnostic code for asthma on January 1, 1994. Patients were included if they were between the ages of 10 and 79 years old. Data for a similar number of age- and sex-matched non-asthmatics were used for comparison. People who had diagnostic codes for IBS, peptic ulcers, cancer, or other confounding conditions were excluded.
Both groups of patients were followed until November 1998. Subjects were excluded if during the study period they became pregnant, turned 80 years of age, developed conditions that met the initial exclusion criteria, or were diagnosed with IBS (the endpoint being sought).
By 1998, a total of 498 asthma patients had new diagnostic codes in the database compatible with IBS, compared with 379 in the general population. Researchers contacted the patients' doctors to confirm the IBS diagnoses. IBS was confirmed for 371 asthmatics and 294 controls.
However, asthmatics who were regularly taking oral corticosteroids at the start of the study were slightly less likely to develop IBS during the study period, compared with other asthmatics. Other asthmatic medications were not associated with any change in IBS risk.
However, the data are not strong enough to show whether or not the steroids offer any protective effect, and did not show a difference between long and short-term use of the drugs, Dr. Huerta and colleagues cautioned.
Further studies in the general population are necessary to confirm whether the use of corticosteroids, regardless asthma status, has a protective effect against IBS, researchers said.