LOS ANGELES — Patients with irritable bowel syndrome are eight times more likely than are other patients to develop ischemic colitis, according to a database study presented in poster form at the annual Digestive Disease Week.
Constipation was another notable risk factor, conferring a 2.6-fold increased risk of the potentially life-threatening condition, reported Mark Cziraky, Pharm.D., vice president of HealthCore Inc., a Wilmington, Del.-based research firm.
The study was funded and conducted on behalf of Novartis Pharmaceuticals Corp., manufacturer of several drugs for irritable bowel syndrome (IBS) and constipation.
Dr. Cziraky and his associates identified 100,143 patients with newly diagnosed IBS in the HealthCore Managed Care Database, which contains medical records for 12 million people. They matched these patients by age and gender to 100,143 controls who saw a physician for a reason other than irritable bowel syndrome during the study period from January 2000 to February 2005.
The same database was used to identify 81,399 patients with newly diagnosed constipation and age- and gender-matched controls.
During a median follow-up time of about 18 months, there were 167 cases of ischemic colitis among the IBS patients, compared with 77 cases among the matched controls (90.37 cases per 100,000 patient-years, compared with 41.47 cases per 100,000 patient-years). In a multivariate model, the relative risk of ischemic colitis was 8.16 for the IBS patients, compared with the controls.
Among the constipation patients, there were 199 cases of ischemic colitis, compared with 64 cases in matched controls (80.44 cases per 100,000 patient-years, compared with 43.03 cases per 100,000 patient-years).
In the multivariate model, the relative risk of ischemic colitis was 2.6 for the constipation patients, compared with the control patients.
When the researchers examined 1-year follow-up data, the data supported “an even stronger relationship” between IBS or constipation and ischemic colitis, they reported in the poster presentation.