CHICAGO – The incidence of Clostridium difficile–associated disease was more than three times as high among patients using proton pump inhibitors, compared with those who were not, results from a Japanese study found.

“In addition to previous use of anti-microbials, long-term use of proton pump inhibitors [PPIs] is pointed out as a risk factor” of C. difficile–associated disease (CDAD), researchers led by Dr. Takatoshi Kitazawa reported during a poster session at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy.

“However, most previous epidemiological studies that showed [a] positive relationship between PPI use and CDAD were conducted retrospectively and in Western countries. In this study, we investigated whether the use of PPIs increases the incidence of CDAD at a single institution in Japan.”

Dr. Kitazawa of Teikyo University, Tokyo, and his associates evaluated the medical records of 793 patients who were admitted to the university’s department of medicine between April and June of 2009. They defined PPI users as those who were prescribed a PPI for more than 30 days. CDAD was defined as detection of C. difficile toxin from stool samples in patients with diarrhea. Use of immunosuppressants was defined as using more than 20 mg of prednisolone and other agents in this class for more than 30 days. A long hospital stay was defined as one that extended 30 days.

PPI users were older than non-PPI users (mean, 69 years vs. 63 years, respectively; P < .01) and a higher proportion were men (69% vs. 58%; P = .04).

The researchers identified CDAD in 19 (3.9%) of the 487 PPI users and in 4 (1.3%) of the 304 non-PPI users. This translated into a relative risk of PPI use on the incidence of CDAD that reached 3.20 (P = .04).

On multivariate analysis controlling for age; sex; use of antibiotics and H2 receptor agonists; and long hospital and ICU stays, the researchers noted no significant differences in the incidence of CDAD between PPI users and non-PPI users because of missing data.

Dr. Kitazawa said that he had no relevant financial conflicts to disclose. The meeting was sponsored by the American Society for Microbiology. An abstract of the study is available at m.core-apps.com/TriStar-ICAAC11/abstract/e7a2fcbf71935cab486ae6701614728e.


Doug Brunk is with the San Diego bureau of Elsevier Global Medical News.