A multicenter prospective study on the prevalence of Helicobacter pylori-negative and nonsteroidal anti-inflammatory drugs-negative idiopathic peptic ulcers in Japan

The prevalence of Helicobacter pylori-negative and nonsteroidal anti-inflammatory drug-negative peptic ulcers, commonly known as idiopathic peptic ulcers (IPUs), has been reported to be very low (0.9-2.6%) in Japan based on data from the 1990s. However, recent trends have yet to be been reported. Herein, we present a multicenter prospective analysis between 2012 and 2013 investigating current trends in the prevalence and characteristics of IPUs in Japan. Methods: Clinical data of all peptic ulcer subjects detected via endoscopy at four participating hospitals were prospectively collected between April 2012 and March 2013. Enrolled subjects were classified according to H.pylori infection status and intake of nonsteroidal anti-inflammatory drugs. Multiple logistic regression analyses were used to determine the risk factors for IPUs. Results: Of 382 enrolled patients with peptic ulcers, 46 (12%) were judged to have IPUs. Compared with those with simple H.pylori-positive ulcers, patients with IPUs were significantly older (P<0.02) and more often had underlying comorbidities such as hypertension (P<0.02) and hyperlipidemia (P<0.05). Multivariate regression analysis indicated that the presence of multiple underlying diseases was the only significant risk factor for IPUs, with an odds ratio of 3.8 (95% confidence interval, 1.3-11.1). Conclusions: This study revealed that the prevalence of IPUs in patients with peptic ulcers in Japan is 12%, much higher than previously reported. Presence of multiple underlying comorbid diseases, rather than aging itself, is an important risk factor for IPUs.