Background: We have previously shown that co-treatment of angiotensin type 1 receptor (AT1R) blocker (ARB) or angiotensin converting enzyme (ACE) inhibitor seem to reduce peptic ulcer among patients taking low dose aspirin. It is reported that a series of renin-angiotensin system (RAS) gene polymorphisms significantly influence the rate of the gene transcription.
Aim: The aim of this study was to examine the genotypes of RAS genes related to the risk of peptic ulcer and ulcer bleeding among patients taking low dose aspirin.
Methods: Patients taking 100 mg of aspirin who were planning to undergo endoscopy for surveillance or who had history of recent upper GI ulcer bleeding were included. ACE (Ins/Del), angiotensinogen (AGT; G-217A, A-20C, A-6G, T174 M, M235T), and AT1R (T-713G, C-521T, A1166C) genotypes were determined by PCR or PCR-RFLP.
Results: Four hundred twenty-five patients were enrolled including 68 patients with peptic ulcer and 20 patients with ulcer bleeding. Co-treatment of ARB was significantly associated with peptic ulcer and ulcer bleeding. AGT-20 CC (adjusted OR 4.94, 95% CI 1.21-20.2) was significantly associated with ulcer bleeding. The CC genotype of AT1R-521 was significantly associated with peptic ulcer only in the subgroup taking neither ACE inhibitor nor ARB.
Conclusions: Co-treatment of ARB reduces peptic ulcer and bleeding among patients taking low dose aspirin. RAS may play an important role in the development of upper GI mucosal injury induced by low dose aspirin.