title: Lack of benefits for prevention of cardiovascular disease with aspirin therapy in type 2 diabetic patients--a longitudinal observational study.
abstract: BACKGROUND
  The risk-benefit ratio of aspirin therapy in prevention of cardiovascular disease (CVD) remains contentious, especially in type 2 diabetes. This study examined the benefit and harm of low-dose aspirin (daily dose < 300 mg) in patients with type 2 diabetes.
  
  
  METHODS
  This is a longitudinal observational study with primary and secondary prevention cohorts based on history of CVD at enrollment. We compared the occurrence of primary composite (non-fatal myocardial infarction or stroke and vascular death) and secondary endpoints (upper GI bleeding and haemorrhagic stroke) between aspirin users and non-users between January 1995 and July 2005.
  
  
  RESULTS
  Of the 6,454 patients (mean follow-up: median [IQR]: 4.7 [4.4] years), usage of aspirin was 18% (n = 1,034) in the primary prevention cohort (n = 5731) and 81% (n = 585) in the secondary prevention cohort (n = 723). After adjustment for covariates, in the primary prevention cohort, aspirin use was associated with a hazard-ratio of 2.07 (95% CI: 1.66, 2.59, p < 0.001) for primary endpoint. There was no difference in CVD event rate in the secondary prevention cohort. Overall, aspirin use was associated with a hazard-ratio of 2.2 (1.53, 3.15, p < 0.001) of GI bleeding and 1.71 (1.00, 2.95, p = 0.051) of haemorrhagic stroke. The absolute risk of aspirin-related GI bleeding was 10.7 events per 1,000 person-years of treatment.
  
  
  CONCLUSIONS
  In Chinese type 2 diabetic patients, low dose aspirin was associated with a paradoxical increase in CVD risk in primary prevention and did not confer benefits in secondary prevention. In addition, the risk of GI bleeding in aspirin users was rather high.
authors.affiliation: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China. wilson_lg@hotmail.com
authors.forename: Wilson Y
authors.initials: WY
authors.lastname: Leung
authors.forename: Wing-yee
authors.initials: WY
authors.lastname: So
authors.forename: Derek
authors.initials: D
authors.lastname: Stewart
authors.forename: Augustine
authors.initials: A
authors.lastname: Lui
authors.forename: Peter C
authors.initials: PC
authors.lastname: Tong
authors.forename: Gary T
authors.initials: GT
authors.lastname: Ko
authors.forename: Alice P
authors.initials: AP
authors.lastname: Kong
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Ma
authors.forename: Francis K
authors.initials: FK
authors.lastname: Chan
authors.forename: Xilin
authors.initials: X
authors.lastname: Yang
authors.forename: Sau-chu
authors.initials: SC
authors.lastname: Chiang
authors.forename: Juliana C
authors.initials: JC
authors.lastname: Chan
mesh_terms: D000328:Adult; D000368:Aged; D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control*; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011322:Primary Prevention / Q000379:methods; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D055502:Secondary Prevention / Q000379:methods
chemical_list: D001241:Aspirin