Lack of benefits for prevention of cardiovascular disease with aspirin therapy in type 2 diabetic patients--a longitudinal observational study.
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.
Leung
Wilson Y
WY
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong SAR, PR China. wilson_lg@hotmail.com
So
Wing-yee
WY
Stewart
Derek
D
Lui
Augustine
A
Tong
Peter C
PC
Ko
Gary T
GT
Kong
Alice P
AP
Ma
Ronald C
RC
Chan
Francis K
FK
Yang
Xilin
X
Chiang
Sau-chu
SC
Chan
Juliana C
JC
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
D001241:Aspirin