title: High prevalence of aspirin resistance in elderly patients with cardiovascular disease and metabolic syndrome.
abstract: BACKGROUND
  Metabolic syndrome is known to be a prothrombotic state. We undertook this study to examine a hypothesis that aspirin resistance may be associated with metabolic syndrome, and to assess other potential determinants of aspirin resistance in patients with cardiovascular disease (CVD).
  
  
  METHODS
  A total of 469 elderly patients with CVD were recruited. One hundred and seventy-two patients with metabolic syndrome and 297 without metabolic syndrome (control group) received daily aspirin therapy (≥ 75 mg) over one month. Platelet aggregation was measured by light transmission aggregometry (LTA). Aspirin resistance was defined as ≥ 20% arachidonic acid (AA)- and ≥ 70% adenosine diphosphate (ADP)-induced aggregation according to LTA. Aspirin semi-responders were defined as meeting one (but not both) of these criteria.
  
  
  RESULTS
  By LTA, 38 of 469 (8.1%) patients were aspirin resistant. The prevalence of aspirin resistance was higher in the metabolic syndrome group compared with the control group [11.6 % vs. 6.6%, odds ratio (OR) = 2.039; 95% confidence interval (CI): 1.047-3.973]. In the multivariate logistic regression analysis, metabolic syndrome (OR = 4.951, 95% CI: 1.440-17.019, P = 0.011) was a significant risk factor for aspirin resistance.
  
  
  CONCLUSIONS
  A significant number of patients with CVD and metabolic syndrome are resistant to aspirin therapy. This might further increase the risk of cardiovascular morbidity and mortality in these patients.
authors: Nanlou Respiratory Disease Department, Chinese PLA General Hospital, Beijing, China.
authors: Lin
authors: L
authors: Liu
authors: Peking University Hepatology Institute, Peking University People's Hospital, Peking University, Beijing, China.
authors: Ying-Hui
authors: YH
authors: Gao
authors: Nanlou Clinical Lab, Chinese PLA General Hospital, Beijing, China.
authors: Jian
authors: J
authors: Cao
authors: Department of Clinical Laboratory of South Building, Chinese PLA General Hospital, Beijing, China.
authors: Hua-Xin
authors: HX
authors: Zhang
authors: Clinical Department of South Building, Chinese PLA General Hospital, Beijing, China.
authors: Li
authors: L
authors: Fan
authors: Clinical Department of South Building, Chinese PLA General Hospital, Beijing, China.
authors: Guo-Liang
authors: GL
authors: Hu
authors: Clinical Department of South Building, Chinese PLA General Hospital, Beijing, China.
authors: Yi-Xin
authors: YX
authors: Hu
authors: Clinical Department of South Building, Chinese PLA General Hospital, Beijing, China.
authors: Xiao-Li
authors: XL
authors: Li
authors: Nanlou Clinical Lab, Chinese PLA General Hospital, Beijing, China.
authors: Xiao
authors: X
authors: Zou
authors: Nanlou Clinical Lab, Chinese PLA General Hospital, Beijing, China.
authors: Jian-Hua
authors: JH
authors: Li
keywords: Aspirin resistance; Cardiovascular disease; Metabolic syndrome