The prevalence of aspirin resistance in patients with metabolic syndrome

Aspirin is recommended for primary prevention in patients with metabolic syndrome (MetS). In this study, we evaluated aspirin resistance in MetS patients. The study included 32 patients (23 males, 9 females; mean age 60.7+/-11.4 years) with the diagnosis of MetS, according to the criteria of the International Diabetes Federation. Aspirin resistance was determined by the PFA-100 analysis (Platelet Function Analyzer). The results were compared with a control group of 30 patients (16 males, 14 females; mean age 61.6+/-7.3 years) without MetS. All the patients were taking aspirin at the time of the PFA-100 analysis. Overall, 21 patients (33.9%) were aspirin nonresponders. The prevalence of aspirin resistance was 46.9% in the MetS group, and 20% in the control group. The difference between the two groups was statistically significant (p=0.033). Compared to aspirin responders, fasting blood glucose level was higher (102.0+/-14.6 mg/dl vs. 95.3+/-9.9 mg/dl; p=0.036) and waist circumference tended to be greater in nonresponders (97.4+/-14.1 cm vs. 89.7+/-15.0 cm; p=0.053). Multivariate logistic regression analysis showed that MetS (OR 0.28, 95% CI 0.09-0.88; p=0.029), fasting blood glucose (OR 0.95, 95% CI 0.91-0.99; p=0.045), uric acid (OR 0.46, 95% CI 0.28-0.76; p=0.002), gamma-glutamyl transferase (OR 1.04, 95% CI 1.00-1.08; p=0.043), high-sensitivity C-reactive protein (OR 1.07, 95% CI 1.01-1.12; p=0.015) levels and platelet count (OR 0.99, 95% CI 0.98-0.99; p=0.034) significantly affected aspirin resistance. Our results show that a significant proportion of MetS patients will not benefit from aspirin use due to high aspirin resistance.