Association between serum sialic acid concentration and carotid atherosclerosis measured by B-mode ultrasound

Background. Previous studies have shown that the serum level of sialic acid is associated positively with mortality from coronary disease and stroke. In this study its relation with carotid atherosclerosis was evaluated. Methods. From the Atherosclerosis Risk in Communities (ARIC) Study, 323 cases with carotid intima-media wall thickness above the 90th percentile (measured with B-mode ultrasound) were matched 1:1 with controls without atherosclerosis. Serum sialic acid, plasma LDL and HDL cholesterol, serum insulin concentrations, blood pressure, antihypertensive medication use, and smoking status were used to assess the independent contribution of the sialic acid level to carotid atherosclerosis. Results. The mean (SD) serum sialic acid concentration was 75.0 (9.7) mg/dl in cases and 70.7 (8.9) mg/dl in controls (P = 0.0001). In a conditional logistic model with adjustment for age, LDL-cholesterol, HDL-cholesterol, serum insulin, smoking and hypertension, the odds ratio associated with sialic acid above the 75th percentile (≤ 78.3 mg/dl) versus below was 1.65 with a 95% confidence interval of 1.01-2.70. Conclusion. The sialic acid level is correlated with the presence of carotid atherosclerosis, independently of major cardiovascular disease risk factors. The biological mechanism behind this association is not resolved.