Raised plasma total sialic acid levels are markers of cardiovascular disease in renal dialysis patients.

Cardiovascular disease (CVD) rates in dialysis patients are very high. One of the many associated risk factors is chronic inflammation. The relationship of baseline markers of chronic inflammation with the presence of CVD was assessed in a large cohort of stable dialysis patients. Median time (IQR) on dialysis treatment was 20(9-52) months. Forty-one patients had CVD (as defined by the history / clinical presence of ischemic heart disease, peripheral vascular disease, or cerebrovascular disease). Patients with CVD were significantly older than patients without (67 + /- 11 vs. 54 + /- 10 yrs, p < 0.03). Time from dialysis, urea reduction ratio (hemodialysis only) and smoking history were similar between the two groups. Patients with CVD had significantly higher levels of sialic acid (SA) (91.2 +/- 24.2 vs. 82.0 + /- 18.2 mg/dL, p = 0.03). Body weight, plasma fibrinogen, C-reactive protein (CRP), homocysteine, creatinine, total-, LDL (low density lipoprotein)-, or HDL (high density lipoprotein)-cholesterol, systolic, diastolic and pulse pressures did not differ between the CVD and CVD(-) groups. Patients on chronic ambulatory peritoneal dialysis (CAPD) had more elevated lipid fractions, inflammatory markers, and SA levels than did patients on hemodialysis (HD). The presence of diabetes, the use of lipid-lowering therapy, and smoking history was not associated with any difference in SA levels. In contrast to C-reactive protein (CRP) concentrations, SA levels were unaffected by the hemodialysis session. SA was strongly correlated with CRP (r = 0.59, p < 0.0001), but not with patient age, any measure of blood pressure (BP), urea reduction ratio, plasma creatinine, lipid fractions or homocysteine. Levels of the chronic inflammation marker sialic acid correlate strongly with CRP and are increased in patients with cardiovascular disease, but show no relationship to hemodialysis session. Thus sialic acid may be a superior marker to CRP for assessment of chronic inflammation in patients undergoing dialysis.