Cardiovascular disease in renal allograft recipients is associated with elevated sialic acid or markers of inflammation.

BACKGROUND: Cardiovascular disease (CVD) is more common in patients with renal failure, even after renal transplantation. We wished to examine the relationship between markers of inflammation and CVD in stable renal transplant patients. METHODS: Ninety stable renal transplant outpatients with no recent illnesses or rejection were invited for study. Blood was drawn for a variety of inflammatory markers including total plasma sialic acid (SA) levels. RESULTS: Patients with CVD were significantly older than patients without (54 +/- 12 vs. 42 +/- 14 yr, p < 0.01) and had significantly lower total cholesterol (4.5 +/- 1.6 vs. 5.1 +/- 1.0 mmol/L, p < 0.01). Time from transplantation, present creatinine and blood pressure, smoking history were similar in both groups. Patients with CVD had significantly higher levels of SA (89.2 +/- 22.3 vs. 77.4 +/- 13.9 mg/dL, p = 0.01); fibrinogen [4.6 (2.2-6.7) vs. 3.6(1.9-5.7) g/L; p = 0.05); and C-reactive protein (CRP) [2.2 (1.5-8.0) vs 1.5 (0.7-3.0) microg/dL] than those without CVD. A logistic multiple linear regression analysis of the data with CVD as the dependent variable, and all the other parameters as independent variables, showed significant associations (F = 16.9; p < 0.001) with diastolic blood pressure (beta = 5.6; p = 0.02) and CRP (beta = 4.4; p = 0.04). CONCLUSIONS: This study suggests that inflammation is associated with a higher prevalence of cardiovascular disease in patients with renal allografts. The measurement of sialic acid as a risk factor may be superior to that of CRP in this group as its concentration is independent of renal function.

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.