Prevalence, determinants, and clinical significance of hyperhomocyst(e)inaemia in renal-transplant recipients

Background. Previous studies have demonstrated that hyperhomocyst(e)inaemia is present in patients with impaired renal function and is correlated with cardiovascular disease. Because conflicting data are available on the prevalence, determinants, and clinical significance of hyperhomocyst(e)inaemia in renal-transplant recipients, we conducted the largest cross-sectional study on homocysteine determinants and clinical correlates in renal transplant recipients. Methods. Plasma homocyst(e)ine concentrations and factors known to influence homocysteine metabolism were analysed in 224 renal transplant recipients. Atherosclerotic complications were evaluated with respect to plasma homocysteine concentrations. Results. Mean plasma homocyst(e)ine was 21.3 +/- 9.7 mu mol/l. After adjusting for age, gender, transplant duration, and creatinine clearance, patients with and without cyclosporin A (CsA) had similar plasma homocyst(e)ine concentrations (16.9 +/- 5.9 mu mol/l in CsA(+) patients vs 16.3 +/- 5.2 mu mol/l in CsA(-) patients: P = 0.3). We found a significant inverse relationship between plasma homocyst(e)ine and folate concentrations in both CsA(+) (r = -0.243; P < 0.005) and CsA(-) (r = -0.396; P<0.05) patients. Patients with a past history of cardiovascular events had higher plasma homocyst(e)ine concentrations (25.2 +/- 11.7 mmol/l vs 20.5 +/- 8.9 mmol/l; P < 0.005). Conclusion. Homocyst(e)inaemia is closely related to renal function and folate concentration in renal transplant recipients. CsA does not seem to have direct effects on homocysteine metabolism. Hyperhomocyst(e)inaemia is associated with cardiovascular disease in renal-transplant recipients. Prospective placebo-controlled homocysteine-lowering therapy studies are required in this patient category.