Lipid metabolism in renal transplant patients receiving tacrolimus/sirolimus combination therapy

INTRODUCTION: The administration of sirolimus has been reported to be associated with high serum cholesterol and high triglyceride values. In a large prospective, multicenter 6-month study in renal transplantation, basic parameters of lipid metabolism (total serum cholesterol and triglycerides) were systematically assessed in patients who received tacrolimus/mycophenolate mofetil/steroids (Tac/MMF), tacrolimus/0.5 mg sirolimus (SIR)/steroids (Tac/0.5SIR) on tacrolimus/2 mg sirolimus/steroids (Tac/2SIR). METHODS: For purposes of analysis, lipid parameters were classified using the National Kidney Foundation Dyslipidemia Classification definitions. RESULTS: Complete sets of data at all visits (baseline, months 1, 3, and 6) were available for 211 Tac/MMF, 210 Tac/0.5SIR, and 203 Tac/2SIR patients. Total serum cholesterol in the Tac/MMF group was 193.4 at baseline and 202.9 mg/dL at month 6. Values increased from 196 mg/dL to 212.5 mg/dL in Tac/0.5SIR and from 200 mg/dL to 230.5 mg/dL in Tac/2SIR. Differences in parameters between treatment groups were statistically significant (P < .05). Serum triglycerides decreased from baseline to 6 months in Tac/MMF, increased from 176.3 mg/dL (baseline) to 191.4 mg/dL (6 months) in Tac/0.5SIR and from 203 mg/dL to 255.3 mg/dL in Tac/2SIR. Parameters differed significantly between Tac/0.5SIR versus Tac/2SIR at P = .0069, and between Tac/MMF versus Tac/2SIR at P = .0013. In the Tac/2SIR group 36.5% had "high" serum cholesterol and 8.3% had "very high" triglyceride levels at 6 months. CONCLUSION: Total serum cholesterol levels were relatively stable and serum triglycerides decreased between baseline and month 6 using a Tac/MMF regimen. Contrastingly, the Tac/SIR combinations led to increased total cholesterol values (at both sirolimus dose levels) and Tac/2SIR also led to increased triglyceride levels.