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

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).

For purposes of analysis, lipid parameters were classified using the National Kidney Foundation Dyslipidemia Classification definitions.

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.

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.