Influence of hypercholesterolemia on patient and graft survival in recipients of kidney transplants

AIM: The aim of this retrospective, single centre study, was to study the effect of pre- and post-transplant serum total cholesterol (TC) on patient and graft survival. We also sought to see whether patients who had very high TC (>8 mmol/L) had a higher incidence of graft failure and patient mortality compared with those whose cholesterol was only moderately elevated. METHODS: Records of 935 cadaver kidney transplants between 1984 and 1998 were examined. Patients were placed into three groups based on TC level: <5.5 mmol/L (group 1), 5.5-8 mmol/L (group 2) and >8 mmol/L (group 3). The mean TC value from the first five post-transplant years was taken to seek a correlation between TC and post-transplant events. RESULTS: The mean graft follow-up was 66.9 +/- 50.1 months, ranging from 0.1 to 191 months, while mean patient follow-up was 83.8 +/- 50.1 months, ranging from 0.5 to 191.6 months. Pre-transplant TC was available in 201 patients (21.5%), and post-transplant data was available (for first 5 yr) in 655 patients (70%). During the study period, 220 patients (23.5%) had died, 285 (30.5%) of the grafts had failed during the follow-up, while 129 (13.8%) of the patients died with a functioning graft. We found significantly longer survival of patients having a pre-transplant TC below 5.5 mmol/L vs. patients whose pre-transplant TC was above 5.6 mmol/L (p = 0.02). We also compared patients who had very high pre-transplant TC (>8 mmol/L) level with those whose TC was moderately elevated (5.5-8 mmol/L) and found that there was no higher incidence of graft failure (p = 0.77) nor patient mortality (p = 0.83). No difference could be found in graft survival based on pre-transplant TC. We also did not find a detrimental influence of post-transplant TC on the patient or graft survival. Diabetes mellitus (p = 0.006) and age over 50 yr (p = 0.007) affected patient survival, while low cyclosporine levels (p = 0.02) and acute rejection episodes (p = 0.009) affected graft survival. The mode of dialysis and time on dialysis prior to transplantation did not affect patient and graft survival. CONCLUSIONS: We found significantly greater survival of patients having a pre-transplant TC below 5.5 mmol/L. No difference could be found in graft survival based on pre-transplant TC. Post-transplant TC did not adversely affect patient or graft survival.